@article {pmid30999182,
year = {2019},
author = {Bharti, A and Garg, N},
title = {SA and AM symbiosis modulate antioxidant defense mechanisms and asada pathway in chickpea genotypes under salt stress.},
journal = {Ecotoxicology and environmental safety},
volume = {178},
number = {},
pages = {66-78},
doi = {10.1016/j.ecoenv.2019.04.025},
pmid = {30999182},
issn = {1090-2414},
abstract = {Salt stress disturbs redox homeostasis by perturbing equilibrium between generation and removal of reactive oxygen species (ROS), which alters the normal metabolism of plants through membrane damage, lipid peroxidation and denaturation of proteins. Salicylic acid (SA) seed priming and arbuscular mycorrhizal (AM) fungi impart salt tolerance in legumes by maintaining redox balance. The present investigation focused on the relative and combined applications of SA and Rhizoglomus intraradices in scavenging ROS in Cicer arietinum L. (chickpea) genotypes (salt tolerant-PBG 5, relatively sensitive-BG 256) subjected to salt stress. Despite the enhanced antioxidant mechanisms under salt stress, ROS (superoxide, O2- and hydrogen peroxide, H2O2) accumulation increased significantly and induced lipid peroxidation and lipoxygenase (LOX) activities, which disrupted membrane stability, more in BG 256 than PBG 5. Salt stress also caused redox imbalance by lowering ascorbate/dehydroascorbate (ASA/DHA) and reduced glutathione/oxidized glutathione (GSH/GSSG) ratios, indicating that redox-homeostasis was crucial for salt-tolerance. Exogenous SA was more promising in reducing ROS-generation and lipid-peroxidation, which provided higher membrane stability as compared to AM inoculation. Although, the enzymatic antioxidants were more active in SA treated plants, yet, AM inoculation outperformed in increasing reformative enzyme activities of Foyer-Halliwell-Asada cycle, which resulted in higher plant biomass in a genotype-dependent manner. SA increased AM root colonization and provided functional complementarity to R. intraradices and thereby strengthening antioxidant defense mechanisms through their cumulative contribution. The study suggested the use of +SA+AM as an eco-friendly tool in imparting salt tolerance in chickpea genotypes subjected to long-term salinity.},
}
@article {pmid30802772,
year = {2019},
author = {Liu, P and Hou, J and Zou, Y and Stephenson, SL and Huo, X and Hu, X and Li, Y},
title = {Developmental features and associated symbiont bacterial diversity in essential life cycle stages of Heterostelium colligatum.},
journal = {European journal of protistology},
volume = {68},
number = {},
pages = {99-107},
doi = {10.1016/j.ejop.2019.02.003},
pmid = {30802772},
issn = {1618-0429},
mesh = {Bacteria/classification ; *Bacterial Physiological Phenomena ; *Biodiversity ; Dictyostelium/*growth & development/*microbiology ; Life Cycle Stages/*physiology ; Symbiosis/*physiology ; },
abstract = {Dictyostelium discoideum is a specialized amoebozoan protist that can feed on, carry and disperse bacteria. However, the symbiont bacterial diversity in other species of dictyostelids and the diversity associated with essential life cycle stages are still unknown until now. Here, another species of dictyostelids, Heterostelium colligatum, a new record for tropical China, was isolated from the soil collected in Xishuangbanna Tropical Botanical Garden, Yunnan Province, China. We describe the complete life cycle of this species and illustrate details of spore-to-spore development. The symbiont bacterial diversity and relative abundance associated with life cycle stages of H. colligatum, including the aggregation, pseudoplasmodium, and sorocarp stages, were investigated by high throughput metagenomic techniques. H. colligatum appears to be capable of carrying different types of bacteria during its life history in addition to those used as a food resource. The dominant groups of those three stages in its life cycle were the Proteobacteria, Actinobacteria and Firmicutes. The relative abundance of the dominant phyla and shared OTUs were different for the aggregation, pseudoplasmodium, and sorocarp stages. A comparison of the symbiont bacterial assemblages associated with D. discoideum and H. colligatum indicated that different dictyostelid species carried different species of symbiont associated bacteria.},
}
@article {pmid30353644,
year = {2019},
author = {Liu, JF and Zhang, ZQ and Beggs, JR},
title = {Tri-partite complexity: odour from a psyllid's mutualist ant increased predation by a predatory mite on the psyllid.},
journal = {Pest management science},
volume = {75},
number = {5},
pages = {1317-1327},
doi = {10.1002/ps.5246},
pmid = {30353644},
issn = {1526-4998},
support = {//University of Auckland/ ; //Core Funding for Crown Research Institutes from the Ministry of Business, Innovation and Employment's Science and Innovation Group/ ; },
mesh = {Animals ; Ants/*metabolism/physiology ; *Hemiptera ; Longevity/drug effects ; Mites/*drug effects/physiology ; *Odorants ; Predatory Behavior/*drug effects ; Reproduction/drug effects ; Survival Analysis ; *Symbiosis ; },
abstract = {BACKGROUND: Predator-prey interactions consist of direct consumption of prey by predators and indirect non-consumptive effects on prey. Predator cues can induce predation stress in prey that negatively influences the survival, development, reproduction, and feeding behaviour of the prey. This study evaluated the effects of hemipteran-tending ant (Technomyrmex albipes) odour on the development, survival, reproduction, and predation rates of the predatory mite Amblydromalus limonicus when feeding on an invasive pest of solanaceous crops, Bactericera cockerelli. The age-stage, two-sex life table theory was used to compare the demographic characteristics and predation rates of A. limonicus in the presence and absence of ant odour.
RESULTS: We show that exposure to ant odour did not alter the development, survival rate, and fecundity of A. limonicus, but induced a sexually dimorphic response in its longevity; consumption rates also showed that dimorphic response-predation rates increased in female A. limonicus, but not in males.
CONCLUSION: To our knowledge, this is the first report indicating increased consumption rates by natural enemies exposed to odour from a mutualist of pest (ant). This finding may provide new insights into understanding tri-partite interaction involving a pest, its predator, and a mutulist of the pest. © 2018 Society of Chemical Industry.},
}
@article {pmid30995278,
year = {2019},
author = {Leinonen, PH and Helander, M and Vázquez-de-Aldana, BR and Zabalgogeazcoa, I and Saikkonen, K},
title = {Local adaptation in natural European host grass populations with asymmetric symbiosis.},
journal = {PloS one},
volume = {14},
number = {4},
pages = {e0215510},
doi = {10.1371/journal.pone.0215510},
pmid = {30995278},
issn = {1932-6203},
abstract = {Recent work on microbiomes is revealing the wealth and importance of plant-microbe interactions. Microbial symbionts are proposed to have profound effects on fitness of their host plants and vice versa, especially when their fitness is tightly linked. Here we studied local adaptation of host plants and possible fitness contribution of such symbiosis in the context of abiotic environmental factors. We conducted a four-way multi-year reciprocal transplant experiment with natural populations of the perennial grass Festuca rubra s.l. from northern and southern Finland, Faroe Islands and Spain. We included F. rubra with and without transmitted symbiotic fungus Epichloë that is vertically transmitted via host seed. We found local adaptation across the European range, as evidenced by higher host fitness of the local geographic origin compared with nonlocals at three of the four studied sites, suggesting that selection pressures are driving evolution in different directions. Abiotic factors did not result in strong fitness effects related to Epichloë symbiosis, indicating that other factors such as herbivory are more likely to contribute to fitness differences between plants naturally occurring with or without Epichloë. Nevertheless, in the case of asymmetric symbiosis that is obligatory for the symbiont, abiotic conditions that affect performance of the host, may also cause selective pressure for the symbiont.},
}
@article {pmid30993446,
year = {2019},
author = {Singh, AN and Sharma, N},
title = {Epigenetic Modulators as Potential Multi-targeted Drugs Against Hedgehog Pathway for Treatment of Cancer.},
journal = {The protein journal},
volume = {},
number = {},
pages = {},
doi = {10.1007/s10930-019-09832-9},
pmid = {30993446},
issn = {1875-8355},
abstract = {The Sonic hedgehog signalling is known to play a crucial role in regulating embryonic development, cancer stem cell maintenance and tissue patterning. Dysregulated hedgehog signalling has been reported to affect tumorigenesis and drug response in various human malignancies. Epigenetic therapy relying on DNA methyltransferase and Histone deacetylase inhibitors are being proposed as potential drug candidates considering their efficiency in preventing development of cancer progenitor cells, killing drug resistant cells and also dictating "on/off" switch of tumor suppressor genes and oncogenes. In this docking approach, epigenetic modulators were virtually screened for their efficiency in inhibiting key regulators of SHH pathway viz., sonic hedgehog, Smoothened and Gli using polypharmacological approach. The control drugs and epigenetic modulators were docked with PDB protein structures using AutoDock vina and further checked for their drug-likeness properties. Further molecular dynamics simulation using VMD and NAMD, and MMP/GBSA energy calculation were employed for verifying the stability and entropy of the ligand-receptor complex. EPZ-6438 and GSK 343 (EZH2 inhibitors), CHR 3996 and Mocetinostat (HDAC inhibitors), GSK 126 (HKMT inhibitor) and UNC 1215 (L3MBTL3 antagonist) exhibited multiple-targeted approach in modulating HH signalling. This is the first study to report these epigenetic drugs as potential multi-targeted hedgehog pathway inhibitors. Thus, epigenetic polypharmacology approach can be explored as a better alternative to challenges of acute long term toxicity and drug resistance occurring due to traditional single targeted chemotherapy in the future.},
}
@article {pmid30991927,
year = {2019},
author = {Dixon, GB and Kenkel, CD},
title = {Molecular convergence and positive selection associated with the evolution of symbiont transmission mode in stony corals.},
journal = {Proceedings. Biological sciences},
volume = {286},
number = {1901},
pages = {20190111},
doi = {10.1098/rspb.2019.0111},
pmid = {30991927},
issn = {1471-2954},
abstract = {Heritable symbioses have been critical for the evolution of life. The genetic consequences of evolving a heritable symbiosis from the perspective of the symbiont are well established, but concomitant changes in the host remain unresolved. In stony corals, heritable, vertical transmission has evolved repeatedly, providing a unique opportunity to investigate the genomic basis of this complex trait. We conducted a comparative analysis of 25 coral transcriptomes to identify orthologous genes exhibiting signatures of positive selection and convergent amino acid substitutions in vertically transmitting lineages. The frequency of convergence events tends to be higher among vertically transmitting lineages, consistent with the proposed role of selection in driving the evolution of convergent transmission mode phenotypes. Of 10 774 orthologous genes, 403 exhibited at least one molecular convergence event and evidence of positive selection in at least one vertically transmitting lineage. Functional enrichments among these top candidate genes include processes previously implicated in symbiosis including endocytosis, immune response, cytoskeletal protein binding and cytoplasmic membrane-bounded vesicles. Finally, several novel candidates were identified among 100 genes showing evidence of positive selection at the particular convergence event, highlighting the value of our approach for generating new insight into host mechanisms associated with the evolution of heritable symbioses.},
}
@article {pmid30991290,
year = {2019},
author = {Ezra, H},
title = {On the relationship between road safety research and the practice of road design and operation.},
journal = {Accident; analysis and prevention},
volume = {128},
number = {},
pages = {114-131},
doi = {10.1016/j.aap.2019.03.016},
pmid = {30991290},
issn = {1879-2057},
abstract = {How do the findings of road safety research affect the practice by which the road infrastructure is built and operated? The question is seldom asked. I discuss the complexities of the research-practice symbiosis in the light of two historical anecdotes. These allow me to point out several issues of concern. My general conclusion is that the relationship, as it evolved over time, is unpremeditated and occasionally dysfunctional. Issues of concern are the lightness with which decisions affecting road-user safety can be based on opinion that is unsupported by evidence, that such opinions can trump inconvenient evidence, that research findings can be willfully distorted or disregarded, that questionable results can be given a ring of consensual truth, and that the questions which research asks and what findings get published are at times influenced by external interest. In sum, the concern is that practice is not sufficiently evidence-based. Road users have a right to expect that decisions substantially affecting their safety take into account fact-based expectation of safety consequences. It is therefore time to endow the research-practice relationship with a premeditated and purposeful structure.},
}
@article {pmid30990223,
year = {2019},
author = {Hugo, MH and Kaech, H and Ganesanandamoorthy, P and Vorburger, C},
title = {Evolutionary costs and benefits of infection with diverse strains of Spiroplasma in pea aphids.},
journal = {Evolution; international journal of organic evolution},
volume = {},
number = {},
pages = {},
doi = {10.1111/evo.13740},
pmid = {30990223},
issn = {1558-5646},
abstract = {The heritable endosymbiont Spiroplasma infects many insects and has repeatedly evolved the ability to protect its hosts against different parasites. Defenses do not come for free to the host, and theory predicts that more costly symbionts need to provide stronger benefits to persist in host populations. We investigated the costs and benefits of Spiroplasma infections in pea aphids (Acyrthosiphon pisum), testing 12 bacterial strains from three different clades. Virtually all strains decreased aphid lifespan and reproduction, but only two had a (weak) protective effect against the parasitoid Aphidius ervi, an important natural enemy of pea aphids. Spiroplasma induced fitness costs were variable, with strains from the most slowly evolving clade reaching higher titers and curtailing aphid lifespan more strongly than other strains. Some Spiroplasma strains shared their host with a second endosymbiont, Regiella insecticola. Although the result of an unfortunate handling error, these co-infections proved instructive, because they showed that the cost of infection with Spiroplasma may be attenuated in the presence of Regiella. These results suggest that mechanisms other than protection against A. ervi maintain pea aphid infections with diverse strains of Spiroplasma, and that studying them in isolation will not provide a complete picture of their effects on host fitness. This article is protected by copyright. All rights reserved.},
}
@article {pmid30990167,
year = {2019},
author = {Zhou, YL and Ślipiński, A and Ren, D and Parker, J},
title = {A Mesozoic clown beetle myrmecophile (Coleoptera: Histeridae).},
journal = {eLife},
volume = {8},
number = {},
pages = {},
doi = {10.7554/eLife.44985},
pmid = {30990167},
issn = {2050-084X},
support = {31402008//National Natural Science Foundation of China/ ; 20150064//International Postdoctoral Exchange Fellowship/ ; },
abstract = {Complex interspecies relationships are widespread among metazoans, but the evolutionary history of these lifestyles is poorly understood. We describe a fossil beetle in 99-million-year-old Burmese amber that we infer to have been a social impostor of the earliest-known ant colonies. Promyrmister kistneri gen. et sp. nov. belongs to the haeteriine clown beetles (Coleoptera: Histeridae), a major clade of 'myrmecophiles'-specialized nest intruders with dramatic anatomical, chemical and behavioral adaptations for colony infiltration. Promyrmister reveals that myrmecophiles evolved close to the emergence of ant eusociality, in colonies of stem-group ants that predominate Burmese amber, or with cryptic crown-group ants that remain largely unknown at this time. The clown beetle-ant relationship has been maintained ever since by the beetles host-switching to numerous modern ant genera, ultimately diversifying into one of the largest radiations of symbiotic animals. We infer that obligate behavioral symbioses can evolve relatively rapidly, and be sustained over deep time.},
}
@article {pmid30990122,
year = {2019},
author = {Shah, S and Thapa, BB and Chand, K and Pradhan, S and Maharjan, A and Verma, A and Sen Thakuri, L and Joshi, P and Pant, B},
title = {Piriformospora indica promotes the growth of the in-vitro-raised Cymbidium aloifolium plantlet and their acclimatization.},
journal = {Plant signaling & behavior},
volume = {},
number = {},
pages = {1-7},
doi = {10.1080/15592324.2019.1596716},
pmid = {30990122},
issn = {1559-2324},
abstract = {Cymbidium aloifolium is known for its ornamental and medicinal values. It has been listed as threatened orchid species. In this study, in vitro propagated C. aloifolium plantlets were interacted with the Piriformospora indica. The growth assay was performed for 45 days; the plant growth pattern such as number and length of roots and shoots were measured. Microscopic study of the root section stained by trypan blue was done to detect the peloton formation. The methanol extracts of the fungal colonized plant as well as uncolonized (control) plant were prepared and various metabolites were identified by gas chromatography mass spectroscopy. Acclimatization was done in a substrate composition of coco peat: gravel: charcoal in ratio 2:2:1. P. indica-colonized plantlet showed the highest growth with the formation of clamdospore in the root section. The growth regulator such as auxin, ascorbic acid, andrographolide, hexadecanoic acid, and DL-proline were identified. After three months of field transfer, plantlet colonized by P. indica survived and remained healthy as compared to uncolonized control plantlet.},
}
@article {pmid30989804,
year = {2019},
author = {Mediavilla, O and Geml, J and Olaizola, J and Oria-de-Rueda, JA and Baldrian, P and Martín-Pinto, P},
title = {Effect of forest fire prevention treatments on bacterial communities associated with productive Boletus edulis sites.},
journal = {Microbial biotechnology},
volume = {},
number = {},
pages = {},
doi = {10.1111/1751-7915.13395},
pmid = {30989804},
issn = {1751-7915},
support = {VA050P17//Junta de Castilla y León/ ; //University of Valladolid programme 'Ayudas para estancias breves en el desarrollo de Tesis Doctorales. Convocatoria 2016'/ ; 2018//Naturalis Biodiversity Center/ ; //European Social Fund/ ; },
abstract = {Cistus ladanifer scrublands, traditionally considered as unproductive, have nonetheless been observed to produce large quantities of king bolete (Boletus edulis) fruitbodies. These pyrophytic scrublands are prone to wildfires, which severely affect fungi, hence the need for fire prevention in producing C. ladanifer scrublands. In addition, B. edulis productions have severely decreased in the last years. A deeper understanding of the B. edulis life cycle and of biotic and abiotic factors influencing sporocarp formation is needed to implement management practices that facilitate B. edulis production. For example, some bacteria likely are involved in sporocarp production, representing a key part in the triple symbiosis (plant-fungus-bacteria). In this study, we used soil DNA metabarcoding in C. ladanifer scrublands to (i) assess the effect of site history and fire prevention treatment on bacterial richness and community composition; (ii) test if there was any correlation between various taxonomic groups of bacteria and mycelial biomass and sporocarp production of B. edulis; and to (iii) identify indicator bacteria associated with the most productive B. edulis sites. Our results show that site history drives bacterial richness and community composition, while fire prevention treatments have a weaker, but still detectable effect, particularly in the senescent plots. Sporocarp production correlated positively with genera in Verrucomicrobia. Several genera, e.g. Azospirillum and Gemmatimonas, were identified as indicators of the most productive sites, suggesting a potential biological role in B. edulis fructification. This study provides a better understanding of the triple symbiosis (plant-fungus-bacteria) involved in C. ladanifer-B. edulis systems.},
}
@article {pmid30989446,
year = {2019},
author = {Zhang, Z and Ke, D and Hu, M and Zhang, C and Deng, L and Li, Y and Li, J and Zhao, H and Cheng, L and Wang, L and Yuan, H},
title = {Quantitative phosphoproteomic analyses provide evidence for extensive phosphorylation of regulatory proteins in the rhizobia-legume symbiosis.},
journal = {Plant molecular biology},
volume = {},
number = {},
pages = {},
doi = {10.1007/s11103-019-00857-3},
pmid = {30989446},
issn = {1573-5028},
support = {182300410063//Natural Science Foundation of Henan Provincial Science and Technology/ ; 18A180031//key scientific research projects of Henan higher education institutions/ ; 31400213//National Natural Science Foundation of China/ ; 2015, 2016//Funding scheme for young core teachers of Xinyang Normal University/ ; 2017//Nanhu Scholars Program for Young Scholars of XYNU/ ; },
abstract = {KEY MESSAGE: Symbiotic nitrogen fixation in root nodules of grain legumes is essential for high yielding. Protein phosphorylation/dephosphorylation plays important role in root nodule development. Differences in the phosphoproteomes may either be developmental specific and related to nitrogen fixation activity. An iTRAQ-based quantitative phosphoproteomic analyses during nodule development enables identification of specific phosphorylation signaling in the Lotus-rhizobia symbiosis. During evolution, legumes (Fabaceae) have evolved a symbiotic relationship with rhizobia, which fix atmospheric nitrogen and produce ammonia that host plants can then absorb. Root nodule development depends on the activation of protein phosphorylation-mediated signal transduction cascades. To investigate possible molecular mechanisms of protein modulation during nodule development, we used iTRAQ-based quantitative proteomic analyses to identify root phosphoproteins during rhizobial colonization and infection of Lotus japonicus. 1154 phosphoproteins with 2957 high-confidence phosphorylation sites were identified. Gene ontology enrichment analysis of functional groups of these genes revealed that the biological processes mediated by these proteins included cellular processes, signal transduction, and transporter activity. Quantitative data highlighted the dynamics of protein phosphorylation during nodule development and, based on regulatory trends, seven groups were identified. RNA splicing and brassinosteroid (BR) signaling pathways were extensively affected by phosphorylation, and most Ser/Arg-rich (SR) proteins were multiply phosphorylated. In addition, many proposed kinase-substrate pairs were predicted, and in these MAPK6 substrates were found to be highly enriched. This study offers insights into the regulatory processes underlying nodule development, provides an accessible resource cataloging the phosphorylation status of thousands of Lotus proteins during nodule development, and develops our understanding of post-translational regulatory mechanisms in the Lotus-rhizobia symbiosis.},
}
@article {pmid30989396,
year = {2019},
author = {Deveau, A and Clowez, P and Petit, F and Maurice, JP and Todesco, F and Murat, C and Harroué, M and Ruelle, J and Le Tacon, F},
title = {New insights into black truffle biology: discovery of the potential connecting structure between a Tuber aestivum ascocarp and its host root.},
journal = {Mycorrhiza},
volume = {},
number = {},
pages = {},
doi = {10.1007/s00572-019-00892-4},
pmid = {30989396},
issn = {1432-1890},
support = {ANR-11-LABX 0002 01//ANR/ ; },
abstract = {According to isotopic labeling experiments, most of the carbon used by truffle (Tuber sp.) fruiting bodies to develop underground is provided by host trees, suggesting that trees and truffles are physically connected. However, such physical link between trees and truffle fruiting bodies has never been observed. We discovered fruiting bodies of Tuber aestivum adhering to the walls of a belowground quarry and we took advantage of this unique situation to analyze the physical structure that supported these fruiting bodies in the open air. Observation of transversal sections of the attachment structure indicated that it was organized in ducts made of gleba-like tissue and connected to a network of hyphae traveling across soil particles. Only one mating type was detected by PCR in the gleba and in the attachment structure, suggesting that these two organs are from maternal origin, leaving open the question of the location of the opposite paternal mating type.},
}
@article {pmid30989224,
year = {2019},
author = {Chong, RA and Park, H and Moran, NA},
title = {Genome evolution of the obligate endosymbiont Buchnera aphidicola.},
journal = {Molecular biology and evolution},
volume = {},
number = {},
pages = {},
doi = {10.1093/molbev/msz082},
pmid = {30989224},
issn = {1537-1719},
abstract = {An evolutionary consequence of uniparentally transmitted symbiosis is degradation of symbiont genomes. We use the system of aphids and their maternally inherited obligate endosymbiont, Buchnera aphidicola, to explore the evolutionary process of genome degradation. We compared complete genome sequences for 39 Buchnera strains, including 23 newly sequenced symbiont genomes from diverse aphid hosts. We reconstructed the genome of the most recent shared Buchnera ancestor, which contained 616 protein-coding genes, and 39 RNA genes. The extent of subsequent gene loss varied across lineages, resulting in modern genomes ranging from 412 to 646 kilobases and containing 354 to 587 protein-coding genes. Loss events were highly non-random across loci. Genes involved in replication, transcription, translation, and amino acid biosynthesis are largely retained, whereas genes underlying ornithine biosynthesis, stress responses and transcriptional regulation were lost repeatedly. Aside from losses, gene order is almost completely stable. The main exceptions involve movement between plasmid and chromosome locations of genes underlying tryptophan and leucine biosynthesis and supporting nutrition of aphid hosts. This set of complete genomes enabled tests for signatures of positive diversifying selection. Of 371 Buchnera genes tested, 29 genes show strong support for ongoing positive selection. These include genes encoding outer membrane porins that are expected to be involved in direct interactions with hosts. Collectively, these results indicate that extensive genome reduction occurred in the ancestral Buchnera prior to aphid diversification and that reduction has continued since, with losses greater in some lineages and for some loci.},
}
@article {pmid30987816,
year = {2019},
author = {Morris, LA and Voolstra, CR and Quigley, KM and Bourne, DG and Bay, LK},
title = {Nutrient Availability and Metabolism Affect the Stability of Coral-Symbiodiniaceae Symbioses.},
journal = {Trends in microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.tim.2019.03.004},
pmid = {30987816},
issn = {1878-4380},
abstract = {Coral reefs rely upon the highly optimized coral-Symbiodiniaceae symbiosis, making them sensitive to environmental change and susceptible to anthropogenic stress. Coral bleaching is predominantly attributed to photo-oxidative stress, yet nutrient availability and metabolism underpin the stability of symbioses. Recent studies link symbiont proliferation under nutrient enrichment to bleaching; however, the interactions between nutrients and symbiotic stability are nuanced. Here, we demonstrate how bleaching is regulated by the forms and ratios of available nutrients and their impacts on autotrophic carbon metabolism, rather than algal symbiont growth. By extension, historical nutrient conditions mediate host-symbiont compatibility and bleaching tolerance over proximate and evolutionary timescales. Renewed investigations into the coral nutrient metabolism will be required to truly elucidate the cellular mechanisms leading to coral bleaching.},
}
@article {pmid30670649,
year = {2019},
author = {Brunetti, AE and Lyra, ML and Melo, WGP and Andrade, LE and Palacios-Rodríguez, P and Prado, BM and Haddad, CFB and Pupo, MT and Lopes, NP},
title = {Symbiotic skin bacteria as a source for sex-specific scents in frogs.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {116},
number = {6},
pages = {2124-2129},
doi = {10.1073/pnas.1806834116},
pmid = {30670649},
issn = {1091-6490},
mesh = {Animals ; Anura ; *Bacteria/classification ; Biodiversity ; Female ; Male ; Sex Factors ; Skin/*microbiology ; *Symbiosis ; Volatile Organic Compounds ; },
abstract = {Amphibians are known to possess a wide variety of compounds stored in their skin glands. While significant progress has been made in understanding the chemical diversity and biological relevance of alkaloids, amines, steroids, and peptides, most aspects of the odorous secretions are completely unknown. In this study, we examined sexual variations in the volatile profile from the skin of the tree frog Boana prasina and combined culture and culture-independent methods to investigate if microorganisms might be a source of these compounds. We found that sesquiterpenes, thioethers, and methoxypyrazines are major contributors to the observed sex differences. We also observed that each sex has a distinct profile of methoxypyrazines, and that the chemical origin of these compounds can be traced to a Pseudomonas sp. strain isolated from the frog's skin. This symbiotic bacterium was present in almost all individuals examined from different sites and was maintained in captive conditions, supporting its significance as the source of methoxypyrazines in these frogs. Our results highlight the potential relevance of bacteria as a source of chemical signals in amphibians and contribute to increasing our understanding of the role that symbiotic associations have in animals.},
}
@article {pmid30456532,
year = {2019},
author = {Schneider, DI and Ehrman, L and Engl, T and Kaltenpoth, M and Hua-Van, A and Le Rouzic, A and Miller, WJ},
title = {Symbiont-Driven Male Mating Success in the Neotropical Drosophila paulistorum Superspecies.},
journal = {Behavior genetics},
volume = {49},
number = {1},
pages = {83-98},
doi = {10.1007/s10519-018-9937-8},
pmid = {30456532},
issn = {1573-3297},
mesh = {Animals ; Behavior, Animal ; Biological Evolution ; Drosophila/*microbiology ; Drosophila Proteins/metabolism ; Female ; Male ; Reproduction/*physiology ; Reproductive Isolation ; Sex Attractants/metabolism/physiology ; Sexual Behavior, Animal/physiology ; Species Specificity ; Symbiosis/*genetics ; Wolbachia/physiology ; },
abstract = {Microbial symbionts are ubiquitous associates of living organisms but their role in mediating reproductive isolation (RI) remains controversial. We addressed this knowledge gap by employing the Drosophila paulistorum-Wolbachia model system. Semispecies in the D. paulistorum species complex exhibit strong RI between each other and knockdown of obligate mutualistic Wolbachia bacteria in female D. paulistorum flies triggers loss of assortative mating behavior against males carrying incompatible Wolbachia strains. Here we set out to determine whether de novo RI can be introduced by Wolbachia-knockdown in D. paulistorum males. We show that Wolbachia-knockdown D. paulistorum males (i) are rejected as mates by wild type females, (ii) express altered sexual pheromone profiles, and (iii) are devoid of the endosymbiont in pheromone producing cells. Our findings suggest that changes in Wolbachia titer and tissue tropism can induce de novo premating isolation by directly or indirectly modulating sexual behavior of their native D. paulistorum hosts.},
}
@article {pmid30440037,
year = {2018},
author = {Castillo, M and Sanfuentes, E and Angulo, A and Becerra, J and Romero-Romero, JL and Arce-Johnson, P},
title = {Biocontrol of Sirex noctilio by the parasitic nematode Deladenus siricidicola: A five season field study in southern Chile.},
journal = {PloS one},
volume = {13},
number = {11},
pages = {e0207529},
pmid = {30440037},
issn = {1932-6203},
mesh = {Animals ; Chile ; Hymenoptera/*physiology ; Nematoda/*pathogenicity ; Pest Control, Biological/*methods ; Pinus/parasitology ; Seasons ; Symbiosis/*physiology ; },
abstract = {In 2001, the woodwasp Sirex noctilio was detected in Pinus radiata plantations in the Biobio region of southern Chile. Subsequently, an intense biological control program using the female sterilizing nematode Deladenus siricidicola was implemented in 2010. During five seasons between 2012 and 2017, we studied the parasitism of D. siricidicola nematode and its effect on woodwasp populations and infestation of P. radiata in different locations within the Biobio region. Parasitism was assessed by dissecting adult females of S. noctilio obtained from infested P. radiata logs. The total population of S. noctilio was determined by the emergence of individuals from the same logs. The level of damage caused by the S. noctilio pest was determined by establishing plots in stands of P. radiata at an intensity of 1 plot every 5 ha-1. During the study period, parasitism of S. noctilio by the nematode D. siricidicola increased from 29.6% in 2012 to 93.1% in 2016, while pest population decreased 3.4% in the same time period. Infestation increased from 0.3 to 11,6% of trees between 2012 and 2015, but subsequently decreased to 5.9% by 2017. We confirmed establishment of the nematode in the region under study and its natural dispersion to non-inoculated areas. Finally, we determined that the effect of inoculation age (antiquity) on parasitism levels reached 90% after three years of inoculation.},
}
@article {pmid29258070,
year = {2018},
author = {Huang, X and Browngardt, CM and Jiang, M and Ahn, SJ and Burne, RA and Nascimento, MM},
title = {Diversity in Antagonistic Interactions between Commensal Oral Streptococci and Streptococcus mutans.},
journal = {Caries research},
volume = {52},
number = {1-2},
pages = {88-101},
pmid = {29258070},
issn = {1421-976X},
support = {K23 DE023579/DE/NIDCR NIH HHS/United States ; R01 DE025832/DE/NIDCR NIH HHS/United States ; R90 DE022530/DE/NIDCR NIH HHS/United States ; T90 DE021990/DE/NIDCR NIH HHS/United States ; },
mesh = {Arginine/metabolism ; Biofilms/growth & development ; Hydrogen Peroxide/metabolism ; Hydrogen-Ion Concentration ; Streptococcus/*growth & development/metabolism ; Streptococcus mutans/*growth & development/metabolism ; Streptococcus sanguis/growth & development ; *Symbiosis ; },
abstract = {Arginine metabolism via the arginine deiminase system (ADS) of oral bacteria generates ammonia, which can increase the pH of oral biofilms and decrease the risk for dental caries. Antagonistic interactions between ADS-positive and cariogenic bacteria in oral biofilms may be an important ecological determinant of caries. This study investigated the antagonistic potential and mechanisms of clinical isolates of arginolytic streptococci on and by Streptococcus mutans UA159, a well-characterized cariogenic human isolate. Low-passage isolates of Streptococcus gordonii, Streptococcus sanguinis, Streptococcus parasanguinis, Streptococcus australis, and Streptococcus cristatus inhibited the growth of S. mutans to various degrees when they were inoculated on growth media first or simultaneously with S. mutans. The antagonistic effects of arginolytic strains against S. mutans and the production of H2O2 by these strains were enhanced during growth in a less-rich medium or when galactose was substituted for glucose as the primary carbohydrate source. Pyruvate oxidase was the dominant pathway for H2O2 production by arginolytic strains, but lactate oxidase activity was also detected in some strains of S. gordonii and S. cristatus. UA159 inhibited the growth of all tested arginolytic strains when inoculated first, especially in aerobic conditions. However, the antagonistic effects of S. mutans on certain strains of S. gordonii and S. australis were not observed during anaerobic growth in the presence of arginine. Thus, arginolytic commensal streptococci may have a synergistically positive impact on the ecology of oral biofilms by moderating biofilm pH while antagonizing the growth and virulence of caries pathogens.},
}
@article {pmid29124868,
year = {2018},
author = {Fadhlaoui, K and Ben Hania, W and Armougom, F and Bartoli, M and Fardeau, ML and Erauso, G and Brasseur, G and Aubert, C and Hamdi, M and Brochier-Armanet, C and Dolla, A and Ollivier, B},
title = {Obligate sugar oxidation in Mesotoga spp., phylum Thermotogae, in the presence of either elemental sulfur or hydrogenotrophic sulfate-reducers as electron acceptor.},
journal = {Environmental microbiology},
volume = {20},
number = {1},
pages = {281-292},
doi = {10.1111/1462-2920.13995},
pmid = {29124868},
issn = {1462-2920},
mesh = {Carbohydrate Metabolism/*physiology ; Coculture Techniques ; Desulfotomaculum/*metabolism ; Desulfovibrio vulgaris/*metabolism ; Fermentation/physiology ; Gram-Negative Anaerobic Straight, Curved, and Helical Rods/growth & development/*metabolism ; Hydrogen/metabolism ; Oxidation-Reduction ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sugars/*metabolism ; Sulfates/metabolism ; Sulfur/metabolism ; Symbiosis/*physiology ; },
abstract = {Mesotoga prima strain PhosAc3 is a mesophilic representative of the phylum Thermotogae comprising only fermentative bacteria so far. We show that while unable to ferment glucose, this bacterium is able to couple its oxidation to reduction of elemental sulfur. We demonstrate furthermore that M. prima strain PhosAc3 as well as M. prima strain MesG1 and Mesotoga infera are able to grow in syntrophic association with sulfate-reducing bacteria (SRB) acting as hydrogen scavengers through interspecies hydrogen transfer. Hydrogen production was higher in M. prima strain PhosAc3 cells co-cultured with SRB than in cells cultured alone in the presence of elemental sulfur. We propose that the efficient sugar-oxidizing metabolism by M. prima strain PhosAc3 in syntrophic association with a hydrogenotrophic sulfate-reducing bacterium can be extrapolated to all members of the Mesotoga genus. Genome comparison of Thermotogae members suggests that the metabolic difference between Mesotoga and Thermotoga species (sugar oxidation versus fermentation) is mainly due to the absence of the bifurcating [FeFe]-hydrogenase in the former. Such an obligate oxidative process for using sugars, unusual within prokaryotes, is the first reported within the Thermotogae. It is hypothesized to be of primary ecological importance for growth of Mesotoga spp. in the environments that they inhabit.},
}
@article {pmid30986120,
year = {2019},
author = {Si, Z and Yang, Q and Liang, R and Chen, L and Chen, DS and Li, Y},
title = {Digalactosyldiacylglycerol synthase gene MtDGD1 plays an essential role in nodule development and nitrogen fixation.},
journal = {Molecular plant-microbe interactions : MPMI},
volume = {},
number = {},
pages = {},
doi = {10.1094/MPMI-11-18-0322-R},
pmid = {30986120},
issn = {0894-0282},
abstract = {Little is known about the genes participating in digalactosyldiacylglycerol (DGDG) synthesis during nodule symbiosis. Here, we identified full-length MtDGD1, a synthase of DGDG, and characterized its effect on symbiotic nitrogen fixation in Medicago truncatula. Immunofluorescence and immunoelectron microscopy showed that MtDGD1 was located on the symbiosome membranes in the infected cells. GUS histochemical staining revealed that MtDGD1 was highly expressed in the infection zone of young nodules as well as in the whole mature nodules. Compared with the control, MtDGD1-RNAi transgenic plants exhibited significant decreases in nodule number, symbiotic nitrogen fixation activity and DGDG abundance in the nodules, as well as abnormal nodule and symbiosome development. Overexpression of MtDGD1 resulted in enhancement of nodule number and nitrogen fixation activity. In response to phosphorus starvation, the MtDGD1 expression level was substantially up-regulated and the abundance of non-phospholipid DGDG was significantly increased in the roots and nodules, accompanied by corresponding decreases in the abundance of phospholipids such as phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol. Overall, our results indicate that DGD1 contributes to effective nodule organogenesis and nitrogen fixation by affecting the synthesis and content of DGDG during symbiosis. Keywords: DGDG; Medicago truncatula; MtDGD1; phospholipids; RNAi; symbiotic phenotype.},
}
@article {pmid30984121,
year = {2019},
author = {Deja-Sikora, E and Mercy, L and Baum, C and Hrynkiewicz, K},
title = {The Contribution of Endomycorrhiza to the Performance of Potato Virus Y-Infected Solanaceous Plants: Disease Alleviation or Exacerbation?.},
journal = {Frontiers in microbiology},
volume = {10},
number = {},
pages = {516},
doi = {10.3389/fmicb.2019.00516},
pmid = {30984121},
issn = {1664-302X},
abstract = {Solanaceae, comprising meaningful crops (as potato, tomato, pepper, eggplant, and tobacco), can benefit from a symbiosis with arbuscular mycorrhizal fungi (AMF), which improve plant fitness and support plant defense against pathogens. Currently, those crops are likely the most impacted by Potato virus Y (PVY). Unfortunately, the effects of AM symbiosis on the severity of disease induced by PVY in solanaceous crops remain uncertain, partly because the interplay between AMF and PVY is poorly characterized. To shed some light on this issue, available studies on interactions in tripartite association between the host plant, its fungal colonizer, and viral pathogen were analyzed and discussed. Although the best-documented PVY transmission pathway is aphid-dependent, PVY infections are also observed in the absence of insect vector. We hypothesize the existence of an additional pathway for virus transmission involving AMF, in which the common mycorrhizal network (CMN) may act as a potential bridge. Therefore, we reviewed (1) the significance of AM colonization for the course of disease, (2) the potential of AMF networks to act as vectors for PVY, and (3) the consequences for crop breeding and production of AM biofertilizers.},
}
@article {pmid30984118,
year = {2019},
author = {Ek-Ramos, MJ and Gomez-Flores, R and Orozco-Flores, AA and Rodríguez-Padilla, C and González-Ochoa, G and Tamez-Guerra, P},
title = {Bioactive Products From Plant-Endophytic Gram-Positive Bacteria.},
journal = {Frontiers in microbiology},
volume = {10},
number = {},
pages = {463},
doi = {10.3389/fmicb.2019.00463},
pmid = {30984118},
issn = {1664-302X},
abstract = {Endophytes constitute plant-colonizing microorganisms in a mutualistic symbiosis relationship. They are found in most ecosystems reducing plant crops' biotic and abiotic stressors by stimulating immune responses, excluding plant pathogens by niche competition, and participating in antioxidant activities and phenylpropanoid metabolism, whose activation produces plant defense, structural support, and survival molecules. In fact, metabolomic studies have demonstrated that endophyte genes associated to specific metabolites are involved in plant growth promotion (PGP) by stimulating plant hormones production such as auxins and gibberellins or as plant protective agents against microbial pathogens, cancer, and insect pests, but eco-friendly and eco-safe. A number of metabolites of Gram-positive endophytes isolated from agriculture, forest, mangrove, and medicinal plants, mainly related to the Firmicutes phyla, possess distinctive biocontrol and plant growth-promoting activities. In general, Actinobacteria and Bacillus endophytes produce aromatic compounds, lipopeptides, plant hormones, polysaccharides, and several enzymes linked to phenylpropanoid metabolism, thus representing high potential for PGP and crop management strategies. Furthermore, Actinobacteria have been shown to produce metabolites with antimicrobial and antitumor activities, useful in agriculture, medicine, and veterinary areas. The great endophytes diversity, their metabolites production, and their adaptation to stress conditions make them a suitable and unlimited source of novel metabolites, whose application could reduce agrochemicals usage in food and drugs production.},
}
@article {pmid30561050,
year = {2019},
author = {Speare, DJ},
title = {Cleaner fish diseases.},
journal = {Journal of fish diseases},
volume = {42},
number = {2},
pages = {155-156},
doi = {10.1111/jfd.12937},
pmid = {30561050},
issn = {1365-2761},
mesh = {Animals ; Fish Diseases/*etiology ; Fishes/*physiology ; *Symbiosis ; },
}
@article {pmid30440041,
year = {2018},
author = {Kawaka, F and Makonde, H and Dida, M and Opala, P and Ombori, O and Maingi, J and Muoma, J},
title = {Genetic diversity of symbiotic bacteria nodulating common bean (Phaseolus vulgaris) in western Kenya.},
journal = {PloS one},
volume = {13},
number = {11},
pages = {e0207403},
pmid = {30440041},
issn = {1932-6203},
mesh = {*Bacteria/classification/genetics ; Kenya ; Nitrogen Fixation/physiology ; Phaseolus/growth & development/*microbiology ; RNA, Bacterial/*genetics ; RNA, Ribosomal, 16S/*genetics ; Root Nodules, Plant/*microbiology ; Symbiosis/*physiology ; },
abstract = {Biological nitrogen fixation (BNF) in legumes plays a critical role in improving soil fertility. Despite this vital role, there is limited information on the genetic diversity and BNF of bacteria nodulating common bean (Phaseolus vulgaris L.). This study evaluated the genetic diversity and symbiotic nitrogen fixation of bacteria nodulating common bean in soils of Western Kenya. The genetic diversity was determined using 16S rRNA gene partial sequences while BNF was estimated in a greenhouse experiment. The sequences of the native isolates were closely affiliated with members from the genera Pantoea, Klebsiella, Rhizobium, Enterobacter and Bacillus. These results show that apart from rhizobia, there are non-rhizobial strains in the nodules of common bean. The symbiotic efficiency (SE) of native isolates varied and exhibited comparable or superior BNF compared to the local commercial inoculants (CIAT 899 and Strain 446). Isolates (MMUST 003 [KP027691], MMUST 004 [KP027687], MMUST 005 [KP027688], KSM 001 [KP027682], KSM 002 [KP027680], KSM 003 [KP027683] and KSM 005 [KP027685]) recorded equal or significantly higher SE (p < 0.05) compared to N supplemented treatments. The results demonstrate the presence of genetic diversity of native bacteria nodulating bean that are effective in N fixation. These elite bacterial strains should be exploited as candidates for the development of Phaseolus vulgaris inoculants.},
}
@article {pmid30408087,
year = {2018},
author = {Elias, LG and Silva, DB and Silva, R and Peng, YQ and Yang, DR and Lopes, NP and Pereira, RAS},
title = {A comparative venomic fingerprinting approach reveals that galling and non-galling fig wasp species have different venom profiles.},
journal = {PloS one},
volume = {13},
number = {11},
pages = {e0207051},
pmid = {30408087},
issn = {1932-6203},
mesh = {Animals ; Ficus/*physiology ; Molecular Weight ; Pollination ; *Symbiosis ; Venoms/chemistry/*metabolism ; Wasps/*metabolism/physiology ; },
abstract = {The galling habit represents a complex type of interaction between insects and plants, ranging from antagonism to mutualism. The obligate pollination mutualism between Ficus and fig wasps relies strongly on the induction of galls in Ficus flowers, where wasps' offspring develop. Even though gall induction plays an important role in many insect-plant interactions, the mechanisms that trigger gall formation are still not completely known. Using a fingerprinting approach, we show here that venom protein profiles from galling fig wasps differ from the venom profiles of non-galling species, suggesting the secretion plays different roles according to the type of interaction it is involved in. Each studied cleptoparasitic species had a distinct venom profile, suggesting that cleptoparasitism in fig wasps covers a vast diversity of molecular interactions. Fig wasp venoms are mainly composed of peptides. No low molecular weight compounds were detected by UPLC-DAD-MS, suggesting that such compounds (e.g., IAA and cytokinines) are not involved in gall induction. The differences in venom composition observed between galling and non-galling fig wasp species bring new perspectives to the study of gall induction processes and the role of insect secretions.},
}
@article {pmid29535364,
year = {2018},
author = {Séne, S and Selosse, MA and Forget, M and Lambourdière, J and Cissé, K and Diédhiou, AG and Rivera-Ocasio, E and Kodja, H and Kameyama, N and Nara, K and Vincenot, L and Mansot, JL and Weber, J and Roy, M and Sylla, SN and Bâ, A},
title = {A pantropically introduced tree is followed by specific ectomycorrhizal symbionts due to pseudo-vertical transmission.},
journal = {The ISME journal},
volume = {12},
number = {7},
pages = {1806-1816},
pmid = {29535364},
issn = {1751-7370},
mesh = {Basidiomycota/classification/genetics/isolation & purification/*physiology ; Brazil ; Caribbean Region ; Japan ; Mycorrhizae/genetics/growth & development/isolation & purification/*physiology ; Polygonaceae/*microbiology ; Seedlings/microbiology/physiology ; Soil ; Spores, Fungal/classification/genetics/isolation & purification/physiology ; *Symbiosis ; Trees/*microbiology/physiology ; },
abstract = {Global trade increases plant introductions, but joint introduction of associated microbes is overlooked. We analyzed the ectomycorrhizal fungi of a Caribbean beach tree, seagrape (Coccoloba uvifera, Polygonacaeae), introduced pantropically to stabilize coastal soils and produce edible fruits. Seagrape displays a limited symbiont diversity in the Caribbean. In five regions of introduction (Brazil, Japan, Malaysia, Réunion and Senegal), molecular barcoding showed that seagrape mostly or exclusively associates with Scleroderma species (Basidiomycota) that were hitherto only known from Caribbean seagrape stands. An unknown Scleroderma species dominates in Brazil, Japan and Malaysia, while Scleroderma bermudense exclusively occurs in Réunion and Senegal. Population genetics analysis of S. bermudense did not detect any demographic bottleneck associated with a possible founder effect, but fungal populations from regions where seagrape is introduced are little differentiated from the Caribbean ones, separated by thousands of kilometers, consistently with relatively recent introduction. Moreover, dry seagrape fruits carry Scleroderma spores, probably because, when drying on beach sand, they aggregate spores from the spore bank accumulated by semi-hypogeous Scleroderma sporocarps. Aggregated spores inoculate seedlings, and their abundance may limit the founder effect after seagrape introduction. This rare pseudo-vertical transmission of mycorrhizal fungi likely contributed to efficient and repeated seagrape/Scleroderma co-introductions.},
}
@article {pmid29476142,
year = {2018},
author = {Desirò, A and Hao, Z and Liber, JA and Benucci, GMN and Lowry, D and Roberson, R and Bonito, G},
title = {Mycoplasma-related endobacteria within Mortierellomycotina fungi: diversity, distribution and functional insights into their lifestyle.},
journal = {The ISME journal},
volume = {12},
number = {7},
pages = {1743-1757},
pmid = {29476142},
issn = {1751-7370},
mesh = {Biodiversity ; Burkholderia/classification/genetics/isolation & purification/*physiology ; Fungi/chemistry/*physiology ; Mycoplasma/classification/genetics/isolation & purification/*physiology ; Phylogeny ; *Symbiosis ; },
abstract = {Bacterial interactions with animals and plants have been examined for over a century; by contrast, the study of bacterial-fungal interactions has received less attention. Bacteria interact with fungi in diverse ways, and endobacteria that reside inside fungal cells represent the most intimate interaction. The most significant bacterial endosymbionts that have been studied are associated with Mucoromycota and include two main groups: Burkholderia-related and Mycoplasma-related endobacteria (MRE). Examples of Burkholderia-related endobacteria have been reported in the three Mucoromycota subphyla. By contrast, MRE have only been identified in Glomeromycotina and Mucoromycotina. This study aims to understand whether MRE dwell in Mortierellomycotina and, if so, to determine their impact on the fungal host. We carried out a large-scale screening of 394 Mortierellomycotina strains and employed a combination of microscopy, molecular phylogeny, next-generation sequencing and qPCR. We detected MRE in 12 strains. These endosymbionts represent novel bacterial phylotypes and show evidence of recombination. Their presence in Mortierellomycotina demonstrates that MRE occur within fungi across Mucoromycota and they may have lived in their common ancestor. We cured the fungus of its endosymbionts with antibiotics and observed improved biomass production in isogenic lines lacking MRE, demonstrating that these endobacteria impose some fitness costs to their fungal host. Here we provided the first functional insights into the lifestyle of MRE. Our findings indicate that MRE may be antagonistic to their fungal hosts, and adapted to a non-lethal parasitic lifestyle in the mycelium of Mucoromycota. However, context-dependent adaptive benefits to their host at minimal cost cannot not be excluded. Finally, we conclude that Mortierellomycotina represent attractive model organisms for exploring interactions between MRE and fungi.},
}
@article {pmid30978547,
year = {2019},
author = {Munzi, S and Cruz, C and Corrêa, A},
title = {When the exception becomes the rule: An integrative approach to symbiosis.},
journal = {The Science of the total environment},
volume = {672},
number = {},
pages = {855-861},
doi = {10.1016/j.scitotenv.2019.04.038},
pmid = {30978547},
issn = {1879-1026},
abstract = {Symbiosis, mainly due to the advances in -omics technology and to the microbiome revolution, is being increasingly acknowledged as fundamental to explain any aspect of life existence. Previously considered an exception, a peculiar characteristic of few systems like lichens, corals and mycorrhizas, symbiosis is nowadays recognized as the rule, with the microbiome being part of all living entities and systems. However, our knowledge of the ecological meaning and functioning of many symbiotic systems is still limited. Here, we discuss a new, integrative approach based on current findings that looks at commonalities among symbiotic systems to produce theoretical models and conceptual knowledge that would allow a more efficient exploitation of symbiosis-based biotechnologies. The microbiome recruitment and assemblage processes are indicated as one of the potential targets where a holistic approach could bring advantages. Finally, we reflect on the potential socio-economic and environmental consequences of a symbiotic view of the world, where co-dependence is the matrix of life.},
}
@article {pmid30977796,
year = {2019},
author = {Salinero-Lanzarote, A and Pacheco-Moreno, A and Domingo-Serrano, L and Durán, D and Ormeño-Orrillo, E and Martínez-Romero, E and Albareda, M and Palacios, JM and Rey, L},
title = {The type VI secretion system of Rhizobium etli Mim1 has a positive effect in symbiosis.},
journal = {FEMS microbiology ecology},
volume = {},
number = {},
pages = {},
doi = {10.1093/femsec/fiz054},
pmid = {30977796},
issn = {1574-6941},
abstract = {The type six secretion systems (T6SSs) allow bacteria to translocate effector proteins to other bacteria or to eukaryotic cells. However, little is known about the role of T6SS in endosymbiotic bacteria. In this work we describe the T6SS of Rhizobium etli Mim1, a bacteria able to effectively nodulate common beans. Structural genes and those encoding possible effectors have been identified in a 28-gene DNA region of R. etli Mim1 pRetMIM1f plasmid. Immunodetection of Hcp protein, a conserved key structural component of T6SS systems, indicates that this secretion system is active at high cell densities, in the presence of root exudates, and in bean nodules. R. etli mutants affected in T6SS structural genes produced plants with lower dry weight and smaller nodules than the wild-type strain, indicating for the first time that the T6SS plays a positive role in Rhizobium-legume symbiosis.},
}
@article {pmid30977533,
year = {2019},
author = {Wu, Z and Wang, M and Yang, S and Chen, S and Chen, X and Liu, C and Wang, S and Wang, H and Zhang, B and Liu, H and Qin, R and Wang, X},
title = {A global coexpression network of soybean genes gives insight into the evolution of nodulation in non-legumes and legumes.},
journal = {The New phytologist},
volume = {},
number = {},
pages = {},
doi = {10.1111/nph.15845},
pmid = {30977533},
issn = {1469-8137},
abstract = {A coexpression network is a powerful tool for revealing genes' relationship with many biological processes. Mass transcriptomic and genomic data from different plant species provide the foundation for understanding the evolution of nodulation across the Viridiplantae at a systematic level. We used weighted coexpression network analysis (WGCNA) to mine a nodule-related module (NRM) in Glycine max. Comparative genomic analysis of 78 green plant species revealed that NRM genes are recruited from different evolutionary nodes along with gene duplication events. A set of core coexpressed genes within legumes that may play vital roles in regulating nodule environments essential for nitrogen fixation, including oxygen concentrations, sulfur transport, and iron homeostasis (such as GmCHY). The regulation of these genes occurred mainly at the transcription level, although some of them, such as sulfate transporters, may also undergo positive selection at protein level. We revealed that ancient orthologs and duplication events prior to the origin of legumes were preadapted for symbiosis. Conserved coregulated genes found within legumes paved the way for nodule formation and nitrogen fixation. These findings provide significant insights into the evolution of nodulation and indicate promising candidates for identifying other key components of legume nodulation and nitrogen fixation. This article is protected by copyright. All rights reserved.},
}
@article {pmid30976084,
year = {2019},
author = {Kim, GB and Son, SU and Yu, HJ and Mun, JH},
title = {MtGA2ox10 encoding C20-GA2-oxidase regulates rhizobial infection and nodule development in Medicago truncatula.},
journal = {Scientific reports},
volume = {9},
number = {1},
pages = {5952},
doi = {10.1038/s41598-019-42407-3},
pmid = {30976084},
issn = {2045-2322},
support = {PJ012251//Rural Development Administration (RDA)/ ; PJ012421//Rural Development Administration (RDA)/ ; },
abstract = {Gibberellin (GA) plays a controversial role in the legume-rhizobium symbiosis. Recent studies have shown that the GA level in legumes must be precisely controlled for successful rhizobial infection and nodule organogenesis. However, regulation of the GA level via catabolism in legume roots has not been reported to date. Here, we investigate a novel GA inactivating C20-GA2-oxidase gene MtGA2ox10 in Medicago truncatula. RNA sequencing analysis and quantitative polymerase chain reaction revealed that MtGA2ox10 was induced as early as 6 h post-inoculation (hpi) of rhizobia and reached peak transcript abundance at 12 hpi. Promoter::β-glucuronidase fusion showed that the promoter activity was localized in the root infection/differentiation zone during the early stage of rhizobial infection and in the vascular bundle of the mature nodule. The CRISPR/Cas9-mediated deletion mutation of MtGA2ox10 suppressed infection thread formation, which resulted in reduced development and retarded growth of nodules on the Agrobacterium rhizogenes-transformed roots. Over-expression of MtGA2ox10 in the stable transgenic plants caused dwarfism, which was rescued by GA3 application, and increased infection thread formation but inhibition of nodule development. We conclude that MtGA2ox10 plays an important role in the rhizobial infection and the development of root nodules through fine catabolic tuning of GA in M. truncatula.},
}
@article {pmid30976027,
year = {2019},
author = {Lefoulon, E and Vaisman, N and Frydman, HM and Sun, L and Foster, JM and Slatko, BE},
title = {Large Enriched Fragment Targeted Sequencing (LEFT-SEQ) Applied to Capture of Wolbachia Genomes.},
journal = {Scientific reports},
volume = {9},
number = {1},
pages = {5939},
doi = {10.1038/s41598-019-42454-w},
pmid = {30976027},
issn = {2045-2322},
abstract = {Symbiosis is a major force of evolutionary change, influencing virtually all aspects of biology, from population ecology and evolution to genomics and molecular/biochemical mechanisms of development and reproduction. A remarkable example is Wolbachia endobacteria, present in some parasitic nematodes and many arthropod species. Acquisition of genomic data from diverse Wolbachia clades will aid in the elucidation of the different symbiotic mechanisms(s). However, challenges of de novo assembly of Wolbachia genomes include the presence in the sample of host DNA: nematode/vertebrate or insect. We designed biotinylated probes to capture large fragments of Wolbachia DNA for sequencing using PacBio technology (LEFT-SEQ: Large Enriched Fragment Targeted Sequencing). LEFT-SEQ was used to capture and sequence four Wolbachia genomes: the filarial nematode Brugia malayi, wBm, (21-fold enrichment), Drosophila mauritiana flies (2 isolates), wMau (11-fold enrichment), and Aedes albopictus mosquitoes, wAlbB (200-fold enrichment). LEFT-SEQ resulted in complete genomes for wBm and for wMau. For wBm, 18 single-nucleotide polymorphisms (SNPs), relative to the wBm reference, were identified and confirmed by PCR. A limit of LEFT-SEQ is illustrated by the wAlbB genome, characterized by a very high level of insertion sequences elements (ISs) and DNA repeats, for which only a 20-contig draft assembly was achieved.},
}
@article {pmid30975812,
year = {2019},
author = {Gogoleva, NE and Nikolaichik, YA and Ismailov, TT and Khlopko, YA and Dmitrieva, SA and Konnova, TA and Ermekkaliev, TS and Safronova, VI and Belimov, AA and Gogolev, YV},
title = {Complete Genome Sequence of Abscisic Acid-Metabolizing Rhizobacterium Rhodococcus sp. Strain P1Y.},
journal = {Microbiology resource announcements},
volume = {8},
number = {15},
pages = {},
doi = {10.1128/MRA.01591-18},
pmid = {30975812},
issn = {2576-098X},
abstract = {Mechanisms of microbial catabolism of phytohormone abscisic acid (ABA) are still unknown. Here, we report the complete genome sequence of ABA-utilizing Rhodococcus sp. strain P1Y, isolated from the rice (Oryza sativa L.) rhizosphere. The sequence was obtained using an approach combining Oxford Nanopore Technologies MinION and Illumina MiSeq sequence data.},
}
@article {pmid30825301,
year = {2019},
author = {Coyne, MJ and Comstock, LE},
title = {Type VI Secretion Systems and the Gut Microbiota.},
journal = {Microbiology spectrum},
volume = {7},
number = {2},
pages = {},
doi = {10.1128/microbiolspec.PSIB-0009-2018},
pmid = {30825301},
issn = {2165-0497},
support = {R01 AI093771/AI/NIAID NIH HHS/United States ; R01 AI120633/AI/NIAID NIH HHS/United States ; },
mesh = {Antibiosis ; Bacteria/*metabolism/pathogenicity ; Bacterial Proteins ; Colon/microbiology ; Ecology ; Gastrointestinal Microbiome/genetics/*physiology ; Gastrointestinal Tract/*microbiology ; Humans ; Proteobacteria/metabolism ; Symbiosis ; *Type VI Secretion Systems/antagonists & inhibitors/genetics/immunology ; },
abstract = {The human colonic microbiota is a dense ecosystem comprised of numerous microbes, including bacteria, phage, fungi, archaea, and protozoa, that compete for nutrients and space. Studies are beginning to reveal the antagonistic mechanisms that gut bacteria use to compete with other members of this ecosystem. In the healthy human colon, the majority of the Gram-negative bacteria are of the order Bacteroidales. Proteobacteria, such as Escherichia coli, are numerically fewer but confer important properties to the host, such as colonization resistance. Several enteric pathogens use type VI secretion systems (T6SSs) to antagonize symbiotic gut E. coli, facilitating colonization and disease progression. T6SS loci are also widely distributed in human gut Bacteroidales, which includes three predominant genera: Bacteroides, Parabacteroides, and Prevotella. There are three distinct genetic architectures of T6SS loci among the gut Bacteroidales, termed GA1, GA2, and GA3. GA1 and GA2 T6SS loci are contained on integrative and conjugative elements and are the first T6SS loci shown to be readily transferred in the human gut between numerous species and families of Bacteroidales. In contrast, the GA3 T6SSs are present exclusively in Bacteroides fragilis. There are divergent regions in all three T6SS GAs that contain genes encoding effector and immunity proteins, many of which function by unknown mechanisms. To date, only the GA3 T6SSs have been shown to antagonize bacteria, and they target nearly all gut Bacteroidales species analyzed. This review delves more deeply into properties of the T6SSs of these human gut bacteria and the ecological outcomes of their synthesis in vivo.},
}
@article {pmid30588764,
year = {2019},
author = {Woyke, T and Schulz, F},
title = {Entities inside one another - a matryoshka doll in biology?.},
journal = {Environmental microbiology reports},
volume = {11},
number = {1},
pages = {26-28},
doi = {10.1111/1758-2229.12716},
pmid = {30588764},
issn = {1758-2229},
mesh = {*Biological Evolution ; Eukaryota/physiology ; Giant Viruses/physiology ; Metagenomics ; Microbial Consortia ; Organelles/physiology ; *Symbiosis ; Thiothrix/physiology ; },
}
@article {pmid30516032,
year = {2019},
author = {Danchin, A},
title = {Conceptual sequel to biological expeditions at the time of global changes.},
journal = {Environmental microbiology reports},
volume = {11},
number = {1},
pages = {38-40},
doi = {10.1111/1758-2229.12722},
pmid = {30516032},
issn = {1758-2229},
mesh = {Adaptation, Physiological ; Biological Evolution ; *Climate Change ; *Expeditions ; Humans ; Intrinsically Disordered Proteins/chemistry/metabolism ; Pacific Ocean ; Symbiosis ; },
}
@article {pmid29514991,
year = {2018},
author = {Lam, WN and Lim, RJY and Wong, SH and Tan, HTW},
title = {Predatory dipteran larva contributes to nutrient sequestration in a carnivorous pitcher plant.},
journal = {Biology letters},
volume = {14},
number = {3},
pages = {},
pmid = {29514991},
issn = {1744-957X},
mesh = {Ammonium Compounds/*metabolism ; Animals ; Diptera/growth & development/*physiology ; Food Chain ; Larva/growth & development/physiology ; Nutrients/metabolism ; *Predatory Behavior ; Sarraceniaceae/*physiology ; Singapore ; *Symbiosis ; },
abstract = {The fluids of Nepenthes pitcher plants are habitats to many specialized animals known as inquilines, which facilitate the conversion of prey protein into pitcher-absorbable nitrogen forms such as ammonium. Xenoplatyura beaveri (Diptera: Mycetophilidae) is a predatory dipteran inquiline that inhabits the pitchers of Nepenthes ampullaria Larvae of X. beaveri construct sticky webs over the fluid surface of N. ampullaria to ensnare emerging adult dipteran inquilines. However, the interaction between X. beaveri and its host has never been examined before, and it is not known if X. beaveri can contribute to nutrient sequestration in N. ampullaria. Xenoplatyura beaveri individuals were reared in artificial pitchers in the laboratory on a diet of emergent Tripteroides tenax mosquitoes, and the ammonium concentration of the pitcher fluids was measured over time. Fluid ammonium concentration in tubes containing X. beaveri was significantly greater than those of the controls. Furthermore, fluid ammonium concentrations increased greatly after X. beaveri larvae metamorphosed, although the cause of this increase could not be identified. Our results show that a terrestrial, inquiline predator can contribute significantly to nutrient sequestration in the phytotelma it inhabits, and suggest that this interaction has a net mutualistic outcome for both species.},
}
@article {pmid30972304,
year = {2019},
author = {Choudhary, E and Sharma, R and Kumar, Y and Agarwal, N},
title = {Conditional Silencing by CRISPRi Reveals the Role of DNA Gyrase in Formation of Drug-Tolerant Persister Population in Mycobacterium tuberculosis.},
journal = {Frontiers in cellular and infection microbiology},
volume = {9},
number = {},
pages = {70},
doi = {10.3389/fcimb.2019.00070},
pmid = {30972304},
issn = {2235-2988},
abstract = {Drug tolerance in mycobacterial pathogens is a global concern. Fluoroquinolone (FQ) treatment is widely used for induction of persisters in bacteria. Although FQs that target DNA gyrase are currently used as second-line anti-tuberculosis (TB) drugs, little is known about their impact on Mycobacterium tuberculosis (Mtb) persister formation. Here we explored the CRISPRi-based genetic repression for better understanding the effect of DNA gyrase depletion on Mtb physiology and response to anti-TB drugs. We find that suppression of DNA gyrase drastically affects intra- and extracellular growth of Mtb. Interestingly, gyrase depletion in Mtb leads to activation of RecA/LexA-mediated SOS response and drug tolerance via induction of persister subpopulation. Chemical inhibition of RecA in gyrase-depleted bacteria results in reversion of persister phenotype and better killing by antibiotics. This study provides evidence that inhibition of SOS response can be advantageous in improving the efficacy of anti-TB drugs and shortening the duration of current TB treatment.},
}
@article {pmid30972043,
year = {2019},
author = {Mills, JG and Brookes, JD and Gellie, NJC and Liddicoat, C and Lowe, AJ and Sydnor, HR and Thomas, T and Weinstein, P and Weyrich, LS and Breed, MF},
title = {Relating Urban Biodiversity to Human Health With the 'Holobiont' Concept.},
journal = {Frontiers in microbiology},
volume = {10},
number = {},
pages = {550},
doi = {10.3389/fmicb.2019.00550},
pmid = {30972043},
issn = {1664-302X},
abstract = {A relatively unaccounted ecosystem service from biodiversity is the benefit to human health via symbiotic microbiota from our environment. This benefit occurs because humans evolved alongside microbes and have been constantly exposed to diverse microbiota. Plants and animals, including humans, are organised as a host with symbiotic microbiota, whose collective genome and life history form a single holobiont. As such, there are interdependencies between biodiversity, holobionts, and public health which lead us to argue that human health outcomes could be improved by increasing contact with biodiversity in an urban context. We propose that humans, like all holobionts, likely require a diverse microbial habitat to appropriate resources for living healthy, long lives. We discuss how industrial urbanisation likely disrupts the symbiosis between microbiota and their hosts, leading to negative health outcomes. The industrialised urban habitat is low in macro and microbial biodiversity and discourages contact with beneficial environmental microbiota. These habitat factors, alongside diet, antibiotics, and others, are associated with the epidemic of non-communicable diseases in these societies. We suggest that restoration of urban microbial biodiversity and micro-ecological processes through microbiome rewilding can benefit holobiont health and aid in treating the urban non-communicable disease epidemic. Further, we identify research gaps and some solutions to economic and strategic hurdles in applying microbiome rewilding into daily urban life.},
}
@article {pmid30971198,
year = {2019},
author = {Malinich, EA and Wang, K and Mukherjee, PK and Kolomiets, M and Kenerley, CM},
title = {Differential expression analysis of Trichoderma virens RNA reveals a dynamic transcriptome during colonization of Zea mays roots.},
journal = {BMC genomics},
volume = {20},
number = {1},
pages = {280},
doi = {10.1186/s12864-019-5651-z},
pmid = {30971198},
issn = {1471-2164},
support = {2016-67013-24730//National Institute of Food and Agriculture/ ; },
abstract = {BACKGROUND: Trichoderma spp. are majorly composed of plant-beneficial symbionts widely used in agriculture as bio-control agents. Studying the mechanisms behind Trichoderma-derived plant benefits has yielded tangible bio-industrial products. To better take advantage of this fungal-plant symbiosis it is necessary to obtain detailed knowledge of which genes Trichoderma utilizes during interaction with its plant host. In this study, we explored the transcriptional activity undergone by T. virens during two phases of symbiosis with maize; recognition of roots and after ingress into the root cortex.
RESULTS: We present a model of T. virens - maize interaction wherein T. virens experiences global repression of transcription upon recognition of maize roots and then induces expression of a broad spectrum of genes during colonization of maize roots. The genes expressed indicate that, during colonization of maize roots, T. virens modulates biosynthesis of phytohormone-like compounds, secretes a plant-environment specific array of cell wall degrading enzymes and secondary metabolites, remodels both actin-based and cell membrane structures, and shifts metabolic activity. We also highlight transcription factors and signal transduction genes important in future research seeking to unravel the molecular mechanisms of T. virens activity in maize roots.
CONCLUSIONS: T. virens displays distinctly different transcriptional profiles between recognizing the presence of maize roots and active colonization of these roots. A though understanding of these processes will allow development of T. virens as a bio-control agent. Further, the publication of these datasets will target future research endeavors specifically to genes of interest when considering T. virens - maize symbiosis.},
}
@article {pmid30603945,
year = {2018},
author = {Pavlova, LV},
title = {First Finding of Representatives of the Eccrinida Order in the Digestive Tract of King Crab Specie from the Barents Sea.},
journal = {Doklady biological sciences : proceedings of the Academy of Sciences of the USSR, Biological sciences sections},
volume = {483},
number = {1},
pages = {231-234},
doi = {10.1134/S0012496618060066},
pmid = {30603945},
issn = {1608-3105},
mesh = {Animals ; Anomura/*anatomy & histology ; Gastrointestinal Tract/*anatomy & histology ; *Symbiosis ; },
abstract = {This is the first report on the finding of large intra-intestinal symbionts belonging to the order Eccrinida in crab-like decapod crustaceans of the family Lithodidae, Paralithodes camtschaticus and Lithodes maja, inhabiting the Barents Sea. Studies have been regularly conducted since the early 2000s in Kola Bay and in one of the inlets of the Eastern Murman Coast. Since 2005, Eccrinida representatives (presumably, a new species of the genus Arundinula) have been found in the guts of the red king crab. A brief description of the endosymbionts and data on their frequency of occurrence are presented. The possible reasons for the distribution of eccrinids in the crab-like decapod crustaceans of the Barents Sea are discussed.},
}
@article {pmid30598000,
year = {2018},
author = {Mannaa, M and Park, I and Seo, YS},
title = {Genomic Features and Insights into the Taxonomy, Virulence, and Benevolence of Plant-Associated Burkholderia Species.},
journal = {International journal of molecular sciences},
volume = {20},
number = {1},
pages = {},
doi = {10.3390/ijms20010121},
pmid = {30598000},
issn = {1422-0067},
support = {918019-04-1-HD030//Strategic Initiative for Microbiomes in Agriculture and Food, Ministry of Agriculture, Food and Rural Affairs, Republic of Korea/ ; },
mesh = {Burkholderia/classification/*genetics/pathogenicity ; Crops, Agricultural/*microbiology ; *Genome, Bacterial ; *Host-Pathogen Interactions ; Phylogeny ; Symbiosis ; },
abstract = {The members of the Burkholderia genus are characterized by high versatility and adaptability to various ecological niches. With the availability of the genome sequences of numerous species of Burkholderia, many studies have been conducted to elucidate the unique features of this exceptional group of bacteria. Genomic and metabolic plasticity are common among Burkholderia species, as evidenced by their relatively large multi-replicon genomes that are rich in insertion sequences and genomic islands and contain a high proportion of coding regions. Such unique features could explain their adaptability to various habitats and their versatile lifestyles, which are reflected in a multiplicity of species including free-living rhizospheric bacteria, plant endosymbionts, legume nodulators, and plant pathogens. The phytopathogenic Burkholderia group encompasses several pathogens representing threats to important agriculture crops such as rice. Contrarily, plant-beneficial Burkholderia have also been reported, which have symbiotic and growth-promoting roles. In this review, the taxonomy of Burkholderia is discussed emphasizing the recent updates and the contributions of genomic studies to precise taxonomic positioning. Moreover, genomic and functional studies on Burkholderia are reviewed and insights are provided into the mechanisms underlying the virulence and benevolence of phytopathogenic and plant-beneficial Burkholderia, respectively, on the basis of cutting-edge knowledge.},
}
@article {pmid30552831,
year = {2019},
author = {Manzello, DP and Matz, MV and Enochs, IC and Valentino, L and Carlton, RD and Kolodziej, G and Serrano, X and Towle, EK and Jankulak, M},
title = {Role of host genetics and heat-tolerant algal symbionts in sustaining populations of the endangered coral Orbicella faveolata in the Florida Keys with ocean warming.},
journal = {Global change biology},
volume = {25},
number = {3},
pages = {1016-1031},
doi = {10.1111/gcb.14545},
pmid = {30552831},
issn = {1365-2486},
mesh = {Alveolata/genetics/*physiology ; Animals ; Anthozoa/genetics/*parasitology/*physiology ; Coral Reefs ; Florida ; Genetic Variation ; *Hot Temperature ; Oceans and Seas ; *Symbiosis ; Thermotolerance/genetics/*physiology ; },
abstract = {Identifying which factors lead to coral bleaching resistance is a priority given the global decline of coral reefs with ocean warming. During the second year of back-to-back bleaching events in the Florida Keys in 2014 and 2015, we characterized key environmental and biological factors associated with bleaching resilience in the threatened reef-building coral Orbicella faveolata. Ten reefs (five inshore, five offshore, 179 corals total) were sampled during bleaching (September 2015) and recovery (May 2016). Corals were genotyped with 2bRAD and profiled for algal symbiont abundance and type. O. faveolata at the inshore sites, despite higher temperatures, demonstrated significantly higher bleaching resistance and better recovery compared to offshore. The thermotolerant Durusdinium trenchii (formerly Symbiondinium trenchii) was the dominant endosymbiont type region-wide during initial (78.0% of corals sampled) and final (77.2%) sampling; >90% of the nonbleached corals were dominated by D. trenchii. 2bRAD host genotyping found no genetic structure among reefs, but inshore sites showed a high level of clonality. While none of the measured environmental parameters were correlated with bleaching, 71% of variation in bleaching resistance and 73% of variation in the proportion of D. trenchii was attributable to differences between genets, highlighting the leading role of genetics in shaping natural bleaching patterns. Notably, D. trenchii was rarely dominant in O. faveolata from the Florida Keys in previous studies, even during bleaching. The region-wide high abundance of D. trenchii was likely driven by repeated bleaching associated with the two warmest years on record for the Florida Keys (2014 and 2015). On inshore reefs in the Upper Florida Keys, O. faveolata was most abundant, had the highest bleaching resistance, and contained the most corals dominated by D. trenchii, illustrating a causal link between heat tolerance and ecosystem resilience with global change.},
}
@article {pmid29584555,
year = {2019},
author = {Garcia-Gutierrez, E and Mayer, MJ and Cotter, PD and Narbad, A},
title = {Gut microbiota as a source of novel antimicrobials.},
journal = {Gut microbes},
volume = {10},
number = {1},
pages = {1-21},
doi = {10.1080/19490976.2018.1455790},
pmid = {29584555},
issn = {1949-0984},
support = {BB/J004529/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; },
mesh = {Anti-Infective Agents/isolation & purification/*metabolism/pharmacology ; Antimicrobial Cationic Peptides/isolation & purification/metabolism/pharmacology ; Bacteria/chemistry/drug effects/*metabolism ; Bacteriocins/isolation & purification/*metabolism/pharmacology ; Gastrointestinal Microbiome/drug effects/*physiology ; Homeostasis ; Humans ; Symbiosis ; },
abstract = {Bacteria, Archaea, Eukarya and viruses coexist in the human gut, and this coexistence is functionally balanced by symbiotic or antagonistic relationships. Antagonism is often characterized by the production of antimicrobials against other organisms occupying the same environmental niche. Indeed, close co-evolution in the gut has led to the development of specialized antimicrobials, which is attracting increased attention as these may serve as novel alternatives to antibiotics and thereby help to address the global problem of antimicrobial resistance. The gastrointestinal (GI) tract is especially suitable for finding novel antimicrobials due to the vast array of microbes that inhabit it, and a considerable number of antimicrobial producers of both wide and narrow spectrum have been described. In this review, we summarize some of the antimicrobial compounds that are produced by bacteria isolated from the gut environment, with a special focus on bacteriocins. We also evaluate the potential therapeutic application of these compounds to maintain homeostasis in the gut and the biocontrol of pathogenic bacteria.},
}
@article {pmid30968126,
year = {2019},
author = {Berger, A and Boscari, A and Frendo, P and Brouquisse, R},
title = {Nitric oxide signaling, metabolism and toxicity in nitrogen-fixing symbiosis.},
journal = {Journal of experimental botany},
volume = {},
number = {},
pages = {},
doi = {10.1093/jxb/erz159},
pmid = {30968126},
issn = {1460-2431},
abstract = {The interactions between legumes and Rhizobia lead to the establishment of a symbiotic relationship characterized by the formation of a new organ, the nodule, which facilitates the fixation of atmospheric nitrogen (N2) by nitrogenase through the creation of a hypoxic environment. Significant amounts of nitric oxide (NO) accumulate at different stages of nodule development, suggesting that NO performs specific signaling and/or metabolic functions during symbiosis. NO, which regulates nodule gene expression, accumulates to high levels in hypoxic nodules. NO accumulation is considered to assist energy metabolism within the hypoxic environment of the nodule via a phytoglobin/NO-mediated respiration process. NO is a potent inhibitor of the activity of nitrogenase and other plant/bacterial enzymes, acting as a developmental signal in the induction of nodule senescence. Hence, key questions concern the relative importance of the signaling/metabolic functions of NO versus its toxic action and how NO levels are regulated to be compatible with nitrogen fixation functions. This review analyses these paradoxical roles of NO at various stages of symbiosis, and highlights the role of plant phytoglobins and bacterial hemoproteins in the control of NO accumulation.},
}
@article {pmid30967024,
year = {2019},
author = {Kang, L},
title = {Overview: biotic signalling for smart pest management.},
journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences},
volume = {374},
number = {1767},
pages = {20180306},
doi = {10.1098/rstb.2018.0306},
pmid = {30967024},
issn = {1471-2970},
abstract = {Biotic signalling refers to species or phylogenetic-clade-specific signals that elicit adaptive and acceptable responses within and among organisms. It is not only the molecular basis of the ecological relationships among different species, such as parasitism, symbiosis and predation, but also serves as ideal targets that can be used to manipulate these ecological relationships. This concept was proposed by a group of scientists from the Chinese Academy of Sciences (CAS) and actively pursued in a five-year research project in 2014 funded by the CAS ($40 million), entitled 'Decoding biotic interactions and mechanism for target management of agricultural pests'. The multi-disciplinary project aimed at a systematic investigation of the intra-species and inter-species and interactions via biotic signalling, with the ultimate goal being the development of novel methods to manage the pest insects and diseases. We hereby propose a topic 'Biotic signalling sheds light on smart pest control' as a theme issue for the Philosophical Transactions of the Royal Society B. It contains a total of 18 reviews and research articles under the topic of signalling manipulation for pest management. Unravelling these complex interactions among plants, microbial pathogens and insects holds promise for developing novel strategies to protect crop plants without compromising agricultural productivity and environmental health. This article is part of the theme issue 'Biotic signalling sheds light on smart pest management'.},
}
@article {pmid30817773,
year = {2019},
author = {Weiss, BL and Maltz, MA and Vigneron, A and Wu, Y and Walter, KS and O'Neill, MB and Wang, J and Aksoy, S},
title = {Colonization of the tsetse fly midgut with commensal Kosakonia cowanii Zambiae inhibits trypanosome infection establishment.},
journal = {PLoS pathogens},
volume = {15},
number = {2},
pages = {e1007470},
doi = {10.1371/journal.ppat.1007470},
pmid = {30817773},
issn = {1553-7374},
support = {U01 AI115648/AI/NIAID NIH HHS/United States ; R01 AI051584/AI/NIAID NIH HHS/United States ; D43 TW007391/TW/FIC NIH HHS/United States ; R21 AI101456/AI/NIAID NIH HHS/United States ; },
mesh = {Adult ; Africa South of the Sahara ; Animals ; Anopheles/microbiology ; Enterobacteriaceae ; Female ; Humans ; Male ; Mosquito Vectors/microbiology/parasitology ; Symbiosis ; Trypanosoma brucei brucei/*pathogenicity ; Trypanosoma congolense/*pathogenicity ; Trypanosomiasis, African/metabolism/microbiology/parasitology/*prevention & control ; Tsetse Flies/*microbiology/*parasitology ; },
abstract = {Tsetse flies (Glossina spp.) vector pathogenic trypanosomes (Trypanosoma spp.) in sub-Saharan Africa. These parasites cause human and animal African trypanosomiases, which are debilitating diseases that inflict an enormous socio-economic burden on inhabitants of endemic regions. Current disease control strategies rely primarily on treating infected animals and reducing tsetse population densities. However, relevant programs are costly, labor intensive and difficult to sustain. As such, novel strategies aimed at reducing tsetse vector competence require development. Herein we investigated whether Kosakonia cowanii Zambiae (Kco_Z), which confers Anopheles gambiae with resistance to Plasmodium, is able to colonize tsetse and induce a trypanosome refractory phenotype in the fly. Kco_Z established stable infections in tsetse's gut and exhibited no adverse effect on the fly's survival. Flies with established Kco_Z infections in their gut were significantly more refractory to infection with two distinct trypanosome species (T. congolense, 6% infection; T. brucei, 32% infection) than were age-matched flies that did not house the exogenous bacterium (T. congolense, 36% infected; T. brucei, 70% infected). Additionally, 52% of Kco_Z colonized tsetse survived infection with entomopathogenic Serratia marcescens, compared with only 9% of their wild-type counterparts. These parasite and pathogen refractory phenotypes result from the fact that Kco_Z acidifies tsetse's midgut environment, which inhibits trypanosome and Serratia growth and thus infection establishment. Finally, we determined that Kco_Z infection does not impact the fecundity of male or female tsetse, nor the ability of male flies to compete with their wild-type counterparts for mates. We propose that Kco_Z could be used as one component of an integrated strategy aimed at reducing the ability of tsetse to transmit pathogenic trypanosomes.},
}
@article {pmid30789967,
year = {2019},
author = {Li, P and Liu, C and Deng, WH and Yao, DM and Pan, LL and Li, YQ and Liu, YQ and Liang, Y and Zhou, XP and Wang, XW},
title = {Plant begomoviruses subvert ubiquitination to suppress plant defenses against insect vectors.},
journal = {PLoS pathogens},
volume = {15},
number = {2},
pages = {e1007607},
doi = {10.1371/journal.ppat.1007607},
pmid = {30789967},
issn = {1553-7374},
mesh = {Animals ; Begomovirus/*metabolism/pathogenicity ; Cyclopentanes/metabolism ; Hemiptera/*metabolism/virology ; Insect Vectors/metabolism ; Oxylipins/metabolism ; Plant Diseases/virology ; Plant Viruses/pathogenicity ; Symbiosis ; Tobacco/virology ; Ubiquitination ; },
abstract = {Most plant viruses are vectored by insects and the interactions of virus-plant-vector have important ecological and evolutionary implications. Insect vectors often perform better on virus-infected plants. This indirect mutualism between plant viruses and insect vectors promotes the spread of virus and has significant agronomical effects. However, few studies have investigated how plant viruses manipulate plant defenses and promote vector performance. Begomoviruses are a prominent group of plant viruses in tropical and sub-tropical agro-ecosystems and are transmitted by whiteflies. Working with the whitefly Bemisia tabaci, begomoviruses and tobacco, we revealed that C2 protein of begomoviruses lacking DNA satellites was responsible for the suppression of plant defenses against whitefly vectors. We found that infection of plants by tomato yellow leaf curl virus (TYLCV), one of the most devastating begomoviruses worldwide, promoted the survival and reproduction of whitefly vectors. TYLCV C2 protein suppressed plant defenses by interacting with plant ubiquitin. This interaction compromised the degradation of JAZ1 protein, thus inhibiting jasmonic acid defense and the expression of MYC2-regulated terpene synthase genes. We further demonstrated that function of C2 protein among begomoviruses not associated with satellites is well conserved and ubiquitination is an evolutionarily conserved target of begomoviruses for the suppression of plant resistance to whitefly vectors. Taken together, these results demonstrate that ubiquitination inhibition by begomovirus C2 protein might be a general mechanism in begomovirus, whitefly and plant interactions.},
}
@article {pmid29895336,
year = {2018},
author = {Harmer, J and Yurchenko, V and Nenarokova, A and Lukeš, J and Ginger, ML},
title = {Farming, slaving and enslavement: histories of endosymbioses during kinetoplastid evolution.},
journal = {Parasitology},
volume = {145},
number = {10},
pages = {1311-1323},
doi = {10.1017/S0031182018000781},
pmid = {29895336},
issn = {1469-8161},
mesh = {Biodiversity ; *Biological Evolution ; Evolution, Molecular ; Genome, Protozoan ; Kinetoplastida/*genetics ; Leishmania/genetics/physiology ; *Symbiosis ; Trypanosoma/genetics/physiology ; Trypanosomatina/*genetics ; },
abstract = {Parasitic trypanosomatids diverged from free-living kinetoplastid ancestors several hundred million years ago. These parasites are relatively well known, due in part to several unusual cell biological and molecular traits and in part to the significance of a few - pathogenic Leishmania and Trypanosoma species - as aetiological agents of serious neglected tropical diseases. However, the majority of trypanosomatid biodiversity is represented by osmotrophic monoxenous parasites of insects. In two lineages, novymonads and strigomonads, osmotrophic lifestyles are supported by cytoplasmic endosymbionts, providing hosts with macromolecular precursors and vitamins. Here we discuss the two independent origins of endosymbiosis within trypanosomatids and subsequently different evolutionary trajectories that see entrainment vs tolerance of symbiont cell divisions cycles within those of the host. With the potential to inform on the transition to obligate parasitism in the trypanosomatids, interest in the biology and ecology of free-living, phagotrophic kinetoplastids is beginning to enjoy a renaissance. Thus, we take the opportunity to additionally consider the wider relevance of endosymbiosis during kinetoplastid evolution, including the indulged lifestyle and reductive evolution of basal kinetoplastid Perkinsela.},
}
@article {pmid29794045,
year = {2018},
author = {Harrison, E and Hall, JPJ and Brockhurst, MA},
title = {Migration promotes plasmid stability under spatially heterogeneous positive selection.},
journal = {Proceedings. Biological sciences},
volume = {285},
number = {1879},
pages = {},
pmid = {29794045},
issn = {1471-2954},
mesh = {Environment ; *Gene Transfer, Horizontal ; Mercury ; Plasmids/*genetics ; Pseudomonas fluorescens/*genetics ; Selection, Genetic ; *Symbiosis ; },
abstract = {Bacteria-plasmid associations can be mutualistic or antagonistic depending on the strength of positive selection for plasmid-encoded genes, with contrasting outcomes for plasmid stability. In mutualistic environments, plasmids are swept to high frequency by positive selection, increasing the likelihood of compensatory evolution to ameliorate the plasmid cost, which promotes long-term stability. In antagonistic environments, plasmids are purged by negative selection, reducing the probability of compensatory evolution and driving their extinction. Here we show, using experimental evolution of Pseudomonas fluorescens and the mercury-resistance plasmid, pQBR103, that migration promotes plasmid stability in spatially heterogeneous selection environments. Specifically, migration from mutualistic environments, by increasing both the frequency of the plasmid and the supply of compensatory mutations, stabilized plasmids in antagonistic environments where, without migration, they approached extinction. These data suggest that spatially heterogeneous positive selection, which is common in natural environments, coupled with migration helps to explain the stability of plasmids and the ecologically important genes that they encode.},
}
@article {pmid29701776,
year = {2018},
author = {Karimi, E and Slaby, BM and Soares, AR and Blom, J and Hentschel, U and Costa, R},
title = {Metagenomic binning reveals versatile nutrient cycling and distinct adaptive features in alphaproteobacterial symbionts of marine sponges.},
journal = {FEMS microbiology ecology},
volume = {94},
number = {6},
pages = {},
doi = {10.1093/femsec/fiy074},
pmid = {29701776},
issn = {1574-6941},
mesh = {Animals ; Carbon/metabolism ; Genome, Bacterial/genetics ; Metagenome ; Metagenomics ; Microbiota ; Nitrogen/metabolism ; Phylogeny ; Porifera/*microbiology ; Rhodospirillaceae/genetics/*metabolism ; Sulfur/metabolism ; Symbiosis/*physiology ; },
abstract = {Marine sponges are early-branched metazoans known to harbor dense and diverse microbial communities. Yet the role of the so far uncultivable alphaproteobacterial lineages that populate these sessile invertebrates remains unclear. We applied a sequence composition-dependent binning approach to assemble one Rhodospirillaceae genome from the Spongia officinalis microbial metagenome and contrast its functional features with those of closely related sponge-associated and free-living genomes. Both symbiotic and free-living Rhodospirillaceae shared a suite of common features, possessing versatile carbon, nitrogen, sulfur and phosphorus metabolisms. Symbiotic genomes could be distinguished from their free-living counterparts by the lack of chemotaxis and motility traits, enrichment of genes required for the uptake and utilization of organic sulfur compounds-particularly taurine-, higher diversity and abundance of ABC transporters, and a distinct repertoire of genes involved in natural product biosynthesis, plasmid stability, cell detoxification and oxidative stress remediation. These sessile symbionts may more effectively contribute to host fitness via nutrient exchange, and also host detoxification and chemical defense. Considering the worldwide occurrence and high diversity of sponge-associated Rhodospirillaceae verified here using a tailored in silico approach, we suggest that these organisms are not only relevant to holobiont homeostasis but also to nutrient cycling in benthic ecosystems.},
}
@article {pmid29668923,
year = {2018},
author = {Lund, MB and Mogensen, MF and Marshall, IPG and Albertsen, M and Viana, F and Schramm, A},
title = {Genomic insights into the Agromyces-like symbiont of earthworms and its distribution among host species.},
journal = {FEMS microbiology ecology},
volume = {94},
number = {6},
pages = {},
doi = {10.1093/femsec/fiy068},
pmid = {29668923},
issn = {1574-6941},
mesh = {Actinomycetales/*classification/*genetics/growth & development ; Animals ; Base Sequence ; DNA, Bacterial/genetics ; Genome, Bacterial/*genetics ; Genomics ; Host Microbial Interactions/physiology ; Host Specificity ; Oligochaeta/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Species Specificity ; Symbiosis/*physiology ; },
abstract = {The nephridia (excretory organs) of lumbricid earthworms generally harbor symbiotic bacteria. In the compost worms Eisenia fetida and E. andrei, these comprise Verminephrobacter, Ca. Nephrothrix and an Agromyces-like symbiont. While diversity, transmission, and function of the first two symbionts has been unraveled in recent years, little is known about the biology of the uncultured Agromyces-like symbiont or about its distribution within lumbricid earthworms.In this study, we sequenced a cocoon metagenome of E. andrei and assembled a 96.3% complete genome of the Agromyces-like symbiont, which indicates a heterotrophic and potentially microaerophilic lifestyle. A 16S rRNA gene based survey showed that the Agromyces-like symbiont has a narrow host range (present in 10 out of 51 investigated lumbricid earthworm species) and is likely species-specific or at least specific for groups of closely related host species. The Agromyces-like symbionts form a monophyletic group and feature a reduced genome with AT-bias and very low genome-wide similarity to closely related Agromyces spp. (average amino acid identity of 64%); therefore, we suggest establishing a novel genus for the Agromyces-like symbionts of earthworms, for which we propose the name Candidatus Lumbricidophila, with the specific symbiont of Eisenia andrei as novel species Ca. L. eiseniae.},
}
@article {pmid29642956,
year = {2018},
author = {Silva, FM and Kostygov, AY and Spodareva, VV and Butenko, A and Tossou, R and Lukeš, J and Yurchenko, V and Alves, JMP},
title = {The reduced genome of Candidatus Kinetoplastibacterium sorsogonicusi, the endosymbiont of Kentomonas sorsogonicus (Trypanosomatidae): loss of the haem-synthesis pathway.},
journal = {Parasitology},
volume = {145},
number = {10},
pages = {1287-1293},
doi = {10.1017/S003118201800046X},
pmid = {29642956},
issn = {1469-8161},
mesh = {Betaproteobacteria/drug effects/*genetics/growth & development ; Biosynthetic Pathways ; *Genome, Bacterial ; Heme/*metabolism/pharmacology ; Phylogeny ; Sequence Analysis, DNA ; *Symbiosis ; Trypanosomatina/*microbiology ; },
abstract = {Trypanosomatids of the genera Angomonas and Strigomonas (subfamily Strigomonadinae) have long been known to contain intracellular beta-proteobacteria, which provide them with many important nutrients such as haem, essential amino acids and vitamins. Recently, Kentomonas sorsogonicus, a divergent member of Strigomonadinae, has been described. Herein, we characterize the genome of its endosymbiont, Candidatus Kinetoplastibacterium sorsogonicusi. This genome is completely syntenic with those of other known Ca. Kinetoplastibacterium spp., but more reduced in size (~742 kb, compared with 810-833 kb, respectively). Gene losses are not concentrated in any hot-spots but are instead distributed throughout the genome. The most conspicuous loss is that of the haem-synthesis pathway. For long, removing haemin from the culture medium has been a standard procedure in cultivating trypanosomatids isolated from insects; continued growth was considered as an evidence of endosymbiont presence. However, we demonstrate that, despite bearing the endosymbiont, K. sorsogonicus cannot grow in culture without haem. Thus, the traditional test cannot be taken as a reliable criterion for the absence or presence of endosymbionts in trypanosomatid flagellates. It remains unclear why the ability to synthesize such an essential compound was lost in Ca. K. sorsogonicusi, whereas all other known bacterial endosymbionts of trypanosomatids retain them.},
}
@article {pmid29463894,
year = {2018},
author = {Nielsen, DA and Petrou, K and Gates, RD},
title = {Coral bleaching from a single cell perspective.},
journal = {The ISME journal},
volume = {12},
number = {6},
pages = {1558-1567},
pmid = {29463894},
issn = {1751-7370},
mesh = {Animals ; Anthozoa/*physiology ; *Coral Reefs ; Dinoflagellida/*physiology ; Fluorescent Dyes/chemistry ; Glutathione/metabolism ; Hawaii ; Lipid Peroxidation ; Microscopy, Confocal ; Oxidative Stress ; Reactive Oxygen Species/metabolism ; Stress, Physiological ; Symbiosis/*physiology ; Temperature ; },
abstract = {Ocean warming is resulting in increased occurrence of mass coral bleaching; a response in which the intracellular algal endosymbionts (Symbiodinium sp.) are expelled from the coral host due to physiological stress. This detrimental process is often attributed to overproduction of reactive oxygen species (ROS) that leak out of the endosymbionts and causes damage to the host cell, though direct evidence validating this link is limited. Here, for the first time, we used confocal microscopy and fluorescent dyes to investigate if endosymbiont ROS production significantly and predictably affects physiological parameters in its host cell. Heat treatment resulted in a 60% reduction in coral symbiont density, a ~70% increase in median endosymbiont ROS and a small reduction in photosystem efficiency (FV/FM, 11%), indicating absence of severe light stress. Notably, no other physiological parameters were affected in either endosymbionts or host cells, including reduced glutathione and ROS-induced lipid peroxidation. Taken together, the increase in endosymbiont ROS could not be linked to physiological damage in either partner, suggesting that oxidative stress is unlikely to have been the driver for symbiont expulsion in this study.},
}
@article {pmid29371249,
year = {2018},
author = {Johnson, JM and Thürich, J and Petutschnig, EK and Altschmied, L and Meichsner, D and Sherameti, I and Dindas, J and Mrozinska, A and Paetz, C and Scholz, SS and Furch, ACU and Lipka, V and Hedrich, R and Schneider, B and Svatoš, A and Oelmüller, R},
title = {A Poly(A) Ribonuclease Controls the Cellotriose-Based Interaction between Piriformospora indica and Its Host Arabidopsis.},
journal = {Plant physiology},
volume = {176},
number = {3},
pages = {2496-2514},
pmid = {29371249},
issn = {1532-2548},
mesh = {Arabidopsis/genetics/metabolism/*microbiology ; Arabidopsis Proteins/genetics/metabolism ; Basidiomycota/*physiology ; Calcium/metabolism ; Cellulose/metabolism ; Exoribonucleases/genetics/*metabolism ; Gene Expression Regulation, Plant ; Mutation ; Plants, Genetically Modified ; Protein-Serine-Threonine Kinases/genetics/metabolism ; Seedlings/metabolism/microbiology ; Signal Transduction ; Symbiosis/*physiology ; Trioses/metabolism ; },
abstract = {Piriformospora indica, an endophytic root-colonizing fungus, efficiently promotes plant growth and induces resistance to abiotic stress and biotic diseases. P. indica fungal cell wall extract induces cytoplasmic calcium elevation in host plant roots. Here, we show that cellotriose (CT) is an elicitor-active cell wall moiety released by P. indica into the medium. CT induces a mild defense-like response, including the production of reactive oxygen species, changes in membrane potential, and the expression of genes involved in growth regulation and root development. CT-based cytoplasmic calcium elevation in Arabidopsis (Arabidopsis thaliana) roots does not require the BAK1 coreceptor or the putative Ca2+ channels TPC1, GLR3.3, GLR2.4, and GLR2.5 and operates synergistically with the elicitor chitin. We identified an ethyl methanesulfonate-induced mutant (cytoplasmiccalcium elevation mutant) impaired in the response to CT and various other cellooligomers (n = 2-7), but not to chitooligomers (n = 4-8), in roots. The mutant contains a single nucleotide exchange in the gene encoding a poly(A) ribonuclease (AtPARN; At1g55870) that degrades the poly(A) tails of specific mRNAs. The wild-type PARN cDNA, expressed under the control of a 35S promoter, complements the mutant phenotype. Our identification of cellotriose as a novel chemical mediator casts light on the complex P. indica-plant mutualistic relationship.},
}
@article {pmid29284744,
year = {2018},
author = {Kryvoruchko, IS and Routray, P and Sinharoy, S and Torres-Jerez, I and Tejada-Jiménez, M and Finney, LA and Nakashima, J and Pislariu, CI and Benedito, VA and González-Guerrero, M and Roberts, DM and Udvardi, MK},
title = {An Iron-Activated Citrate Transporter, MtMATE67, Is Required for Symbiotic Nitrogen Fixation.},
journal = {Plant physiology},
volume = {176},
number = {3},
pages = {2315-2329},
pmid = {29284744},
issn = {1532-2548},
mesh = {Carrier Proteins/genetics/metabolism ; Citrates/metabolism ; Gene Expression Regulation, Plant ; Iron/*metabolism/pharmacokinetics ; Medicago truncatula/microbiology/*physiology ; Mutation ; Nitrogen Fixation/*physiology ; Phylogeny ; Plant Proteins/genetics/*metabolism ; Plants, Genetically Modified ; Root Nodules, Plant/growth & development/metabolism/microbiology ; Symbiosis/physiology ; },
abstract = {Iron (Fe) is an essential micronutrient for symbiotic nitrogen fixation in legume nodules, where it is required for the activity of bacterial nitrogenase, plant leghemoglobin, respiratory oxidases, and other Fe proteins in both organisms. Fe solubility and transport within and between plant tissues is facilitated by organic chelators, such as nicotianamine and citrate. We have characterized a nodule-specific citrate transporter of the multidrug and toxic compound extrusion family, MtMATE67 of Medicago truncatula The MtMATE67 gene was induced early during nodule development and expressed primarily in the invasion zone of mature nodules. The MtMATE67 protein was localized to the plasma membrane of nodule cells and also the symbiosome membrane surrounding bacteroids in infected cells. In oocytes, MtMATE67 transported citrate out of cells in an Fe-activated manner. Loss of MtMATE67 gene function resulted in accumulation of Fe in the apoplasm of nodule cells and a substantial decrease in symbiotic nitrogen fixation and plant growth. Taken together, the results point to a primary role of MtMATE67 in citrate efflux from nodule cells in response to an Fe signal. This efflux is necessary to ensure Fe(III) solubility and mobility in the apoplasm and uptake into nodule cells. Likewise, MtMATE67-mediated citrate transport into the symbiosome space would increase the solubility and availability of Fe(III) for rhizobial bacteroids.},
}
@article {pmid30963950,
year = {2019},
author = {Uchiumi, Y and Ohtsuki, H and Sasaki, A},
title = {Evolution of self-limited cell division of symbionts.},
journal = {Proceedings. Biological sciences},
volume = {286},
number = {1895},
pages = {20182238},
doi = {10.1098/rspb.2018.2238},
pmid = {30963950},
issn = {1471-2954},
abstract = {In mutualism between unicellular hosts and their endosymbionts, symbiont's cell division is often synchronized with its host's, ensuring the permanent relationship between endosymbionts and their hosts. The evolution of synchronized cell division thus has been considered to be an essential step in the evolutionary transition from symbionts to organelles. However, if symbionts would accelerate their cell division without regard for the synchronization with the host, they would proliferate more efficiently. Thus, it is paradoxical that symbionts evolve to limit their own division for synchronized cell division. Here, we theoretically explore the condition for the evolution of self-limited cell division of symbionts, by assuming that symbionts control their division rate and that hosts control symbionts' death rate by intracellular digestion and nutrient supply. Our analysis shows that symbionts can evolve to limit their own cell division. Such evolution occurs if not only symbiont's but also host's benefit through symbiosis is large. Moreover, the coevolution of hosts and symbionts leads to either permanent symbiosis where symbionts proliferate to keep pace with their host, or the arms race between symbionts that behave as lytic parasites and hosts that resist them by rapid digestion.},
}
@article {pmid30963860,
year = {2019},
author = {Skelton, J and Johnson, AJ and Jusino, MA and Bateman, CC and Li, Y and Hulcr, J},
title = {A selective fungal transport organ (mycangium) maintains coarse phylogenetic congruence between fungus-farming ambrosia beetles and their symbionts.},
journal = {Proceedings. Biological sciences},
volume = {286},
number = {1894},
pages = {20182127},
doi = {10.1098/rspb.2018.2127},
pmid = {30963860},
issn = {1471-2954},
abstract = {Thousands of species of ambrosia beetles excavate tunnels in wood to farm fungi. They maintain associations with particular lineages of fungi, but the phylogenetic extent and mechanisms of fidelity are unknown. We test the hypothesis that selectivity of their mycangium enforces fidelity at coarse phylogenetic scales, while permitting promiscuity among closely related fungal mutualists. We confirm a single evolutionary origin of the Xylosandrus complex-a group of several xyleborine genera that farm fungi in the genus Ambrosiella. Multi-level co-phylogenetic analysis revealed frequent symbiont switching within major Ambrosiella clades, but not between clades. The loss of the mycangium in Diuncus, a genus of evolutionary cheaters, was commensurate with the loss of fidelity to fungal clades, supporting the hypothesis that the mycangium reinforces fidelity. Finally, in vivo experiments tracked symbiotic compatibility throughout the symbiotic life cycle of Xylosandrus compactus and demonstrated that closely related Ambrosiella symbionts are interchangeable, but the probability of fungal uptake in the mycangium was significantly lower in more phylogenetically distant species of symbionts. Symbiont loads in experimental subjects were similar to wild-caught beetles. We conclude that partner choice in ambrosia beetles is achieved in the mycangium, and co-phylogenetic inferences can be used to predict the likelihood of specific symbiont switches.},
}
@article {pmid30962361,
year = {2019},
author = {Jäckle, O and Seah, BKB and Tietjen, M and Leisch, N and Liebeke, M and Kleiner, M and Berg, JS and Gruber-Vodicka, HR},
title = {Chemosynthetic symbiont with a drastically reduced genome serves as primary energy storage in the marine flatworm Paracatenula.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {},
number = {},
pages = {},
doi = {10.1073/pnas.1818995116},
pmid = {30962361},
issn = {1091-6490},
abstract = {Hosts of chemoautotrophic bacteria typically have much higher biomass than their symbionts and consume symbiont cells for nutrition. In contrast to this, chemoautotrophic Candidatus Riegeria symbionts in mouthless Paracatenula flatworms comprise up to half of the biomass of the consortium. Each species of Paracatenula harbors a specific Ca Riegeria, and the endosymbionts have been vertically transmitted for at least 500 million years. Such prolonged strict vertical transmission leads to streamlining of symbiont genomes, and the retained physiological capacities reveal the functions the symbionts provide to their hosts. Here, we studied a species of Paracatenula from Sant'Andrea, Elba, Italy, using genomics, gene expression, imaging analyses, as well as targeted and untargeted MS. We show that its symbiont, Ca R. santandreae has a drastically smaller genome (1.34 Mb) than the symbiont´s free-living relatives (4.29-4.97 Mb) but retains a versatile and energy-efficient metabolism. It encodes and expresses a complete intermediary carbon metabolism and enhanced carbon fixation through anaplerosis and accumulates massive intracellular inclusions such as sulfur, polyhydroxyalkanoates, and carbohydrates. Compared with symbiotic and free-living chemoautotrophs, Ca R. santandreae's versatility in energy storage is unparalleled in chemoautotrophs with such compact genomes. Transmission EM as well as host and symbiont expression data suggest that Ca R. santandreae largely provisions its host via outer-membrane vesicle secretion. With its high share of biomass in the symbiosis and large standing stocks of carbon and energy reserves, it has a unique role for bacterial symbionts-serving as the primary energy storage for its animal host.},
}
@article {pmid30961763,
year = {2019},
author = {Jin, Y and Kim, HU and Hong, S and Shin, C and Kulkarni, A and Kim, T},
title = {Effect of Copper Foil Crystal Orientation on Graphene Quality Synthesized by Chemical Vapor Deposition.},
journal = {Journal of nanoscience and nanotechnology},
volume = {19},
number = {9},
pages = {5942-5948},
doi = {10.1166/jnn.2019.16599},
pmid = {30961763},
issn = {1533-4880},
abstract = {Line defects such as wrinkles are believed to change the electrical properties of graphene. However, they are often observed in graphene grown via chemical vapor deposition; hence, it is important to study the impact of the substrate condition on graphene quality. In this work, graphene was synthesized on various copper domains with different crystal orientations and surface morphologies. During the synthesis process, three typical crystal orientations were obtained Cu(001), Cu(101), and Cu(111) showing different surface morphologies with various densities of wrinkles. Graphene wrinkles along with copper wrinkles were studied using atomic force microscopy and Kelvin probe force microscopy. The quality of graphene on different crystal orientations and morphologies was evaluated as well. It was found that different crystallographic orientations lead to different degrees of wrinkle and roughness. In addition, these wrinkle defects exhibited characteristic surface potential variations and the density of substrate wrinkles was closely associated with the uniformity of graphene and led to a disordered structure and low crystallinity.},
}
@article {pmid30958898,
year = {2019},
author = {Zlatogursky, VV and Gerasimova, EA and Drachko, D and Klimov, VI and Shɨshkin, Y and Plotnikov, AO},
title = {Pinjata ruminata gen. et sp. n. - a New Member of Centrohelid Family Yogsothothidae (Haptista: Centroplasthelida) from the Brackish River.},
journal = {The Journal of eukaryotic microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/jeu.12737},
pmid = {30958898},
issn = {1550-7408},
abstract = {A new genus and species of centrohelid heliozoan Pinjata ruminata from the Tuzlukkol' River (Orenburg Region of Russia) and Gor'koe Lake (Chelyabinsk Region of Russia) is studied with light- and electron microscopy. P. ruminata has two types of plate scales, partially running up the sides of the axopodia. Inner plate scales (3.2-4.9 × 1.5-2.6 μm) are flat, ovate-oblong and have a broad axial thickening and a thin electron-dense border. Outer plate scales (4.2-6.7 ×1.5-3.0 μm) are concave, elongated, of irregular shape, often curved and broadened towards one end. Roundish depressions are forming two rows on both sides of the narrow axial thickening. The cells are attached to the substratum. Molecular phylogenetic analysis based on the SSU rDNA robustly placed P. ruminata in the family Yogsothothidae. This position is confirmed with presence of 5 panacanthocystid increase regions. The morphology of the new genus is in a good accordance with diagnosis of the family. The status of a genus "Heteroraphidiophrys" is discussed. Other potential findings of Pinjata from literature are analyzed. Pinjata represents the third lineage of centrohelids, characterized with the presence of only tangentially-oriented plate scales. The halophilic nature of Yogsothothidae is suggested. This article is protected by copyright. All rights reserved.},
}
@article {pmid30957149,
year = {2019},
author = {Wu, QS and He, JD and Srivastava, AK and Zou, YN and Kuča, K},
title = {Mycorrhiza enhances drought tolerance of citrus by altering root fatty acid compositions and their saturation levels.},
journal = {Tree physiology},
volume = {},
number = {},
pages = {},
doi = {10.1093/treephys/tpz039},
pmid = {30957149},
issn = {1758-4469},
abstract = {Arbuscular mycorrhizas (AMs) have the ability to enhance drought tolerance of citrus, while the underlying mechanisms are not clearly elucidated. Considering the strong association of cell membrane fatty acid (FA) unsaturation with plant drought tolerance, the present study hypothesized that arbuscular mycorrhizal fungi (AMF) modulated the composition and unsaturation of FAs to enhance drought tolerance of host plants. A drought-sensitive citrus rootstock, trifoliate orange (Poncirus trifoliata) seedlings, were inoculated with AMF (Funneliformis mosseae) for 3 months, and were subsequently exposed to drought stress (DS) for 8 weeks. Mycorrhizal seedlings exhibited better plant growth performance, higher leaf water potential, and lower root abscisic acid concentrations under both well-watered (WW) and DS, respectively. AMF inoculation considerably increased root methyl oleate (C18:1), methyl linoleate (C18:2) and methyl linolenate (C18:3 N3) concentrations under both WW and DS and root methyl palmitoleate (C16:1) concentrations under WW, while decreased root methyl stearate (C18:0) levels under both WW and DS. These changes in the composition of FAs of mycorrhized roots resulted in higher unsaturation index of root FAs (UIFA), which later aided in reducing the oxidative damage on account of lower concentration of malondialdehyde and superoxide radicals. The changes of these FAs were a result of AMF-up-regulating root fatty acid desaturase 2 (PtFAD2), fatty acid desaturase 6 (PtFAD6) and Δ9 fatty acid desaturase (PtΔ9) genes under WW and PtFAD2, PtFAD6 and Δ15 fatty acid desaturase (PtΔ15) genes under DS. Our results confirmed that mycorrhization brought significant changes in root FA compositions, in addition to regulation of gene expression responsible for increasing the unsaturation level of FAs, a pre-disposing physiological event for better drought tolerance of citrus.},
}
@article {pmid30955777,
year = {2019},
author = {McCauley, M and Goulet, TL},
title = {Caribbean gorgonian octocorals cope with nutrient enrichment.},
journal = {Marine pollution bulletin},
volume = {141},
number = {},
pages = {621-628},
doi = {10.1016/j.marpolbul.2019.02.067},
pmid = {30955777},
issn = {1879-3363},
abstract = {Corals inhabit oligotrophic waters, thriving amidst limited nutrients such as nitrogen and phosphorous. When nutrient levels increase, usually due to human activity, the symbiosis of dinoflagellates (family Symbiodiniaceae) with scleractinian corals can break down. Although gorgonian corals dominate many Caribbean reefs, the impact of enrichment on them and their algae is understudied. We exposed two gorgonian species, Pseudoplexaura porosa and Eunicea tourneforti, to elevated concentrations of either ammonium (10 μM or 50 μM) or phosphate (4 μM). Enrichment with 10 μM ammonium increased chlorophyll content and algal density in both species, whereas the host biochemical composition was unaffected. Exposure to 50 μM ammonium only reduced the quantum yield in P. porosa and mitotic indices in both species. Conversely, algal carbon and nitrogen content within E. tourneforti increased with 4 μM phosphate exposure. These gorgonian species coped with short-term nutrient enrichment, furthering our understanding of the success of Caribbean gorgonians.},
}
@article {pmid30545059,
year = {2018},
author = {Neupane, A and Feng, C and Feng, J and Kafle, A and Bücking, H and Lee Marzano, SY},
title = {Metatranscriptomic Analysis and In Silico Approach Identified Mycoviruses in the Arbuscular Mycorrhizal Fungus Rhizophagus spp.},
journal = {Viruses},
volume = {10},
number = {12},
pages = {},
doi = {10.3390/v10120707},
pmid = {30545059},
issn = {1999-4915},
mesh = {Fungal Viruses/*genetics/isolation & purification ; *Gene Expression Profiling ; Genome, Viral ; Mycorrhizae/*virology ; Plant Roots/*genetics/microbiology ; Plants/microbiology ; Symbiosis ; },
abstract = {Arbuscular mycorrhizal fungi (AMF), including Rhizophagus spp., can play important roles in nutrient cycling of the rhizosphere. However, the effect of virus infection on AMF's role in nutrient cycling cannot be determined without first knowing the diversity of the mycoviruses in AMF. Therefore, in this study, we sequenced the R. irregularis isolate-09 due to its previously demonstrated high efficiency in increasing the N/P uptake of the plant. We identified one novel mitovirus contig of 3685 bp, further confirmed by reverse transcription-PCR. Also, publicly available Rhizophagus spp. RNA-Seq data were analyzed to recover five partial virus sequences from family Narnaviridae, among which four were from R. diaphanum MUCL-43196 and one was from R. irregularis strain-C2 that was similar to members of the Mitovirus genus. These contigs coded genomes larger than the regular mitoviruses infecting pathogenic fungi and can be translated by either a mitochondrial translation code or a cytoplasmic translation code, which was also reported in previously found mitoviruses infecting mycorrhizae. The five newly identified virus sequences are comprised of functionally conserved RdRp motifs and formed two separate subclades with mitoviruses infecting Gigasporamargarita and Rhizophagusclarus, further supporting virus-host co-evolution theory. This study expands our understanding of virus diversity. Even though AMF is notably hard to investigate due to its biotrophic nature, this study demonstrates the utility of whole root metatranscriptome.},
}
@article {pmid30427852,
year = {2018},
author = {Brito, TL and Campos, AB and Bastiaan von Meijenfeldt, FA and Daniel, JP and Ribeiro, GB and Silva, GGZ and Wilke, DV and de Moraes, DT and Dutilh, BE and Meirelles, PM and Trindade-Silva, AE},
title = {The gill-associated microbiome is the main source of wood plant polysaccharide hydrolases and secondary metabolite gene clusters in the mangrove shipworm Neoteredo reynei.},
journal = {PloS one},
volume = {13},
number = {11},
pages = {e0200437},
pmid = {30427852},
issn = {1932-6203},
mesh = {Animals ; Bivalvia/*microbiology/physiology ; Gammaproteobacteria/*enzymology/genetics/*physiology ; Genomics ; Gills/microbiology ; Glycoside Hydrolases/genetics/*metabolism ; Metagenome ; Microbiota ; Multigene Family ; Phylogeny ; Polysaccharides/*metabolism ; Secondary Metabolism ; *Symbiosis ; Wood/metabolism/parasitology ; },
abstract = {Teredinidae are a family of highly adapted wood-feeding and wood-boring bivalves, commonly known as shipworms, whose evolution is linked to the acquisition of cellulolytic gammaproteobacterial symbionts harbored in bacteriocytes within the gills. In the present work we applied metagenomics to characterize microbiomes of the gills and digestive tract of Neoteredo reynei, a mangrove-adapted shipworm species found over a large range of the Brazilian coast. Comparative metagenomics grouped the gill symbiont community of different N. reynei specimens, indicating closely related bacterial types are shared. Similarly, the intestine and digestive gland communities were related, yet were more diverse than and showed no overlap with the gill community. Annotation of assembled metagenomic contigs revealed that the gill symbiotic community of N. reynei encodes a plethora of plant cell wall polysaccharides degrading glycoside hydrolase encoding genes, and Biosynthetic Gene Clusters (BGCs). In contrast, the digestive tract microbiomes seem to play little role in wood digestion and secondary metabolites biosynthesis. Metagenome binning recovered the nearly complete genome sequences of two symbiotic Teredinibacter strains from the gills, a representative of Teredinibacter turnerae "clade I" strain, and a yet to be cultivated Teredinibacter sp. type. These Teredinibacter genomes, as well as un-binned gill-derived gammaproteobacteria contigs, also include an endo-β-1,4-xylanase/acetylxylan esterase multi-catalytic carbohydrate-active enzyme, and a trans-acyltransferase polyketide synthase (trans-AT PKS) gene cluster with the gene cassette for generating β-branching on complex polyketides. Finally, we use multivariate analyses to show that the secondary metabolome from the genomes of Teredinibacter representatives, including genomes binned from N. reynei gills' metagenomes presented herein, stands out within the Cellvibrionaceae family by size, and enrichments for polyketide, nonribosomal peptide and hybrid BGCs. Results presented here add to the growing characterization of shipworm symbiotic microbiomes and indicate that the N. reynei gill gammaproteobacterial community is a prolific source of biotechnologically relevant enzymes for wood-digestion and bioactive compounds production.},
}
@article {pmid30244151,
year = {2019},
author = {Schön, I and Kamiya, T and Van den Berghe, T and Van den Broecke, L and Martens, K},
title = {Novel Cardinium strains in non-marine ostracod (Crustacea) hosts from natural populations.},
journal = {Molecular phylogenetics and evolution},
volume = {130},
number = {},
pages = {406-415},
doi = {10.1016/j.ympev.2018.09.008},
pmid = {30244151},
issn = {1095-9513},
mesh = {Animals ; Aquatic Organisms/*microbiology ; Bacteroidetes/genetics/*physiology ; Base Sequence ; Crustacea/genetics/*microbiology ; Diptera/genetics ; Electron Transport Complex IV/genetics ; Genetic Variation ; Phylogeny ; Sequence Analysis, DNA ; Species Specificity ; Symbiosis ; },
abstract = {Endosymbiotic bacteria are known from many metazoan taxa, where they manipulate host biology and reproduction. Here, we used classic PCR amplification and direct DNA sequencing with universal primers for four different endosymbionts to test for their presence in more than 300 specimens of three recent non-marine ostracod superfamilies from different geographic areas and aquatic habitats. We verified these results with "high throughput" amplicon sequencing of 16S of nine selected specimens and evolutionary placement algorithms. The phylogenetic position of endosymbionts detected in ostracod hosts was compared to known endosymbionts from other metazoans. While Wolbachia, Spiroplasma and Rickettsia are absent, we find evidence for the general presence of Cardinium bacteria in natural populations of various non-marine ostracod species. Phylogenetic reconstructions based on Cardinium 16S data and estimates of genetic distances both indicate that Cardinium from ostracods are distantly related to Cardinium from Diptera and Nematoda but represent novel strains with a monophyletic origin. Cardinium bacteria from different ostracod hosts have genetic distances of up to 3.8%, providing evidence against recent and frequent horizontal transmissions amongst the three ostracod superfamilies. High throughput sequencing reveals more than 400 different 16S amplicon sequence variants in the investigated ostracods as well as the presence of different Cardinium strains within individual Eucypris virens and Heterocypris hosts. These results call for future, more in-depth investigations. Mapping Cardinium infections on COI trees of non-marine ostracod hosts shows that the occurrence of these endosymbionts is not linked to genetic species identity or phylogenetic host groups and, except for one ostracod morphospecies, prevalence never reaches 100%.},
}
@article {pmid29934746,
year = {2018},
author = {Fan, X and Song, F},
title = {Responses of nonenzymatic antioxidants to atrazine in arbuscular mycorrhizal roots of Medicago sativa L.},
journal = {Mycorrhiza},
volume = {28},
number = {5-6},
pages = {567-571},
pmid = {29934746},
issn = {1432-1890},
support = {31500431//National Natural Science Foundation of China/ ; 31270535//National Natural Science Foundation of China/ ; 31570635//National Natural Science Foundation of China/ ; UNPYSCT-2016077//Innovative Talents Training Program of Heilongjiang Province for General Universities/ ; 2017RAQXJ065//Scientific and Technological Innovation Talent Project of Harbin/ ; 2017RALXJ008//Scientific and Technological Innovation Talent Project of Harbin/ ; },
mesh = {Antioxidants/*analysis ; Atrazine/*pharmacology ; Flavonoids/analysis ; Medicago sativa/*metabolism/microbiology ; Mycorrhizae/*drug effects/metabolism ; Plant Roots/*drug effects/microbiology ; Stress, Physiological ; *Symbiosis ; },
abstract = {Atrazine induces the production of reactive oxygen species (ROS), which are detoxified by enzymatic and nonenzymatic mechanisms in plants. Arbuscular mycorrhizal fungi improve on this first level of plant resistance to environmental stresses through the antioxidant defense system, but the way in which nonenzymatic antioxidants relate to atrazine in arbuscular mycorrhizal roots is not well-known. In this study, a symbiotic relationship between Funneliformis mosseae and Medicago sativa L. roots was established successfully. Then, a non-targeted metabolite analysis which was hypothesis-free concerning particular metabolites was used to provide a comprehensive metabolic fingerprint and to subsequently identify, quantify, and finally find different nonenzymatic antioxidants in mycorrhizal and non-mycorrhizal roots following atrazine addition. Tocotrienol, (iso)flavonoids, and their derivate concentrations in F. mosseae-M. sativa mycorrhizal roots were significantly higher than in non-mycorrhizal roots. The majority of (iso)flavonoids and their derivates increased significantly via methylation or glycosylation, but dehydroascorbic acid in its oxidized form decreased significantly in mycorrhizal roots. In general, F. mosseae colonization results in significantly greater nonenzymatic antioxidant tocotrienol and (iso)flavonoids derivate concentrations in M. sativa roots, which may be associated with resistance to atrazine.},
}
@article {pmid29931404,
year = {2018},
author = {Gryndler, M and Šmilauer, P and Püschel, D and Bukovská, P and Hršelová, H and Hujslová, M and Gryndlerová, H and Beskid, O and Konvalinková, T and Jansa, J},
title = {Appropriate nonmycorrhizal controls in arbuscular mycorrhiza research: a microbiome perspective.},
journal = {Mycorrhiza},
volume = {28},
number = {5-6},
pages = {435-450},
pmid = {29931404},
issn = {1432-1890},
mesh = {Andropogon/microbiology ; Bacteria/metabolism ; Biomass ; High-Throughput Nucleotide Sequencing ; *Microbiota ; Mycorrhizae/*physiology ; Phosphorus/analysis ; Plant Roots/*microbiology ; *Soil Microbiology ; Symbiosis ; },
abstract = {Establishment of nonmycorrhizal controls is a "classic and recurrent theme" in mycorrhizal research. For decades, authors reported mycorrhizal plant growth/nutrition as compared to various nonmycorrhizal controls. In such studies, uncertainties remain about which nonmycorrhizal controls are most appropriate and, in particular, what effects the control inoculations have on substrate and root microbiomes. Here, different types of control and mycorrhizal inoculations were compared with respect to plant growth and nutrition, as well as the structure of root and substrate microbiomes, assessed by next-generation sequencing. We compared uninoculated ("absolute") control to inoculation with blank pot culture lacking arbuscular mycorrhizal fungi, filtrate of that blank inoculum, and filtrate of complex pot-produced mycorrhizal inoculum. Those treatments were compared to a standard mycorrhizal treatment, where the previously sterilized substrate was inoculated with complex pot-produced inoculum containing Rhizophagus irregularis SYM5. Besides this, monoxenically produced inoculum of the same fungus was applied either alone or in combination with blank inoculum. The results indicate that the presence of mycorrhizal fungus always resulted in stimulation of Andropogon gerardii plant biomass as well as in elevated phosphorus content of the plants. The microbial (bacterial and fungal) communities developing in the differently inoculated treatments, however, differed substantially from each other and no control could be obtained comparable with the treatment inoculated with complex mycorrhizal inoculum. Soil microorganisms with significant biological competences that could potentially contribute to the effects of the various inoculants on the plants were detected in roots and in plant cultivation substrate in some of the treatments.},
}
@article {pmid29766387,
year = {2018},
author = {Shutoh, K and Suetsugu, K and Kaneko, S and Kurosawa, T},
title = {Comparative morphological analysis of two parallel mycoheterotrophic transitions reveals divergent and convergent traits in the genus Pyrola (Pyroleae, Ericaceae).},
journal = {Journal of plant research},
volume = {131},
number = {4},
pages = {589-597},
pmid = {29766387},
issn = {1618-0860},
support = {a Grant-in-Aid from Japan Society for the Promotio//Japan Society for the Promotion of Science/ ; },
mesh = {Biological Evolution ; Flowers/anatomy & histology ; Fungi/physiology ; Phylogeny ; Plant Leaves/anatomy & histology ; Pyrola/*anatomy & histology/microbiology/physiology ; Quantitative Trait, Heritable ; *Symbiosis/physiology ; },
abstract = {The genus Pyrola includes species with different degree of mycoheterotrophy; some species possess individuals that rely on all carbon through their associations with fungi (full mycoheterotrophy, FM), whereas some species obtain carbon through both fungi and photosynthesis by itself (partial mycoheterotrophy, PM). To investigate how plant functional traits of photosynthesis and reproduction are related to the degree of mycoheterotrophy in the initial stage of the transition from PM to FM, we determined morphological traits in FM (or nearly FM) and PM species in two independent lineages, P. picta and P. japonica complexes. We used herbarium specimens and examined leaf number, leaf area, flower number, and scape length in FM or nearly FM species (P. aphylla and P. subaphylla) and PM species (P. picta s.l. and P. japonica). We found a leaf area reduction in FM (or nearly FM) species in both lineages, suggesting that this is a convergent trait. The number of flowers was not significantly different between FM (or nearly FM) and PM species in both lineages. On the other hand, differences in the variation between FM (or nearly FM) and PM species were found in some traits between the two lineages. The FM (or nearly FM) species in one lineage only possessed rudimentary leaves, whereas that in the other linage possessed a few small, ordinary leaves in addition to those with only rudimentary leaves. The scape length of the FM (or nearly FM) species was significantly longer than that of PM species in one lineage, whereas it was shorter in the other lineage. The different and common variations are divergent and convergent traits, respectively, that could be associated with the transition to FM in Pylora. In addition, shoots of both PM species occasionally lacked ordinary leaves, possibly indicating possession of these shoots is preadaptation for the transition to FM in Pyrola.},
}
@article {pmid28842582,
year = {2017},
author = {Tornabene, C and Martindale, RC and Wang, XT and Schaller, MF},
title = {Detecting Photosymbiosis in Fossil Scleractinian Corals.},
journal = {Scientific reports},
volume = {7},
number = {1},
pages = {9465},
pmid = {28842582},
issn = {2045-2322},
mesh = {Animals ; Anthozoa/*physiology ; Biological Evolution ; Coral Reefs ; *Fossils ; Nitrogen Isotopes/analysis ; Nutrients/metabolism ; Pacific Ocean ; *Photosynthesis ; *Symbiosis ; },
abstract = {The evolutionary success of reef-building corals is often attributed to photosymbiosis, a mutualistic relationship scleractinian corals developed with zooxanthellae; however, because zooxanthellae are not fossilized, it is difficult (and contentious) to determine whether ancient corals harbored symbionts. In this study, we analyze the δ15N of skeletal organic matrix in a suite of modern and fossil scleractinian corals (zooxanthellate- and azooxanthellate-like) with varying levels of diagenetic alteration. Significantly, we report the first analyses that distinguish shallow-water zooxanthellate and deep-water azooxanthellate fossil corals. Early Miocene (18-20 Ma) corals exhibit the same nitrogen isotopic ratio offset identified in modern corals. These results suggest that the coral organic matrix δ15N proxy can successfully be used to detect photosymbiosis in the fossil record. This proxy will significantly improve our ability to effectively define the evolutionary relationship between photosymbiosis and reef-building through space and time. For example, Late Triassic corals have symbiotic values, which tie photosymbiosis to major coral reef expansion. Furthermore, the early Miocene corals from Indonesia have low δ15N values relative to modern corals, implying that the west Pacific was a nutrient-depleted environment and that oligotrophy may have facilitated the diversification of the reef builders in the Coral Triangle.},
}
@article {pmid30953569,
year = {2019},
author = {Arimoto, A and Hikosaka-Katayama, T and Hikosaka, A and Tagawa, K and Inoue, T and Ueki, T and Yoshida, MA and Kanda, M and Shoguchi, E and Hisata, K and Satoh, N},
title = {A draft nuclear-genome assembly of the acoel flatworm Praesagittifera naikaiensis.},
journal = {GigaScience},
volume = {8},
number = {4},
pages = {},
doi = {10.1093/gigascience/giz023},
pmid = {30953569},
issn = {2047-217X},
abstract = {BACKGROUND: Acoels are primitive bilaterians with very simple soft bodies, in which many organs, including the gut, are not developed. They provide platforms for studying molecular and developmental mechanisms involved in the formation of the basic bilaterian body plan, whole-body regeneration, and symbiosis with photosynthetic microalgae. Because genomic information is essential for future research on acoel biology, we sequenced and assembled the nuclear genome of an acoel, Praesagittifera naikaiensis.
FINDINGS: To avoid sequence contamination derived from symbiotic microalgae, DNA was extracted from embryos that were free of algae. More than 290x sequencing coverage was achieved using a combination of Illumina (paired-end and mate-pair libraries) and PacBio sequencing. RNA sequencing and Iso-Seq data from embryos, larvae, and adults were also obtained. First, a preliminary ∼17-kilobase pair (kb) mitochondrial genome was assembled, which was deleted from the nuclear sequence assembly. As a result, a draft nuclear genome assembly was ∼656 Mb in length, with a scaffold N50 of 117 kb and a contig N50 of 57 kb. Although ∼70% of the assembled sequences were likely composed of repetitive sequences that include DNA transposons and retrotransposons, the draft genome was estimated to contain 22,143 protein-coding genes, ∼99% of which were substantiated by corresponding transcripts. We could not find horizontally transferred microalgal genes in the acoel genome. Benchmarking Universal Single-Copy Orthologs analyses indicated that 77% of the conserved single-copy genes were complete. Pfam domain analyses provided a basic set of gene families for transcription factors and signaling molecules.
CONCLUSIONS: Our present sequencing and assembly of the P. naikaiensis nuclear genome are comparable to those of other metazoan genomes, providing basic information for future studies of genic and genomic attributes of this animal group. Such studies may shed light on the origins and evolution of simple bilaterians.},
}
@article {pmid30952658,
year = {2019},
author = {Mohammed, M and Jaiswal, SK and Dakora, FD},
title = {Insights into the phylogeny, nodule functioning and biogeographic distribution of microsymbionts nodulating the orphan Kersting's groundnut [Macrotyloma geocarpum (Harms) Marechal & Baudet] in African soils.},
journal = {Applied and environmental microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1128/AEM.00342-19},
pmid = {30952658},
issn = {1098-5336},
abstract = {Kersting's groundnut [Macrotyloma geocarpum (Harms) Marechal & Baudet] is a neglected indigenous African legume adapted to growth in N-deficient soils due to its ability to fix atmospheric N2 via symbiosis with rhizobia. Despite its nutritional and medicinal uses, to date, there is little information on the phylogeny and functional traits of its microsymbionts, an aspect much needed for its conservation and improvement. This study explored the morpho-genetic diversity, phylogenetic relationships and N2-fixing efficiency of Kersting's groundnut rhizobial isolates from contrasting environments in Ghana, South Africa and Mozambique. Box-PCR fingerprinting revealed high diversity among rhizobial populations which was influenced by geographic origin. Of the 164 isolates evaluated, 130 Box-PCR types were identified at 70% similarity coefficient, indicating that they were not clones. Soil pH and mineral concentrations were found to influence the distribution of bradyrhizobial populations in African soils. Phylogenetic analysis of 16S rRNA gene and multilocus sequence analysis of protein-coding genes (atpD, glnII, gyrB and rpoB) and symbiotic genes (nifH and nodC) showed that, Kersting's groundnut is primarily nodulated by members of genus Bradyrhizobium, which are closely related to B. vignae 7-2T, B. kavangense 14-3T, B. subterraneum 58-2-1T, B. pachyrhizi PAC48T, B. elkaniiT and novel groups of Bradyrhizobium species. The bradyrhizobial populations identified exhibited high N2 fixation, and induced greater nodulation, leaf chlorophyll concentration and photosynthetic rates on their homologous host when compared to the 5 mM KNO3-fed plants and/or the commercial Bradyrhizobium strain CB756, suggesting that they could be good candidates for inoculant formulations upon field testing.IMPORTANCE Rhizobia play important roles in agroecosystems where they contribute to improving overall soil health through their symbiotic relationship with legumes. This study explored the microsymbionts nodulating Kersting's groundnut, a neglected orphan legume. The results revealed the presence of different bradyrhizobial populations with high N2-fixing efficiencies as the dominant symbionts of this legume across diverse agroecologies in Africa. Our findings represent a useful contribution to the literature in terms of the community of microsymbionts nodulating a neglected cultivated legume, and its potential for elevation as a major food crop. The presence of potentially novel bradyrhizobial symbionts of Kersting's groundnut found in this study offers an opportunity for future studies to properly describe, characterize and delineate these isolates functionally and phylogenetically for use in inoculant production to enhance food/nutritional security.},
}
@article {pmid30952451,
year = {2019},
author = {Camacho, M and Medina, C and Rodríguez-Navarro, DN and Temprano Vera, F},
title = {Biodiversity of rhizobia present in plant nodules of Biserrula pelecinus across Southwest Spain.},
journal = {Systematic and applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.syapm.2019.03.005},
pmid = {30952451},
issn = {1618-0984},
abstract = {Biodiversity studies of native Mesorhizobium spp. strains able to nodulate the annual herbaceous legume Biserrula pelecinus L. in soils from Southwest Spain have been carried out. One or two isolates per plant, 30 in total, were randomly selected for further characterization. There was no association between the presence of mesorhizobia nodulating-B. pelecinus and the chemical or textural properties of the soils. The isolates were tested for their symbiotic effectiveness on this forage legume under greenhouse conditions and characterized on the basis of physiological parameters: carbon source utilisation (API 50CH), 16S rRNA sequencing and ERIC-PCR, lipopolysaccharide, protein and plasmid profiles. Our results show that in spite of the great diversity found among the native isolates, most of them belong to the genus Mesorhizobium, the exception being strain B24 which sequence matches 97.52% with Neorhizobium huautlense; this is the first description of a Neorhizobium strain effectively nodulating-biserrula plants. Results of a field trial indicated that some of these isolates could be recommended as inoculants for this legume. B24=DSM 28743=CECT 8815; ENA (HF955513) 16S rRNA sequences of isolates B13, B18, B26, B30 and B1 are deposited at ENA under numbers LS999402 to LS999406, respectively.},
}
@article {pmid30951191,
year = {2019},
author = {Benavent-González, A and Raggio, J and Villagra, J and Blanquer, JM and Pintado, A and Rozzi, R and Green, TGA and Sancho, LG},
title = {High nitrogen contribution by Gunnera magellanica and nitrogen transfer by mycorrhizas drive an extraordinarily fast primary succession in Sub-Antarctic Chile.},
journal = {The New phytologist},
volume = {},
number = {},
pages = {},
doi = {10.1111/nph.15838},
pmid = {30951191},
issn = {1469-8137},
abstract = {Chronosequences at the forefront of retreating glaciers provide information about colonization rates of bare surfaces. In the northern hemisphere, forest development can take centuries, with rates often limited by low nutrient availability. In contrast, in front of the retreating Pia Glacier (Tierra del Fuego, Chile), a Nothofagus forest is in place after only 34 years of development, while total soil nitrogen (N) increased from near zero to 1.5%, suggesting a strong input of this nutrient. We measured N-fixation rates, carbon fluxes, leaf N and phosphorus contents and leaf δ15 N in the dominant plants, including the herb Gunnera magellanica, which is endosymbiotically associated with a cyanobacterium, in order to investigate the role of N-fixing and mycorrhizal symbionts in N-budget during successional transition. Gunnera magellanica presented some of the highest nitrogenase activities yet reported (potential maximal contribution of 300 kg N ha-1 yr-1). Foliar δ15 N results support the framework of a highly efficient N-uptake and transfer system based on mycorrhizas, with about 80% of N taken up by the mycorrhizas potentially transferred to the host plant. Our results suggest the symbiosis of G. magellanica with cyanobacteria, and trees and shrubs with mycorrhizas, to be the key processes driving this rapid succession. This article is protected by copyright. All rights reserved.},
}
@article {pmid30950432,
year = {2019},
author = {Tiwari, R and Negandhi, H and Zodpey, S},
title = {Forecasting the future need and gaps in requirements for public health professionals in India up to 2026.},
journal = {WHO South-East Asia journal of public health},
volume = {8},
number = {1},
pages = {56-65},
doi = {10.4103/2224-3151.255351},
pmid = {30950432},
issn = {2304-5272},
abstract = {Current ambitious reforms in India mean that public health professionals (PHPs) will become an increasingly vital component of the health workforce. Despite a rapid growth in schools of public health in India, uptake of places by students without a medical background is low. This paper reports the results of an exercise to estimate the baseline supply of, and need for, PHPs in India in 2017 and to forecast possible supply-need scenarios up to 2026. Supply was estimated using the stock and flow approach and the service-target approach was used to estimate need. The additional need resulting from development of a new public health cadre, as stated in the National Health Policy 2017, was also included. Supply-need gaps were forecast according to three scenarios, which varied according to the future intensity of policy intervention to increase occupancy of training places for PHPs from a non-medical background: "best guess" (no intervention), "optimistic" (feasible intervention), and "aspirational" (significant intervention) scenarios. In the best guess scenario in 2017, i.e. with a low non-medical place occupancy of 60%, there is a supply-need gap of around 28 000 PHPs. In the absence of any intervention to increase place occupancy, this shortfall is forecast to increase to 45 000 PHPs by the year 2026. By contrast, in the aspirational scenario, i.e. with a high place occupancy of 75% for non-medical places, the baseline gap for 2017 of almost 26 000 PHPs reduces by 2026 to around 21 000 PHPs. By 2026, most new PHPs will be produced by public health training programmes offered by institutions other than medical colleges. Without significant interventions, India is likely to have a significant shortfall in PHPs in 2026. Policy-makers will have to carefully examine issues surrounding the current low uptake of non-medical public health seats and review the current framework regulating training of PHPs, in order to respond adequately to future requirements.},
}
@article {pmid30950320,
year = {2019},
author = {Ingavle, G and Vaidya, A and Kale, V},
title = {Constructing 3D microenvironments using engineered biomaterials for HSC expansion.},
journal = {Tissue engineering. Part B, Reviews},
volume = {},
number = {},
pages = {},
doi = {10.1089/ten.TEB.2018.0286},
pmid = {30950320},
issn = {1937-3376},
abstract = {In a native bone marrow tissue-microenvironment, mesenchymal stem/stromal cells (MSCs) form an important constituent of the stem cell niche, which is composed of extra-cellular matrix (ECM), niche cells, biophysical cues and growth factors. These micro-environmental elements play a major role in guiding stem cell behaviour, such as growth, stemness, maintenance and lineage differentiation. The rapid progress in biomaterials advancement and stem cell biology has opened new directions in stem cell therapy. Ideally, biomaterials intended for tissue regenerative medicine applications should perform the structural and biochemical functions of the native ECM, which provides cells with physical (structural/morphological), chemical and mechanical cues via its three-dimensional architecture, until the cells' own ECM takes over. Advanced techniques related to materials synthesis are significantly important for designing temporary tissue engineering scaffolds, which not only support cell growth but also facilitates three-dimensional tissue formation. This review concisely describes the types of natural and synthetic polymeric biomaterials and the different approaches of designing and developing of porous scaffolds for the expansion of hematopoietic stem cells (HSCs). It also illustrates the relationship between material science and tissue engineering and reviews the most frequently used materials and some exciting recent advancements in scaffold manufacture technologies. Further, this review focuses on an introduction to existing HSC niche concepts and summarizes approaches to mimic them in vitro.},
}
@article {pmid30949766,
year = {2019},
author = {Rajan, A and Valla, JM and Alappatt, JA and Sharda, M and Shah, A and Ingalhalikar, M and Singh, NC},
title = {Wired for musical rhythm? A diffusion MRI-based study of individual differences in music perception.},
journal = {Brain structure & function},
volume = {},
number = {},
pages = {},
doi = {10.1007/s00429-019-01868-y},
pmid = {30949766},
issn = {1863-2661},
abstract = {Music perceptual abilities are subjective and exhibit high inter-individual variability. Twenty-nine participants with varying degrees of musical training were tested for musical perception ability with the Profile of Music Perception Skills (PROMS) and brain structural measures obtained via diffusion tensor imaging. Controlling for the period of training, TBSS results showed that individuals with better musical perception abilities showed increased deviations from linear anisotropy in the corpus callosum. Specifically, mode of anisotropy in the genu and body of the corpus callosum was negatively correlated with music perception score suggesting the presence of crossing fibers. A multi-compartment model of crossing fibers revealed a significant positive relation for partial volumes of secondary fiber populations with timing aspects of music perception. Our results suggest that inter-hemispheric connectivity differences in the anterior parts of the corpus callosum may reflect innate differences in the processing of the rhythmic aspects of music.},
}
@article {pmid30949751,
year = {2019},
author = {Hughey, MC and Sokol, ER and Walke, JB and Becker, MH and Belden, LK},
title = {Ecological Correlates of Large-Scale Turnover in the Dominant Members of Pseudacris crucifer Skin Bacterial Communities.},
journal = {Microbial ecology},
volume = {},
number = {},
pages = {},
doi = {10.1007/s00248-019-01372-0},
pmid = {30949751},
issn = {1432-184X},
support = {DEB-1136640//National Science Foundation/ ; D10ZO-028//Morris Animal Foundation/ ; },
abstract = {Animals host a wide diversity of symbiotic microorganisms that contribute important functions to host health, and our knowledge of what drives variation in the composition of these complex communities continues to grow. Microbiome studies at larger spatial scales present opportunities to evaluate the contribution of large-scale factors to variation in the microbiome. We conducted a large-scale field study to assess variation in the bacterial symbiont communities on adult frog skin (Pseudacris crucifer), characterized using 16S rRNA gene amplicon sequencing. We found that skin bacterial communities on frogs were less diverse than, and structurally distinct from, the surrounding habitat. Frog skin was typically dominated by one of two bacterial OTUs: at western sites, a Proteobacteria dominated the community, whereas eastern sites were dominated by an Actinobacteria. Using a metacommunity framework, we then sought to identify factors explaining small- and large-scale variation in community structure-that is, among hosts within a pond, and among ponds spanning the study transect. We focused on the presence of a fungal skin pathogen, Batrachochytrium dendrobatidis (Bd) as one potential driver of variation. We found no direct link between skin bacterial community structure and Bd infection status of individual frog hosts. Differences in pond-level community structure, however, were explained by Bd infection prevalence. Importantly, Bd infection prevalence itself was correlated with numerous other environmental factors; thus, skin bacterial diversity may be influenced by a complex suite of extrinsic factors. Our findings indicate that large-scale factors and processes merit consideration when seeking to understand microbiome diversity.},
}
@article {pmid30837458,
year = {2019},
author = {Reveillaud, J and Bordenstein, SR and Cruaud, C and Shaiber, A and Esen, ÖC and Weill, M and Makoundou, P and Lolans, K and Watson, AR and Rakotoarivony, I and Bordenstein, SR and Eren, AM},
title = {The Wolbachia mobilome in Culex pipiens includes a putative plasmid.},
journal = {Nature communications},
volume = {10},
number = {1},
pages = {1051},
doi = {10.1038/s41467-019-08973-w},
pmid = {30837458},
issn = {2041-1723},
support = {R01 AI132581/AI/NIAID NIH HHS/United States ; R21 AI133522/AI/NIAID NIH HHS/United States ; },
mesh = {Animals ; Bacteriophages/genetics ; Culex/*microbiology ; Female ; France ; Genome, Bacterial/*genetics ; Host Microbial Interactions/genetics ; Metagenome/*genetics ; Metagenomics/methods ; Mosquito Vectors/microbiology ; Ovary/microbiology ; Plasmids/*genetics ; Sequence Analysis, DNA ; Symbiosis/genetics ; Wolbachia/*genetics/virology ; },
abstract = {Wolbachia is a genus of obligate intracellular bacteria found in nematodes and arthropods worldwide, including insect vectors that transmit dengue, West Nile, and Zika viruses. Wolbachia's unique ability to alter host reproductive behavior through its temperate bacteriophage WO has enabled the development of new vector control strategies. However, our understanding of Wolbachia's mobilome beyond its bacteriophages is incomplete. Here, we reconstruct near-complete Wolbachia genomes from individual ovary metagenomes of four wild Culex pipiens mosquitoes captured in France. In addition to viral genes missing from the Wolbachia reference genome, we identify a putative plasmid (pWCP), consisting of a 9.23-kbp circular element with 14 genes. We validate its presence in additional Culex pipiens mosquitoes using PCR, long-read sequencing, and screening of existing metagenomes. The discovery of this previously unrecognized extrachromosomal element opens additional possibilities for genetic manipulation of Wolbachia.},
}
@article {pmid30674665,
year = {2019},
author = {Bosch, TCG},
title = {Squid genomes in a bacterial world.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {116},
number = {8},
pages = {2799-2801},
doi = {10.1073/pnas.1822166116},
pmid = {30674665},
issn = {1091-6490},
mesh = {Animals ; Bacteria ; *Cephalopoda ; *Decapodiformes ; Seafood ; Symbiosis ; },
}
@article {pmid30944875,
year = {2019},
author = {Vannier, N and Mony, C and Bittebiere, AK and Theis, KR and Rosenberg, E and Vandenkoornhuyse, P},
title = {Clonal Plants as Meta-Holobionts.},
journal = {mSystems},
volume = {4},
number = {2},
pages = {},
doi = {10.1128/mSystems.00213-18},
pmid = {30944875},
issn = {2379-5077},
abstract = {The holobiont concept defines a given organism and its associated symbionts as a potential level of selection over evolutionary time. In clonal plants, recent experiments demonstrated vertical transmission of part of the microbiota from one ramet (i.e., potentially autonomous individual) to another within the clonal network (i.e., connections by modified stems present in ∼35% of all plants). Because of this heritability, and potentially reciprocal exchange of microbes between generations of ramets, we propose to extend the existing holobiont framework to the concept of meta-holobiont. A meta-holobiont is a network of holobionts that can exchange biomolecules and microbiota across generations, thus impacting the fitness of both biological scales: holobionts and meta-holobionts. Specifically, meta-holobiont dynamics can result in sharing, specialization, and division of labor across plant clonal generations. This paper, which coins the meta-holobiont concept, is expected to stimulate discussion and to be applied beyond the context of networked clonal plants (e.g., to social insects).},
}
@article {pmid30944488,
year = {2019},
author = {Richards, TA and McCutcheon, JP},
title = {Coral symbiosis is a three-player game.},
journal = {Nature},
volume = {568},
number = {7750},
pages = {41-42},
doi = {10.1038/d41586-019-00949-6},
pmid = {30944488},
issn = {1476-4687},
}
@article {pmid30824706,
year = {2019},
author = {Lurgi, M and Thomas, T and Wemheuer, B and Webster, NS and Montoya, JM},
title = {Modularity and predicted functions of the global sponge-microbiome network.},
journal = {Nature communications},
volume = {10},
number = {1},
pages = {992},
doi = {10.1038/s41467-019-08925-4},
pmid = {30824706},
issn = {2041-1723},
mesh = {Animals ; Bacteria/classification/genetics ; Biodiversity ; Biological Evolution ; Ecology ; Host Microbial Interactions/*physiology ; Microbiota/genetics/*physiology ; Phylogeny ; Porifera/classification/*microbiology ; RNA, Ribosomal, 16S/genetics ; Species Specificity ; Symbiosis ; },
abstract = {Defining the organisation of species interaction networks and unveiling the processes behind their assembly is fundamental to understanding patterns of biodiversity, community stability and ecosystem functioning. Marine sponges host complex communities of microorganisms that contribute to their health and survival, yet the mechanisms behind microbiome assembly are largely unknown. We present the global marine sponge-microbiome network and reveal a modular organisation in both community structure and function. Modules are linked by a few sponge species that share microbes with other species around the world. Further, we provide evidence that abiotic factors influence the structuring of the sponge microbiome when considering all microbes present, but biotic interactions drive the assembly of more intimately associated 'core' microorganisms. These findings suggest that both ecological and evolutionary processes are at play in host-microbe network assembly. We expect mechanisms behind microbiome assembly to be consistent across multicellular hosts throughout the tree of life.},
}
@article {pmid30482513,
year = {2019},
author = {Díaz-Sánchez, S and Hernández-Jarguín, A and Torina, A and de Mera, IGF and Blanda, V and Caracappa, S and Gortazar, C and de la Fuente, J},
title = {Characterization of the bacterial microbiota in wild-caught Ixodes ventalloi.},
journal = {Ticks and tick-borne diseases},
volume = {10},
number = {2},
pages = {336-343},
doi = {10.1016/j.ttbdis.2018.11.014},
pmid = {30482513},
issn = {1877-9603},
mesh = {Anaplasma/genetics ; Animals ; Borrelia/genetics ; DNA, Bacterial/genetics ; Female ; High-Throughput Nucleotide Sequencing ; Ixodes/*microbiology ; Metagenomics ; *Microbiota ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sicily ; Symbiosis ; },
abstract = {Exploring the microbial diversity of ticks is crucial to understand geographical dispersion and pathogen transmission. Tick microbes participate in many biological processes implicated in the acquisition, maintenance, and transmission of pathogens, and actively promote host phenotypic changes, and adaptation to new environments. The microbial community of Ixodes ventalloi still remains unexplored. In this study, the bacterial microbiota of wild-caught I. ventalloi was characterized using shotgun-metagenomic sequencing in samples from unfed adults collected during December 2013-January 2014 in two locations from Sicily, Italy. The microbiota identified in I. ventalloi was mainly composed of symbiotic, commensal, and environmental bacteria. Interestingly, we identified the genera Anaplasma and Borrelia as members of the microbiota of I. ventalloi. These results advance our information on I. ventalloi microbiota composition, with potential implications in tick-host adaptation, geographic expansion, and vector competence.},
}
@article {pmid30941441,
year = {2019},
author = {Parihar, M and Meena, VS and Mishra, PK and Rakshit, A and Choudhary, M and Yadav, RP and Rana, K and Bisht, JK},
title = {Arbuscular mycorrhiza: a viable strategy for soil nutrient loss reduction.},
journal = {Archives of microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1007/s00203-019-01653-9},
pmid = {30941441},
issn = {1432-072X},
abstract = {Arbuscular mycorrhiza fungi's (AMF) role in plant nutrition and stress management is well known, but very few researches and studies have been conducted so far on the fungal ability to reduce different nutrient losses (runoff, leaching and volatilization) from the soil system. This important ecosystem service of AMF had been neglected largely. From the recent findings, it has been confirmed that mycorrhizal symbiosis has potential to check the losses of applied nutrients. The role of soil biota in nutrient cycling is indispensable and determines the nutrient availability to plants. Among these biota, AMF's association with plants is the most prevalent, but the exact mechanisms followed by AMF in nutrient cycling, transformation and reducing nutrient loss ability are still inconclusive. In this review, we will try to unlock this particular aspect of AMF which is important to achieve global food demand in a sustainable way.},
}
@article {pmid30940052,
year = {2019},
author = {Matthews, AC and Mikonranta, L and Raymond, B},
title = {Shifts along the parasite-mutualist continuum are opposed by fundamental trade-offs.},
journal = {Proceedings. Biological sciences},
volume = {286},
number = {1900},
pages = {20190236},
doi = {10.1098/rspb.2019.0236},
pmid = {30940052},
issn = {1471-2954},
abstract = {Theory suggests that symbionts can readily evolve more parasitic or mutualistic strategies with respect to hosts. However, many symbionts have stable interactions with hosts that improve nutrient assimilation or confer protection from pathogens. We explored the potential for evolution of increased parasitism or decreased parasitism and mutualism in a natural gut symbiosis between larvae of Plutella xylostella and the microbe Enterobacter cloacae. We focused on interactions with the pathogen, Bacillus thuringiensis: selecting for parasitism in terms of facilitating pathogen infection, or increased mutualism in terms of host protection. Selection for parasitism led to symbionts increasing pathogen-induced mortality but reduced their competitive ability with pathogens and their in vitro growth rates. Symbionts did not evolve to confer protection from pathogens. However, several lineages evolved reduced parasitism, primarily in terms of moderating impacts on host growth, potentially because prudence pays dividends through increased host size. Overall, the evolution of increased parasitism was achievable but was opposed by trade-offs likely to reduce fitness. The evolution of protection may not have occurred because suppressing growth of B. thuringiensis in the gut might provide only weak protection or because evolution towards protective interactions was opposed by the loss of competitive fitness in symbionts.},
}
@article {pmid30939810,
year = {2019},
author = {Kirienko, AN and Vishnevskaya, NA and Kitaeva, AB and Shtark, OY and Kozyulina, PY and Thompson, R and Dalmais, M and Bendahmane, A and Tikhonovich, IA and Dolgikh, EA},
title = {Structural Variations in LysM Domains of LysM-RLK PsK1 May Result in a Different Effect on Pea⁻Rhizobial Symbiosis Development.},
journal = {International journal of molecular sciences},
volume = {20},
number = {7},
pages = {},
doi = {10.3390/ijms20071624},
pmid = {30939810},
issn = {1422-0067},
support = {16-16-10043//Russian Science Foundation/ ; },
abstract = {Lysin-motif receptor-like kinase PsK1 is involved in symbiosis initiation and the maintenance of infection thread (IT) growth and bacterial release in pea. We verified PsK1 specificity in relation to the Nod factor structure using k1 and rhizobial mutants. Inoculation with nodO and nodE nodO mutants significantly reduced root hair deformations, curling, and the number of ITs in k1-1 and k1-2 mutants. These results indicated that PsK1 function may depend on Nod factor structures. PsK1 with replacement in kinase domain and PsSYM10 co-production in Nicotiana benthamiana leaves did not induce a hypersensitive response (HR) because of the impossibility of signal transduction into the cell. Replacement of P169S in LysM3 domain of PsK1 disturbed the extracellular domain (ECD) interaction with PsSYM10's ECD in Y2H system and reduced HR during the co-production of full-length PsK1 and PsSYM0 in N. benthamiana. Lastly, we explored the role of PsK1 in symbiosis with arbuscular mycorrhizal (AM) fungi; no significant differences between wild-type plants and k1 mutants were found, suggesting a specific role of PsK1 in legume⁻rhizobial symbiosis. However, increased sensitivity to a highly aggressive Fusarium culmorum strain was found in k1 mutants compared with the wild type, which requires the further study of the role of PsK1 in immune response regulation.},
}
@article {pmid29779668,
year = {2018},
author = {Moore, BS},
title = {Preface.},
journal = {Methods in enzymology},
volume = {604},
number = {},
pages = {xv-xvi},
doi = {10.1016/S0076-6879(18)30193-9},
pmid = {29779668},
issn = {1557-7988},
mesh = {Animals ; *Aquatic Organisms ; Bacteria/enzymology/metabolism ; Enzymes/*metabolism ; Invertebrates/*microbiology ; Symbiosis ; },
}
@article {pmid29779656,
year = {2018},
author = {Uria, AR and Piel, J and Wakimoto, T},
title = {Biosynthetic Insights of Calyculin- and Misakinolide-Type Compounds in "Candidatus Entotheonella sp.".},
journal = {Methods in enzymology},
volume = {604},
number = {},
pages = {287-330},
doi = {10.1016/bs.mie.2018.02.017},
pmid = {29779656},
issn = {1557-7988},
mesh = {Animals ; Biochemistry/*methods ; Biological Products/*metabolism ; Biosynthetic Pathways ; Computational Biology ; Macrolides/metabolism ; Metagenome ; Metagenomics/*methods ; Multigene Family ; Oxazoles/metabolism ; Peptide Biosynthesis, Nucleic Acid-Independent ; Polyketides/chemistry/*metabolism ; Porifera ; Symbiosis ; },
abstract = {Microbial symbionts are recognized as the important sources of numerous sponge-derived metabolites with potent biological activities. The limitation to cultivate the majority of potential symbionts has hampered attempts to explore and exploit their natural products for further development toward medical applications. Metagenomics-guided approaches have enabled cloning of natural product biosynthesis genes from uncultured microbial symbionts. Subsequent activation of biosynthesis genes in easily culturable bacteria could lead to the sustainable production of rare sponge-derived compounds. In this chapter, we highlight metagenomic strategies to reveal natural product biosynthetic pathways in sponge metagenomes based on the calyculin and misakinolide polyketides. Techniques to identify the compound producer are briefly discussed. We further describe examples of functional studies of the biosynthetic pathways of these two compound types with a special emphasis on the general experimental protocols for the activity assays of key proteins involved in their biosynthesis.},
}
@article {pmid29045380,
year = {2017},
author = {Bucci, M},
title = {Host-microbe interactions: Aiming at GPCRs.},
journal = {Nature chemical biology},
volume = {13},
number = {11},
pages = {1139},
pmid = {29045380},
issn = {1552-4469},
mesh = {*Bacteria ; Humans ; Ligands ; *Symbiosis ; },
}
@article {pmid28892653,
year = {2018},
author = {Buskermolen, JK and Janus, MM and Roffel, S and Krom, BP and Gibbs, S},
title = {Saliva-Derived Commensal and Pathogenic Biofilms in a Human Gingiva Model.},
journal = {Journal of dental research},
volume = {97},
number = {2},
pages = {201-208},
doi = {10.1177/0022034517729998},
pmid = {28892653},
issn = {1544-0591},
mesh = {*Biofilms ; Cell Line ; Cells, Cultured ; Cytokines/metabolism ; Elafin/metabolism ; Gingiva/*cytology/*microbiology ; *Host-Pathogen Interactions ; Humans ; In Situ Hybridization, Fluorescence ; In Vitro Techniques ; Phenotype ; Saliva/*microbiology ; Symbiosis ; Tissue Engineering ; },
abstract = {In vitro models that closely mimic human host-microbiome interactions can be a powerful screening tool for antimicrobials and will hold great potential for drug validation and discovery. The aim of this study was to develop an organotypic oral mucosa model that could be exposed to in vitro cultured commensal and pathogenic biofilms in a standardized and scalable manner. The oral mucosa model consisted of a tissue-engineered human gingiva equivalent containing a multilayered differentiated gingiva epithelium (keratinocytes) grown on a collagen hydrogel, containing gingiva fibroblasts, which represented the lamina propria. Keratinocyte and fibroblast telomerase reverse transcriptase-immortalized cell lines were used to overcome the limitations of isolating cells from small biopsies when scalable culture experiments were required. The oral biofilms were grown under defined conditions from human saliva to represent 3 distinct phenotypes: commensal, gingivitis, and cariogenic. The in vitro grown biofilms contained physiologic numbers of bacterial species, averaging >70 operational taxonomic units, including 20 differentiating operational taxonomic units. When the biofilms were applied topically to the gingiva equivalents for 24 h, the gingiva epithelium increased its expression of elafin, a protease inhibitor and antimicrobial protein. This increased elafin expression was observed as a response to all 3 biofilm types, commensal as well as pathogenic (gingivitis and cariogenic). Biofilm exposure also increased secretion of the antimicrobial cytokine CCL20 and inflammatory cytokines IL-6, CXCL8, and CCL2 from gingiva equivalents. This inflammatory response was far greater after commensal biofilm exposure than after pathogenic biofilm exposure. These results show that pathogenic oral biofilms have early immune evasion properties as compared with commensal oral biofilms. The novel host-microbiome model provides an ideal tool for future investigations of gingiva responses to commensal and pathogenic biofilms and for testing novel therapeutics.},
}
@article {pmid30939335,
year = {2019},
author = {Pereda-Goikoetxea, B and Marín-Fernández, B and Liceaga-Otazu, NE and Elorza-Puyadena, MI},
title = {A qualitative study of hospital birth perceptions: The helix of priority needs.},
journal = {Midwifery},
volume = {74},
number = {},
pages = {91-98},
doi = {10.1016/j.midw.2019.03.018},
pmid = {30939335},
issn = {1532-3099},
abstract = {OBJECTIVE: To understand which needs are considered priorities in the hospital birth experience from the perspectives of postpartum women.
DESIGN: This qualitative prospective study used a phenomenological approach. Data were collected through participant observations and semi-structured interviews recorded at eight weeks and eight months after childbirth. The data were analysed using a thematic approach.
PARTICIPANTS: The study cohort consisted of 43 participants at eight weeks after childbirth and 33 participants eight months after childbirth.
SETTING: Donostia University Hospital, San Sebastián, Spain, in 2016-2017.
FINDINGS: Through the analysis, the following four main themes emerged, each in different categories: (a) Professional care: symbiosis between the woman and the professional: (a.1) professional treatment and its characteristics, (a.2) professional competence, and (a.3) professional information and listening: pillars in the support relationship. (b) Control and hospital safety: (b.1) hospital environment: external control. (c) Presence of the partner: (c.1) support, guidance, and participation. (d) Perception of observed feelings: (d.1) fear of complications or separation from the child, (d.2) fear of internal lack of control, and (d.3) fear of an instrumental delivery and/or caesarean section.
The core of the hospital birth experience is constituted by the need to establish a supportive relationship based on mutual trust, exchange information that offers internal and external control and the security necessary to overcome feelings of fear, and obtain support and guidance from an involved partner.},
}
@article {pmid30939203,
year = {2019},
author = {Hernandez-Agreda, A and Leggat, W and Ainsworth, TD},
title = {A place for taxonomic profiling in the study of the coral prokaryotic microbiome.},
journal = {FEMS microbiology letters},
volume = {},
number = {},
pages = {},
doi = {10.1093/femsle/fnz063},
pmid = {30939203},
issn = {1574-6968},
abstract = {The enormous variability in richness, abundance, and diversity of unknown bacterial organisms inhabiting the coral microbiome have challenged our understanding of their functional contribution to coral health. Identifying the attributes of the healthy meta-organism is paramount for contemporary approaches aiming to manipulate dysbiotic stages of the coral microbiome. This review evaluates the current knowledge on the structure and mechanisms driving bacterial communities in the coral microbiome and discusses two topics requiring further research to define the healthy coral microbiome. 1) We examine the necessity to establish microbial baselines to understand the spatial and temporal dynamics of the healthy coral microbiome and summarize conceptual and logistic challenges to consider in the design of these baselines. 2) We propose potential mechanical, physical and chemical mechanisms driving bacterial distribution within coral compartments and suggest experiments to test them. Finally, we highlight aspects of the use of 16S amplicon sequencing requiring standardization and discuss its contribution to other multi-omics approaches.},
}
@article {pmid30937635,
year = {2019},
author = {Baruah, MM and Sharma, N},
title = {In silico identification of key genes and signaling pathways targeted by a panel of signature microRNAs in prostate cancer.},
journal = {Medical oncology (Northwood, London, England)},
volume = {36},
number = {5},
pages = {43},
doi = {10.1007/s12032-019-1268-y},
pmid = {30937635},
issn = {1559-131X},
abstract = {Accumulating evidence have suggested that some microRNAs are aberrantly expressed in prostate cancer. In our previous work, we had identified a panel of four differentially expressed microRNAs in prostate cancer. In the present study, we have investigated common molecular targets of this panel of miRNAs (DEMs) and key hub genes that can serve as potential candidate biomarkers in the pathogenesis and progression of prostate cancer. A joint bioinformatics approach was employed to identify differentially expressed genes (DEGs) in prostate cancer. Gene enrichment analysis followed by the protein-protein interaction (PPI) network construction and selection of hub genes was further performed using String and Cytoscape, respectively. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of the identified hub genes was conducted using the Database for Annotation, Visualization and Integrated Discovery (DAVID) tool. In total, 496 genes were identified to be common targets of DEMs in prostate cancer and 13 key hub genes were identified from three modules of the PPI network of the DEGs. Further top five genes viz Rhoa, PI3KCA, CDC42, MAPK3, TP53 were used for Enrichment analysis which revealed their association with vital cellular and functional pathways in prostate cancer indicating their potential as candidate biomarkers in prostate cancer.},
}
@article {pmid30936859,
year = {2019},
author = {Mewalal, R and Yin, H and Hu, R and Jawdy, S and Vion, P and Tuskan, GA and Le Tacon, F and Labbé, JL and Yang, X},
title = {Identification of Populus Small RNAs Responsive to Mutualistic Interactions With Mycorrhizal Fungi, Laccaria bicolor and Rhizophagus irregularis.},
journal = {Frontiers in microbiology},
volume = {10},
number = {},
pages = {515},
doi = {10.3389/fmicb.2019.00515},
pmid = {30936859},
issn = {1664-302X},
abstract = {Ecto- and endo-mycorrhizal colonization of Populus roots have a positive impact on the overall tree health and growth. A complete molecular understanding of these interactions will have important implications for increasing agricultural or forestry sustainability using plant:microbe-based strategies. These beneficial associations entail extensive morphological changes orchestrated by the genetic reprogramming in both organisms. In this study, we performed a comparative analysis of two Populus species (Populus deltoides and P. trichocarpa) that were colonized by either an arbuscular mycorrhizal fungus (AmF), Rhizophagus irregularis or an ectomycorrhizal fungus (EmF), Laccaria bicolor, to describe the small RNA (sRNA) landscape including small open reading frames (sORFs) and micro RNAs (miRNAs) involved in these mutualistic interactions. We identified differential expression of sRNAs that were, to a large extent, (1) within the genomic regions lacking annotated genes in the Populus genome and (2) distinct for each fungal interaction. These sRNAs may be a source of novel sORFs within a genome, and in this regard, we identified potential sORFs encoded by the sRNAs. We predicted a higher number of differentially-expressed miRNAs in P. trichocarpa (4 times more) than in P. deltoides (conserved and novel). In addition, 44 miRNAs were common in P. trichocarpa between the EmF and AmF treatments, and only 4 miRNAs were common in P. deltoides between the treatments. Root colonization by either fungus was more effective in P. trichocarpa than in P. deltoides, thus the relatively few differentially-expressed miRNAs predicted in P. deltoides might reflect the extent of the symbiosis. Finally, we predicted several genes targets for the plant miRNAs identified here, including potential fungal gene targets. Our findings shed light on additional molecular tiers with a role in Populus-fungal mutualistic associations and provides a set of potential molecular targets for future enhancement.},
}
@article {pmid30936484,
year = {2019},
author = {Tianero, MD and Balaich, JN and Donia, MS},
title = {Localized production of defence chemicals by intracellular symbionts of Haliclona sponges.},
journal = {Nature microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41564-019-0415-8},
pmid = {30936484},
issn = {2058-5276},
abstract = {Marine sponges often house small-molecule-producing symbionts extracellularly in their mesohyl, providing the host with a means of chemical defence against predation and microbial infection. Here, we report an intriguing case of chemically mediated symbiosis between the renieramycin-containing sponge Haliclona sp. and its herein discovered renieramycin-producing symbiont Candidatus Endohaliclona renieramycinifaciens. Remarkably, Ca. E. renieramycinifaciens has undergone extreme genome reduction where it has lost almost all necessary elements for free living while maintaining a complex, multi-copy plasmid-encoded biosynthetic gene cluster for renieramycin biosynthesis. In return, the sponge houses Ca. E. renieramycinifaciens in previously uncharacterized cellular reservoirs (chemobacteriocytes), where it can acquire nutrients from the host and avoid bacterial competition. This relationship is highly specific to a single clade of Haliclona sponges. Our study reveals intracellular symbionts as an understudied source for defence chemicals in the oldest-living metazoans and paves the way towards discovering similar systems in other marine sponges.},
}
@article {pmid30936458,
year = {2019},
author = {Ippolito, L and Morandi, A and Taddei, ML and Parri, M and Comito, G and Iscaro, A and Raspollini, MR and Magherini, F and Rapizzi, E and Masquelier, J and Muccioli, GG and Sonveaux, P and Chiarugi, P and Giannoni, E},
title = {Cancer-associated fibroblasts promote prostate cancer malignancy via metabolic rewiring and mitochondrial transfer.},
journal = {Oncogene},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41388-019-0805-7},
pmid = {30936458},
issn = {1476-5594},
support = {fellowship to Andrea Morandi//Fondazione Umberto Veronesi (Umberto Veronesi Foundation)/ ; 0203607//Istituto Toscano Tumori (ITT)/ ; 19515//Associazione Italiana per la Ricerca sul Cancro (Italian Association for Cancer Research)/ ; },
abstract = {Cancer-associated fibroblasts (CAFs) are the major cellular stromal component of many solid tumors. In prostate cancer (PCa), CAFs establish a metabolic symbiosis with PCa cells, contributing to cancer aggressiveness through lactate shuttle. In this study, we report that lactate uptake alters the NAD+/NADH ratio in the cancer cells, which culminates with SIRT1-dependent PGC-1α activation and subsequent enhancement of mitochondrial mass and activity. The high exploitation of mitochondria results in tricarboxylic acid cycle deregulation, accumulation of oncometabolites and in the altered expression of mitochondrial complexes, responsible for superoxide generation. Additionally, cancer cells hijack CAF-derived functional mitochondria through the formation of cellular bridges, a phenomenon that we observed in both in vitro and in vivo PCa models. Our work reveals a crucial function of tumor mitochondria as the energy sensors and transducers of CAF-dependent metabolic reprogramming and underscores the reliance of PCa cells on CAF catabolic activity and mitochondria trading.},
}
@article {pmid30935957,
year = {2019},
author = {Shibasaki, S},
title = {The evolutionary game of interspecific mutualism in the multi-species model.},
journal = {Journal of theoretical biology},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.jtbi.2019.03.026},
pmid = {30935957},
issn = {1095-8541},
abstract = {Mutualistic interspecific interactions, including Müllerian mimicry and division of labor, are common in nature. In contrast to antagonistic interactions, where faster evolution is favored, mutualism can favor slower evolution under certain conditions. This is called the Red King effect. Since Bergstrom and Lachmann (2003) proposed the Red King effect, it has been investigated only in two-species models. However, biological examples suggest that mutualism can include three or more species. Here, I modeled the evolutionary dynamics of mutualism in communities where involving two or more species, and in which all species mutually interact. Regardless of the number of species in the community, it is possible to derive conditions for stable equilibria. Although nonlinear relationships exist between the evolutionary rates and the evolutionary fate of each species in the multi-species communities, the model suggests that it is possible to predict whether faster evolution is favored or disfavored for the relatively rapidly evolving species; however, it is difficult to predict the evolutionary fate of species that evolve relatively slowly because their evolutionary dynamics are affected by the evolutionary fate of species evolving rapidly.},
}
@article {pmid30934751,
year = {2019},
author = {Ali, A and Ghani, MI and Ding, H and Fan, Y and Cheng, Z and Iqbal, M},
title = {Co-Amended Synergistic Interactions between Arbuscular Mycorrhizal Fungi and the Organic Substrate-Induced Cucumber Yield and Fruit Quality Associated with the Regulation of the AM-Fungal Community Structure under Anthropogenic Cultivated Soil.},
journal = {International journal of molecular sciences},
volume = {20},
number = {7},
pages = {},
doi = {10.3390/ijms20071539},
pmid = {30934751},
issn = {1422-0067},
support = {2016KTCL02-01//Shaanxi Provincial Sci-Tech Innovation Plan/ ; 2016NY-048//Shaanxi Provincial Agricultural Sci-Tech Innovation and Development Plan/ ; },
abstract = {Monotonous cucumber double-cropping systems under plastic greenhouse vegetable cultivation (PGVC) previously intensified by long-term anthropogenic activities and manipulative treatments leads to a crop productivity reduction and soil biota disturbances. In this study, the role of the indigenous arbuscular mycorrhizal strain (AM: Glomus versiforme L.) and organic substrate (GS: Garlic stalk) application were assessed for plant microbe interaction and crop productivity feedback in a greenhouse (2016⁻2018) under a cultivated Anthrosol characterized as a replanted degraded soil. We found that repetitively adding AM inocula with organic substrates (GS) improved the cucumber growth and physiology. The useful trait of AM symbiosis with C-amended organic substrates preferentially manifested as increased root colonization, hyphal density proliferation, AM sporulation, root activity, and suppressed Fusarium incidence. The post AM development further prevailed the synergistic interaction, and the co-inoculation effect resulted in an increase in fruit nutrition uptake, seasonal cucumber yield and fruit quality attributes. Illumina MiSeq analysis of the 18S rRNA gene amplicons revealed that the dominant AM genera that are particularly enriched with the Glomus taxon may be important ecological drivers associated with plant productivity and fruit quality characteristics. These results suggest that the AM-organic substrate association might be a pragmatic option for use as an economic and efficient biological resource and as a newly-sustainable plant microbe mediator to enhance the regional ecosystem services and plant productivity of the anthropogenic PGVC of this region.},
}
@article {pmid30934700,
year = {2019},
author = {Shan, H and Yang, J and Wei, G},
title = {Industrial Symbiosis Systems: Promoting Carbon Emission Reduction Activities.},
journal = {International journal of environmental research and public health},
volume = {16},
number = {7},
pages = {},
doi = {10.3390/ijerph16071093},
pmid = {30934700},
issn = {1660-4601},
support = {71503135//National Natural Science Foundation of China/ ; },
abstract = {The carbon emission problem in China needs to be solved urgently. Industrial symbiosis, as an effective means to improve resource efficiency, can better alleviate the carbon emission problem. Under such a circumstance, this paper regards an industrial symbiosis system as a collection of producers, consumers and decomposers, and analyzes the strategic selections and behavioral characteristics of their carbon emission reduction activities through a tripartite evolutionary game model, and then the effects of related parameters on the evolutionary stable strategies of stakeholders are discussed. The results demonstrate that: (1) the regular return and the rate of return determine the ability of stakeholders to undertake carbon reduction activities; (2) the initial willingness of stakeholders to participate will affect the evolutionary speed of the strategies; (3) a high opportunity cost reduces the inertia of stakeholders to carry out carbon emission reductions; (4) producers, consumers and decomposers can avoid "free rides" by signing agreements or adopting punitive measures.},
}
@article {pmid30930920,
year = {2019},
author = {Serova, TA and Tsyganova, AV and Tikhonovich, IA and Tsyganov, VE},
title = {Gibberellins Inhibit Nodule Senescence and Stimulate Nodule Meristem Bifurcation in Pea (Pisum sativum L.).},
journal = {Frontiers in plant science},
volume = {10},
number = {},
pages = {285},
doi = {10.3389/fpls.2019.00285},
pmid = {30930920},
issn = {1664-462X},
abstract = {The development of nitrogen-fixing nodules formed during Rhizobium-legume symbiosis is strongly controlled by phytohormones. In this study, we investigated the effect of gibberellins (GAs) on senescence of pea (Pisum sativum) symbiotic nodules. Pea wild-type line SGE, as well as corresponding mutant lines SGEFix--1 (sym40), SGEFix--2 (sym33), SGEFix--3 (sym26), and SGEFix--7 (sym27), blocked at different stages of nodule development, were used in the study. An increase in expression of the GA2ox1 gene, encoding an enzyme involved in GA deactivation (GA 2-oxidase), and a decrease in the transcript abundance of the GA20ox1 gene, encoding one of the enzymes involved in GA biosynthesis (GA 20-oxidase), were observed in analyzed genotypes during nodule aging. A reduction in the amount of bioactive GA3 was demonstrated by immunolocalization in the early senescent mutant and wild-type lines during aging of symbiotic nodules. Down-regulated expression of senescence-associated genes encoding cysteine proteases 1 and 15a, thiol protease, bZIP transcription factor, 1-aminocyclopropane-1-carboxylate (ACC) synthase, ACC oxidase, and aldehyde oxidase was observed in the nodules of wild-type plants treated with exogenous GA3 relative to the untreated plants. GA3-treated plants also showed increases in nodule size and the nitrogen fixation zone, and decreases in the number of nodules and the senescence zone. Immunogold localization revealed higher levels of GA3 in the peribacteroid spaces in symbiosomes than in the matrix of infection threads. Furthermore, a decrease in GA3 label in mature and senescent symbiosomes in comparison with juvenile symbiosomes was observed. These results suggest a negative effect of GAs on the senescence of the pea symbiotic nodule and possible involvement of GAs in functioning of the mature nodule. Simultaneously, GA3 treatment led to nodule meristem bifurcation, indicating a possible role of GAs in nodule meristem functioning.},
}
@article {pmid30930915,
year = {2019},
author = {Ho-Plágaro, T and Molinero-Rosales, N and Fariña Flores, D and Villena Díaz, M and García-Garrido, JM},
title = {Identification and Expression Analysis of GRAS Transcription Factor Genes Involved in the Control of Arbuscular Mycorrhizal Development in Tomato.},
journal = {Frontiers in plant science},
volume = {10},
number = {},
pages = {268},
doi = {10.3389/fpls.2019.00268},
pmid = {30930915},
issn = {1664-462X},
abstract = {The formation and functioning of arbuscular mycorrhizal (AM) symbiosis are complex and tightly regulated processes. Transcriptional regulation mechanisms have been reported to mediate gene expression changes closely associated with arbuscule formation, where nutrients move between the plant and fungus. Numerous genes encoding transcription factors (TFs), with those belonging to the GRAS family being of particular importance, are induced upon mycorrhization. In this study, a screening for candidate transcription factor genes differentially regulated in AM tomato roots showed that more than 30% of known GRAS tomato genes are upregulated upon mycorrhization. Some AM-upregulated GRAS genes were identified as encoding for transcription factors which are putative orthologs of previously identified regulators of mycorrhization in other plant species. The symbiotic role played by other newly identified AM-upregulated GRAS genes remains unknown. Preliminary results on the involvement of tomato SlGRAS18, SlGRAS38, and SlGRAS43 from the SCL3, SCL32, and SCR clades, respectively, in mycorrhization are presented. All three showed high transcript levels in the late stages of mycorrhization, and the analysis of promoter activity demonstrated that SlGRAS18 and SlGRAS43 are significantly induced in cells containing arbuscules. When SlGRAS18 and SlGRAS38 genes were silenced using RNA interference in hairy root composite tomato plants, a delay in mycorrhizal infection was observed, while an increase in mycorrhizal colonization was observed in SlGRAS43 RNAi roots. The possible mode of action of these TFs during mycorrhization is discussed, with a particular emphasis on the potential involvement of the SHR/SCR/SCL3 module of GRAS TFs in the regulation of gibberellin signaling during mycorrhization, which is analogous to other plant developmental processes.},
}
@article {pmid30930885,
year = {2019},
author = {Safronova, V and Belimov, A and Sazanova, A and Chirak, E and Kuznetsova, I and Andronov, E and Pinaev, A and Tsyganova, A and Seliverstova, E and Kitaeva, A and Tsyganov, V and Tikhonovich, I},
title = {Two Broad Host Range Rhizobial Strains Isolated From Relict Legumes Have Various Complementary Effects on Symbiotic Parameters of Co-inoculated Plants.},
journal = {Frontiers in microbiology},
volume = {10},
number = {},
pages = {514},
doi = {10.3389/fmicb.2019.00514},
pmid = {30930885},
issn = {1664-302X},
abstract = {Two bacterial strains Ach-343 and Opo-235 were isolated, respectively from nodules of Miocene-Pliocene relict legumes Astragalus chorinensis Bunge and Oxytropis popoviana Peschkova originated from Buryatia (Baikal Lake region, Russia). For identification of these strains the sequencing of 16S rRNA (rrs) gene was used. Strain Opo-235 belonged to the species Mesorhizobium japonicum, while the strain Ach-343 was identified as M. kowhaii (100 and 99.9% rrs similarity with the type strains MAFF 303099T and ICMP 19512T, respectively). Symbiotic genes of these strains as well as some genes that promote plant growth (acdS, gibberellin- and auxin-synthesis related genes) were searched throughout the whole genome sequences. The sets of plant growth-promoting genes found were almost identical in both strains, whereas the sets of symbiotic genes were different and complemented each other with several nod, nif, and fix genes. Effects of mono- and co-inoculation of Astragalus sericeocanus, Oxytropis caespitosa, Glycyrrhiza uralensis, Medicago sativa, and Trifolium pratense plants with the strains M. kowhaii Ach-343 and M. japonicum Opo-235 expressing fluorescent proteins mCherry (red) and EGFP (green) were studied in the gnotobiotic plant nodulation assay. It was shown that both strains had a wide range of host specificity, including species of different legume genera from two tribes (Galegeae and Trifolieae). The effects of co-microsymbionts on plants depended on the plant species and varied from decrease, no effect, to increase in the number of nodules, nitrogen-fixing activity and plant biomass. One of the reasons for this phenomenon may be the discovered complementarity in co-microsymbionts of symbiotic genes responsible for the specific modification of Nod-factors and nitrogenase activity. Localization and co-localization of the strains in nodules was confirmed by the confocal microscopy. Analysis of histological and ultrastructural organization of A. chorinensis and O. popoviana root nodules was performed. It can be concluded that the strains M. kowhaii Ach-343 and M. japonicum Opo-235 demonstrate lack of high symbiotic specificity that is characteristic for primitive legume-rhizobia systems. Further study of the root nodule bacteria having complementary sets of symbiotic genes will contribute to clarify the evolutionary paths of legume-rhizobia relationships and the mechanisms of effective integration between partners.},
}
@article {pmid30152217,
year = {2018},
author = {Liu, J and Liu, Y and Lv, H and Liu, Q and Li, M},
title = {[Research progress in human symbiotic bacteria and their antibacterial molecules].},
journal = {Sheng wu gong cheng xue bao = Chinese journal of biotechnology},
volume = {34},
number = {8},
pages = {1316-1325},
doi = {10.13345/j.cjb.170520},
pmid = {30152217},
issn = {1000-3061},
mesh = {Anti-Bacterial Agents/*chemistry ; Bacteria/*chemistry ; Genomics ; Humans ; *Symbiosis ; Synthetic Biology ; },
abstract = {With the emergence and globally spread of drug-resistant bacteria, the discovery and development of new antibacterial drugs is imminent. The symbiotic bacteria distributed in different parts of the body can produce a variety of antibacterial molecules to inhibit the colonization and infection of pathogenic bacteria. Human symbiotic bacteria provide a potential treasure house of resource for the research and development of new drugs with broad new molecular structures and action mechanism. With the further development of bioinformatics tools, synthetic biology and omics technology such as genomics, the mining of human symbiotic bacteria antibacterial molecules will be more in-depth and provide an effective way to solve the problem of drug resistance. Here, we review the antimicrobial molecules produced by human symbiotic bacteria and introduce several methods to explore the resources of natural antibacterial drugs. With the development of modern biotechnology, the antimicrobial molecules of human symbiotic bacteria will be more comprehensively and systematically explored and applied.},
}
@article {pmid29987713,
year = {2018},
author = {Botté, CY and Yamaryo-Botté, Y},
title = {Complex Endosymbioses II: The Nonphotosynthetic Plastid of Apicomplexa Parasites (The Apicoplast) and Its Integrated Metabolism.},
journal = {Methods in molecular biology (Clifton, N.J.)},
volume = {1829},
number = {},
pages = {37-54},
doi = {10.1007/978-1-4939-8654-5_3},
pmid = {29987713},
issn = {1940-6029},
mesh = {Antiparasitic Agents/pharmacology ; Apicoplasts/drug effects/*physiology ; Drug Development ; Energy Metabolism ; Genome ; Malaria ; Metabolic Networks and Pathways ; Photosynthesis ; Plastids/*genetics/*metabolism ; Protein Transport ; *Symbiosis ; },
abstract = {Chloroplasts are essential organelles that are responsible for photosynthesis in a wide range of organisms that have colonized all biotopes on Earth such as plants and unicellular algae. Interestingly, a secondary endosymbiotic event of a red algal ancestor gave rise to a group of organisms that have adopted an obligate parasitic lifestyle named Apicomplexa parasites. Apicomplexa parasites are some of the most widespread and poorly controlled pathogens in the world. These infectious agents are responsible for major human diseases such as toxoplasmosis, caused by Toxoplasma gondii, and malaria caused by Plasmodium spp. Most of these parasites harbor this relict plastid named the apicoplast, which is essential for parasite survival. The apicoplast has lost photosynthetic capacities but are metabolically similar to plant and algal chloroplasts. The apicoplast is considered a novel and important drug target against Apicomplexa parasites. This chapter focuses on the apicoplast of apicomplexa parasites, its maintenance, and its metabolic pathways.},
}
@article {pmid29987712,
year = {2018},
author = {Füssy, Z and Oborník, M},
title = {Complex Endosymbioses I: From Primary to Complex Plastids, Multiple Independent Events.},
journal = {Methods in molecular biology (Clifton, N.J.)},
volume = {1829},
number = {},
pages = {17-35},
doi = {10.1007/978-1-4939-8654-5_2},
pmid = {29987712},
issn = {1940-6029},
mesh = {Biological Evolution ; Eukaryota/classification/genetics/metabolism ; Photosynthesis ; Plastids/*genetics/*metabolism ; *Symbiosis ; },
abstract = {A substantial portion of eukaryote diversity consists of algae with complex plastids, i.e., plastids originating from eukaryote-to-eukaryote endosymbioses. These plastids are characteristic by a deviating number of envelope membranes (higher than two), and sometimes a remnant nucleus of the endosymbiont alga, termed the nucleomorph, is present. Complex plastid-bearing algae are therefore much like living matryoshka dolls, eukaryotes within eukaryotes. In comparison, primary plastids of Archaeplastida (plants, green algae, red algae, and glaucophytes) arose upon a single endosymbiosis event with a cyanobacterium and are surrounded by two membranes. Complex plastids were acquired several times by unrelated groups nested within eukaryotic heterotrophs, suggesting complex plastids are somewhat easier to obtain than primary plastids. This is consistent with the existence of higher-order and serial endosymbioses, i.e., engulfment of complex plastid-bearing algae by (tertiary) eukaryotic hosts and functional plastid replacements, respectively. Plastid endosymbiosis is typical by a massive transfer of genetic material from the endosymbiont to the host nucleus and metabolic rearrangements related to the trophic switch to phototrophy; this is necessary to establish metabolic integration of the plastid and control over its division. Although photosynthesis is the main advantage of plastid acquisition, algae that lost photosynthesis often maintain complex plastids, suggesting their roles beyond photosynthesis. This chapter summarizes basic knowledge on acquisition and functions of complex plastid.},
}
@article {pmid29987711,
year = {2018},
author = {Maréchal, E},
title = {Primary Endosymbiosis: Emergence of the Primary Chloroplast and the Chromatophore, Two Independent Events.},
journal = {Methods in molecular biology (Clifton, N.J.)},
volume = {1829},
number = {},
pages = {3-16},
doi = {10.1007/978-1-4939-8654-5_1},
pmid = {29987711},
issn = {1940-6029},
mesh = {Alphaproteobacteria/genetics ; Cell Membrane/metabolism ; Chlamydia/genetics/metabolism ; Chloroplasts/*pathology ; Chromatophores/*physiology ; Cyanobacteria/metabolism ; Eukaryota/physiology ; Gene Transfer, Horizontal ; Genes, Bacterial ; Glaucophyta/genetics/metabolism ; Inheritance Patterns ; Mitochondria/genetics/metabolism ; Rhizaria ; *Symbiosis ; },
abstract = {The emergence of semiautonomous organelles, such as the mitochondrion, the chloroplast, and more recently, the chromatophore, are critical steps in the evolution of eukaryotes. They resulted from primary endosymbiotic events that seem to share general features, i.e., an acquisition of a bacterium/cyanobacteria likely via a phagocytic membrane, a genome reduction coinciding with an escape of genes from the organelle to the nucleus, and finally the appearance of an active system translocating nuclear-encoded proteins back to the organelles. An intense mobilization of foreign genes of bacterial origin, via horizontal gene transfers, plays a critical role. Some third partners, like Chlamydia, might have facilitated the transition from cyanobacteria to the early chloroplast. This chapter describes our current understanding of primary endosymbiosis, with a specific focus on primary chloroplasts considered to have emerged more than one billion years ago, and on the chromatophore, having emerged about one hundred million years ago.},
}
@article {pmid29650391,
year = {2018},
author = {Dietel, AK and Kaltenpoth, M and Kost, C},
title = {Convergent Evolution in Intracellular Elements: Plasmids as Model Endosymbionts.},
journal = {Trends in microbiology},
volume = {26},
number = {9},
pages = {755-768},
doi = {10.1016/j.tim.2018.03.004},
pmid = {29650391},
issn = {1878-4380},
mesh = {*Bacteria/genetics/metabolism ; Chromosome Segregation ; Cytoplasm ; DNA Transposable Elements ; Eukaryota ; Evolution, Molecular ; Gene Transfer, Horizontal ; Host Microbial Interactions/genetics/physiology ; Mutation ; *Plasmids/genetics/metabolism ; *Symbiosis/genetics/physiology ; },
abstract = {Endosymbionts are organisms that live inside the cells of other species. This lifestyle is ubiquitous across the tree of life and is featured by unicellular eukaryotes, prokaryotes, and by extrachromosomal genetic elements such as plasmids. Given that all of these elements dwell in the cytoplasm of their host cell, they should be subject to similar selection pressures. Here we show that strikingly similar features have evolved in both bacterial endosymbionts and plasmids. Since host and endosymbiont are often metabolically tightly intertwined, they are difficult to disentangle experimentally. We propose that using plasmids as tractable model systems can help to solve this problem, thus allowing fundamental questions to be experimentally addressed about the ecology and evolution of endosymbiotic interactions.},
}
@article {pmid30928040,
year = {2019},
author = {Yoshino, K and Yamamoto, K and Hara, K and Sonoda, M and Yamamoto, Y and Sakamoto, K},
title = {The conservation of polyol transporter proteins and their involvement in lichenized Ascomycota.},
journal = {Fungal biology},
volume = {123},
number = {4},
pages = {318-329},
doi = {10.1016/j.funbio.2019.01.006},
pmid = {30928040},
issn = {1878-6146},
abstract = {In lichen symbiosis, polyol transfer from green algae is important for acquiring the fungal carbon source. However, the existence of polyol transporter genes and their correlation with lichenization remain unclear. Here, we report candidate polyol transporter genes selected from the genome of the lichen-forming fungus (LFF) Ramalina conduplicans. A phylogenetic analysis using characterized polyol and monosaccharide transporter proteins and hypothetical polyol transporter proteins of R. conduplicans and various ascomycetous fungi suggested that the characterized yeast' polyol transporters form multiple clades with the polyol transporter-like proteins selected from the diverse ascomycetous taxa. Thus, polyol transporter genes are widely conserved among Ascomycota, regardless of lichen-forming status. In addition, the phylogenetic clusters suggested that LFFs belonging to Lecanoromycetes have duplicated proteins in each cluster. Consequently, the number of sequences similar to characterized yeast' polyol transporters were evaluated using the genomes of 472 species or strains of Ascomycota. Among these, LFFs belonging to Lecanoromycetes had greater numbers of deduced polyol transporter proteins. Thus, various polyol transporters are conserved in Ascomycota and polyol transporter genes appear to have expanded during the evolution of Lecanoromycetes.},
}
@article {pmid30925791,
year = {2019},
author = {Somerville, J and Zhou, L and Raymond, B},
title = {Aseptic Rearing and Infection with Gut Bacteria Improve the Fitness of Transgenic Diamondback Moth, Plutella xylostella.},
journal = {Insects},
volume = {10},
number = {4},
pages = {},
doi = {10.3390/insects10040089},
pmid = {30925791},
issn = {2075-4450},
support = {BB/L00819X/2//Biotechnology and Biological Sciences Research Council/United Kingdom ; },
abstract = {Mass insect rearing can have a range of applications, for example in biological control of pests. The competitive fitness of released insects is extremely important in a number of applications. Here, we investigated how to improve the fitness of a transgenic diamondback moth, which has shown variation in mating ability when reared in different insectaries. Specifically we tested whether infection with a gut bacteria, Enterobacter cloacae, and aseptic rearing of larvae could improve insect growth and male performance. All larvae were readily infected with E. cloacae. Under aseptic rearing, pupal weights were reduced and there was a marginal reduction in larval survival. However, aseptic rearing substantially improved the fitness of transgenic males. In addition, under aseptic rearing, inoculation with E. cloacae increased pupal weights and male fitness, increasing the proportion of transgenic progeny from 20% to 30% relative to uninfected insects. Aseptic conditions may improve the fitness of transgenic males by excluding microbial contaminants, while symbiont inoculation could further improve fitness by providing additional protection against infection, or by normalizing insect physiology. The simple innovation of incorporating antibiotic into diet, and inoculating insects with symbiotic bacteria that are resistant to that antibiotic, could provide a readily transferable tool for other insect rearing systems.},
}
@article {pmid30925664,
year = {2019},
author = {da Costa, RR and Hu, H and Li, H and Poulsen, M},
title = {Symbiotic Plant Biomass Decomposition in Fungus-Growing Termites.},
journal = {Insects},
volume = {10},
number = {4},
pages = {},
doi = {10.3390/insects10040087},
pmid = {30925664},
issn = {2075-4450},
support = {VKR10101//Villum Fonden/ ; DE-FC02-07ER64494//Department of Energy Great Lakes Bioenergy Research Center Office of Science Grant/ ; },
abstract = {Termites are among the most successful animal groups, accomplishing nutrient acquisition through long-term associations and enzyme provisioning from microbial symbionts. Fungus farming has evolved only once in a single termite sub-family: Macrotermitinae. This sub-family has become a dominant decomposer in the Old World; through enzymatic contributions from insects, fungi, and bacteria, managed in an intricate decomposition pathway, the termites obtain near-complete utilisation of essentially any plant substrate. Here we review recent insights into our understanding of the process of plant biomass decomposition in fungus-growing termites. To this end, we outline research avenues that we believe can help shed light on how evolution has shaped the optimisation of plant-biomass decomposition in this complex multipartite symbiosis.},
}
@article {pmid30923350,
year = {2019},
author = {Raina, JB and Fernandez, V and Lambert, B and Stocker, R and Seymour, JR},
title = {The role of microbial motility and chemotaxis in symbiosis.},
journal = {Nature reviews. Microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41579-019-0182-9},
pmid = {30923350},
issn = {1740-1534},
abstract = {Many symbiotic relationships rely on the acquisition of microbial partners from the environment. However, the mechanisms by which microbial symbionts find and colonize their hosts are often unknown. We propose that the acquisition of environmental symbionts often necessitates active migration and colonization by the symbionts through motility and chemotaxis. The pivotal role of these behaviours in the onset and maintenance of symbiotic interactions is well established in a small number of model systems but remains largely overlooked for the many symbioses that involve the recruitment of microbial partners from the environment. In this Review, we highlight when, where and how chemotaxis and motility can enable symbiont recruitment and propose that these symbiont behaviours are important across a wide range of hosts and environments.},
}
@article {pmid30922601,
year = {2019},
author = {Buysse, M and Plantard, O and McCoy, KD and Duron, O and Menard, C},
title = {Tissue localization of Coxiella-like endosymbionts in three European tick species through fluorescence in situ hybridization.},
journal = {Ticks and tick-borne diseases},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.ttbdis.2019.03.014},
pmid = {30922601},
issn = {1877-9603},
abstract = {Ticks are commonly infected by Coxiella-like endosymbionts (Coxiella-LE) which are thought to supply missing B vitamin nutrients required for blood digestion.While this nutritional symbiosis is essential for the survival and reproduction of infected tick species, our knowledge of where Coxiella-LE is localized in tick tissues is partial at best since previous studies have focused on a limited number of Asian or American tick species. To fill this gap, we investigated the tissue localization of Coxiella-LE in three European tick species, Ornithodoros maritimus, Dermacentor marginatus and Ixodes hexagonus, using a diagnostic fluorescence in situ hybridization (FISH) assay, combined with PCR-based detection. Specific fluorescent foci were observed in several tick tissues. We visualized a pronounced tissue tropism of Coxiella-LE for tick ovaries and Malpighian tubules, a pattern suggestive of a high degree of lifestyle specialization toward mutualism: infection of the ovaries is indicative of transovarial transmission, whereas infection of the Malpighian tubules suggests a nutritional function. We postulate that Malpighian tubules are key organs for the nutritional symbiosis, notably the synthesis of B vitamins by Coxiella-LE, whereas the infection of the ovaries ensures vertical transmission of the symbionts to future generations. We also detected occasional infections in other organs, such as salivary glands and the midgut. Finally, we discuss the potential significance of the different tissue tropism for tick biology.},
}
@article {pmid30835731,
year = {2019},
author = {Di Lelio, I and Illiano, A and Astarita, F and Gianfranceschi, L and Horner, D and Varricchio, P and Amoresano, A and Pucci, P and Pennacchio, F and Caccia, S},
title = {Evolution of an insect immune barrier through horizontal gene transfer mediated by a parasitic wasp.},
journal = {PLoS genetics},
volume = {15},
number = {3},
pages = {e1007998},
doi = {10.1371/journal.pgen.1007998},
pmid = {30835731},
issn = {1553-7404},
mesh = {Animals ; *Evolution, Molecular ; Gene Transfer, Horizontal/*genetics ; Hemolymph/immunology/virology ; Larva/genetics/*immunology/virology ; Phylogeny ; Proteomics ; Symbiosis/genetics/immunology ; Wasps/genetics/*immunology/virology ; },
abstract = {Genome sequencing data have recently demonstrated that eukaryote evolution has been remarkably influenced by the acquisition of a large number of genes by horizontal gene transfer (HGT) across different kingdoms. However, in depth-studies on the physiological traits conferred by these accidental DNA acquisitions are largely lacking. Here we elucidate the functional role of Sl gasmin, a gene of a symbiotic virus of a parasitic wasp that has been transferred to an ancestor of the moth species Spodoptera littoralis and domesticated. This gene is highly expressed in circulating immune cells (haemocytes) of larval stages, where its transcription is rapidly boosted by injection of microorganisms into the body cavity. RNAi silencing of Sl gasmin generates a phenotype characterized by a precocious suppression of phagocytic activity by haemocytes, which is rescued when these immune cells are incubated in plasma samples of control larvae, containing high levels of the encoded protein. Proteomic analysis demonstrates that the protein Sl gasmin is released by haemocytes into the haemolymph, where it opsonizes the invading bacteria to promote their phagocytosis, both in vitro and in vivo. Our results show that important physiological traits do not necessarily originate from evolution of pre-existing genes, but can be acquired by HGT events, through unique pathways of symbiotic evolution. These findings indicate that insects can paradoxically acquire selective advantages with the help of their natural enemies.},
}
@article {pmid30818326,
year = {2019},
author = {von Geldern, TW and Morton, HE and Clark, RF and Brown, BS and Johnston, KL and Ford, L and Specht, S and Carr, RA and Stolarik, DF and Ma, J and Rieser, MJ and Struever, D and Frohberger, SJ and Koschel, M and Ehrens, A and Turner, JD and Hübner, MP and Hoerauf, A and Taylor, MJ and Ward, SA and Marsh, K and Kempf, DJ},
title = {Discovery of ABBV-4083, a novel analog of Tylosin A that has potent anti-Wolbachia and anti-filarial activity.},
journal = {PLoS neglected tropical diseases},
volume = {13},
number = {2},
pages = {e0007159},
doi = {10.1371/journal.pntd.0007159},
pmid = {30818326},
issn = {1935-2735},
mesh = {Animals ; Anti-Bacterial Agents/pharmacokinetics/*pharmacology ; *Drug Discovery ; Elephantiasis, Filarial/drug therapy ; Female ; Filaricides/pharmacokinetics/*pharmacology ; Filarioidea/drug effects/microbiology ; Gerbillinae ; Mice ; Mice, Inbred BALB C ; Onchocerciasis/drug therapy ; Symbiosis/drug effects ; Tylosin/*analogs & derivatives/*pharmacology ; Wolbachia/*drug effects ; },
abstract = {There is a significant need for improved treatments for onchocerciasis and lymphatic filariasis, diseases caused by filarial worm infection. In particular, an agent able to selectively kill adult worms (macrofilaricide) would be expected to substantially augment the benefits of mass drug administration (MDA) with current microfilaricides, and to provide a solution to treatment of onchocerciasis / loiasis co-infection, where MDA is restricted. We have identified a novel macrofilaricidal agent, Tylosin A (TylA), which acts by targeting the worm-symbiont Wolbachia bacterium. Chemical modification of TylA leads to improvements in anti-Wolbachia activity and oral pharmacokinetic properties; an optimized analog (ABBV-4083) has been selected for clinical evaluation.},
}
@article {pmid30741934,
year = {2019},
author = {Osterman, J and Wintermantel, D and Locke, B and Jonsson, O and Semberg, E and Onorati, P and Forsgren, E and Rosenkranz, P and Rahbek-Pedersen, T and Bommarco, R and Smith, HG and Rundlöf, M and de Miranda, JR},
title = {Clothianidin seed-treatment has no detectable negative impact on honeybee colonies and their pathogens.},
journal = {Nature communications},
volume = {10},
number = {1},
pages = {692},
doi = {10.1038/s41467-019-08523-4},
pmid = {30741934},
issn = {2041-1723},
mesh = {Animals ; Bacteria/drug effects/pathogenicity ; Bees/*drug effects/growth & development/immunology ; Dicistroviridae/drug effects ; Environmental Monitoring ; Gammaproteobacteria/drug effects ; Gene Expression/drug effects ; Guanidines/*pharmacology ; Honey/analysis ; Neonicotinoids/*pharmacology ; Plant Extracts/*pharmacology ; Plant Nectar/chemistry ; Plant Oils/pharmacology ; Pollen/chemistry ; Seeds/*chemistry ; Sweden ; Symbiosis ; Thiazoles/*pharmacology ; Viruses/drug effects/pathogenicity ; },
abstract = {Interactions between multiple stressors have been implicated in elevated honeybee colony losses. Here, we extend our landscape-scale study on the effects of placement at clothianidin seed-treated oilseed rape fields on honeybees with an additional year and new data on honeybee colony development, swarming, mortality, pathogens and immune gene expression. Clothianidin residues in pollen, nectar and honeybees were consistently higher at clothianidin-treated fields, with large differences between fields and years. We found large variations in colony development and microbial composition and no observable negative impact of placement at clothianidin-treated fields. Clothianidin treatment was associated with an increase in brood, adult bees and Gilliamella apicola (beneficial gut symbiont) and a decrease in Aphid lethal paralysis virus and Black queen cell virus - particularly in the second year. The results suggest that at colony level, honeybees are relatively robust to the effects of clothianidin in real-world agricultural landscapes, with moderate, natural disease pressure.},
}
@article {pmid29693244,
year = {2018},
author = {Hembry, DH and Raimundo, RLG and Newman, EA and Atkinson, L and Guo, C and Guimarães, PR and Gillespie, RG},
title = {Does biological intimacy shape ecological network structure? A test using a brood pollination mutualism on continental and oceanic islands.},
journal = {The Journal of animal ecology},
volume = {87},
number = {4},
pages = {1160-1171},
doi = {10.1111/1365-2656.12841},
pmid = {29693244},
issn = {1365-2656},
mesh = {Animals ; Biological Evolution ; Insect Proteins/analysis ; Islands ; Japan ; Larva/growth & development/physiology ; Moths/growth & development/*physiology ; Phyllanthus/growth & development/*physiology ; *Phylogeny ; *Pollination ; Polynesia ; Sequence Analysis, DNA ; *Symbiosis ; },
abstract = {Biological intimacy-the degree of physical proximity or integration of partner taxa during their life cycles-is thought to promote the evolution of reciprocal specialization and modularity in the networks formed by co-occurring mutualistic species, but this hypothesis has rarely been tested. Here, we test this "biological intimacy hypothesis" by comparing the network architecture of brood pollination mutualisms, in which specialized insects are simultaneously parasites (as larvae) and pollinators (as adults) of their host plants to that of other mutualisms which vary in their biological intimacy (including ant-myrmecophyte, ant-extrafloral nectary, plant-pollinator and plant-seed disperser assemblages). We use a novel dataset sampled from leafflower trees (Phyllanthaceae: Phyllanthus s. l. [Glochidion]) and their pollinating leafflower moths (Lepidoptera: Epicephala) on three oceanic islands (French Polynesia) and compare it to equivalent published data from congeners on continental islands (Japan). We infer taxonomic diversity of leafflower moths using multilocus molecular phylogenetic analysis and examine several network structural properties: modularity (compartmentalization), reciprocality (symmetry) of specialization and algebraic connectivity. We find that most leafflower-moth networks are reciprocally specialized and modular, as hypothesized. However, we also find that two oceanic island networks differ in their modularity and reciprocal specialization from the others, as a result of a supergeneralist moth taxon which interacts with nine of 10 available hosts. Our results generally support the biological intimacy hypothesis, finding that leafflower-moth networks (usually) share a reciprocally specialized and modular structure with other intimate mutualisms such as ant-myrmecophyte symbioses, but unlike nonintimate mutualisms such as seed dispersal and nonintimate pollination. Additionally, we show that generalists-common in nonintimate mutualisms-can also evolve in intimate mutualisms, and that their effect is similar in both types of assemblages: once generalists emerge they reshape the network organization by connecting otherwise isolated modules.},
}
@article {pmid29603211,
year = {2018},
author = {Simmons, BI and Sutherland, WJ and Dicks, LV and Albrecht, J and Farwig, N and García, D and Jordano, P and González-Varo, JP},
title = {Moving from frugivory to seed dispersal: Incorporating the functional outcomes of interactions in plant-frugivore networks.},
journal = {The Journal of animal ecology},
volume = {87},
number = {4},
pages = {995-1007},
doi = {10.1111/1365-2656.12831},
pmid = {29603211},
issn = {1365-2656},
mesh = {Animals ; Birds/*physiology ; *Food Chain ; Fruit/physiology ; *Herbivory ; Magnoliopsida/*physiology ; *Seed Dispersal ; Symbiosis ; },
abstract = {There is growing interest in understanding the functional outcomes of species interactions in ecological networks. For many mutualistic networks, including pollination and seed dispersal networks, interactions are generally sampled by recording animal foraging visits to plants. However, these visits may not reflect actual pollination or seed dispersal events, despite these typically being the ecological processes of interest. Frugivorous animals can act as seed dispersers, by swallowing entire fruits and dispersing their seeds, or as pulp peckers or seed predators, by pecking fruits to consume pieces of pulp or seeds. These processes have opposing consequences for plant reproductive success. Therefore, equating visitation with seed dispersal could lead to biased inferences about the ecology, evolution and conservation of seed dispersal mutualisms. Here, we use natural history information on the functional outcomes of pairwise bird-plant interactions to examine changes in the structure of seven European plant-frugivore visitation networks after non-mutualistic interactions (pulp pecking and seed predation) have been removed. Following existing knowledge of the contrasting structures of mutualistic and antagonistic networks, we hypothesized a number of changes following interaction removal, such as increased nestedness and lower specialization. Non-mutualistic interactions with pulp peckers and seed predators occurred in all seven networks, accounting for 21%-48% of all interactions and 6%-24% of total interaction frequency. When non-mutualistic interactions were removed, there were significant increases in network-level metrics such as connectance and nestedness, while robustness decreased. These changes were generally small, homogenous and driven by decreases in network size. Conversely, changes in species-level metrics were more variable and sometimes large, with significant decreases in plant degree, interaction frequency, specialization and resilience to animal extinctions and significant increases in frugivore species strength. Visitation data can overestimate the actual frequency of seed dispersal services in plant-frugivore networks. We show here that incorporating natural history information on the functions of species interactions can bring us closer to understanding the processes and functions operating in ecological communities. Our categorical approach lays the foundation for future work quantifying functional interaction outcomes along a mutualism-antagonism continuum, as documented in other frugivore faunas.},
}
@article {pmid29504629,
year = {2018},
author = {Câmara, T and Leal, IR and Blüthgen, N and Oliveira, FMP and Queiroz, RT and Arnan, X},
title = {Effects of chronic anthropogenic disturbance and rainfall on the specialization of ant-plant mutualistic networks in the Caatinga, a Brazilian dry forest.},
journal = {The Journal of animal ecology},
volume = {87},
number = {4},
pages = {1022-1033},
doi = {10.1111/1365-2656.12820},
pmid = {29504629},
issn = {1365-2656},
mesh = {Animal Husbandry ; Animals ; Ants/*physiology ; Brazil ; Climate Change ; Forestry ; *Forests ; *Human Activities ; Humans ; *Plant Physiological Phenomena ; *Rain ; *Symbiosis ; },
abstract = {Anthropogenic disturbance and climate change might negatively affect the ecosystem services provided by mutualistic networks. However, the effects of such forces remain poorly characterized. They may be especially important in dry forests, which (1) experience chronic anthropogenic disturbances (CADs) as human populations exploit forest resources, and (2) are predicted to face a 22% decline in rainfall under climate change. In this study, we investigated the separate and combined effects of CADs and rainfall levels on the specialization of mutualistic networks in the Caatinga, a seasonally dry tropical forest typical of north-eastern Brazil. More specifically, we examined interactions between plants bearing extrafloral nectaries (EFNs) and ants. We analysed whether differences in network specialization could arise from environmentally mediated variation in the species composition, namely via the replacement of specialist by generalist species. We characterized these ant-plant networks in 15 plots (20 × 20 m) that varied in CAD intensity and mean annual rainfall. We quantified CAD intensity by calculating three indices related to the main sources of disturbance in the Caatinga: livestock grazing (LG), wood extraction (WE) and miscellaneous resource use (MU). We determined the degree of ant-plant network specialization using four metrics: generality, vulnerability, interaction evenness and H2 '. Our results indicate that CADs differentially influenced network specialization: we observed positive, negative, and neutral responses along LG, MU and WE gradients, respectively. The pattern was most pronounced with LG. Rainfall also shaped network specialization, markedly increasing it. While LG and rainfall were associated with changes in network species composition, this trend was not related to the degree of species specialization. This result suggests that shifts in network specialization might be related to changes in species behaviour, not species composition. Our study highlights the vulnerability of such dry forest ant-plant networks to climate change. Moreover, dry forests experience highly heterogeneous anthropogenic disturbances, creating a geographic mosaic of selective forces that may shape the co-evolution of interactions between ants and EFN-bearing plants.},
}
@article {pmid30919981,
year = {2019},
author = {Field, KJ and Bidartondo, MI and Rimington, WR and Hoysted, GA and Beerling, DJ and Cameron, DD and Duckett, JG and Leake, JR and Pressel, S},
title = {Functional complementarity of ancient plant-fungal mutualisms: contrasting nitrogen, phosphorus and carbon exchanges between Mucoromycotina and Glomeromycotina fungal symbionts of liverworts.},
journal = {The New phytologist},
volume = {},
number = {},
pages = {},
doi = {10.1111/nph.15819},
pmid = {30919981},
issn = {1469-8137},
abstract = {Liverworts, which are amongst the earliest-divergent plant lineages and important ecosystem pioneers, often form nutritional mutualisms with arbuscular mycorrhiza-forming Glomeromycotina and fine root endophyte Mucoromycotina fungi, both of which co-evolved with early land plants. Some liverworts, in common with many later-divergent plants, harbour both fungal groups, suggesting these fungi may complementarily improve plant access to different soil nutrients. We tested this hypothesis by growing liverworts in single and dual fungal partnerships under a modern atmosphere and under 1500 ppm [CO2 ], as experienced by early land plants. Access to soil nutrients via fungal partners was investigated with 15 N-labelled algal necromass and 33 P orthophosphate. Photosynthate allocation to fungi was traced using 14 CO2 . Only Mucoromycotina fungal partners provided liverworts with substantial access to algal 15 N, irrespective of atmospheric CO2 concentration. Both symbionts increased 33 P uptake, but Glomeromycotina were often more effective. Dual partnerships showed complementarity of nutrient pool use and greatest photosynthate allocation to symbiotic fungi. We show there are important functional differences between the plant-fungal symbioses tested, providing new insights into the functional biology of Glomeromycotina and Mucoromycotina fungal groups that form symbioses with plants. This may explain the persistence of both fungal lineages in symbioses across the evolution of land plants. This article is protected by copyright. All rights reserved.},
}
@article {pmid30919462,
year = {2019},
author = {Matsuo, K and Haku, A and Bi, B and Takahashi, H and Kamada, N and Yaguchi, T and Saijo, S and Yoneyama, M and Goto, Y},
title = {Fecal microbiota transplantation prevents Candida albicans from colonizing the gastrointestinal tract.},
journal = {Microbiology and immunology},
volume = {},
number = {},
pages = {},
doi = {10.1111/1348-0421.12680},
pmid = {30919462},
issn = {1348-0421},
abstract = {Gut microbes symbiotically colonize the gastrointestinal (GI) tract, interacting with each other and their host to maintain GI tract homeostasis. Recent reports have shown that gut microbes help protect the gut from colonization by pathogenic microbes. Here, we report that commensal microbes prevent colonization of the pathogenic fungus, Candida albicans, in the GI tract. Wild-type specific pathogen-free (SPF) mice are resistant to C. albicans colonization in the GI tract. However, administering certain antibiotics to SPF mice enables C. albicans colonization. Quantitative kinetics of commensal bacteria are inversely correlated with the number of C. albicans in the gut. Here, we provide further evidence that fecal microbiota transplantation effectively prevents Candida colonization in the GI tract. These data demonstrate the importance of commensal bacteria as a barrier of the GI tract surface, and highlight the potential clinical applications of commensal bacteria for preventing pathogenic fungal infections. This article is protected by copyright. All rights reserved.},
}
@article {pmid30918316,
year = {2019},
author = {Nissinen, R and Helander, M and Kumar, M and Saikkonen, K},
title = {Heritable Epichloë symbiosis shapes fungal but not bacterial communities of plant leaves.},
journal = {Scientific reports},
volume = {9},
number = {1},
pages = {5253},
doi = {10.1038/s41598-019-41603-5},
pmid = {30918316},
issn = {2045-2322},
abstract = {Keystone microbial species have driven eco-evolutionary processes since the origin of life. However, due to our inability to detect the majority of microbiota, members of diverse microbial communities of fungi, bacteria and viruses have largely been ignored as keystone species in past literature. Here we tested whether heritable Epichloë species of pooidae grasses modulate microbiota of their shared host plant.},
}
@article {pmid30917916,
year = {2019},
author = {Hajialilo, E and Rezaeian, M and Niyyati, M and Pourmand, MR and Mohebali, M and Norouzi, M and Pashabeyg, KR and Rezaie, S and Khodavaisy, S},
title = {Molecular characterization of bacterial, viral and fungal endosymbionts of Acanthamoeba isolates in keratitis patients of Iran.},
journal = {Experimental parasitology},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.exppara.2019.03.013},
pmid = {30917916},
issn = {1090-2449},
abstract = {Free-living amoebae belong to the genus Acanthamoeba; can feed on microbial population by phagocytosis, and with the capability to act as a reservoir and a vehicle of microorganisms to susceptible host. Therefore, the role of endosymbiosis in the pathogenesis of Acanthamoeba is complex and not fully understood. The aim of the present study was to identify bacterial, fungal, and human adenovirus (HADV) endosymbionts as well as evaluating the endosymbionts role of such organisms in the pathogenesis of Acanthamoeba in keratitis patients living in Iran. Fifteen Acanthamoeba (T4 genotype) isolates were recovered from corneal scrapes and contact lenses of patients with keratitis. Cloning and purification was performed for all isolate. Gram staining was performed to identify bacterial endosymbionts. DNA extraction, PCR, and nested PCR was set up to identify endosymbiont of amoeba. Evaluation of pathogenicity was conducted by osmo-tolerance and thermo-tolerance assays and cell culture, and then CPE (cytopathic effect) was survey. Statistical analysis was used between Acanthamoeba associated endosymbionts and Acanthamoeba without endosymbiont at 24, 48, 72, and 96 h. A p value < 0.05 was considered as significant, statistically. A total of 9 (60%) Acanthamoeba (T4 genotypes) isolates were successfully cloned for detecting microorganism endosymbionts. The only isolate negative for the presence of endosymbiont was ICS9. ICS7 (Pseudomonas aeruginosa, Aspergillus sp., and human adenovirus endosymbionts) and ICS2 (Escherichia coli endosymbiont) isolates were considered as Acanthamoeba associated endosymbionts. ICS7 and ICS2 isolates were highly pathogen whereas ICS9 isolate showed low pathogenicity in pathogenicity evaluated. Positive CPE for ICS7 and ICS2 isolates and negative CPE for ICS9 isolate were observed in cell culture. The average number of cells, trophozoites, and cysts among ICS7, ICS2, and ICS9 isolates at 24, 48, 72, and 96 h was significant. This is the first survey on microbial endosymbionts of Acanthamoeba in keratitis patients of Iran, and also the first report of Aspergillus sp, Achromobacter sp., Microbacterium sp., Brevibacillus sp, Brevundimonas sp and Mastadenovirus sp in Acanthamoeba as endosymbionts. Our study demonstrated that microbial endosymbionts can affect the pathogenicity of Acanthamoeba; however, further research is required to clarify the exact pattern of symbiosis, in order to modify treatment protocol.},
}
@article {pmid30917551,
year = {2019},
author = {Qi, Y and Chen, X and Hu, Z and Song, C and Cui, Y},
title = {Bibliometric Analysis of Algal-Bacterial Symbiosis in Wastewater Treatment.},
journal = {International journal of environmental research and public health},
volume = {16},
number = {6},
pages = {},
doi = {10.3390/ijerph16061077},
pmid = {30917551},
issn = {1660-4601},
support = {2016YFB0601003//National key research and development program-China/ ; 16JCYBJC20700//Natural Science Foundation of Tianjin/ ; },
abstract = {In recent years, the algae-bacteria symbiotic system has played a significant role in the sustainable development of wastewater treatment. With the continuous expansion of research outputs, publications related to wastewater treatment via algal-bacterial consortia appear to be on the rise. Based on SCI-EXPANDED database, this study investigated the research activities and tendencies of algae-bacteria symbiotic wastewater treatment technology by bibliometric method from 1998 to 2017. The results indicated that environmental sciences and ecology was the most productive subject categories, followed by engineering. Bioresource Technology was the most prominent journal in this field with considerable academic influence. China (146), USA (139) and Spain (76) had the largest amount of publications. Among them, USA was in a leading position in international cooperation, with the highest h-index (67) in 79 countries/territories. The cooperation between China and USA was the closest. The cooperative publishing rate of the Chinese Academy of Sciences was 83.33%, but most of them were in cooperation with domestic institutions, while international cooperation was relatively limited. Methane production, biofuel production, and extracellular polymeric substance were future focal frontiers of research, and this field had gradually become a multi-perspective and inter-disciplinary approach combining biological, environmental and energy technologies.},
}
@article {pmid30917525,
year = {2019},
author = {Salgado-Morales, R and Martínez-Ocampo, F and Obregón-Barboza, V and Vilchis-Martínez, K and Jiménez-Pérez, A and Dantán-González, E},
title = {Assessing the Pathogenicity of Two Bacteria Isolated from the Entomopathogenic Nematode Heterorhabditis indica against Galleria mellonella and Some Pest Insects.},
journal = {Insects},
volume = {10},
number = {3},
pages = {},
doi = {10.3390/insects10030083},
pmid = {30917525},
issn = {2075-4450},
support = {PDCPN 0247780//Consejo Nacional de Ciencia y Tecnología/ ; 296934//Consejo Nacional de Ciencia y Tecnología/ ; },
abstract = {The entomopathogenic nematodes Heterorhabditis are parasites of insects and are associated with mutualist symbiosis enterobacteria of the genus Photorhabdus; these bacteria are lethal to their host insects. Heterorhabditis indica MOR03 was isolated from sugarcane soil in Morelos state, Mexico. The molecular identification of the nematode was confirmed using sequences of the ITS1-5.8S-ITS2 region and the D2/D3 expansion segment of the 28S rRNA gene. In addition, two bacteria HIM3 and NA04 strains were isolated from the entomopathogenic nematode. The genomes of both bacteria were sequenced and assembled de novo. Phylogenetic analysis was confirmed by concatenated gene sequence datasets as Photorhabdus luminescens HIM3 (16S rRNA, 23S rRNA, dnaN, gyrA, and gyrB genes) and Pseudomonas aeruginosa NA04 (16S rRNA, 23S rRNA and gyrB genes). H. indica MOR03 infects Galleria mellonella, Tenebrio molitor, Heliothis subflexa, and Diatraea magnifactella larvae with LC50 values of 1.4, 23.5, 13.7, and 21.7 IJs/cm², respectively, at 48 h. These bacteria are pathogenic to various insects and have high injectable insecticide activity at 24 h.},
}
@article {pmid30026291,
year = {2018},
author = {Magne, K and Couzigou, JM and Schiessl, K and Liu, S and George, J and Zhukov, V and Sahl, L and Boyer, F and Iantcheva, A and Mysore, KS and Wen, J and Citerne, S and Oldroyd, GED and Ratet, P},
title = {MtNODULE ROOT1 and MtNODULE ROOT2 Are Essential for Indeterminate Nodule Identity.},
journal = {Plant physiology},
volume = {178},
number = {1},
pages = {295-316},
pmid = {30026291},
issn = {1532-2548},
mesh = {Amino Acid Sequence ; *Gene Expression Regulation, Developmental ; *Gene Expression Regulation, Plant ; Medicago truncatula/*genetics/growth & development/metabolism ; Meristem/genetics/growth & development/metabolism ; Mutation ; Nitrogen Fixation/genetics ; Phylogeny ; Plant Proteins/classification/*genetics/metabolism ; Plant Roots/genetics/growth & development/metabolism ; Plants, Genetically Modified ; Root Nodules, Plant/*genetics/growth & development/metabolism ; Sequence Homology, Amino Acid ; Symbiosis/genetics ; },
abstract = {Symbiotic interactions between legume plants and rhizobia result in the formation of nitrogen-fixing nodules, but the molecular actors and the mechanisms allowing for the maintenance of nodule identity are poorly understood. Medicago truncatula NODULE ROOT1 (MtNOOT1), Pisum sativum COCHLEATA1 (PsCOCH1), and Lotus japonicus NOOT-BOP-COCH-LIKE1 (LjNBCL1) are orthologs of Arabidopsis (Arabidopsis thaliana) AtBLADE-ON-PETIOLE1/2 and are members of the NBCL gene family, which has conserved roles in plant development and is essential for indeterminate and determinate nodule identity in legumes. The loss of function of MtNOOT1, PsCOCH1, and LjNBCL1 triggers a partial loss of nodule identity characterized by the development of ectopic roots arising from nodule vascular meristems. Here, we report the identification and characterization of a second gene involved in regulating indeterminate nodule identity in M. truncatula, MtNOOT2MtNOOT2 is the paralog of MtNOOT1 and belongs to a second legume-specific NBCL subclade, the NBCL2 clade. MtNOOT2 expression was induced during early nodule formation, and it was expressed primarily in the nodule central meristem. Mtnoot2 mutants did not present any particular symbiotic phenotype; however, the loss of function of both MtNOOT1 and MtNOOT2 resulted in the complete loss of nodule identity and was accompanied by drastic changes in the expression of symbiotic, defense, and root apical meristem marker genes. Mtnoot1 noot2 double mutants developed only nonfixing root-like structures that were no longer able to host symbiotic rhizobia. This study provides original insights into the molecular basis underlying nodule identity in legumes forming indeterminate nodules.},
}
@article {pmid29676724,
year = {2018},
author = {Monsanto-Hearne, V and Johnson, KN},
title = {Wolbachia-mediated protection of Drosophila melanogaster against systemic infection with its natural viral pathogen Drosophila C virus does not involve changes in levels of highly abundant miRNAs.},
journal = {The Journal of general virology},
volume = {99},
number = {6},
pages = {827-831},
doi = {10.1099/jgv.0.001064},
pmid = {29676724},
issn = {1465-2099},
mesh = {Animals ; Dicistroviridae/*pathogenicity ; Drosophila melanogaster/*genetics/microbiology/virology ; Host-Pathogen Interactions/*genetics ; MicroRNAs/*genetics ; Real-Time Polymerase Chain Reaction ; Symbiosis ; Virus Diseases/microbiology ; Wolbachia/*physiology ; },
abstract = {The presence of Wolbachia confers virus protection to insects. The molecular mechanism underlying Wolbachia-mediated protection in this tripartite host-endosymbiont-virus interaction is not yet fully understood. In the bipartite association between Drosophila melanogaster and Drosophila C virus (DCV), changes in the expression of microRNAs (miRNAs) influence the outcome of viral pathogenesis. Here we examined whether changes in miRNA expression are similarly involved in the Drosophila-Wolbachia-DCV association. The levels of highly abundant miRNAs in D. melanogaster, Wolbachia-mono-infected D. melanogaster, and DCV- and Wolbachia-bi-infected D. melanogaster were quantified using RT-qPCR and compared. The results show that the abundance of the 17 tested D. melanogaster miRNAs is not affected by Wolbachia endosymbiosis or by bi-infection of Wolbachia and DCV. These results suggest that the in vivo protection conferred by Wolbachia to its native host against D. melanogaster's natural pathogen DCV is not likely to be dependent on or associated with changes in the levels of highly expressed miRNAs.},
}
@article {pmid30917160,
year = {2019},
author = {Del Cerro, P and Megías, M and López-Baena, FJ and Gil-Serrano, A and Pérez-Montaño, F and Ollero, FJ},
title = {Osmotic stress activates nif and fix genes and induces the Rhizobium tropici CIAT 899 Nod factor production via NodD2 by up-regulation of the nodA2 operon and the nodA3 gene.},
journal = {PloS one},
volume = {14},
number = {3},
pages = {e0213298},
doi = {10.1371/journal.pone.0213298},
pmid = {30917160},
issn = {1932-6203},
abstract = {The symbiosis between rhizobia and legumes is characterized by a complex molecular dialogue in which the bacterial NodD protein plays a major role due to its capacity to activate the expression of the nodulation genes in the presence of appropiate flavonoids. These genes are involved in the synthesis of molecules, the nodulation factors (NF), responsible for launching the nodulation process. Rhizobium tropici CIAT 899, a rhizobial strain that nodulates Phaseolus vulgaris, is characterized by its tolerance to multiple environmental stresses such as high temperatures, acidity or elevated osmolarity. This strain produces nodulation factors under saline stress and the same set of CIAT 899 nodulation genes activated by inducing flavonoids are also up-regulated in a process controlled by the NodD2 protein. In this paper, we have studied the effect of osmotic stress (high mannitol concentrations) on the R. tropici CIAT 899 transcriptomic response. In the same manner as with saline stress, the osmotic stress mediated NF production and export was controlled directly by NodD2. In contrast to previous reports, the nodA2FE operon and the nodA3 and nodD1 genes were up-regulated with mannitol, which correlated with an increase in the production of biologically active NF. Interestingly, in these conditions, this regulatory protein controlled not only the expression of nodulation genes but also the expression of other genes involved in protein folding and synthesis, motility, synthesis of polysaccharides and, surprinsingly, nitrogen fixation. Moreover, the non-metabolizable sugar dulcitol was also able to induce the NF production and the activation of nod genes in CIAT 899.},
}
@article {pmid30916398,
year = {2019},
author = {Quiroga, G and Erice, G and Ding, L and Chaumont, F and Aroca, R and Ruiz-Lozano, JM},
title = {The arbuscular mycorrhizal symbiosis regulates aquaporins activity and improves root cell water permeability in maize plants subjected to water stress.},
journal = {Plant, cell & environment},
volume = {},
number = {},
pages = {},
doi = {10.1111/pce.13551},
pmid = {30916398},
issn = {1365-3040},
abstract = {Studies have suggested that increased root hydraulic conductivity in mycorrhizal roots could be the result of increased cell-to-cell water flux via aquaporins. This study aimed to elucidate if the key effect of the regulation of maize aquaporins by the arbuscular mycorrhizal (AM) symbiosis is the enhancement of root cell water transport capacity. Thus water permeability coefficient (Pf) and cell hydraulic conductivity (Lpc) were measured in root protoplast and intact cortex cells of AM and non-AM plants subjected or not to water stress. Results showed that cells from droughted-AM roots maintained Pf and Lpc values of non-stressed plants, while in non-AM roots these values declined drastically as consequence of water deficit. Interestingly, the phosphorylation status of PIP2 aquaporins increased in AM plants subjected to water deficit, and Pf values higher than 12 μm s-1 were found only in protoplasts from AM roots, revealing the higher water permeability of AM root cells. In parallel, the AM symbiosis increased stomatal conductance, net photosynthesis and related parameters, showing a higher photosynthetic capacity in these plants. This study demonstrate a better performance of AM root cells in water transport under water deficit, which is connected to the shoot physiological performance in terms of photosynthetic capacity.},
}
@article {pmid30915091,
year = {2019},
author = {Goh, DM and Cosme, M and Kisiala, AB and Mulholland, S and Said, ZMF and Spíchal, L and Emery, RJN and Declerck, S and Guinel, FC},
title = {A Stimulatory Role for Cytokinin in the Arbuscular Mycorrhizal Symbiosis of Pea.},
journal = {Frontiers in plant science},
volume = {10},
number = {},
pages = {262},
doi = {10.3389/fpls.2019.00262},
pmid = {30915091},
issn = {1664-462X},
abstract = {The arbuscular mycorrhizal (AM) symbiosis between terrestrial plants and AM fungi is regulated by plant hormones. For most of these, a role has been clearly assigned in this mutualistic interaction; however, there are still contradictory reports for cytokinin (CK). Here, pea plants, the wild type (WT) cv. Sparkle and its mutant E151 (Pssym15), were inoculated with the AM fungus Rhizophagus irregularis. E151 has previously been characterized as possessing high CK levels in non-mycorrhizal (myc-) roots and exhibiting high number of fungal structures in mycorrhizal (myc+) roots. Myc- and myc+ plants were treated 7, 9, and 11 days after inoculation (DAI) with synthetic compounds known to alter CK status. WT plants were treated with a synthetic CK [6-benzylaminopurine (BAP)] or the CK degradation inhibitor INCYDE, whereas E151 plants were treated with the CK receptor antagonist PI-55. At 13 DAI, plant CK content was analyzed by mass spectrometry. The effects of the synthetic compounds on AM colonization were assessed at 28 (WT) or 35 (E151) DAI via a modified magnified intersections method. The only noticeable difference seen between myc- and myc+ plants in terms of CK content was in the levels of nucleotides (NTs). Whereas WT plants responded to fungi by lowering their NT levels, E151 plants did not. Since NTs are thought to be converted into active CK forms, this result suggests that active CKs were synthesized more effectively in WT than in E151. In general, myc+ and myc- WT plants responded similarly to INCYDE by lowering significantly their NT levels and increasing slightly their active CK levels; these responses were less obvious in BAP-treated WT plants. In contrast, the response of E151 plants to PI-55 depended on the plant mycorrhizal status. Whereas treated myc- plants exhibited high NT and low active CK levels, treated myc+ plants displayed low levels of both NTs and active CKs. Moreover, treated WT plants were more colonized than treated E151 plants. We concluded that CKs have a stimulatory role in AM colonization because increased active CK levels were paralleled with increased AM colonization while decreased CK levels corresponded to reduced AM colonization.},
}
@article {pmid30914318,
year = {2019},
author = {Xiao, R and Wang, X and Xie, E and Ji, T and Li, X and Muhammad, A and Yin, X and Hou, Y and Shi, Z},
title = {An IMD-like pathway mediates the intestinal immunity to modulate the homeostasis of gut microbiota in Rhynchophorus ferrugineus Olivier (Coleoptera: Dryophthoridae).},
journal = {Developmental and comparative immunology},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.dci.2019.03.013},
pmid = {30914318},
issn = {1879-0089},
abstract = {Most animals have established the mutualistic interactions with their intestinal microbes which provide multiple benefits to their host physiology. However, the mechanisms behind hosts determine the load and composition of gut microbiota are still poorly understood outside dipteran insects. Here, the gene, encoding the NF-κB-like transcription factor Relish, being designated as RfRelish, was identified and analyzed in red palm weevil (RPW), Rhynchophorus ferrugineus Olivier. We revealed that the abundance of RfRelish transcripts in the fat body, hemolymph and gut are significantly higher than that in non-immunity-related tissues, and its expression level can be markedly induced by bacterial challenges. When RfRelish was silenced, the ability of individuals to clear the pathogenic bacteria in body cavity and gut was significantly compromised, suggesting that both the systemic and gut local immunity were impaired dramatically by RfRelish knockdown. Additionally, the silenced insects exhibited increased gut bacterial load, and the relative abundance of some gut bacteria was changed as compared to controls. Collectively, our findings demonstrate that the IMD-like pathway restricts the proliferation of gut bacteria and shapes the commensal community structure in the intestine of R. ferrugineus by mediating the secretion of antimicrobial peptides. We provide a striking example on how an insect pest maintains the homeostasis of gut microbiota via a conserved immune pathway without compromising the advantages of the mutualistic relationships.},
}
@article {pmid29688526,
year = {2018},
author = {Arkhipova, IR},
title = {Neutral Theory, Transposable Elements, and Eukaryotic Genome Evolution.},
journal = {Molecular biology and evolution},
volume = {35},
number = {6},
pages = {1332-1337},
doi = {10.1093/molbev/msy083},
pmid = {29688526},
issn = {1537-1719},
support = {R01 GM111917/GM/NIGMS NIH HHS/United States ; },
mesh = {Animals ; *DNA Transposable Elements ; *Genetic Drift ; *Genome ; Humans ; Metagenomics ; Symbiosis ; },
abstract = {Among the multitude of papers published yearly in scientific journals, precious few publications may be worth looking back in half a century to appreciate the significance of the discoveries that would later become common knowledge and get a chance to shape a field or several adjacent fields. Here, Kimura's fundamental concept of neutral mutation-random drift, which was published 50 years ago, is re-examined in light of its pervasive influence on comparative genomics and, more specifically, on the contribution of transposable elements to eukaryotic genome evolution.},
}
@article {pmid29580322,
year = {2018},
author = {Zhang, P and Liu, W and Cao, M and Massart, S and Wang, X},
title = {Two novel totiviruses in the white-backed planthopper, Sogatella furcifera.},
journal = {The Journal of general virology},
volume = {99},
number = {5},
pages = {710-716},
doi = {10.1099/jgv.0.001052},
pmid = {29580322},
issn = {1465-2099},
mesh = {Animals ; Genome, Viral ; Hemiptera/*virology ; Hemolymph/virology ; High-Throughput Nucleotide Sequencing ; Insect Viruses/*classification/genetics/isolation & purification ; Phylogeny ; Symbiosis ; Totivirus/*classification/genetics/isolation & purification ; Virus Diseases/transmission ; },
abstract = {There is little information about commensal viruses in the white-backed planthopper, Sogatella furcifera, although it is an important agricultural insect. Here, two novel double-stranded RNA viruses related to the viruses in the family Totiviridae were identified using next-generation sequencing and tentatively named Sogatella furcifera totivirus 1 and 2 (SfTV1 and SfTV2). Their complete genomes consist of 6310 and 6303 nt, respectively, showing typical genomic features with viruses in the family Totiviridae. Identity, phylogenetic and conserved sequence analyses showed that SfTV1, SfTV2 and three other insect viruses may form a proposed novel genus of the family Totiviridae. Vertical transmission of the two viruses was highly efficient, and they were detected in all insect tissues and developmental stages, with the highest titres in the adult and in the haemolymph and reproductive organs. To our knowledge, this is the first report of viruses in the family Totiviridae found in a hemipteran insect.},
}
@article {pmid30913327,
year = {2019},
author = {Fan, J and Qin, H and Zhang, Y and Jiang, S},
title = {Degradation of 4-chlorophenol by BM Fe/Cu-O2 system: The symbiosis of ·O2- and ·OH radicals.},
journal = {Water environment research : a research publication of the Water Environment Federation},
volume = {},
number = {},
pages = {},
doi = {10.1002/wer.1107},
pmid = {30913327},
issn = {1061-4303},
abstract = {In this study, Fe/Cu bimetal composite was prepared by high energy ball milling (BM) method for the removal of refractory organics. The BM Fe/Cu bimetal was characterized by SEM-EDS, XRD, and XPS. Evenly distributed Fe and Cu was observed in the EDS-mapping. In contrasting experiments, the removal rate of 4-chlorophenol (4-CP) by BM Fe/Cu materials was about 10-fold faster than that by chemical substitution deposition (CSD) Fe/Cu material. Complete 4-CP removal and 66.7% of total organic carbon (TOC) mineralization in the BM Fe/Cu-O2 system were achieved. Dissolved oxygen plays a crucial role for 4-CP degradation through the in situ generation of reactive oxygen species (ROSs) like H2 O2 , ·OH and ·O2- via oxygen activation reactions. The predominant reactive radicals were identified to be ·O2- and ·OH through ESR technique and inhibition experiments. The coexistence of oxidation and reduction of 4-CP in the BM Fe/Cu-O2 system was proposed. This article is protected by copyright. All rights reserved.},
}
@article {pmid30912397,
year = {2019},
author = {Chen, BD and Yu, M and Hao, ZP and Xie, W and Zhang, X},
title = {Research progress in arbuscular mycorrhizal technology.},
journal = {Ying yong sheng tai xue bao = The journal of applied ecology},
volume = {30},
number = {3},
pages = {1035-1046},
doi = {10.13287/j.1001-9332.201903.037},
pmid = {30912397},
issn = {1001-9332},
abstract = {Arbuscular mycorrhizal (AM) symbiosis facilitates plant mineral nutrient acquisition and plays key roles in plant adaptation to environmental stresses. The application of AM fungi is a component of sustainable agriculture and ecological restoration. We introduced the current status of AM fungi collections, production of commercial inocula and AM fungi related patents, summarized the research advances in inoculum production, inoculation techniques, and factors influencing the success of inoculation practice in the field, based on case studies of mycorrhizal technology in agriculture, horticulture, and ecological restoration. Finally, we proposed some basic scientific questions and technical bottleneck that deserve futher studies, to promote the development and application of mycorrhizal technologies.},
}
@article {pmid30911691,
year = {2019},
author = {Agarkar, AA and Agrawal, H},
title = {LRSPPP: lightweight R-LWE-based secure and privacy-preserving scheme for prosumer side network in smart grid.},
journal = {Heliyon},
volume = {5},
number = {3},
pages = {e01321},
doi = {10.1016/j.heliyon.2019.e01321},
pmid = {30911691},
issn = {2405-8440},
abstract = {In recent years, researchers have made tremendous progress to address an important question of how to provide security and privacy in Internet of Things systems. Privacy protection refers to safeguarding leakage of private information of the customers. In the context of Smart Grid, majority of the studies are based on addressing consumer side privacy. A recent research work has revealed that consumer side network has evolved into prosumer side network. Prosumer refers to consumer and producer, which means a dual role of a customer in the smart grid network. In this paper, we attempt to address the security and privacy issues at the prosumer side of smart grid network. Our work is different from the previous works in two ways. The paper proposes a lightweight encryption based privacy preservation scheme; Lightweight R-LWE-based Secure and Privacy-Preserving Scheme for Prosumer side network (LRSPPP). In LRSPPP, a new messaging scheme is defined which effectively minimizes the number of messages thus making it lightweight. Furthermore, the proposed privacy preservation scheme is using Learning With Errors over Rings (R-LWE) lattice cryptography. There is no previous evidence of use of R-LWE based encryption for prosumer's privacy protection in smart grid. The security and performance analysis shows that the LRSPPP is superior compared to three other existing schemes.},
}
@article {pmid30911658,
year = {2018},
author = {Oliver Goetze, T and Al-Batran, SE and Pabst, U and Reymond, M and Tempfer, C and Bechstein, WO and Bankstahl, U and Gockel, I and Königsrainer, A and Kraus, T and Mönig, SP and Rau, B and Schwarzbach, M and Piso, P},
title = {Pressurized intraperitoneal aerosol chemotherapy (PIPAC) in combination with standard of care chemotherapy in primarily untreated chemo naïve upper gi-adenocarcinomas with peritoneal seeding - a phase II/III trial of the AIO/CAOGI/ACO.},
journal = {Pleura and peritoneum},
volume = {3},
number = {2},
pages = {20180113},
doi = {10.1515/pp-2018-0113},
pmid = {30911658},
issn = {2364-768X},
abstract = {Background: Peritoneal metastasis is a common and dismal evolution of several gastrointestinal (GI) tumors, including gastric, colorectal, hepatobiliary, pancreatic, and other cancers. The therapy of peritoneal metastasis is largely palliative; with the aim of prolonging life and preserving its quality. In the meantime, a significant pharmacological advantage of intraperitoneal chemotherapy was documented in the preclinical model, and numerous clinical studies have delivered promising clinical results.
Methods: This is a prospective, open, randomized multicenter phase III clinical study with two arms that aims to evaluate the effects of pressurized intraperitoneal aerosol chemotherapy (PIPAC) combined with systemic chemotherapy vs. intravenous systemic chemotherapy alone on patients with metastatic upper GI tumors with a peritoneal seeding. Upper GI-adenocarcinomas originated from biliary tract, pancreas and stomach, or esophago- gastric junction are eligible. Patients in the study are treated with standard of care systemic palliative chemotherapy (mFOLFOX6) vs. PIPAC with intravenous (i.v.) chemotherapy (mFOLFOX6). Patients in first line with first diagnosed peritoneal seeding are eligible. Primary outcome is progression free survival (PFS).
Conclusions: PIPAC-procedure is explicit a palliative method but it delivers cytotoxic therapy like in hyperthermic intraperitoneal chemotherapy (HIPEC)-procedure directly to the tumor in a minimally invasive technique, without the need for consideration of the peritoneal-plasma barrier. The technique of PIPAC is minimally invasive and very gentle and the complete procedure takes only round about 45 min and, therefore, optimal in a clearly palliative situation where cure is not the goal. It is also ideal for using this approach in a first line situation, where deepest response should be achieved. The symbiosis of systemic therapy and potentially effective surgery has to be well-planned without deterioration of the patient due to aggressive way of surgery like in cytoreductive surgery (CRS)+HIPEC.
Trial registration: EudraCT: 2018-001035-40.},
}
@article {pmid30910773,
year = {2019},
author = {Chiu, CH and Paszkowski, U},
title = {Mechanisms and Impact of Symbiotic Phosphate Acquisition.},
journal = {Cold Spring Harbor perspectives in biology},
volume = {},
number = {},
pages = {},
doi = {10.1101/cshperspect.a034603},
pmid = {30910773},
issn = {1943-0264},
abstract = {Phosphorous is important for life but often limiting for plants. The symbiotic pathway of phosphate uptake via arbuscular mycorrhizal fungi (AMF) is evolutionarily ancient and today occurs in natural and agricultural ecosystems alike. Plants capable of this symbiosis can obtain up to all of the phosphate from symbiotic fungi, and this offers potential means to develop crops less dependent on unsustainable P fertilizers. Here, we review the mechanisms and insights gleaned from the fine-tuned signal exchanges that orchestrate the intimate mutualistic symbiosis between plants and AMF. As the currency of trade, nutrients have signaling functions beyond being the nutritional goal of mutualism. We propose that such signaling roles and metabolic reprogramming may represent commitments for a mutualistic symbiosis that act across the stages of symbiosis development.},
}
@article {pmid30658297,
year = {2019},
author = {Company, R and Antúnez, O and Cosson, RP and Serafim, A and Shillito, B and Cajaraville, M and Bebianno, MJ and Torreblanca, A},
title = {Protein expression profiles in Bathymodiolus azoricus exposed to cadmium.},
journal = {Ecotoxicology and environmental safety},
volume = {171},
number = {},
pages = {621-630},
doi = {10.1016/j.ecoenv.2019.01.031},
pmid = {30658297},
issn = {1090-2414},
mesh = {Animals ; Bacteria/drug effects/metabolism ; Cadmium/*toxicity ; Electrophoresis, Gel, Two-Dimensional ; Gene Expression Regulation ; Gills/drug effects/metabolism/microbiology ; Hydrothermal Vents ; Mytilidae/*drug effects/metabolism/microbiology ; Oxidative Stress/drug effects ; *Proteome/metabolism ; Symbiosis ; },
abstract = {Proteomic changes in the "gill-bacteria complex" of the hydrothermal vent mussel B. azoricus exposed to cadmium in pressurized chambers ((Incubateurs Pressurises pour l'Observation en Culture d'Animaux Marins Profonds - IPOCAMP) were analyzed and compared with the non-exposed control group. 2-D Fluorescence Difference Gel Electrophoresis (2D-DIGE) showed that less than 1.5% of the proteome of mussels and symbiotic bacteria were affected by a short-term (24 h) Cd exposure. Twelve proteins of the more abundant differentially expressed proteins of which six were up-regulated and six were down-regulated were excised, digested and identified by mass spectrometry. The identified proteins included structural proteins (actin/actin like proteins), metabolic proteins (calreticulin/calnexin, peptidyl-prolyl cis-trans isomerase, aminotransferase class-III, electron transfer flavoprotein, proteasome, alpha-subunit and carbonic anhydrase) and stress response proteins (chaperone protein htpG, selenium-binding protein and glutathione transferases). All differently expressed proteins are tightly connected to Cd exposure and are affected by oxidative stress. It was also demonstrated that B. azoricus was well adapted to Cd contamination therefore B. azoricus from hydrothermal vent areas may be considered a good bioindicator.},
}
@article {pmid30443676,
year = {2019},
author = {Hettiarachchige, IK and Elkins, AC and Reddy, P and Mann, RC and Guthridge, KM and Sawbridge, TI and Forster, JW and Spangenberg, GC},
title = {Genetic modification of asexual Epichloë endophytes with the perA gene for peramine biosynthesis.},
journal = {Molecular genetics and genomics : MGG},
volume = {294},
number = {2},
pages = {315-328},
doi = {10.1007/s00438-018-1510-x},
pmid = {30443676},
issn = {1617-4623},
mesh = {Alkaloids/genetics ; Animals ; Disease Resistance/genetics ; Endophytes/*genetics ; Epichloe/*genetics/growth & development ; Gene Editing ; Heterocyclic Compounds, 2-Ring/*metabolism ; Pest Control, Biological ; Phylogeny ; Plant Diseases/genetics/microbiology ; Poaceae/*genetics/microbiology ; Polyamines/*metabolism ; Reproduction, Asexual/genetics ; Symbiosis/genetics ; Weevils/genetics/pathogenicity ; },
abstract = {Development of grass-endophyte associations with minimal or no detrimental effects in combination with beneficial characteristics is important for pastoral agriculture. The feasibility of enhancing production of an endophyte-derived beneficial alkaloid through introduction of an additional gene copy was assessed in a proof-of-concept study. Sexual and asexual Epichloë species that form symbiotic associations with cool-season grasses of the Poaceae sub-family Pooideae produce bioactive alkaloids that confer resistance to herbivory by a number of organisms. Of these, peramine is thought to be crucial for protection of perennial ryegrass (Lolium perenne L.) from the Argentinian stem weevil, an economically important exotic pest in New Zealand, contributing significantly to pasture persistence. A single gene (perA) has been identified as solely responsible for peramine biosynthesis and is distributed widely across Epichloë taxa. In the present study, a functional copy of the perA gene was introduced into three recipient endophyte genomes by Agrobacterium tumefaciens-mediated transformation. The target strains included some that do not produce peramine, and others containing different perA gene copies. Mitotically stable transformants generated from all three endophyte strains were able to produce peramine in culture and in planta at variable levels. In summary, this study provides an insight into the potential for artificial combinations of alkaloid biosynthesis in a single endophyte strain through transgenesis, as well as the possibility of using novel genome editing techniques to edit the perA gene of non-peramine producing strains.},
}
@article {pmid30905896,
year = {2019},
author = {Uchi, N and Fukudome, M and Nozaki, N and Suzuki, M and Osuki, KI and Shigenobu, S and Uchiumi, T},
title = {Antimicrobial Activities of Cysteine-rich Peptides Specific to Bacteriocytes of the Pea Aphid Acyrthosiphon pisum.},
journal = {Microbes and environments},
volume = {},
number = {},
pages = {},
doi = {10.1264/jsme2.ME18148},
pmid = {30905896},
issn = {1347-4405},
abstract = {Aphids have a mutualistic relationship with the bacterial endosymbiont Buchnera aphidicola. We previously reported seven cysteine-rich peptides in the pea aphid Acyrthosiphon pisum and named them Bacteriocyte-specific Cysteine-Rich (BCR) peptides; these peptides are exclusively expressed in bacteriocytes, special aphid cells that harbor symbionts. Similar symbiotic organ-specific cysteine-rich peptides identified in the root nodules of leguminous plants are named Nodule-specific Cysteine-Rich (NCR) peptides. NCR peptides target rhizobia in the nodules and are essential for symbiotic nitrogen fixation. A BacA (membrane protein) mutant of Sinorhizobium is sensitive to NCR peptides and is unable to establish symbiosis. Based on the structural and expressional similarities between BCR peptides and NCR peptides, we hypothesized that aphid BCR peptides exhibit antimicrobial activity, similar to some NCR peptides. We herein synthesized BCR peptides and investigated their antimicrobial activities and effects on the bacterial membrane of Escherichia coli. The peptides BCR1, BCR3, BCR5, and BCR8 exhibited antimicrobial activities with increased membrane permeability. An sbmA mutant of E. coli, a homolog of bacA of S. meliloti, was more sensitive to BCR peptides than the wild type. Our results suggest that BCR peptides have properties that may be required to control the endosymbiont, similar to NCR peptides in legumes.},
}
@article {pmid30905198,
year = {2019},
author = {Bartolomaeus, H and Markó, L and Wilck, N and Luft, FC and Forslund, SK and Muller, DN},
title = {Precarious Symbiosis Between Host and Microbiome in Cardiovascular Health.},
journal = {Hypertension (Dallas, Tex. : 1979)},
volume = {},
number = {},
pages = {HYPERTENSIONAHA11911786},
doi = {10.1161/HYPERTENSIONAHA.119.11786},
pmid = {30905198},
issn = {1524-4563},
}
@article {pmid30903405,
year = {2019},
author = {Kord, H and Fakheri, B and Ghabooli, M and Solouki, M and Emamjomeh, A and Khatabi, B and Sepehri, M and Salekdeh, GH and Ghaffari, MR},
title = {Salinity-associated microRNAs and their potential roles in mediating salt tolerance in rice colonized by the endophytic root fungus Piriformospora indica.},
journal = {Functional & integrative genomics},
volume = {},
number = {},
pages = {},
doi = {10.1007/s10142-019-00671-6},
pmid = {30903405},
issn = {1438-7948},
support = {-//Agricultural Biotechnology Research Institute of Iran/ ; },
abstract = {Piriformospora indica (P. indica), an endophytic root fungus, supports the growth and enhanced tolerance of plants to biotic and abiotic stresses. Several recent studies showed the significant role of small RNA (sRNA) molecules including microRNAs (miRNAs) in plant adaption to environmental stress, but little is known concerning the symbiosis-mediated salt stress tolerance regulated at miRNAs level. The overarching goal of this research is to elucidate the impact of miRNAs in regulating the P. indica-mediated salt tolerance in rice. Applying sRNA-seq analysis led to identify a set of 547 differentially abundant miRNAs in response to P. indica inoculation and salt stress. These included 206 rice-specific and 341 previously known miRNAs from other plant species. In silico analysis of miRNAs predictions of the differentially abundant miRNAs led to identifying of 193 putatively target genes, most of which were encoded either genes or transcription factors involved in nutrient uptake, sodium ion transporters, growth regulators, and auxin- responsive proteins. The rice-specific miRNAs targeted the transcription factors involved in the import of potassium ions into the root cells, the export of sodium ions, and plant growth and development. Interestingly, P. indica affected the differential abundance of miRNAs regulated genes and transcription factors linked to salt stress tolerance. Our data helps to understand the molecular basis of salt stress tolerance mediated by symbionts in plant and the potential impact of miRNAs for genetic improvement of rice varieties for tolerance to salt stress.},
}
@article {pmid30544819,
year = {2018},
author = {Strodtman, KN and Frank, S and Stevenson, S and Thelen, JJ and Emerich, DW},
title = {Proteomic Characterization of Bradyrhizobium diazoefficiens Bacteroids Reveals a Post-Symbiotic, Hemibiotrophic-Like Lifestyle of the Bacteria within Senescing Soybean Nodules.},
journal = {International journal of molecular sciences},
volume = {19},
number = {12},
pages = {},
doi = {10.3390/ijms19123947},
pmid = {30544819},
issn = {1422-0067},
support = {2004-35604-14708//United States Department of Agriculure Cooperative State Research Education and Extension Service National Research Initiative/ ; 2004-35604-14708//United States Department of Agriculture Cooperative State Research Education and Extension Service National Research Initiative/ ; },
mesh = {Bacterial Proteins/metabolism ; Bacteroides/enzymology/isolation & purification/*metabolism ; Bradyrhizobium/*metabolism ; Hydroxybutyrates/metabolism ; Leghemoglobin/metabolism ; Periplasm/metabolism ; Polyesters/metabolism ; Proteomics/*methods ; Root Nodules, Plant/*microbiology ; Soybeans/*growth & development/*microbiology ; *Symbiosis ; },
abstract = {The form and physiology of Bradyrhizobium diazoefficiens after the decline of symbiotic nitrogen fixation has been characterized. Proteomic analyses showed that post-symbiotic B. diazoefficiens underwent metabolic remodeling as well-defined groups of proteins declined, increased or remained unchanged from 56 to 119 days after planting, suggesting a transition to a hemibiotrophic-like lifestyle. Enzymatic analysis showed distinct patterns in both the cytoplasm and the periplasm. Similar to the bacteroid, the post-symbiotic bacteria rely on a non-citric acid cycle supply of succinate and, although viable, they did not demonstrate the ability to grow within the senescent nodule.},
}
@article {pmid30007415,
year = {2018},
author = {Martin, WF and Allen, JF},
title = {An Algal Greening of Land.},
journal = {Cell},
volume = {174},
number = {2},
pages = {256-258},
doi = {10.1016/j.cell.2018.06.034},
pmid = {30007415},
issn = {1097-4172},
mesh = {Biological Evolution ; Chara/*genetics ; Eukaryota/*genetics ; Plants/genetics ; Symbiosis/genetics ; },
abstract = {Photosynthetic eukaryotes arose ∼1.5 billion years ago by endosymbiosis with a cyanobacterium. Algae then evolved for a billion years before one lineage finally colonized land. Why the wait? The Chara braunii genome details a decisive step linking plant origins with Earth's history.},
}
@article {pmid30900053,
year = {2019},
author = {Ricks, KD and Koide, RT},
title = {Biotic filtering of endophytic fungal communities in Bromus tectorum.},
journal = {Oecologia},
volume = {},
number = {},
pages = {},
doi = {10.1007/s00442-019-04388-y},
pmid = {30900053},
issn = {1432-1939},
support = {2011-67009-20072//National Institute of Food and Agriculture/ ; },
abstract = {The assembly of horizontally transmitted endophytic fungi within plant tissues may be affected by "biotic filtering". In other words, only particular endophytic fungal taxa from the available inoculum pool may be able to colonize a given plant species. We tested that hypothesis in Bromus tectorum, an important invasive species in the arid, western United States. We collected seed from Bromus tectorum and sources of inoculum for endophytic fungi including soil and various kinds of plant litter at a field site in central Utah. We characterized, using Illumina sequencing, the endophytic fungal communities in the various inoculum sources, inoculated Bromus tectorum seedlings under gnotobiotic conditions with the various sources, and then characterized the communities of endophytic fungi that assembled in their roots and leaves. Different inoculum sources containing significantly different endophytic fungal communities produced complex communities of endophytic fungi in leaves and roots of Bromus tectorum. In leaves, the communities assembling from the various inoculum sources were not significantly different from each other and, in roots, they were only slightly different from each other, mainly due to variation in a single fungal OTU, Coprinopsis brunneofibrillosa. Consequently, there was significantly more variation in the structure of the communities of endophytic fungi among the inoculum sources than in the resultant endophytic fungal communities in the leaves and roots of Bromus tectorum. These results are consistent with biotic filtering playing a significant role in endophytic fungal community assembly.},
}
@article {pmid30898860,
year = {2019},
author = {Zhang, D and Frenette, PS},
title = {Crosstalk between neutrophils and the microbiota.},
journal = {Blood},
volume = {},
number = {},
pages = {},
doi = {10.1182/blood-2018-11-844555},
pmid = {30898860},
issn = {1528-0020},
abstract = {TThe microbiota has emerged as an important regulator of the host immunity by the induction, functional modulation or suppression of local and systemic immune responses. In return, the host immune system restricts translocation and fine-tunes the composition and distribution of the microbiota to maintain a beneficial symbiosis. This paradigm applies to neutrophils, a critical component of the innate immunity, allowing their production and function to be influenced by microbial components and metabolites derived from the microbiota, and engaging them in the process of microbiota containment and regulation. The crosstalk between neutrophils and the microbiota adjusts the magnitude of neutrophil-mediated inflammation upon challenge while preventing neutrophil responses against commensals under steady state. Here, we review the major molecular and cellular mediators of the interactions between neutrophils and the microbiota, and discuss their interplay and contribution in chronic inflammatory diseases and cancer.},
}
@article {pmid30626679,
year = {2019},
author = {Dunigan, DD and Al-Sammak, M and Al-Ameeli, Z and Agarkova, IV and DeLong, JP and Van Etten, JL},
title = {Chloroviruses Lure Hosts through Long-Distance Chemical Signaling.},
journal = {Journal of virology},
volume = {93},
number = {7},
pages = {},
doi = {10.1128/JVI.01688-18},
pmid = {30626679},
issn = {1098-5514},
abstract = {Chloroviruses exist in aquatic systems around the planet and they infect certain eukaryotic green algae that are mutualistic endosymbionts in a variety of protists and metazoans. Natural chlorovirus populations are seasonally dynamic, but the precise temporal changes in these populations and the mechanisms that underlie them have heretofore been unclear. We recently reported the novel concept that predator/prey-mediated virus activation regulates chlorovirus population dynamics, and in the current study, we demonstrate virus-packaged chemotactic modulation of prey behavior.IMPORTANCE Viruses have not previously been reported to act as chemotactic/chemoattractive agents. Rather, viruses as extracellular entities are generally viewed as non-metabolically active spore-like agents that await further infection events upon collision with appropriate host cells. That a virus might actively contribute to its fate via chemotaxis and change the behavior of an organism independent of infection is unprecedented.},
}
@article {pmid30261347,
year = {2019},
author = {Nalini, S and Inbakandan, D and Venkatnarayanan, S and Mohammed Riyaz, SU and Dheenan, PS and Vinithkumar, NV and Sriyutha Murthy, P and Parthasarathi, R and Kirubagaran, R},
title = {PYRROLO isolated from marine sponge associated bacterium Halobacillus kuroshimensis SNSAB01 - Antifouling study based on molecular docking, diatom adhesion and mussel byssal thread inhibition.},
journal = {Colloids and surfaces. B, Biointerfaces},
volume = {173},
number = {},
pages = {9-17},
doi = {10.1016/j.colsurfb.2018.09.044},
pmid = {30261347},
issn = {1873-4367},
mesh = {Acetylglucosamine/analogs & derivatives/metabolism ; Animals ; Anti-Infective Agents/chemistry/isolation & purification/*pharmacology ; Binding Sites ; Bivalvia/*drug effects/growth & development ; Complex Mixtures/chemistry ; Diatoms/*drug effects/growth & development ; Extracellular Matrix/chemistry ; Halobacillus/*chemistry/classification ; Microbial Sensitivity Tests ; Molecular Docking Simulation ; Phylogeny ; Porifera/microbiology ; Pyrazines/chemistry/isolation & purification/*pharmacology ; Pyrroles/chemistry/isolation & purification/*pharmacology ; Symbiosis/physiology ; },
abstract = {In the present study, an attempt has been made to explore the antifouling potential of bioactive compound isolated from sponge associated bacterium Halobacillus kuroshimensis SNSAB01. The crude extract of SNSAB01 strongly inhibited the growth of fouling bacterial strains with least minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The bioactive compound was characterized through FT-IR, HPLC, GCMS and NMR predicted as 'pyrrolo". From the mass spectral library, structure was elucidated as pyrrolo [1, 2-a] pyrazine-1, 4-dione, hexahydro. The in silico studies provided encouraging docking scores with two interactions by GLN 200 and GLU 304. The extract inhibited 89% diatom adhesion at 350 μg/ml concentration against Amphora sp. An EC50 value of 150 μg/ml for 50% inhibition of byssal thread of Perna viridis and LC50 was found to be 500 μg/ml. The LC50/EC50 ratio of 3.0 indicated nontoxic to nature. The result suggested that pyrrolo[1,2-a]pyrazine-1,4-dione can be used for antifouling coating.},
}
@article {pmid29664560,
year = {2018},
author = {McCormick, S},
title = {An arbuscular mycorrhizal fungus adjusts its secretome depending on developmental stage and host plant.},
journal = {The Plant journal : for cell and molecular biology},
volume = {94},
number = {3},
pages = {409-410},
doi = {10.1111/tpj.13917},
pmid = {29664560},
issn = {1365-313X},
mesh = {*Glomeromycota ; *Mycorrhizae ; Plants ; Symbiosis ; },
}
@article {pmid30895295,
year = {2019},
author = {Jonnalagadda, M and Ashhad Faizan, M and Ozarkar, S and Ashma, R and Kulkarni, S and Norton, HL and Parra, E},
title = {A genome-wide association study of skin and iris pigmentation among individuals of South Asian ancestry.},
journal = {Genome biology and evolution},
volume = {},
number = {},
pages = {},
doi = {10.1093/gbe/evz057},
pmid = {30895295},
issn = {1759-6653},
abstract = {South Asia has a complex history of migrations, and is characterized by substantial pigmentary and genetic diversity. For this reason, it is an ideal region to study the genetic architecture of normal pigmentation variation. Here, we present a meta-analysis of two GWAS of skin pigmentation using skin reflectance (M-index) as a quantitative phenotype. The meta-analysis includes a sample of individuals of South Asian descent living in Canada (N = 348), and a sample of individuals from two caste and four tribal groups from West Maharashtra, India (N = 480). We also present the first GWAS of iris color in South Asian populations. This GWAS was based on quantitative measures of iris color obtained from high resolution iris pictures. We identified genome-wide significant associations of variants within the well-known gene SLC24A5, including the non-synonymous rs1426654 polymorphism, with both skin pigmentation and iris color, highlighting the pleiotropic effects of this gene on pigmentation. Variants in the HERC2 gene (e.g. rs12913832) were also associated with iris color and iris heterochromia. Our study emphasizes the usefulness of quantitative methods to study iris color variation. We also identified novel genome-wide significant associations with skin pigmentation and iris color, but we could not replicate these associations due to the lack of independent samples. It will be critical to expand the number of studies in South Asian populations in order to better understand the genetic variation driving the diversity of skin pigmentation and iris color observed in this region.},
}
@article {pmid30894837,
year = {2019},
author = {Tolley, SJA and Nonacs, P and Sapountzis, P},
title = {Wolbachia Horizontal Transmission Events in Ants: What Do We Know and What Can We Learn?.},
journal = {Frontiers in microbiology},
volume = {10},
number = {},
pages = {296},
doi = {10.3389/fmicb.2019.00296},
pmid = {30894837},
issn = {1664-302X},
abstract = {While strict vertical transmission insures the durability of intracellular symbioses, phylogenetic incongruences between hosts and endosymbionts suggest horizontal transmission must also occur. These horizontal acquisitions can have important implications for the biology of the host. Wolbachia is one of the most ecologically successful prokaryotes in arthropods, infecting an estimated 50-70% of all insect species. Much of this success is likely due to the fact that, in arthropods, Wolbachia is notorious for manipulating host reproduction to favor transmission through the female germline. However, its natural potential for horizontal transmission remains poorly understood. Here we evaluate the fundamental prerequisites for successful horizontal transfer, including necessary environmental conditions, genetic potential of bacterial strains, and means of mediating transfers. Furthermore, we revisit the relatedness of Wolbachia strains infecting the Panamanian leaf-cutting ant, Acromyrmex echinatior, and its inquiline social parasite, Acromyrmex insinuator, and compare our results to a study published more than 15 years ago by Van Borm et al. (2003). The results of this pilot study prompt us to reevaluate previous notions that obligate social parasitism reliably facilitates horizontal transfer and suggest that not all Wolbachia strains associated with ants have the same genetic potential for horizontal transmission.},
}
@article {pmid30629162,
year = {2019},
author = {Ševcíková, T and Yurchenko, T and Fawley, KP and Amaral, R and Strnad, H and Santos, LMA and Fawley, MW and Eliáš, M},
title = {Plastid Genomes and Proteins Illuminate the Evolution of Eustigmatophyte Algae and Their Bacterial Endosymbionts.},
journal = {Genome biology and evolution},
volume = {11},
number = {2},
pages = {362-379},
doi = {10.1093/gbe/evz004},
pmid = {30629162},
issn = {1759-6653},
support = {P20 GM103429/GM/NIGMS NIH HHS/United States ; },
mesh = {Amino Acid Sequence ; *Biological Evolution ; *Genome, Plastid ; *Operon ; Rickettsiaceae/*genetics ; Stramenopiles/*genetics/microbiology ; Symbiosis ; },
abstract = {Eustigmatophytes, a class of stramenopile algae (ochrophytes), include not only the extensively studied biotechnologically important genus Nannochloropsis but also a rapidly expanding diversity of lineages with much less well characterized biology. Recent discoveries have led to exciting additions to our knowledge about eustigmatophytes. Some proved to harbor bacterial endosymbionts representing a novel genus, Candidatus Phycorickettsia, and an operon of unclear function (ebo) obtained by horizontal gene transfer from the endosymbiont lineage was found in the plastid genomes of still other eustigmatophytes. To shed more light on the latter event, as well as to generally improve our understanding of the eustigmatophyte evolutionary history, we sequenced plastid genomes of seven phylogenetically diverse representatives (including new isolates representing undescribed taxa). A phylogenomic analysis of plastid genome-encoded proteins resolved the phylogenetic relationships among the main eustigmatophyte lineages and provided a framework for the interpretation of plastid gene gains and losses in the group. The ebo operon gain was inferred to have probably occurred within the order Eustigmatales, after the divergence of the two basalmost lineages (a newly discovered hitherto undescribed strain and the Pseudellipsoidion group). When looking for nuclear genes potentially compensating for plastid gene losses, we noticed a gene for a plastid-targeted acyl carrier protein that was apparently acquired by horizontal gene transfer from Phycorickettsia. The presence of this gene in all eustigmatophytes studied, including representatives of both principal clades (Eustigmatales and Goniochloridales), is a genetic footprint indicating that the eustigmatophyte-Phycorickettsia partnership started no later than in the last eustigmatophyte common ancestor.},
}
@article {pmid30561673,
year = {2019},
author = {Amos, BA and Hayes, RA and Leemon, DM and Furlong, MJ},
title = {Small Hive Beetle (Coleoptera: Nitidulidae) and the Yeast, Kodamaea ohmeri: A Facultative Relationship Under Laboratory Conditions.},
journal = {Journal of economic entomology},
volume = {112},
number = {2},
pages = {515-524},
doi = {10.1093/jee/toy378},
pmid = {30561673},
issn = {1938-291X},
abstract = {The small hive beetle, Aethina tumida Murray, is a pest of honeybees, Apis mellifera L. (Hymenoptera: Apidae). We investigated the significance of its association with the yeast, Kodamaea ohmeri (Etchells & Bell) (Ascomycota: Saccharomycotina), in laboratory experiments. The mean (± SEM) viability of A. tumida eggs was 84 (± 3)%; the viability was not affected if eggs were separated from clutches or if mucilage containing K. ohmeri was removed from the egg surface. Life tables of conventional (= K. ohmeri contaminated) A. tumida and K. ohmeri-free A. tumida revealed no differences in stage-specific mortality between the treatments; in both cases, the highest mortality occurred in the first larval instar. There was no significant difference in the initial egg production of conventionally reared and K. ohmeri-free A. tumida under laboratory conditions. The volatile profiles of pollen dough (Bee Build) fed on by conventional and K. ohmeri-free A. tumida larvae were qualitatively and quantitatively different; the volatiles produced by pollen dough fed on by conventional A. tumida were more attractive to adult beetles. There was a clear difference between growth of K. ohmeri on pollen dough substrate in the presence and absence of A. tumida. Results suggest that this association is facultative for A. tumida under laboratory conditions but has benefit for the yeast associate, K. ohmeri. A clearer understanding of the nature of this fungus-insect association is essential for the development of management strategies for this pest, especially in the development of fermentate-based attractants in trapping systems.},
}
@article {pmid30497380,
year = {2018},
author = {Zamora-Lagos, MA and Eckstein, S and Langer, A and Gazanis, A and Pfeiffer, F and Habermann, B and Heermann, R},
title = {Phenotypic and genomic comparison of Photorhabdus luminescens subsp. laumondii TT01 and a widely used rifampicin-resistant Photorhabdus luminescens laboratory strain.},
journal = {BMC genomics},
volume = {19},
number = {1},
pages = {854},
pmid = {30497380},
issn = {1471-2164},
support = {HE5247/5-2//Deutsche Forschungsgemeinschaft/ ; },
mesh = {Anti-Bacterial Agents/pharmacology ; Base Sequence ; Biofilms/drug effects ; DNA Transposable Elements/genetics ; Drug Resistance, Bacterial/drug effects/*genetics ; *Genome, Bacterial ; *Genomics ; Hemolysis/drug effects ; Mutation/genetics ; Open Reading Frames/genetics ; Phenotype ; Photorhabdus/drug effects/*genetics/growth & development/isolation & purification ; Prophages/physiology ; Rifampin/*pharmacology ; Sequence Analysis, DNA ; Symbiosis/drug effects/genetics ; },
abstract = {BACKGROUND: Photorhabdus luminescens is an enteric bacterium, which lives in mutualistic association with soil nematodes and is highly pathogenic for a broad spectrum of insects. A complete genome sequence for the type strain P. luminescens subsp. laumondii TT01, which was originally isolated in Trinidad and Tobago, has been described earlier. Subsequently, a rifampicin resistant P. luminescens strain has been generated with superior possibilities for experimental characterization. This strain, which is widely used in research, was described as a spontaneous rifampicin resistant mutant of TT01 and is known as TT01-RifR.
RESULTS: Unexpectedly, upon phenotypic comparison between the rifampicin resistant strain and its presumed parent TT01, major differences were found with respect to bioluminescence, pigmentation, biofilm formation, haemolysis as well as growth. Therefore, we renamed the strain TT01-RifR to DJC. To unravel the genomic basis of the observed differences, we generated a complete genome sequence for strain DJC using the PacBio long read technology. As strain DJC was supposed to be a spontaneous mutant, only few sequence differences were expected. In order to distinguish these from potential sequencing errors in the published TT01 genome, we re-sequenced a derivative of strain TT01 in parallel, also using the PacBio technology. The two TT01 genomes differed at only 30 positions. In contrast, the genome of strain DJC varied extensively from TT01, showing 13,000 point mutations, 330 frameshifts, and 220 strain-specific regions with a total length of more than 300 kb in each of the compared genomes.
CONCLUSIONS: According to the major phenotypic and genotypic differences, the rifampicin resistant P. luminescens strain, now named strain DJC, has to be considered as an independent isolate rather than a derivative of strain TT01. Strains TT01 and DJC both belong to P. luminescens subsp. laumondii.},
}
@article {pmid30160099,
year = {2018},
author = {Dose, B and Niehs, SP and Scherlach, K and Flórez, LV and Kaltenpoth, M and Hertweck, C},
title = {Unexpected Bacterial Origin of the Antibiotic Icosalide: Two-Tailed Depsipeptide Assembly in Multifarious Burkholderia Symbionts.},
journal = {ACS chemical biology},
volume = {13},
number = {9},
pages = {2414-2420},
doi = {10.1021/acschembio.8b00600},
pmid = {30160099},
issn = {1554-8937},
mesh = {Animals ; Anti-Bacterial Agents/*metabolism ; Burkholderia/enzymology/genetics/*physiology ; Coleoptera/*microbiology ; Genes, Bacterial ; Peptide Synthases/genetics/metabolism ; Peptides, Cyclic/genetics/*metabolism ; *Symbiosis ; },
abstract = {Icosalide is an unusual two-tailed lipocyclopeptide antibiotic that was originally isolated from a fungal culture. Yet, its biosynthesis and ecological function have remained enigmatic. By genome mining and metabolic profiling of a bacterial endosymbiont (Burkholderia gladioli) of the pest beetle Lagria villosa, we unveiled a bacterial origin of icosalide. Functional analysis of the biosynthetic gene locus revealed an unprecedented nonribosomal peptide synthetase (NRPS) that incorporates two β-hydroxy acids by means of two starter condensation domains in different modules. This unusual assembly line, which may inspire new synthetic biology approaches, is widespread among many symbiotic Burkholderia species from diverse habitats. Biological assays showed that icosalide is active against entomopathogenic bacteria, thus adding to the chemical armory protecting beetle offspring. By creating a null mutant, we found that icosalide is a swarming inhibitor, which may play a role in symbiotic interactions and bears the potential for therapeutic applications.},
}
@article {pmid30009332,
year = {2019},
author = {Bag, S and Ghosh, TS and Banerjee, S and Mehta, O and Verma, J and Dayal, M and Desigamani, A and Kumar, P and Saha, B and Kedia, S and Ahuja, V and Ramamurthy, T and Das, B},
title = {Molecular Insights into Antimicrobial Resistance Traits of Commensal Human Gut Microbiota.},
journal = {Microbial ecology},
volume = {77},
number = {2},
pages = {546-557},
doi = {10.1007/s00248-018-1228-7},
pmid = {30009332},
issn = {1432-184X},
support = {BT/MB/THSTI/HMC-SFC/2011//Department of Biotechnology , Ministry of Science and Technology/ ; },
mesh = {Anti-Bacterial Agents/pharmacology ; Bacteria/drug effects/genetics/isolation & purification ; DNA Transposable Elements/genetics ; Drug Resistance, Bacterial/*genetics ; Feces/microbiology ; Gastrointestinal Microbiome/drug effects/*genetics ; Gene Transfer, Horizontal/genetics ; Genes, Bacterial/*genetics ; Genome, Bacterial ; Genotype ; Humans ; Interspersed Repetitive Sequences/genetics ; Metagenome/genetics ; Microbial Sensitivity Tests ; *Phenotype ; *Symbiosis ; Transformation, Genetic/genetics ; Vibrio cholerae/genetics ; Whole Genome Sequencing ; },
abstract = {Antimicrobial resistance (AMR) among bacterial species that resides in complex ecosystems is a natural phenomenon. Indiscriminate use of antimicrobials in healthcare, livestock, and agriculture provides an evolutionary advantage to the resistant variants to dominate the ecosystem. Ascendency of resistant variants threatens the efficacy of most, if not all, of the antimicrobial drugs commonly used to prevent and/or cure microbial infections. Resistant phenotype is very common in enteric bacteria. The most common mechanisms of AMR are enzymatic modifications to the antimicrobials or their target molecules. In enteric bacteria, most of the resistance traits are acquired by horizontal gene transfer from closely or distantly related bacterial population. AMR traits are generally linked with mobile genetic elements (MGEs) and could rapidly disseminate to the bacterial species through horizontal gene transfer (HGT) from a pool of resistance genes. Although prevalence of AMR genes among pathogenic bacteria is widely studied in the interest of infectious disease management, the resistance profile and the genetic traits that encode resistance to the commensal microbiota residing in the gut of healthy humans are not well-studied. In the present study, we have characterized AMR phenotypes and genotypes of five dominant commensal enteric bacteria isolated from the gut of healthy Indians. Our study revealed that like pathogenic bacteria, enteric commensals are also multidrug-resistant. The genes encoding antibiotic resistance are physically linked with MGEs and could disseminate vertically to the progeny and laterally to the distantly related microbial species. Consequently, the AMR genes present in the chromosome of commensal gut bacteria could be a potential source of resistance functions for other enteric pathogens.},
}
@article {pmid30003276,
year = {2019},
author = {Miranda, V and Rothen, C and Yela, N and Aranda-Rickert, A and Barros, J and Calcagno, J and Fracchia, S},
title = {Subterranean Desert Rodents (Genus Ctenomys) Create Soil Patches Enriched in Root Endophytic Fungal Propagules.},
journal = {Microbial ecology},
volume = {77},
number = {2},
pages = {451-459},
doi = {10.1007/s00248-018-1227-8},
pmid = {30003276},
issn = {1432-184X},
support = {PICT 0546//Consejo Nacional de Innovación, Ciencia y Tecnología/ ; },
mesh = {Animals ; Argentina ; *Desert Climate ; Ecosystem ; Endophytes/*growth & development ; Environment ; Fungi/*growth & development ; Mycorrhizae/growth & development ; Plant Roots/*microbiology ; Rodentia/*physiology ; Soil/*chemistry ; Soil Microbiology ; Symbiosis ; },
abstract = {Subterranean rodents are considered major soil engineers, as they can locally modify soil properties by their burrowing activities. In this study, the effect of a subterranean rodent of the genus Ctenomys on soil properties and root endophytic fungal propagules in a shrub desert of northwest Argentina was examined. Our main goal was to include among root endophytic fungi not only arbuscular mycorrhiza but also the dark septate endophytes. We compared the abundance of fungal propagules as well as several microbiological and physicochemical parameters between soils from burrows and those from the surrounding landscape. Our results show that food haulage, the deposition of excretions, and soil mixing by rodents' burrowing promote soil patchiness by (1) the enrichment in both types of root endophytic fungal propagules; (2) the increase in organic matter and nutrients; and (3) changes in soil edaphic properties including moisture, field capacity, and texture. These patches may play a critical role as a source of soil heterogeneity in desert ecosystems, where burrows constructed in interpatches of bare soil can act, once abandoned, as "islands of fertility," promoting the establishment of plants in an otherwise hostile environment.},
}
@article {pmid30893001,
year = {2019},
author = {Jonathan, RL and Hernández-López, A and Estrada-Navarrete, G and Sanchez, F and Díaz-Camino, C},
title = {The non-canonical heat shock protein PvNod22 is essential for infection thread progression during rhizobial endosymbiosis in common bean.},
journal = {Molecular plant-microbe interactions : MPMI},
volume = {},
number = {},
pages = {},
doi = {10.1094/MPMI-02-19-0041-R},
pmid = {30893001},
issn = {0894-0282},
abstract = {In the establishment of plant-rhizobial symbiosis, the plant hosts express nodulin proteins during root nodule organogenesis. A limited number of nodulins have been characterized, and these perform essential functions in root nodule development and metabolism. Most nodulins are expressed in the nodule and at lower levels in other plant tissues. Previously, we isolated Nodulin 22 (PvNod22) from a common bean (Phaseolus vulgaris L.) cDNA library derived from Rhizobium-infected roots. PvNod22 is a non-canonical, endoplasmic reticulum (ER)-localized, small heat shock protein (sHsp) that confers protection against oxidative stress when over-expressed in Escherichia coli. Virus-induced gene silencing of PvNod22 resulted in necrotic lesions in the aerial organs of P. vulgaris plants cultivated under optimal conditions, activation of the ER-unfolded protein response (UPR) and, finally, in plant death. Here, we examined the expression of PvNod22 in common bean plants during the establishment of rhizobial endosymbiosis and its relationship with two cellular processes associated with plant immunity, the UPR and autophagy. In the RNA interference lines, numerous infection threads stopped their progression before reaching the cortex cell layer of the root, and nodules contained fewer nitrogen-fixing bacteroids. Collectively, our results suggest that PvNod22 has a non-redundant function during legume-rhizobia symbiosis associated with infection thread elongation likely by sustaining protein homeostasis in the ER.},
}
@article {pmid30891218,
year = {2019},
author = {Bayliss, SLJ and Scott, ZR and Coffroth, MA and terHorst, CP},
title = {Genetic variation in Breviolum antillogorgium, a coral reef symbiont, in response to temperature and nutrients.},
journal = {Ecology and evolution},
volume = {9},
number = {5},
pages = {2803-2813},
doi = {10.1002/ece3.4959},
pmid = {30891218},
issn = {2045-7758},
abstract = {Symbionts within the family Symbiodiniaceae are important on coral reefs because they provide significant amounts of carbon to many different reef species. The breakdown of this mutualism that occurs as a result of increasingly warmer ocean temperatures is a major threat to coral reef ecosystems globally. Recombination during sexual reproduction and high rates of somatic mutation can lead to increased genetic variation within symbiont species, which may provide the fuel for natural selection and adaptation. However, few studies have asked whether such variation in functional traits exists within these symbionts. We used several genotypes of two closely related species, Breviolum antillogorgium and B. minutum, to examine variation of traits related to symbiosis in response to increases in temperature or nitrogen availability in laboratory cultures. We found significant genetic variation within and among symbiont species in chlorophyll content, photosynthetic efficiency, and growth rate. Two genotypes showed decreases in traits in response to increased temperatures predicted by climate change, but one genotype responded positively. Similarly, some genotypes within a species responded positively to high-nitrogen environments, such as those expected within hosts or eutrophication associated with global change, while other genotypes in the same species responded negatively, suggesting context-dependency in the strength of mutualism. Such variation in traits implies that there is potential for natural selection on symbionts in response to temperature and nutrients, which could confer an adaptive advantage to the holobiont.},
}
@article {pmid30825940,
year = {2019},
author = {Afzal, I and Shinwari, ZK and Sikandar, S and Shahzad, S},
title = {Plant beneficial endophytic bacteria: Mechanisms, diversity, host range and genetic determinants.},
journal = {Microbiological research},
volume = {221},
number = {},
pages = {36-49},
doi = {10.1016/j.micres.2019.02.001},
pmid = {30825940},
issn = {1618-0623},
mesh = {Bacteria/genetics/growth & development/*metabolism ; Endophytes/genetics/growth & development/*metabolism ; Host Specificity ; Plant Development/*physiology ; Plant Roots/*microbiology ; Plants/*microbiology ; Rhizosphere ; Symbiosis/physiology ; },
abstract = {Endophytic bacteria are the plant beneficial bacteria that thrive inside plants and can improve plant growth under normal and challenging conditions. They can benefit host plants directly by improving plant nutrient uptake and by modulating growth and stress related phytohormones. Indirectly, endophytic bacteria can improve plant health by targeting pests and pathogens with antibiotics, hydrolytic enzymes, nutrient limitation, and by priming plant defenses. To confer these benefits, the bacteria have to colonize the plant endosphere after colonizing the rhizosphere. The colonization is achieved using a battery of traits involving motility, attachment, plant-polymer degradation, and evasion of plant defenses. The diversity of endophytic colonizers depends on several bacteria, plant and environment specific factors. Some endophytic bacteria can have a broad host range and can be used as bioinoculants in developing a safe and sustainable agriculture system. This review elaborates the factors affecting diversity of bacterial endophytes, their host specificity and mechanisms of plant growth promotion. The review also accentuates various methods used to study endophytic communities, wild plants as a source of novel endophytic bacteria, and innovative approaches that may improve plant-endophyte association. Moreover, bacterial genes expressed in planta and challenges to study them are also discussed.},
}
@article {pmid30825937,
year = {2019},
author = {Muresu, R and Porceddu, A and Sulas, L and Squartini, A},
title = {Nodule-associated microbiome diversity in wild populations of Sulla coronaria reveals clues on the relative importance of culturable rhizobial symbionts and co-infecting endophytes.},
journal = {Microbiological research},
volume = {221},
number = {},
pages = {10-14},
doi = {10.1016/j.micres.2019.01.004},
pmid = {30825937},
issn = {1618-0623},
mesh = {Actinobacteria/classification/genetics/isolation & purification ; Endophytes/classification/genetics/*isolation & purification ; Fabaceae/*microbiology ; Microbiota ; Pantoea/genetics/isolation & purification ; Pseudomonas/classification/genetics/isolation & purification ; RNA, Ribosomal, 16S/genetics ; Rhizobium/classification/genetics/*isolation & purification ; Root Nodules, Plant/*microbiology ; Sequence Analysis, DNA ; Symbiosis ; },
abstract = {The culturable bacteria from root nodules of Sulla coronaria growing in spontaneous conditions in Sardinia were characterized. This plant's peculiarity is to represent a legume still found in both wild and cropped statuses. We tested whether culturable bacteria would differ from those commonly isolated from its field-cropped varieties, to date exclusively represented by Rhizobium sullae. 63 isolates from 60 surface-sterilized nodules were analyzed by ARDRA and 16S rDNA sequencing. The official nitrogen-fixing symbiont Rhizobium sullae was found only in 25 nodules out of 60. The remaining nodules did not yield culturable rhizobia but a number of different endophytic genera including Pseudomonas sp. (17 nodules), Microbacterium sp. (15 nodules), Pantoea agglomerans (5 nodules). The situation appears therefore a hybrid between what is commonly observed in other Mediterranean legumes occurring only in wild status (featuring non-culturable rhizobia and arrays of culturable endophytes within nodules), as opposed to cropped legumes (endowed with fully culturable rhizobia and minimal endophytic occurrence). These findings, within a species bridging the ecology between native and cropped conditions, suggest insights on the relative importance of endophytic co-occupancy vs. true N-fixing symbiont culturability within nodules. The latter trait thus appears to accompany the domestication path of plants with a main trade-off of renouncing to interactions with a diversity of endophytic co-invaders; the relationships with those being critical in the non-cropped status. In fact, endophytes are known to promote plant growth in harsh conditions, which can be particularly stressful in the Mediterranean due to drought, highly calcareous soils, and pathogens outbreaks.},
}
@article {pmid30651549,
year = {2019},
author = {Wu, F and Lopatkin, AJ and Needs, DA and Lee, CT and Mukherjee, S and You, L},
title = {A unifying framework for interpreting and predicting mutualistic systems.},
journal = {Nature communications},
volume = {10},
number = {1},
pages = {242},
doi = {10.1038/s41467-018-08188-5},
pmid = {30651549},
issn = {2041-1723},
support = {R01GM098642/NH/NIH HHS/United States ; R01GM110494/NH/NIH HHS/United States ; },
mesh = {Calibration ; Feasibility Studies ; Food Chain ; *Models, Biological ; Probability ; *Support Vector Machine ; *Symbiosis ; },
abstract = {Coarse-grained rules are widely used in chemistry, physics and engineering. In biology, however, such rules are less common and under-appreciated. This gap can be attributed to the difficulty in establishing general rules to encompass the immense diversity and complexity of biological systems. Furthermore, even when a rule is established, it is often challenging to map it to mechanistic details and to quantify these details. Here we report a framework that addresses these challenges for mutualistic systems. We first deduce a general rule that predicts the various outcomes of mutualistic systems, including coexistence and productivity. We further develop a standardized machine-learning-based calibration procedure to use the rule without the need to fully elucidate or characterize their mechanistic underpinnings. Our approach consistently provides explanatory and predictive power with various simulated and experimental mutualistic systems. Our strategy can pave the way for establishing and implementing other simple rules for biological systems.},
}
@article {pmid30588205,
year = {2018},
author = {Cropp, RA and Norbury, J},
title = {Obligate Mutualism in an Extended Consumer-Resource Framework.},
journal = {The Yale journal of biology and medicine},
volume = {91},
number = {4},
pages = {375-389},
pmid = {30588205},
issn = {1551-4056},
mesh = {Linear Models ; Models, Biological ; *Symbiosis ; },
abstract = {The development of a theory to underpin the obligate mutualist interactions that appear to be ubiquitous in nature has not proceeded at the same pace as the development of theory to support competition and predation. A constraint may be that obligate mutualism appears unable to be presented in the simple linear models that have so successfully served as heuristics for the other interactions. A number of simple nonlinear models have been used to propose explanations of obligate mutualism, but these solutions are often predicated on careful choices of functional forms. We present a theory of obligate mutualism in an explicit mass-conserving framework using simple models that are robust to choices of functional forms.},
}
@article {pmid30419937,
year = {2018},
author = {Derakhshani, H and Plaizier, JC and De Buck, J and Barkema, HW and Khafipour, E},
title = {Association of bovine major histocompatibility complex (BoLA) gene polymorphism with colostrum and milk microbiota of dairy cows during the first week of lactation.},
journal = {Microbiome},
volume = {6},
number = {1},
pages = {203},
pmid = {30419937},
issn = {2049-2618},
mesh = {Animals ; Cattle ; Colostrum/*microbiology ; DNA, Intergenic/genetics ; Female ; Genetic Predisposition to Disease ; Histocompatibility Antigens Class II/*genetics ; Lactation/*genetics ; Mastitis, Bovine/*genetics/microbiology ; Microbiota ; Milk/*microbiology ; Polymorphism, Single Nucleotide/genetics ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; },
abstract = {BACKGROUND: The interplay between host genotype and commensal microbiota at different body sites can have important implications for health and disease. In dairy cows, polymorphism of bovine major histocompatibility complex (BoLA) gene has been associated with susceptibility to several infectious diseases, most importantly mastitis. However, mechanisms underlying this association are yet poorly understood. In the present study, we sought to explore the association of BoLA gene polymorphism with the dynamics of mammary microbiota during the first week of lactation.
RESULTS: Colostrum and milk samples were collected from multiparous Holstein dairy cows at the day of calving and days 1 and 6 after calving. Microbiota profiling was performed using high-throughput sequencing of the V1-V2 regions of the bacterial 16S rRNA genes and ITS2 region of the fungal ribosomal DNA. Polymorphism of BoLA genes was determined using PCR-RFLP of exon 2 of the BoLA-DRB3. In general, transition from colostrum to milk resulted in increased species richness and diversity of both bacterial and fungal communities. The most dominant members of intramammary microbiota included Staphylococcus, Ruminococcaceae, and Clostridiales within the bacterial community and Alternaria, Aspergillus, Candida, and Cryptococcus within the fungal community. Comparing the composition of intramammary microbiota between identified BoLA-DRB3.2 variants (n = 2) revealed distinct clustering pattern on day 0, whereas this effect was not significant on the microbiota of milk samples collected on subsequent days. On day 0, proportions of several non-aureus Staphylococcus (NAS) OTUs, including those aligned to Staphylococcus equorum, Staphylococcus gallinarum, Staphylococcus sciuri, and Staphylococcus haemolyticus, were enriched within the microbiota of one of the BoLA-DRB3.2 variants, whereas lactic acid bacteria (LAB) including Lactobacillus and Enterococcus were enriched within the colostrum microbiota of the other variant.
CONCLUSION: Our results suggest a potential role for BoLA-gene polymorphism in modulating the composition of colostrum microbiota in dairy cows. Determining whether BoLA-mediated shifts in the composition of colostrum microbiota are regulated directly by immune system or indirectly by microbiota-derived colonization resistant can have important implications for future development of preventive/therapeutic strategies for controlling mastitis.},
}
@article {pmid30389767,
year = {2019},
author = {Sommer, AJ and Newell, PD},
title = {Metabolic Basis for Mutualism between Gut Bacteria and Its Impact on the Drosophila melanogaster Host.},
journal = {Applied and environmental microbiology},
volume = {85},
number = {2},
pages = {},
doi = {10.1128/AEM.01882-18},
pmid = {30389767},
issn = {1098-5336},
abstract = {Interactions between species shape the formation and function of microbial communities. In the gut microbiota of animals, cross-feeding of metabolites between microbes can enhance colonization and influence host physiology. We examined a mutually beneficial interaction between two bacteria isolated from the gut microbiota of Drosophila, i.e., Acetobacter fabarum and Lactobacillus brevis After developing an in vitro coculture assay, we utilized a genetic screen to identify A. fabarum genes required for enhanced growth with L. brevis The screen, and subsequent genetic analyses, showed that the gene encoding pyruvate phosphate dikinase (ppdK) is required for A. fabarum to benefit fully from coculture. By testing strains with mutations in a range of metabolic genes, we provide evidence that A. fabarum can utilize multiple fermentation products of L. brevis Mutualism between the bacteria in vivo affects gnotobiotic Drosophila melanogaster; flies associated with A. fabarum and L. brevis showed >1,000-fold increases in bacterial cell density and significantly lower triglyceride storage than monocolonized flies. Mutation of ppdK decreased A. fabarum density in flies cocolonized with L. brevis, consistent with the model in which Acetobacter employs gluconeogenesis to assimilate Lactobacillus fermentation products as a source of carbon in vivo We propose that cross-feeding between these groups is a common feature of microbiota in DrosophilaIMPORTANCE The digestive tracts of animals are home to a community of microorganisms, the gut microbiota, which affects the growth, development, and health of the host. Interactions among microbes in this inner ecosystem can influence which species colonize the gut and can lead to changes in host physiology. We investigated a mutually beneficial interaction between two bacterial species from the gut microbiota of fruit flies. By coculturing the bacteria in vitro, we were able to identify a metabolic gene required for the bacteria to grow better together than they do separately. Our data suggest that one species consumes the waste products of the other, leading to greater productivity of the microbial community and modifying the nutrients available to the host. This study provides a starting point for investigating how these and other bacteria mutually benefit by sharing metabolites and for determining the impact of mutualism on host health.},
}
@article {pmid30367675,
year = {2018},
author = {Grier, A and McDavid, A and Wang, B and Qiu, X and Java, J and Bandyopadhyay, S and Yang, H and Holden-Wiltse, J and Kessler, HA and Gill, AL and Huyck, H and Falsey, AR and Topham, DJ and Scheible, KM and Caserta, MT and Pryhuber, GS and Gill, SR},
title = {Neonatal gut and respiratory microbiota: coordinated development through time and space.},
journal = {Microbiome},
volume = {6},
number = {1},
pages = {193},
pmid = {30367675},
issn = {2049-2618},
support = {HHSN272201200005C/AI/NIAID NIH HHS/United States ; K08 AI108870/AI/NIAID NIH HHS/United States ; },
mesh = {Child Development/*physiology ; Female ; Gastrointestinal Microbiome/*physiology ; Gestational Age ; Humans ; Infant, Newborn ; Infant, Premature ; Male ; Nose/*microbiology ; Pharynx/*microbiology ; Pregnancy ; Rectum/*microbiology ; Symbiosis ; },
abstract = {BACKGROUND: Postnatal development of early life microbiota influences immunity, metabolism, neurodevelopment, and infant health. Microbiome development occurs at multiple body sites, with distinct community compositions and functions. Associations between microbiota at multiple sites represent an unexplored influence on the infant microbiome. Here, we examined co-occurrence patterns of gut and respiratory microbiota in pre- and full-term infants over the first year of life, a period critical to neonatal development.
RESULTS: Gut and respiratory microbiota collected as longitudinal rectal, throat, and nasal samples from 38 pre-term and 44 full-term infants were first clustered into community state types (CSTs) on the basis of their compositional profiles. Multiple methods were used to relate the occurrence of CSTs to temporal microbiota development and measures of infant maturity, including gestational age (GA) at birth, week of life (WOL), and post-menstrual age (PMA). Manifestation of CSTs followed one of three patterns with respect to infant maturity: (1) chronological, with CST occurrence frequency solely a function of post-natal age (WOL), (2) idiosyncratic to maturity at birth, with the interval of CST occurrence dependent on infant post-natal age but the frequency of occurrence dependent on GA at birth, and (3) convergent, in which CSTs appear first in infants of greater maturity at birth, with occurrence frequency in pre-terms converging after a post-natal interval proportional to pre-maturity. The composition of CSTs was highly dissimilar between different body sites, but the CST of any one body site was highly predictive of the CSTs at other body sites. There were significant associations between the abundance of individual taxa at each body site and the CSTs of the other body sites, which persisted after stringent control for the non-linear effects of infant maturity. Canonical correlations exist between the microbiota composition at each pair of body sites, with the strongest correlations between proximal locations.
CONCLUSION: These findings suggest that early microbiota is shaped by neonatal innate and adaptive developmental responses. Temporal progression of CST occurrence is influenced by infant maturity at birth and post-natal age. Significant associations of microbiota across body sites reveal distal connections and coordinated development of the infant microbial ecosystem.},
}
@article {pmid30298548,
year = {2018},
author = {Song, Y and Cai, ZH and Lao, YM and Jin, H and Ying, KZ and Lin, GH and Zhou, J},
title = {Antibiofilm activity substances derived from coral symbiotic bacterial extract inhibit biofouling by the model strain Pseudomonas aeruginosa PAO1.},
journal = {Microbial biotechnology},
volume = {11},
number = {6},
pages = {1090-1105},
pmid = {30298548},
issn = {1751-7915},
mesh = {Animals ; Anthozoa/*microbiology/physiology ; Anti-Bacterial Agents/chemistry/metabolism/*pharmacology ; Bacteria/*chemistry/classification/isolation & purification ; Bacterial Proteins/genetics/metabolism ; Biofilms/*drug effects ; Biofouling ; Pseudomonas aeruginosa/*drug effects/pathogenicity/physiology ; Quorum Sensing ; Symbiosis ; Virulence ; },
abstract = {The mitigation of biofouling has received significant research attention, with particular focus on non-toxic and sustainable strategies. Here, we investigated quorum sensing inhibitor (QSI) bacteria as a means of controlling biofouling in a laboratory-scale system. Approximately, 200 strains were isolated from coral (Pocillopora damicornis) and screened for their ability to inhibit quorum sensing (QS). Approximately, 15% of the isolates exhibited QSI activity, and a typical coral symbiotic bacterium, H12-Vibrio alginolyticus, was selected in order for us to investigate quorum sensing inhibitory activity further. Confocal microscopy revealed that V. alginolyticus extract inhibited biofilm formation from Pseudomonas aeruginosa PAO1. In addition, the secondary metabolites of V. alginolyticus inhibited PAO1 virulence phenotypes by downregulating motility ability, elastase activity and rhamnolipid production. NMR and MS spectrometry suggested that the potential bioactive compound involved was rhodamine isothiocyanate. Quantitative real-time PCR indicated that the bacterial extract induced a significant downregulation of QS regulatory genes (lasB, lasI, lasR, rhlI, rhlR) and virulence-related genes (pqsA, pqsR). The possible mechanism underlying the action of rhodamine isothiocyanate analogue involves the disruption of the las and/or rhl system of PAO1. Our results highlight coral microbes as a bioresource pool for developing QS inhibitors and identifying novel antifouling agents.},
}
@article {pmid30270261,
year = {2018},
author = {Guo, Y and Narisawa, K},
title = {Fungus-Bacterium Symbionts Promote Plant Health and Performance.},
journal = {Microbes and environments},
volume = {33},
number = {3},
pages = {239-241},
pmid = {30270261},
issn = {1347-4405},
mesh = {*Bacterial Physiological Phenomena ; Biological Coevolution ; Fungi/*physiology ; Host-Pathogen Interactions ; Plant Development ; Plant Diseases/microbiology ; Plants/metabolism/*microbiology ; *Symbiosis ; },
}
@article {pmid30205294,
year = {2018},
author = {Santos, SR and Coffroth, MA},
title = {Revisiting "Genetic Diversity of Symbiotic Dinoflagellates in the Genus Symbiodinium".},
journal = {Protist},
volume = {169},
number = {5},
pages = {784-787},
doi = {10.1016/j.protis.2018.06.008},
pmid = {30205294},
issn = {1618-0941},
mesh = {Animals ; Anthozoa/*parasitology/physiology ; Coral Reefs ; Dinoflagellida/classification/*genetics/isolation & purification/physiology ; *Genetic Variation ; Phylogeny ; *Symbiosis ; },
}
@article {pmid29593170,
year = {2018},
author = {Wasai, S and Minamisawa, K},
title = {Plant-Associated Microbes: From Rhizobia To Plant Microbiomes.},
journal = {Microbes and environments},
volume = {33},
number = {1},
pages = {1-3},
pmid = {29593170},
issn = {1347-4405},
mesh = {Host Microbial Interactions/*physiology ; Microbiota/genetics/*physiology ; Plants/*microbiology ; Rhizobium/genetics/*physiology ; Symbiosis ; },
}
@article {pmid29279575,
year = {2017},
author = {Imachi, H},
title = {Topic of Influence, Methane and Microbes.},
journal = {Microbes and environments},
volume = {32},
number = {4},
pages = {297-299},
pmid = {29279575},
issn = {1347-4405},
mesh = {Archaea/*metabolism ; Bacteria/*metabolism ; *Environmental Microbiology ; Eukaryota/metabolism ; Methane/*metabolism ; Microbial Consortia ; Symbiosis ; },
}
@article {pmid29176283,
year = {2017},
author = {},
title = {.},
journal = {Nihon Rinsho Men'eki Gakkai kaishi = Japanese journal of clinical immunology},
volume = {40},
number = {4},
pages = {257b},
doi = {10.2177/jsci.40.257b},
pmid = {29176283},
issn = {1349-7413},
mesh = {Dysbiosis ; *Gastrointestinal Microbiome/genetics/immunology/physiology ; Humans ; Symbiosis ; },
}
@article {pmid28791805,
year = {2019},
author = {Mech, AM and Harper, SJ and Havill, NP and von Dohlen, CD and Burke, GR},
title = {Ecological factors influencing the beneficial endosymbionts of the hemlock woolly adelgid (Hemiptera: Adelgidae).},
journal = {Insect science},
volume = {26},
number = {1},
pages = {97-107},
doi = {10.1111/1744-7917.12514},
pmid = {28791805},
issn = {1744-7917},
support = {//University of Georgia's Research Foundation/ ; //Office for the Vice President for Research/ ; //Agricultural Experiment Station/ ; //University of Washington School of Environmental and Forest Sciences/ ; 15-DG-11083150-068//USDA Forest Service Forest Health Protection/ ; },
mesh = {Animals ; Hemiptera/*microbiology ; Hot Temperature ; Pseudomonas/physiology ; Serratia/physiology ; Stress, Physiological ; Symbiosis ; Tsuga ; },
abstract = {Bacterial endosymbionts of sap-sucking insects provide their host with a number of beneficial qualities, including the supply of nutrition, defense against parasitoids, and protection from heat stress. Damage to these bacterial associates can therefore have a negative impact on the fitness of their insect host. We evaluated observational and experimental factors regarding the nonnative hemlock woolly adelgid (Adelges tsugae Annand) (Hemiptera: Adelgidae) to help understand the roles of its three recently identified symbionts, including under heat stress conditions. The prevalence of A. tsugae's facultative symbiont (Serratia symbiotica) was examined at different spatial scales to determine how variable infection rates are for this symbiont. There was no significant difference found in infection rates between adelgids on a tree, within a plot, or within a state. However, significantly more adelgids in Georgia (95%) had S. symbiotica compared to those in New York (68%). Microsatellite genotyping of the adelgids found that this difference was most likely not the result of a second introduction of A. tsugae into eastern North America. Comparison of S. symbiotica proportions between first and fourth instars showed that symbiont absence did not affect the ability of A. tsugae to survive aestivation. Evaluations of symbiont densities within each adelgid found that when S. symbiotica was absent, the density of obligate symbionts was significantly higher. Exposure to heat stress (32.5 °C) was not consistently correlated with changes in symbiont densities over a 4-d period. Overall, we have shown that symbiont prevalence and densities vary within the broad population of A. tsugae in eastern North America, with potentially significant effects upon the ecology of this important pest.},
}
@article {pmid28785009,
year = {2017},
author = {Cheng, M and Chen, Y and Wang, L and Chen, W and Yang, L and Shen, G and Xu, T and Shen, G and Tian, Z and Hu, S},
title = {Commensal microbiota maintains alveolar macrophages with a low level of CCL24 production to generate anti-metastatic tumor activity.},
journal = {Scientific reports},
volume = {7},
number = {1},
pages = {7471},
pmid = {28785009},
issn = {2045-2322},
mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Bacteria/classification/*drug effects/immunology ; Bacterial Physiological Phenomena ; Cell Line, Tumor ; Chemokine CCL24/*metabolism ; Cytokines/genetics/metabolism ; Female ; Intraepithelial Lymphocytes/drug effects/immunology ; Macrophages, Alveolar/drug effects/*immunology ; Melanoma, Experimental/immunology/microbiology/*therapy ; Mice ; Microbiota ; Sequence Analysis, DNA ; Signal Transduction ; Symbiosis ; },
abstract = {Microbiota maintains host tissue homeostasis and influences tissue-resident macrophages. However, the mechanisms by which commensal bacteria in regulating the alveolar macrophages remain unclear. Here, by using an antibiotic-treated (Abt) mouse model, we found commensal bacteria depletion induced lower frequencies and numbers of alveolar macrophages. This effect was accompanied by the altered levels of genes involved in several biological pathways, including M2 macrophage polarization, as determined by gene expression analysis. Alveolar macrophages from the Abt mice had higher protein and gene levels of Arg1, CCL24, IL-13, IL-10, IL-6 and IL-1β, which could be recovered to normal levels by reconstructing commensal bacteria in the upper respiratory of Abt mice. Moreover, alveolar macrophages performed significant enhancement of M2 functions, especially CCL24 secretion, in the Abt mice challenged with B16/F10 melanoma. Adoptive transfer of normal alveolar macrophages or antibody neutralization of CCL24 significantly recovered the decrease of γδT17 cells and rescued the defect anti-tumor response of Abt mice, indicating the elevated amount of alveolar macrophage-derived CCL24 inhibited γδT cell mediated anti-tumor response. In conclusion, we demonstrated the ability of commensal bacteria to maintain alveolar macrophages with a low level of CCL24 production, which was necessary for the normal anti-tumor response in the lung.},
}
@article {pmid28334388,
year = {2017},
author = {Cooper, WR and Garczynski, SF and Horton, DR and Unruh, TR and Beers, EH and Peter, WS and Hilton, RJ},
title = {Bacterial Endosymbionts of the Psyllid Cacopsylla pyricola (Hemiptera: Psyllidae) in the Pacific Northwestern United States.},
journal = {Environmental entomology},
volume = {46},
number = {2},
pages = {393-402},
doi = {10.1093/ee/nvx031},
pmid = {28334388},
issn = {1938-2936},
mesh = {Animals ; Bacteria/classification/genetics ; *Bacterial Physiological Phenomena ; Female ; Hemiptera/*microbiology ; Male ; Oregon ; Pyrus/growth & development ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Seasons ; Sequence Analysis, RNA ; *Symbiosis ; Washington ; },
abstract = {Insects often have facultative associations with bacterial endosymbionts, which can alter the insects' susceptibility to parasitism, pathogens, plant defenses, and certain classes of insecticides. We collected pear psylla, Cacopsylla pyricola (Förster) (Hemiptera: Psyllidae), from pear orchards in Washington and Oregon, and surveyed them for the presence of bacterial endosymbionts. Adult psyllids were collected on multiple dates to allow us to assay specimens of both the summer ("summerform") and the overwintering ("winterform") morphotypes. Two endosymbionts, Arsenophonus and Phytoplasma pyri, were detected in psyllids of both morphotypes in both states. A separate survey revealed similar associations present in psyllids collected in 1987. Arsenophonus was present in 80-100% of psyllids in all growing regions. A slightly lower proportion of summerform than winterform psyllids harbored the bacterium. Arsenophonus was present in the bacteriomes and developing oocytes of most psyllids, indicating that this endosymbiont is transovarially transmitted. This bacterium was also observed in the salivary glands and midguts of some psyllids. Phytoplasma pyri was present in a greater proportion of pear psylla from orchards near Yakima, WA, than from other regions, and was present in a higher proportion of winterforms than summerforms. We did not detect Wolbachia, Profftella, or Liberibacter europaeus, which are associated with other psyllid pests, including other species of Cacopsylla. Our study is the first to survey North American populations of C. pyricola for endosymbionts, and provides a foundation for further research on how bacterial associations may influence the ecology and management of this pest.},
}
@article {pmid28332822,
year = {2017},
author = {Khoshmanesh, A and Christensen, D and Perez-Guaita, D and Iturbe-Ormaetxe, I and O'Neill, SL and McNaughton, D and Wood, BR},
title = {Screening of Wolbachia Endosymbiont Infection in Aedes aegypti Mosquitoes Using Attenuated Total Reflection Mid-Infrared Spectroscopy.},
journal = {Analytical chemistry},
volume = {89},
number = {10},
pages = {5285-5293},
doi = {10.1021/acs.analchem.6b04827},
pmid = {28332822},
issn = {1520-6882},
mesh = {Aedes/chemistry/*microbiology ; Aging ; Animals ; Discriminant Analysis ; Female ; Least-Squares Analysis ; Male ; Sex Factors ; Spectroscopy, Fourier Transform Infrared/*methods ; Symbiosis ; Wolbachia/*pathogenicity/physiology ; },
abstract = {Dengue fever is the most common mosquito transmitted viral infection afflicting humans, estimated to generate around 390 million infections each year in over 100 countries. The introduction of the endosymbiotic bacterium Wolbachia into Aedes aegypti mosquitoes has the potential to greatly reduce the public health burden of the disease. This approach requires extensive polymerase chain reaction (PCR) testing of the Wolbachia-infection status of mosquitoes in areas where Wolbachia-A. aegypti are released. Here, we report the first example of small organism mid-infrared spectroscopy where we have applied attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectroscopy and multivariate modeling methods to determine sex, age, and the presence of Wolbachia (wMel strain) in laboratory mosquitoes and sex and age in field mosquitoes. The prediction errors using partial least squares discriminant analysis (PLS-DA) discrimination models for laboratory studies on independent test sets ranged from 0 to 3% for age and sex grading and 3% to 5% for Wolbachia infection diagnosis using dry mosquito abdomens while field study results using an artificial neural network yielded a 10% error. The application of FT-IR analysis is inexpensive, easy to use, and portable and shows significant potential to replace the reliance on more expensive and laborious PCR assays.},
}
@article {pmid28111719,
year = {2018},
author = {Amid, C and Olstedt, M and Gunnarsson, JS and Le Lan, H and Tran Thi Minh, H and Van den Brink, PJ and Hellström, M and Tedengren, M},
title = {Additive effects of the herbicide glyphosate and elevated temperature on the branched coral Acropora formosa in Nha Trang, Vietnam.},
journal = {Environmental science and pollution research international},
volume = {25},
number = {14},
pages = {13360-13372},
pmid = {28111719},
issn = {1614-7499},
support = {54090026//SIDA/ ; Minor Field Study scholarship fellowship program//SIDA/ ; },
mesh = {Animals ; Anthozoa/*physiology ; Chlorophyll A/*chemistry ; Coral Reefs ; Dinoflagellida/*chemistry ; Glycine/*analogs & derivatives/chemistry ; Herbicides/*chemistry ; Symbiosis ; Taiwan ; Temperature ; Vietnam ; },
abstract = {The combined effects of the herbicide glyphosate and elevated temperature were studied on the tropical staghorn coral Acropora formosa, in Nha Trang bay, Vietnam. The corals were collected from two different reefs, one close to a polluted fish farm and one in a marine-protected area (MPA). In the laboratory, branches of the corals were exposed to the herbicide glyphosate at ambient (28 °C) and at 3 °C elevated water temperatures (31 °C). Effects of herbicide and elevated temperature were studied on coral bleaching using photography and digital image analysis (new colorimetric method developed here based on grayscale), chlorophyll a analysis, and symbiotic dinoflagellate (Symbiodinium, referred to as zooxanthellae) counts. All corals from the MPA started to bleach in the laboratory before they were exposed to the treatments, indicating that they were very sensitive, as opposed to the corals collected from the more polluted site, which were more tolerant and showed no bleaching response to temperature increase or herbicide alone. However, the combined exposure to the stressors resulted in significant loss of color, proportional to loss in chlorophyll a and zooxanthellae. The difference in sensitivity of the corals collected from the polluted site versus the MPA site could be explained by different symbiont types: the resilient type C3u and the stress-sensitive types C21 and C23, respectively. The additive effect of elevated temperatures and herbicides adds further weight to the notion that the bleaching of coral reefs is accelerated in the presence of multiple stressors. These results suggest that the corals in Nha Trang bay have adapted to the ongoing pollution to become more tolerant to anthropogenic stressors, and that multiple stressors hamper this resilience. The loss of color and decrease of chlorophyll a suggest that bleaching is related to concentration of chloro-pigments. The colorimetric method could be further fine-tuned and used as a precise, non-intrusive tool for monitoring coral bleaching in situ.},
}
@article {pmid28073980,
year = {2017},
author = {Ploetz, RC and Konkol, JL and Narvaez, T and Duncan, RE and Saucedo, RJ and Campbell, A and Mantilla, J and Carrillo, D and Kendra, PE},
title = {Presence and Prevalence of Raffaelea lauricola, Cause of Laurel Wilt, in Different Species of Ambrosia Beetle in Florida, USA.},
journal = {Journal of economic entomology},
volume = {110},
number = {2},
pages = {347-354},
doi = {10.1093/jee/tow292},
pmid = {28073980},
issn = {1938-291X},
mesh = {Animals ; Female ; Florida ; Ophiostomatales/*physiology ; Persea/*microbiology ; Plant Diseases/*microbiology ; *Symbiosis ; Weevils/*microbiology/*physiology ; },
abstract = {We summarize the information available on ambrosia beetle species that have been associated in Florida with Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva, the primary symbiont of Xyleborus glabratus Eichhoff and cause of laurel wilt. In total, 14 species in Ambrosiodmus, Euwallacea, Premnobius, Xyleborus, Xyleborinus, and Xylosandrus were either reared from laurel wilt-affected host trees or trapped in laurel wilt-affected stands of the same, and assayed for R. lauricola. In six collections from native species in the southeastern United States [Persea borbonia (L.), Persea palustris (Raf.) Sarg., and Persea humilis Nash] and four from avocado (Persea americana Mill.), extracted mycangia or heads (taxa with mandibular mycangia) or intact bodies (taxa with mycangia in other locations) were surface-disinfested before assays on a semi-selective medium for the isolation of Raffaelea (CSMA+). Raffaelea lauricola was identified based on its characteristic phenotype on CSMA+, and the identity of a random subset of isolates was confirmed with taxon-specific microsatellite markers. The pathogen was recovered from 34% (246 of 726) of the individuals that were associated with the native Persea spp., but only 6% (58 of 931) of those that were associated with avocado. Over all studies, R. lauricola was recovered from 10 of the ambrosia beetle species, but it was most prevalent in Xyleborus congeners. This is the first record of R. lauricola in Ambrosiodmus lecontei Hopkins, Xyleborinus andrewesi (Blandford), and Xyleborus bispinatus Eichhoff. The potential effects of R. lauricola's promiscuity are discussed.},
}
@article {pmid30721615,
year = {2017},
author = {Bogacheva, AS and Shaikevich, EV and Rakova, VM and Ganushkina, LA},
title = {[(THE FAUNA OF BLOODSUCKING MOSQUITOES IN THE NIZHNY NOVGOROD REGION, THEIR INFECTION WITH DIROFILARIA AND ENDOSYMBIOTIC BACTERIA)].},
journal = {Meditsinskaia parazitologiia i parazitarnye bolezni},
volume = {1},
number = {1},
pages = {43-47},
pmid = {30721615},
issn = {0025-8326},
mesh = {Aedes/microbiology/parasitology ; Animals ; DNA, Helminth/genetics ; Dirofilaria immitis/microbiology/pathogenicity ; Dirofilaria repens/microbiology/pathogenicity ; Dirofilariasis/*microbiology/*parasitology ; Dogs ; Humans ; Mosquito Vectors/genetics/*microbiology/*parasitology ; *Symbiosis ; Wolbachia/isolation & purification/pathogenicity ; },
abstract = {The fauna of bloodsucking mosquitoes in the Nizhny Novgorod Region is represented by 11 species from 5 genera of the family Culicidae. During 2014-2015, the predominant species were Ochlerotatus cantans and Aedes cinereus mosqui- toes in both a population aggregate and woodland. The infected mosquitoes accounted for 1.3% of their total number and were registered only in the village of Fokino. The investigators identified two human pathogenic nematode species: Diro- filaria immits and Dirofilaria repens (0.9% and 0.4% respectively). The effective carriers of Dirofilaria in the examined area can be Ae.cinereus and Och.cantans as only these species were found to have an invasive stage of the parasite. The symbiotic bacterium Wolbachia was detected in the mosquitoes that were not infected with dirofilariasis. This is the first study in Russia to investigate the effects of Wolbachia on the susceptibility of dirofilariasis vectors to infection.},
}
@article {pmid30888510,
year = {2019},
author = {Prasad, S and Shah, A and Bhalsing, KS and Kumar, KJ and Saini, J and Ingalhalikar, M and Pal, PK},
title = {Abnormal hippocampal subfields are associated with cognitive impairment in Essential Tremor.},
journal = {Journal of neural transmission (Vienna, Austria : 1996)},
volume = {},
number = {},
pages = {},
doi = {10.1007/s00702-019-01992-3},
pmid = {30888510},
issn = {1435-1463},
support = {ECR/2016/000808//Science and Engineering Research Board/ ; },
abstract = {Multi-domain cognitive impairment (CI) has been frequently described in patients with essential tremor (ET). However, the exact neuroanatomical basis for this impairment is uncertain. This study aims to ascertain the role of the hippocampal formation in cognitive impairment in ET. Forty patients with ET and 40 age, gender and education matched healthy controls (HC) were enrolled. Cognition was assessed using a structured neuropsychological battery and patients were categorized as ET with CI (ETCI) and ET without CI (ETNCI). Automatic segmentation of hippocampal subfields was performed using FreeSurfer 6.0. The obtained volumes were correlated with scores of neuropsychological tests. Significant atrophy of the left subiculum, CA4, granule-cell layer of dentate gyrus, right molecular layer, and hypertrophy of bilateral parasubiculum, right hippocampus-amygdala-transition-area, bilateral hippocampal tail (HT) and widening of right hippocampal fissure was observed in ET. Trends toward atrophy of right subiculum, and widening of left HF was also observed. Comparison of HC and ETCI revealed atrophy of right subiculum, hypertrophy of bilateral parasubiculum, HT, and widening of left HF. ETCI showed a trend toward widening of right HF. ETNCI had isolated left parasubicular hypertrophy and in comparison, to ETNCI the ETCI subgroup had atrophy of bilateral fimbria. Significant correlations were observed between the volumes of HT, HF, fimbria and scores of tests for executive function, working and verbal memory. Patients with ET have significant volumetric abnormalities of several hippocampal subfields and these abnormalities may be important contributors for some forms of cognitive impairment observed in ET.},
}
@article {pmid30887877,
year = {2019},
author = {Polzin, J and Arevalo, P and Nussbaumer, T and Polz, MF and Bright, M},
title = {Polyclonal symbiont populations in hydrothermal vent tubeworms and the environment.},
journal = {Proceedings. Biological sciences},
volume = {286},
number = {1896},
pages = {20181281},
doi = {10.1098/rspb.2018.1281},
pmid = {30887877},
issn = {1471-2954},
abstract = {Horizontally transmitted symbioses usually house multiple and variable symbiont genotypes that are acquired from a much more diverse environmental pool via partner choice mechanisms. However, in the deep-sea hydrothermal vent tubeworm Riftia pachyptila (Vestimentifera, Siboglinidae), it has been suggested that the Candidatus Endoriftia persephone symbiont is monoclonal. Here, we show with high-coverage metagenomics that adult R. pachyptila house a polyclonal symbiont population consisting of one dominant and several low-frequency variants. This dominance of one genotype is confirmed by multilocus gene sequencing of amplified housekeeping genes in a broad range of host individuals where three out of four loci (atpA, uvrD and recA) revealed no genomic differences, while one locus (gyrB) was more diverse in adults than in juveniles. We also analysed a metagenome of free-living Endoriftia and found that the free-living population showed greater sequence variability than the host-associated population. Most juveniles and adults shared a specific dominant genotype, while other genotypes can dominate in few individuals. We suggest that although generally permissive, partner choice is selective enough to restrict uptake of some genotypes present in the environment.},
}
@article {pmid30887662,
year = {2019},
author = {Gano-Cohen, KA and Wendlandt, CE and Stokes, PJ and Blanton, MA and Quides, KW and Zomorrodian, A and Adinata, ES and Sachs, JL},
title = {Interspecific conflict and the evolution of ineffective rhizobia.},
journal = {Ecology letters},
volume = {},
number = {},
pages = {},
doi = {10.1111/ele.13247},
pmid = {30887662},
issn = {1461-0248},
support = {//University of California Riverside/ ; DEB 1150278//NSF/ ; 1738028//NSF/ ; },
abstract = {Microbial symbionts exhibit broad genotypic variation in their fitness effects on hosts, leaving hosts vulnerable to costly partnerships. Interspecific conflict and partner-maladaptation are frameworks to explain this variation, with different implications for mutualism stability. We investigated the mutualist service of nitrogen fixation in a metapopulation of root-nodule forming Bradyrhizobium symbionts in Acmispon hosts. We uncovered Bradyrhizobium genotypes that provide negligible mutualist services to hosts and had superior in planta fitness during clonal infections, consistent with cheater strains that destabilise mutualisms. Interspecific conflict was also confirmed at the metapopulation level - by a significant negative association between the fitness benefits provided by Bradyrhizobium genotypes and their local genotype frequencies - indicating that selection favours cheating rhizobia. Legumes have mechanisms to defend against rhizobia that fail to fix sufficient nitrogen, but these data support predictions that rhizobia can subvert plant defenses and evolve to exploit hosts.},
}
@article {pmid30886436,
year = {2019},
author = {Shi, YM and Brachmann, AO and Westphalen, MA and Neubacher, N and Tobias, NJ and Bode, HB},
title = {Dual phenazine gene clusters enable diversification during biosynthesis.},
journal = {Nature chemical biology},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41589-019-0246-1},
pmid = {30886436},
issn = {1552-4469},
abstract = {Biosynthetic gene clusters (BGCs) bridging genotype and phenotype continuously evolve through gene mutations and recombinations to generate chemical diversity. Phenazine BGCs are widespread in bacteria, and the biosynthetic mechanisms of the formation of the phenazine structural core have been illuminated in the last decade. However, little is known about the complex phenazine core-modification machinery. Here, we report the diversity-oriented modifications of the phenazine core through two distinct BGCs in the entomopathogenic bacterium Xenorhabdus szentirmaii, which lives in symbiosis with nematodes. A previously unidentified aldehyde intermediate, which can be modified by multiple enzymatic and non-enzymatic reactions, is a common intermediate bridging the pathways encoded by these BGCs. Evaluation of the antibiotic activity of the resulting phenazine derivatives suggests a highly effective strategy to convert Gram-positive specific phenazines into broad-spectrum antibiotics, which might help the bacteria-nematode complex to maintain its special environmental niche.},
}
@article {pmid30720419,
year = {2019},
author = {Maciel, JF and Matter, LB and Tasca, C and Scheid, DAR and Gressler, LT and Ziech, RE and Vargas, AC},
title = {Characterization of intestinal Escherichia coli isolated from calves with diarrhea due to rotavirus and coronavirus.},
journal = {Journal of medical microbiology},
volume = {68},
number = {3},
pages = {417-423},
doi = {10.1099/jmm.0.000937},
pmid = {30720419},
issn = {1473-5644},
mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Cattle/microbiology/virology ; Cattle Diseases/virology ; Coronavirus ; Coronavirus Infections/*veterinary ; Diarrhea/*veterinary/virology ; Drug Resistance, Multiple, Bacterial ; Escherichia coli/drug effects/genetics/*isolation & purification ; Feces/microbiology ; Fimbriae, Bacterial/genetics ; Intestines/*microbiology ; Phylogeny ; Rotavirus ; Rotavirus Infections/*veterinary ; Symbiosis ; Virulence Factors/genetics ; },
abstract = {PURPOSE: To address more information about changes in commensal Escherichia coli during virus intestinal infection, we characterized 30 faecal E. coli isolates from calves (21 to 60 days old) with diarrhea due to rotavirus and coronavirus, which received, before diagnosis, tetracycline, gentamicin and enrofloxacin drugs.
METHODOLOGY: Clermont's phylogenetic classification; presence of genes for curli, cellulose, fimbriae (F4, F5, F6, F18, F41); and antimicrobial susceptibility were used to characterize the isolates. Disk diffusion technique and PCR were used as methodologies.
RESULTS: E. coli isolates from calves with diarrhea were phylogenetically classified as B1 (70%, 21/30), B2 (3.33%, 1/30), C (3.33%, 1/30), D (3.33%, 1/30), E (13.33%, 4/30) and unknown (6.7 %; 2/30), whereas E. coli isolates from the control group were classified only as B1 (83.3%, 25/30), E (10 %; 3/30) and unknown (6,7 %; 2/30). E. coli isolates from calves with diarrhea showed a much higher resistance profile with 16 (53.3%) multiresistant isolates. Only isolates (30%-9/30) from diarrheic calves were also positive for fimbriae, specifically 16.7% (5/30) for F5 and 13.3% (4/30) for F18.
CONCLUSION: To sum up, E. coli isolates from calves with diarrhea showed differences in relation to the control group, confirming changes in commensal E. coli during virus intestinal infection. It can be emphasized that some care should be taken to manage diarrheic calves: the pathological agent must be diagnosed prior to treatment; antibacterial treatment should be with antimicrobials with a different mechanism of action; and finally, treated animals should be maintained separately from others because they can carry micro-organisms with a resistant profile.},
}
@article {pmid30660739,
year = {2019},
author = {Mirandola Dias Vieira, DH and Abdallah, VD and José da Silva, R and Kozlowiski de Azevedo, R},
title = {Skin nodules associated with parasitism with Henneguya sp. (Cnidaria: Myxosporea) in the neotropical fish Cyphocharax modestus.},
journal = {Microbial pathogenesis},
volume = {128},
number = {},
pages = {294-300},
doi = {10.1016/j.micpath.2019.01.027},
pmid = {30660739},
issn = {1096-1208},
mesh = {Animals ; Brazil ; Characiformes/*parasitology ; Fishes/*parasitology ; Myxozoa/anatomy & histology/cytology/*isolation & purification/*pathogenicity ; Parasitic Diseases, Animal/*parasitology/pathology ; Phylogeny ; Rivers ; Seafood/parasitology ; Skin/*parasitology ; Species Specificity ; Spores ; Subcutaneous Tissue/parasitology/pathology ; *Symbiosis ; },
abstract = {A new myxozoan species, Henneguya sp., is described based on material from skin of Cyphocharax modestus. Mature myxospores are were elongate and ellipsoidal, measuring 21.4 ± 1.2 (19.4-23.2) μm in total length, 5.1 ± 0.3 (4.5-5.8) μm in width, 11.9 ± 0.5 (10.9-12.7) μm in body length and 9.6 ± 0.7 (8.4-10.5) μm in length of the caudal process. The polar capsules were elongated and had unequal sizes, with length of 5.1 ± 0.4 (4.5-6.0) μm and 5.6 ± 0.4 (4.9-6.3) μm for smaller and larger respectively and width of 1.8 ± 0.2 (1.4-2.0) μm. The larger polar capsule had 8 turns in polar filament while the smaller polar capsule had 5 turns in polar filament. The macroscopic analysis revealed the presence of large nodules, which were located before and after the dorsal fin of the hosts. The histopathological analysis showed the development of nodules filled with plasmodia, surrounded by loose connective tissue, developed in the dermis of the skin. Many cysts containing countless spores, as well as free spores, were located in the dermis and hypodermis of the hosts, causing the disorganization of the connective tissue that is responsible for the support. This is the first record of a Henneguya species in C. modestus.},
}
@article {pmid30558527,
year = {2018},
author = {Pandey, P and Wang, M and Baldwin, IT and Pandey, SP and Groten, K},
title = {Complex regulation of microRNAs in roots of competitively-grown isogenic Nicotiana attenuata plants with different capacities to interact with arbuscular mycorrhizal fungi.},
journal = {BMC genomics},
volume = {19},
number = {1},
pages = {937},
doi = {10.1186/s12864-018-5338-x},
pmid = {30558527},
issn = {1471-2164},
support = {293926//H2020 European Research Council/ ; Max Planck Partner Group//Max-Planck-Gesellschaft/ ; },
mesh = {Calcium-Calmodulin-Dependent Protein Kinases/genetics/metabolism ; Genotype ; MicroRNAs/genetics/*metabolism ; Mycorrhizae/*physiology ; Plant Growth Regulators/metabolism ; Plant Proteins/genetics/metabolism ; Plant Roots/genetics/metabolism/microbiology ; Symbiosis ; Tobacco/*genetics/metabolism/microbiology ; Transcriptome ; },
abstract = {BACKGROUND: Nicotiana attenuata is an ecological model plant whose 2.57 Gb genome has recently been sequenced and assembled and for which miRNAs and their genomic locations have been identified. To understand how this plant's miRNAs are reconfigured during plant-arbuscular mycorrhizal fungal (AMF) interactions and whether hostplant calcium- and calmodulin dependent protein kinase (CCaMK) expression which regulates the AMF interaction also modulates miRNAs levels and regulation, we performed a large-scale miRNA analysis of this plant-AMF interaction.
RESULTS: Next generation sequencing of miRNAs in roots of empty vector (EV) N. attenuata plants and an isogenic line silenced in CCaMK expression (irCCaMK) impaired in AMF-interactions grown under competitive conditions with and without AMF inoculum revealed a total of 149 unique miRNAs: 67 conserved and 82 novel ones. The majority of the miRNAs had a length of 21 nucleotides. MiRNA abundances were highly variable ranging from 400 to more than 25,000 reads per million. The miRNA profile of irCCaMK plants impaired in AMF colonization was distinct from fully AMF-functional EV plants grown in the same pot. Six conserved miRNAs were present in all conditions and accumulated differentially depending on treatment and genotype; five (miR6153, miR403a-3p, miR7122a, miR167-5p and miR482d, but not miR399a-3p) showed the highest accumulation in AMF inoculated EV plants compared to inoculated irCCaMK plants. Furthermore, the accumulation patterns of sequence variants of selected conserved miRNAs showed a very distinct pattern related to AMF colonization - one variant of miR473-5p specifically accumulated in AMF-inoculated plants. Also abundances of miR403a-3p, miR171a-3p and one of the sequence variants of miR172a-3p increased in AMF-inoculated EV compared to inoculated irCCaMK plants and to non-inoculated EV plants, while miR399a-3p was most strongly enriched in AMF inoculated irCCaMK plants grown in competition with EV. The analysis of putative targets of selected miRNAs revealed an involvement in P starvation (miR399), phytohormone signaling (Nat-R-PN59, miR172, miR393) and defense (e.g. miR482, miR8667, Nat-R-PN-47).
CONCLUSIONS: Our study demonstrates (1) a large-scale reprograming of miRNAs induced by AMF colonization and (2) that the impaired AMF signaling due to CCaMK silencing and the resulting reduced competitive ability of irCCaMK plants play a role in modulating signal-dependent miRNA accumulation.},
}
@article {pmid30558255,
year = {2018},
author = {Heo, YM and Kim, K and Ryu, SM and Kwon, SL and Park, MY and Kang, JE and Hong, JH and Lim, YW and Kim, C and Kim, BS and Lee, D and Kim, JJ},
title = {Diversity and Ecology of Marine Algicolous Arthrinium Species as a Source of Bioactive Natural Products.},
journal = {Marine drugs},
volume = {16},
number = {12},
pages = {},
doi = {10.3390/md16120508},
pmid = {30558255},
issn = {1660-3397},
support = {2017R1A2B4002071//National Research Foundation of Korea/ ; 201701104//National Institute of Biological Resources/ ; },
mesh = {Animals ; Anti-Bacterial Agents/isolation & purification/metabolism/pharmacology ; Antifungal Agents/isolation & purification/metabolism/pharmacology ; Antioxidants/isolation & purification/metabolism/pharmacology ; Aquatic Organisms/genetics/*metabolism ; Biofilms/drug effects ; Biological Assay/methods ; Biological Products/isolation & purification/metabolism/*pharmacology ; Chromobacterium/drug effects ; DNA, Fungal/genetics/isolation & purification ; Enzyme Inhibitors/isolation & purification/metabolism/pharmacology ; Monophenol Monooxygenase/antagonists & inhibitors ; Oocytes/microbiology ; Perciformes/microbiology ; Phylogeny ; Quorum Sensing/drug effects ; Seaweed/*microbiology ; *Symbiosis ; Xylariales/genetics/*metabolism ; },
abstract = {In our previous study, all Arthrinium isolates from Sargassum sp. showed high bioactivities, but studies on marine Arthrinium spp. are insufficient. In this study, a phylogenetic analysis of 28 Arthrinium isolates from seaweeds and egg masses of Arctoscopus japonicus was conducted using internal transcribed spacers, nuclear large subunit rDNA, β-tubulin, and translation elongation factor region sequences, and their bioactivities were investigated. They were analyzed as 15 species, and 11 of them were found to be new species. Most of the extracts exhibited radical-scavenging activity, and some showed antifungal activities, tyrosinase inhibition, and quorum sensing inhibition. It was implied that marine algicolous Arthrinium spp. support the regulation of reactive oxygen species in symbiotic algae and protect against pathogens and bacterial biofilm formation. The antioxidant from Arthrinium sp. 10 KUC21332 was separated by bioassay-guided isolation and identified to be gentisyl alcohol, and the antioxidant of Arthrinium saccharicola KUC21221 was identical. These results demonstrate that many unexploited Arthrinium species still exist in marine environments and that they are a great source of bioactive compounds.},
}
@article {pmid30300424,
year = {2018},
author = {Kobayashi, G and Araya, JF},
title = {Southernmost records of Escarpia spicata and Lamellibrachia barhami (Annelida: Siboglinidae) confirmed with DNA obtained from dried tubes collected from undiscovered reducing environments in northern Chile.},
journal = {PloS one},
volume = {13},
number = {10},
pages = {e0204959},
pmid = {30300424},
issn = {1932-6203},
mesh = {Animals ; Annelida/classification/*genetics/microbiology ; Bacteria/genetics/isolation & purification ; Chile ; DNA/*chemistry/isolation & purification/metabolism ; Electron Transport Complex IV/classification/genetics ; Hemoglobins/classification/genetics ; Mitochondria/genetics ; Phylogeny ; Protein Subunits/classification/genetics ; RNA, Ribosomal, 16S/chemistry/isolation & purification/metabolism ; Sequence Analysis, DNA ; Symbiosis ; },
abstract = {Deep-sea fishing bycatch enables collection of samples of rare species that are not easily accessible, for research purposes. However, these specimens are often degraded, losing diagnostic morphological characteristics. Several tubes of vestimentiferans, conspicuous annelids endemic to chemosynthetic environments, were obtained from a single batch of deep-sea fishing bycatch at depths of around 1,500 m off Huasco, northern Chile, as part of an ongoing study examining bycatch species. DNA sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene and an intron region within the hemoglobin subunit B2 (hbB2i) were successfully determined using vestimentiferans' dried-up tubes and their degraded inner tissue. Molecular phylogenetic analyses based on DNA sequence identified the samples as Escarpia spicata Jones, 1985, and Lamellibrachia barhami Webb, 1969. These are the southernmost records, vastly extending the geographical ranges of both species from Santa Catalina Island, California to northern Chile for E. spicata (over 8,000 km), and from Vancouver Island Margin to northern Chile for L. barhami (over 10,000 km). We also determined a 16S rRNA sequence of symbiotic bacteria of L. barhami. The sequence of the bacteria is the same as that of E. laminata, Lamellibrachia sp. 1, and Lamellibrachia sp.2 known from the Gulf of Mexico. The present study provides sound evidence forthe presence of reducing environments along the continental margin of northern Chile.},
}
@article {pmid29374030,
year = {2018},
author = {Mockler, BK and Kwong, WK and Moran, NA and Koch, H},
title = {Microbiome Structure Influences Infection by the Parasite Crithidia bombi in Bumble Bees.},
journal = {Applied and environmental microbiology},
volume = {84},
number = {7},
pages = {},
pmid = {29374030},
issn = {1098-5336},
support = {R01 GM108477/GM/NIGMS NIH HHS/United States ; },
abstract = {Recent declines in bumble bee populations are of great concern and have prompted critical evaluations of the role of pathogen introductions and host resistance in bee health. One factor that may influence host resilience when facing infection is the gut microbiota. Previous experiments with Bombus terrestris, a European bumble bee, showed that the gut microbiota can protect against Crithidia bombi, a widespread trypanosomatid parasite of bumble bees. However, the particular characteristics of the microbiome responsible for this protective effect have thus far eluded identification. Using wild and commercially sourced Bombus impatiens, an important North American pollinator, we conducted cross-wise microbiota transplants to naive hosts of both backgrounds and challenged them with a Crithidia parasite. As with B. terrestris, we find that microbiota-dependent protection against Crithidia operates in B. impatiens Lower Crithidia infection loads were experimentally associated with high microbiome diversity, large gut bacterial populations, and the presence of Apibacter, Lactobacillus Firm-5, and Gilliamella spp. in the gut community. These results indicate that even subtle differences between gut community structures can have a significant impact on a microbiome's ability to defend against parasite infections.IMPORTANCE Many wild bumble bee populations are under threat due to human activity, including through the introduction of pathogens via commercially raised bees. Recently, it was found that the bumble bee gut microbiota can help defend against a common parasite, Crithidia bombi, but the particular factors contributing to this protection are unknown. Using both wild and commercially raised bees, we conducted microbiota transplants to show that microbiome diversity, total gut bacterial load, and the presence of certain core members of the microbiota may all impact bee susceptibility to Crithidia infection. Bee origin (genetic background) was also a factor. Finally, by examining this phenomenon in a previously uninvestigated bee species, our study demonstrates that microbiome-mediated resistance to Crithidia is conserved across multiple bumble bee species. These findings highlight how intricate interactions between hosts, microbiomes, and parasites can have wide-ranging consequences for the health of ecologically important species.},
}
@article {pmid30884285,
year = {2019},
author = {Azmat, R and Moin, S},
title = {The remediation of drought stress under VAM inoculation through proline chemical transformation action.},
journal = {Journal of photochemistry and photobiology. B, Biology},
volume = {193},
number = {},
pages = {155-161},
doi = {10.1016/j.jphotobiol.2019.03.002},
pmid = {30884285},
issn = {1873-2682},
abstract = {This article discussed the enhanced drought tolerance under arbuscular mycorrhizal (AM) inoculation and normal growth of plants which linked with the activity of photoreceptors. The photoreceptor action in dual symbiosis under drought stress showed not only the high photosynthetic activity but also provide information about the broad range of physiological responses. The pot experiment conducted in a natural environment where drought condition was observed twice a week via regular irrigation with water up to twelve months. Plants analysis showed the high contents of water, hydrogen peroxide, carotenoids, proline, antioxidant enzymes like super dismutase (SOD) and catalase(CAT) in both leaves and roots with a large surface area of leaves over control. The elevated concentration of hydrogen peroxide (0.04 ± 0.0 μmol/g) coupled with singlet oxygen species was the main modified molecular mechanism which was operative in drought condition. The accretion of proline under drought stress in dual symbiosis (32.3 ± 0.3 μg/mL) was related to the highest branching pattern of young leaves and the chemical transformation of reactive oxygen species (ROS) including H2O2 and 3O2 into useful molecules like water and triplet molecular oxygen. The higher contents of carotenoids (5.0 ± 1.2 mg/g) in drought over control (4.8 ± 1.6 mg/g) and AM plant (4.9 ± 1.2 mg/g) was found to be supportive in the conversion of singlet oxygen into triplet one.},
}
@article {pmid30883790,
year = {2019},
author = {Fernández, I and Cosme, M and Stringlis, IA and Yu, K and de Jonge, R and Van Wees, SCM and Pozo, MJ and Pieterse, CMJ and Van der Heijden, MGA},
title = {Molecular dialogue between arbuscular mycorrhizal fungi and the non-host plant Arabidopsis thaliana switches from initial detection to antagonism.},
journal = {The New phytologist},
volume = {},
number = {},
pages = {},
doi = {10.1111/nph.15798},
pmid = {30883790},
issn = {1469-8137},
abstract = {Approximately 29% of all vascular plant species are unable to establish an arbuscular mycorrhizal (AM) symbiosis. Despite this, AM fungi (Rhizophagus spp.) are enriched in the root microbiome of the non-host Arabidopsis thaliana and Arabidopsis roots become colonized when AM networks nurtured by host plants are available. Here, we investigated the non-host-AM fungus interaction by analyzing transcriptional changes in Rhizophagus, Arabidopsis, and the host plant Medicago truncatula while growing in the same mycorrhizal network. In early interaction stages, Rhizophagus activated the Arabidopsis strigolactone biosynthesis genes CCD7 and CCD8, suggesting that detection of AM fungi is not completely impaired. However, in colonized Arabidopsis roots, fungal nutrient transporter genes GintPT, GintAMT2, GintMST2 and GintMST4, essential for AM symbiosis, were not activated. RNA-seq transcriptome analysis pointed to activation of costly defenses in colonized Arabidopsis roots. Moreover, Rhizophagus colonization caused a 50% reduction in shoot biomass, but also led to enhanced systemic immunity against Botrytis cinerea. This suggests that early signaling between AM fungi and Arabidopsis is not completely impaired and that incompatibility appears at later interaction stages. Moreover, Rhizophagus-mediated defenses coincide with reduced Arabidopsis growth, but also with systemic disease resistance, highlighting the multifunctional role of AM fungi in host and non-host interactions. This article is protected by copyright. All rights reserved.},
}
@article {pmid30882293,
year = {2019},
author = {Hapeshi, A and Benarroch, JM and Clarke, DJ and Waterfield, NR},
title = {Iso-propyl stilbene: a life cycle signal?.},
journal = {Microbiology (Reading, England)},
volume = {},
number = {},
pages = {},
doi = {10.1099/mic.0.000790},
pmid = {30882293},
issn = {1465-2080},
abstract = {Members of the Gram-negative bacterial genus Photorhabdus are all highly insect pathogenic and exist in an obligate symbiosis with the entomopathogenic nematode worm Heterorhabditis. All members of the genus produce the small-molecule 3,5-dihydroxy-4-isopropyl-trans-stilbene (IPS) as part of their secondary metabolism. IPS is a multi-potent compound that has antimicrobial, antifungal, immunomodulatory and anti-cancer activities and also plays an important role in symbiosis with the nematode. In this study we have examined the response of Photorhabdus itself to exogenous ectopic addition of IPS at physiologically relevant concentrations. We observed that the bacteria had a measureable phenotypic response, which included a decrease in bioluminescence and pigment production. This was reflected in changes in its transcriptomic response, in which we reveal a reduction in transcript levels of genes relating to many fundamental cellular processes, such as translation and oxidative phosphorylation. Our observations suggest that IPS plays an important role in the biology of Photorhabdus bacteria, fulfilling roles in quorum sensing, antibiotic-competition advantage and maintenance of the symbiotic developmental cycle.},
}
@article {pmid30881924,
year = {2019},
author = {Tribble, GD and Angelov, N and Weltman, R and Wang, BY and Eswaran, SV and Gay, IC and Parthasarathy, K and Dao, DV and Richardson, KN and Ismail, NM and Sharina, IG and Hyde, ER and Ajami, NJ and Petrosino, JF and Bryan, NS},
title = {Frequency of Tongue Cleaning Impacts the Human Tongue Microbiome Composition and Enterosalivary Circulation of Nitrate.},
journal = {Frontiers in cellular and infection microbiology},
volume = {9},
number = {},
pages = {39},
doi = {10.3389/fcimb.2019.00039},
pmid = {30881924},
issn = {2235-2988},
abstract = {The oral microbiome has the potential to provide an important symbiotic function in human blood pressure physiology by contributing to the generation of nitric oxide (NO), an essential cardiovascular signaling molecule. NO is produced by the human body via conversion of arginine to NO by endogenous nitric oxide synthase (eNOS) but eNOS activity varies by subject. Oral microbial communities are proposed to supplement host NO production by reducing dietary nitrate to nitrite via bacterial nitrate reductases. Unreduced dietary nitrate is delivered to the oral cavity in saliva, a physiological process termed the enterosalivary circulation of nitrate. Previous studies demonstrated that disruption of enterosalivary circulation via use of oral antiseptics resulted in increases in systolic blood pressure. These previous studies did not include detailed information on the oral health of enrolled subjects. Using 16S rRNA gene sequencing and analysis, we determined whether introduction of chlorhexidine antiseptic mouthwash for 1 week was associated with changes in tongue bacterial communities and resting systolic blood pressure in healthy normotensive individuals with documented oral hygiene behaviors and free of oral disease. Tongue cleaning frequency was a predictor of chlorhexidine-induced changes in systolic blood pressure and tongue microbiome composition. Twice-daily chlorhexidine usage was associated with a significant increase in systolic blood pressure after 1 week of use and recovery from use resulted in an enrichment in nitrate-reducing bacteria on the tongue. Individuals with relatively high levels of bacterial nitrite reductases had lower resting systolic blood pressure. These results further support the concept of a symbiotic oral microbiome contributing to human health via the enterosalivary nitrate-nitrite-NO pathway. These data suggest that management of the tongue microbiome by regular cleaning together with adequate dietary intake of nitrate provide an opportunity for the improvement of resting systolic blood pressure.},
}
@article {pmid30880586,
year = {2019},
author = {Bamba, M and Aoki, S and Kajita, T and Setoguchi, H and Watano, Y and Sato, S and Tsuchimatsu, T},
title = {Exploring Genetic Diversity and Signatures of Horizontal Gene Transfer in Nodule Bacteria Associated with Lotus japonicus in Natural Environments.},
journal = {Molecular plant-microbe interactions : MPMI},
volume = {},
number = {},
pages = {},
doi = {10.1094/MPMI-02-19-0039-R},
pmid = {30880586},
issn = {0894-0282},
abstract = {To investigate the genetic diversity and understand the process of horizontal gene transfer (HGT) in nodule bacteria associated with Lotus japonicus, we analyzed sequences of three housekeeping and five symbiotic genes using samples from a geographically wide range in Japan. A phylogenetic analysis of the housekeeping genes indicated that L. japonicus in natural environments was associated with diverse lineages of Mesorhizobium species, whereas the sequences of symbiotic genes were highly similar between strains, resulting in remarkably low nucleotide diversity at both synonymous and non-synonymous sites. Guanine-cytosine content values were lower in symbiotic genes, and relative frequencies of recombination between symbiotic genes were also lower than those between housekeeping genes. An analysis of molecular variance showed significant genetic differentiation among populations in both symbiotic and housekeeping genes. These results confirm that the Mesorhizobium genes required for symbiosis with L. japonicus behave as a genomic island (i. e. a symbiosis island) and suggest that this island has spread into diverse genomic backgrounds of Mesorhizobium via HGT events in natural environments. Furthermore, our data compilation revealed that the genetic diversity of symbiotic genes in L. japonicus-associated symbionts was among the lowest compared with reports of other species, which may be related to the recent population expansion proposed in Japanese populations of L. japonicus.},
}
@article {pmid30880549,
year = {2019},
author = {Shitole, AA and Giram, PS and Raut, PW and Rade, PP and Khandwekar, AP and Sharma, N and Garnaik, B},
title = {Clopidogrel eluting electrospun polyurethane/polyethylene glycol thromboresistant, hemocompatible nanofibrous scaffolds.},
journal = {Journal of biomaterials applications},
volume = {},
number = {},
pages = {885328219832984},
doi = {10.1177/0885328219832984},
pmid = {30880549},
issn = {1530-8022},
abstract = {Biomaterials used as blood-contacting material must be hemocompatible and exhibit lower thrombotic potential while maintaining hemostasis and angiogenesis. With the aim of developing thromboresistant, hemocompatible nanofibrous scaffolds, polyurethane/polyethylene glycol scaffolds incorporated with 1, 5, and 10 wt% Clopidogrel were fabricated and evaluated for their physiochemical properties, biocompatibility, hemocompatibility, and antithrombotic potential. The results of physicochemical characterization revealed the fabrication of nanometer-sized scaffolds with smooth surfaces. The incorporation of both polyethylene glycol and Clopidogrel to polyurethane enhanced the hydrophilicity and water uptake potential of polyurethane/polyethylene glycol/Clopidogrel scaffolds. The dynamic mechanical analysis revealed the enhancement in mechanical strength of the polyurethane/polyethylene glycol scaffolds on incorporation of Clopidogrel. The polyurethane/polyethylene glycol/Clopidogrel scaffolds showed a tri-phasic drug release pattern. The results of hemocompatibility assessment demonstrated the excellent blood compatibility of the polyurethane/polyethylene glycol/Clopidogrel scaffolds, with the developed scaffolds exhibiting lower hemolysis, increased albumin and plasma protein adsorption while reduction in fibrinogen adsorption. Further, the platelet adhesion was highly suppressed and significant increase in coagulation period was observed for Clopidogrel incorporated scaffolds. The results of cell adhesion and cell viability substantiate the biocompatibility of the developed nanofibrous scaffolds with the HUVEC cell viability on polyurethane/polyethylene glycol, polyurethane/polyethylene glycol/Clopidogrel-1, 5, and 10% at day 7 found to be 12.35, 13.36, 14.85, and 4.18% higher as compared to polyurethane scaffolds, and the NIH/3T3 cell viability found to be 35.27, 70.82, 36.60, and 7.95% higher as compared to polyurethane scaffolds, respectively. Altogether the results of the study advocate the incorporation of Clopidogrel to the polyurethane/polyethylene glycol blend in order to fabricate scaffolds with appropriate antithrombotic property, hemocompatibility, and cell proliferation capacity and thus, might be successfully used as antithrombotic material for biomedical application.},
}
@article {pmid30559205,
year = {2019},
author = {Townsend, GE and Han, W and Schwalm, ND and Raghavan, V and Barry, NA and Goodman, AL and Groisman, EA},
title = {Dietary sugar silences a colonization factor in a mammalian gut symbiont.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {116},
number = {1},
pages = {233-238},
doi = {10.1073/pnas.1813780115},
pmid = {30559205},
issn = {1091-6490},
support = {R01 GM123798/GM/NIGMS NIH HHS/United States ; },
mesh = {Animals ; Bacterial Proteins/*antagonists & inhibitors/metabolism ; Bacteroides thetaiotaomicron/*drug effects ; Dietary Carbohydrates/*pharmacology ; Dietary Sugars/*pharmacology ; Fructose/administration & dosage/pharmacology ; Gastrointestinal Microbiome/*drug effects ; Gene Expression Regulation, Bacterial/drug effects ; Gene Silencing/drug effects ; Glucose/administration & dosage/pharmacology ; Mice ; Polysaccharides/administration & dosage/pharmacology ; Symbiosis/drug effects ; },
abstract = {The composition of the gut microbiota is largely determined by environmental factors including the host diet. Dietary components are believed to influence the composition of the gut microbiota by serving as nutrients to a subset of microbes, thereby favoring their expansion. However, we now report that dietary fructose and glucose, which are prevalent in the Western diet, specifically silence a protein that is necessary for gut colonization, but not for utilization of these sugars, by the human gut commensal Bacteroides thetaiotaomicron Silencing by fructose and glucose requires the 5' leader region of the mRNA specifying the protein, designated Roc for regulator of colonization. Incorporation of the roc leader mRNA in front of a heterologous gene was sufficient for fructose and glucose to turn off expression of the corresponding protein. An engineered strain refractory to Roc silencing by these sugars outcompeted wild-type B. thetaiotaomicron in mice fed a diet rich in glucose and sucrose (a disaccharide composed of glucose and fructose), but not in mice fed a complex polysaccharide-rich diet. Our findings underscore a role for dietary sugars that escape absorption by the host intestine and reach the microbiota: regulation of gut colonization by beneficial microbes independently of supplying nutrients to the microbiota.},
}
@article {pmid29669904,
year = {2018},
author = {Hayashi, M and Nomura, M and Kageyama, D},
title = {Rapid comeback of males: evolution of male-killer suppression in a green lacewing population.},
journal = {Proceedings. Biological sciences},
volume = {285},
number = {1877},
pages = {},
pmid = {29669904},
issn = {1471-2954},
mesh = {Animals ; *Biological Evolution ; Cell Nucleus/genetics ; Female ; *Genetic Variation ; Insecta/genetics/*microbiology/*physiology ; Japan ; Male ; *Sex Ratio ; Spiroplasma/*physiology ; Symbiosis ; },
abstract = {Evolutionary theory predicts that the spread of cytoplasmic sex ratio distorters leads to the evolution of host nuclear suppressors, although there are extremely few empirical observations of this phenomenon. Here, we demonstrate that a nuclear suppressor of a cytoplasmic male killer has spread rapidly in a population of the green lacewing Mallada desjardinsi An M. desjardinsi population, which was strongly female-biased in 2011 because of a high prevalence of the male-killing Spiroplasma endosymbiont, had a sex ratio near parity in 2016, despite a consistent Spiroplasma prevalence. Most of the offspring derived from individuals collected in 2016 had 1 : 1 sex ratios in subsequent generations. Contrastingly, all-female or female-biased broods appeared frequently from crossings of these female offspring with males derived from a laboratory line founded by individuals collected in 2011. These results suggest near-fixation of a nuclear suppressor against male killing in 2016 and reject the notion that a non-male-killing Spiroplasma variant has spread in the population. Consistently, no significant difference was detected in mitochondrial haplotype variation between 2011 and 2016. These findings, and earlier findings in the butterfly Hypolimnas bolina in Samoa, suggest that these quick events of male recovery occur more commonly than is generally appreciated.},
}
@article {pmid29669898,
year = {2018},
author = {Cziesielski, MJ and Liew, YJ and Cui, G and Schmidt-Roach, S and Campana, S and Marondedze, C and Aranda, M},
title = {Multi-omics analysis of thermal stress response in a zooxanthellate cnidarian reveals the importance of associating with thermotolerant symbionts.},
journal = {Proceedings. Biological sciences},
volume = {285},
number = {1877},
pages = {},
pmid = {29669898},
issn = {1471-2954},
mesh = {Animals ; Coral Reefs ; Dinoflagellida/*physiology ; Hawaii ; Heat-Shock Response ; North Carolina ; *Proteome ; Saudi Arabia ; Sea Anemones/*physiology ; *Symbiosis ; *Thermotolerance ; *Transcriptome ; },
abstract = {Corals and their endosymbiotic dinoflagellates of the genus Symbiodinium have a fragile relationship that breaks down under heat stress, an event known as bleaching. However, many coral species have adapted to high temperature environments such as the Red Sea (RS). To investigate mechanisms underlying temperature adaptation in zooxanthellate cnidarians we compared transcriptome- and proteome-wide heat stress response (24 h at 32°C) of three strains of the model organism Aiptasia pallida from regions with differing temperature profiles; North Carolina (CC7), Hawaii (H2) and the RS. Correlations between transcript and protein levels were generally low but inter-strain comparisons highlighted a common core cnidarian response to heat stress, including protein folding and oxidative stress pathways. RS anemones showed the strongest increase in antioxidant gene expression and exhibited significantly lower reactive oxygen species (ROS) levels in hospite However, comparisons of antioxidant gene and protein expression between strains did not show strong differences, indicating similar antioxidant capacity across the strains. Subsequent analysis of ROS production in isolated symbionts confirmed that the observed differences of ROS levels in hospite were symbiont-driven. Our findings indicate that RS anemones do not show increased antioxidant capacity but may have adapted to higher temperatures through association with more thermally tolerant symbionts.},
}
@article {pmid29462153,
year = {2018},
author = {Herrera Paredes, S and Gao, T and Law, TF and Finkel, OM and Mucyn, T and Teixeira, PJPL and Salas González, I and Feltcher, ME and Powers, MJ and Shank, EA and Jones, CD and Jojic, V and Dangl, JL and Castrillo, G},
title = {Design of synthetic bacterial communities for predictable plant phenotypes.},
journal = {PLoS biology},
volume = {16},
number = {2},
pages = {e2003962},
pmid = {29462153},
issn = {1545-7885},
support = {F32 GM117758/GM/NIGMS NIH HHS/United States ; T32 GM067553/GM/NIGMS NIH HHS/United States ; /HHMI/Howard Hughes Medical Institute/United States ; },
mesh = {Bacteria/genetics/*isolation & purification ; Brassicaceae/genetics/metabolism/*microbiology ; Genes, Bacterial ; Genes, Plant ; *Host Microbial Interactions ; *Microbial Consortia ; Phosphates/metabolism ; Plant Roots/microbiology ; Plant Shoots/metabolism ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; },
abstract = {Specific members of complex microbiota can influence host phenotypes, depending on both the abiotic environment and the presence of other microorganisms. Therefore, it is challenging to define bacterial combinations that have predictable host phenotypic outputs. We demonstrate that plant-bacterium binary-association assays inform the design of small synthetic communities with predictable phenotypes in the host. Specifically, we constructed synthetic communities that modified phosphate accumulation in the shoot and induced phosphate starvation-responsive genes in a predictable fashion. We found that bacterial colonization of the plant is not a predictor of the plant phenotypes we analyzed. Finally, we demonstrated that characterizing a subset of all possible bacterial synthetic communities is sufficient to predict the outcome of untested bacterial consortia. Our results demonstrate that it is possible to infer causal relationships between microbiota membership and host phenotypes and to use these inferences to rationally design novel communities.},
}
@article {pmid30879199,
year = {2019},
author = {Sugiyama, Y and Murata, M and Kanetani, S and Nara, K},
title = {Towards the conservation of ectomycorrhizal fungi on endangered trees: native fungal species on Pinus amamiana are rarely conserved in trees planted ex situ.},
journal = {Mycorrhiza},
volume = {},
number = {},
pages = {},
doi = {10.1007/s00572-019-00887-1},
pmid = {30879199},
issn = {1432-1890},
support = {26870163//Japan Society for the Promotion of Science/ ; 15H02449//Japan Society for the Promotion of Science/ ; 18H03955//Japan Society for the Promotion of Science/ ; L-2018-1-006//Institute for Fermentation, Osaka/ ; },
abstract = {Ectomycorrhizal (ECM) symbiosis is essential for the survival of both host trees and associated ECM fungi. However, during conservation activities of endangered tree species, their ECM symbionts are largely ignored. Here, we investigated ECM fungi in ex situ populations established for the conservation of Pinus amamiana, an endangered species distributed on Yakushima Island, Japan. Our objective was to determine whether ECM fungi in natural forests are conserved in ex situ populations on the same island. In particular, we focused on the existence of Rhizopogon yakushimensis, which is specific to P. amamiana and the most dominant in natural P. amamiana forests. Molecular identification of ECM fungi in resident tree roots and soil propagule banks indicated that ECM fungal species native to natural forests were rarely conserved in ex situ populations. Furthermore, R. yakushimensis was not confirmed in any of the resident root or spore bioassay samples from the ex situ populations. Thus, ECM fungal spores may not be effectively dispersed from natural forests located on the same island. Instead, ECM fungi distributed in other geographical regions occurred more frequently in the ex situ populations, indicating unintentional introductions of non-native ECM fungi from the nurseries where seedlings were raised before transplanting. These findings imply that the current ex situ conservation practices of endangered tree do not work for the conservation of native ECM fungi, and instead may need modification to avoid the risk of introducing non-native ECM fungi near the endangered forest sites.},
}
@article {pmid30877310,
year = {2019},
author = {Frank, AC},
title = {Molecular host mimicry and manipulation in bacterial symbionts.},
journal = {FEMS microbiology letters},
volume = {366},
number = {4},
pages = {},
doi = {10.1093/femsle/fnz038},
pmid = {30877310},
issn = {1574-6968},
abstract = {It is common among intracellular bacterial pathogens to use eukaryotic-like proteins that mimic and manipulate host cellular processes to promote colonization and intracellular survival. Eukaryotic-like proteins are bacterial proteins with domains that are rare in bacteria, and known to function in the context of a eukaryotic cell. Such proteins can originate through horizontal gene transfer from eukaryotes or, in the case of simple repeat proteins, through convergent evolution. Recent studies of microbiomes associated with several eukaryotic hosts suggest that similar molecular strategies are deployed by cooperative bacteria that interact closely with eukaryotic cells. Some mimics, like ankyrin repeats, leucine rich repeats and tetratricopeptide repeats are shared across diverse symbiotic systems ranging from amoebae to plants, and may have originated early, or evolved independently in multiple systems. Others, like plant-mimicking domains in members of the plant microbiome are likely to be more recent innovations resulting from horizontal gene transfer from the host, or from microbial eukaryotes occupying the same host. Host protein mimics have only been described in a limited set of symbiotic systems, but are likely to be more widespread. Systematic searches for eukaryote-like proteins in symbiont genomes could lead to the discovery of novel mechanisms underlying host-symbiont interactions.},
}
@article {pmid30877285,
year = {2019},
author = {De Meyer, F and Danneels, B and Acar, T and Rasolomampianina, R and Rajaonah, MT and Jeannoda, V and Carlier, A},
title = {Adaptations and evolution of a heritable leaf nodule symbiosis between Dioscorea sansibarensis and Orrella dioscoreae.},
journal = {The ISME journal},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41396-019-0398-8},
pmid = {30877285},
issn = {1751-7370},
support = {G017717N//Fonds Wetenschappelijk Onderzoek (Research Foundation Flanders)/ ; BOF17/STA/024//Bijzonder Onderzoeksfonds (Special Research Fund)/ ; },
abstract = {Various plant species establish intimate symbioses with bacteria within their aerial organs. The bacteria are contained within nodules or glands often present in distinctive patterns on the leaves in what is commonly referred to as leaf nodule symbiosis. We describe here a highly specific symbiosis between a wild yam species from Madagascar, Dioscorea sansibarensis and bacteria of the species Orrella dioscoreae. Using whole-genome sequencing of plastids and bacteria from wild-collected samples, we show phylogenetic patterns consistent with a dominant vertical mode of transmission of the symbionts. Unique so far among leaf nodule symbioses, the bacteria can be cultured and are amenable to comparative transcriptomics, revealing a potential role in complementing the host's arsenal of secondary metabolites. We propose a recent establishment of a vertical mode of transmission in this symbiosis which, together with a large effective population size explains the cultivability and apparent lack of genome reductive evolution in O. dioscoreae. We leverage these unique features to reveal pathways and functions under positive selection in these specialized endophytes, highlighting the candidate mechanisms enabling a permanent association in the phyllosphere.},
}
@article {pmid30875770,
year = {2019},
author = {Adler, PH and Courtney, GW},
title = {Ecological and Societal Services of Aquatic Diptera.},
journal = {Insects},
volume = {10},
number = {3},
pages = {},
doi = {10.3390/insects10030070},
pmid = {30875770},
issn = {2075-4450},
support = {SC-1700527//National Institute of Food and Agriculture/ ; IOW05473//National Institute of Food and Agriculture/ ; },
abstract = {More than any other group of macro-organisms, true flies (Diptera) dominate the freshwater environment. Nearly one-third of all flies-roughly 46,000 species-have some developmental connection with an aquatic environment. Their abundance, ubiquity, and diversity of adaptations to the aquatic environment position them as major drivers of ecosystem processes and as sources of products and bioinspiration for the benefit of human society. Larval flies are well represented as ecosystem engineers and keystone species that alter the abiotic and biotic environments through activities such as burrowing, grazing, suspension feeding, and predation. The enormous populations sometimes achieved by aquatic flies can provide the sole or major dietary component for other organisms. Harnessing the services of aquatic Diptera for human benefit depends on the ingenuity of the scientific community. Aquatic flies have played a role as indicators of water quality from the earliest years of bioassessment. They serve as indicators of historical and future ecological and climate change. As predators and herbivores, they can serve as biological control agents. The association of flies with animal carcasses in aquatic environments provides an additional set of tools for forensic science. The extremophilic attributes of numerous species of Diptera offer solutions for human adaptation to harsh terrestrial and extraterrestrial environments. The potential pharmaceutical and industrial applications of the symbiotic microbial community in extremophilic Diptera are better explored than are those of dipteran chemistry. Many flies provide valuable ecological and human services as aquatic immatures, but are also pests and vectors of disease agents as terrestrial adults. The scientific community, thus, is challenged with balancing the benefits and costs of aquatic Diptera, while maintaining sustainable populations as more species face extinction.},
}
@article {pmid30873199,
year = {2019},
author = {Rípodas, C and Castaingts, M and Clúa, J and Villafañe, J and Blanco, FA and Zanetti, ME},
title = {The PvNF-YA1 and PvNF-YB7 Subunits of the Heterotrimeric NF-Y Transcription Factor Influence Strain Preference in the Phaseolus vulgaris-Rhizobium etli Symbiosis.},
journal = {Frontiers in plant science},
volume = {10},
number = {},
pages = {221},
doi = {10.3389/fpls.2019.00221},
pmid = {30873199},
issn = {1664-462X},
abstract = {Transcription factors of the Nuclear Factor Y (NF-Y) family play essential functions in plant development and plasticity, including the formation of lateral root organs such as lateral root and symbiotic nodules. NF-Ys mediate transcriptional responses by acting as heterotrimers composed of three subunits, NF-YA, NF-YB, and NF-YC, which in plants are encoded by relatively large gene families. We have previously shown that, in the Phaseolus vulgaris × Rhizobium etli interaction, the PvNF-YC1 subunit is involved not only in the formation of symbiotic nodules, but also in the preference exhibited by the plant for rhizobial strains that are more efficient and competitive in nodule formation. PvNF-YC1 forms a heterotrimer with the PvNF-YA1 and PvNF-YB7 subunits. Here, we used promoter:reporter fusions to show that both PvNF-YA1 and PvNF-YB7 are expressed in symbiotic nodules. In addition, we report that knock-down of PvNF-YA1 and its close paralog PvNF-YA9 abolished nodule formation by either high or low efficient strains and arrested rhizobial infection. On the other hand, knock-down of PvNF-YB7 only affected the symbiotic outcome of the high efficient interaction, suggesting that other symbiotic NF-YB subunits might be involved in the more general mechanisms of nodule formation. More important, we present functional evidence supporting that both PvNF-YA1 and PvNF-YB7 are part of the mechanisms that allow P. vulgaris plants to discriminate and select those bacterial strains that perform better in nodule formation, most likely by acting in the same heterotrimeric complex that PvNF-YC1.},
}
@article {pmid30872027,
year = {2019},
author = {Skiada, V and Faccio, A and Kavroulakis, N and Genre, A and Bonfante, P and Papadopoulou, KK},
title = {Colonization of Legumes by an Endophytic Fusarium solani strain FsK Reveals Common Features to Symbionts or Pathogens.},
journal = {Fungal genetics and biology : FG & B},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.fgb.2019.03.003},
pmid = {30872027},
issn = {1096-0937},
abstract = {Plant cellular responses to endophytic filamentous fungi are scarcely reported, with the majority of described colonization processes in plant-fungal interactions referring to either pathogens or true symbionts. Fusarium solani strain K (FsK) is a root endophyte of Solanum lycopersicum, which protects against root and foliar pathogens. Here, we investigated the association of FsK with two legumes (Lotus japonicus and Medicago truncatula) and report on colonization patterns and plant responses during the establishment of the interaction. L. japonicus plants colonized by FsK complete their life cycle and exhibit no apparent growth defects under normal conditions. We followed the growth of FsK within root-inoculated plants spatiotemporally and showed the capability of the endophyte to migrate to the stem. In a bipartite system comprising of the endophyte and either whole plants or root organ cultures, we studied the plant sub-cellular responses to FsK recognition, using optical, confocal and transmission electron microscopy. A polarized reorganization of the root cell occurs: endoplasmic reticulum/cytoplasm accumulation and nuclear placement at contact sites, occasional development of papillae underneath hyphopodia and membranous material rearrangements towards penetrating hyphae. Fungal hyphae proliferate within the vascular bundle of the plant. Plant cell death is involved in fungal colonization of the root. Our data suggest that the establishment of FsK within legume tissues requires fungal growth adaptations and plant cell-autonomous responses, known to occur during both symbiotic and pathogenic plant-fungal interactions. We highlight the overlooked plasticity of endophytic fungi upon plant colonization, and introduce a novel plant-endophyte association.},
}
@article {pmid30425149,
year = {2018},
author = {Campbell, MA and Łukasik, P and Meyer, MC and Buckner, M and Simon, C and Veloso, C and Michalik, A and McCutcheon, JP},
title = {Changes in Endosymbiont Complexity Drive Host-Level Compensatory Adaptations in Cicadas.},
journal = {mBio},
volume = {9},
number = {6},
pages = {},
pmid = {30425149},
issn = {2150-7511},
mesh = {Alphaproteobacteria/genetics ; Animals ; Evolution, Molecular ; Female ; Genome, Bacterial ; Hemiptera/*microbiology/*physiology ; *Host Microbial Interactions ; Ovum/microbiology ; Phylogeny ; *Symbiosis ; },
abstract = {For insects that depend on one or more bacterial endosymbionts for survival, it is critical that these bacteria are faithfully transmitted between insect generations. Cicadas harbor two essential bacterial endosymbionts, "Candidatus Sulcia muelleri" and "Candidatus Hodgkinia cicadicola." In some cicada species, Hodgkinia has fragmented into multiple distinct but interdependent cellular and genomic lineages that can differ in abundance by more than two orders of magnitude. This complexity presents a potential problem for the host cicada, because low-abundance but essential Hodgkinia lineages risk being lost during the symbiont transmission bottleneck from mother to egg. Here we show that all cicada eggs seem to receive the full complement of Hodgkinia lineages, and that in cicadas with more complex Hodgkinia this outcome is achieved by increasing the number of Hodgkinia cells transmitted by up to 6-fold. We further show that cicada species with varying Hodgkinia complexity do not visibly alter their transmission mechanism at the resolution of cell biological structures. Together these data suggest that a major cicada adaptation to changes in endosymbiont complexity is an increase in the number of Hodgkinia cells transmitted to each egg. We hypothesize that the requirement to increase the symbiont titer is one of the costs associated with Hodgkinia fragmentation.IMPORTANCE Sap-feeding insects critically rely on one or more bacteria or fungi to provide essential nutrients that are not available at sufficient levels in their diets. These microbes are passed between insect generations when the mother places a small packet of microbes into each of her eggs before it is laid. We have previously described an unusual lineage fragmentation process in a nutritional endosymbiotic bacterium of cicadas called Hodgkinia In some cicadas, a single Hodgkinia lineage has split into numerous related lineages, each performing a subset of original function and therefore each required for normal host function. Here we test how this splitting process affects symbiont transmission to eggs. We find that cicadas dramatically increase the titer of Hodgkinia cells passed to each egg in response to lineage fragmentation, and we hypothesize that this increase in bacterial cell count is one of the major costs associated with endosymbiont fragmentation.},
}
@article {pmid30175507,
year = {2018},
author = {Kothe, E},
title = {Special Focus: Actinobacteria.},
journal = {Journal of basic microbiology},
volume = {58},
number = {9},
pages = {719},
doi = {10.1002/jobm.201870028},
pmid = {30175507},
issn = {1521-4028},
mesh = {*Actinobacteria/genetics/metabolism/physiology ; Anti-Bacterial Agents/biosynthesis ; Environmental Microbiology ; Symbiosis ; },
}
@article {pmid30043295,
year = {2018},
author = {Burks, D and Azad, R and Wen, J and Dickstein, R},
title = {The Medicago truncatula Genome: Genomic Data Availability.},
journal = {Methods in molecular biology (Clifton, N.J.)},
volume = {1822},
number = {},
pages = {39-59},
doi = {10.1007/978-1-4939-8633-0_3},
pmid = {30043295},
issn = {1940-6029},
mesh = {Computational Biology/methods ; Consensus Sequence ; Databases, Genetic ; Expressed Sequence Tags ; Gene Expression Profiling ; Gene Expression Regulation, Plant ; Gene Library ; *Genome, Plant ; *Genomics/methods ; High-Throughput Nucleotide Sequencing ; Medicago truncatula/*genetics/metabolism ; Metabolic Networks and Pathways ; Nitrogen Fixation ; Symbiosis ; Web Browser ; },
abstract = {Medicago truncatula emerged in 1990 as a model for legumes, comprising the third largest land plant family. Most legumes form symbiotic nitrogen-fixing root nodules with compatible soil bacteria and thus are important contributors to the global nitrogen cycle and sustainable agriculture. Legumes and legume products are important sources for human and animal protein as well as for edible and industrial oils. In the years since M. truncatula was chosen as a legume model, many genetic, genomic, and molecular resources have become available, including reference quality genome sequences for two widely used genotypes. Accessibility of genomic data is important for many different types of studies with M. truncatula as well as for research involving crop and forage legumes. In this chapter, we discuss strategies to obtain archived M. truncatula genomic data originally deposited into custom databases that are no longer maintained but are now accessible in general databases. We also review key current genomic databases that are specific to M. truncatula as well as those that contain M. truncatula data in addition to data from other plants.},
}
@article {pmid30021316,
year = {2018},
author = {Ranjbar Jafarabadi, A and Riyahi Bakhtiari, A and Maisano, M and Pereira, P and Cappello, T},
title = {First record of bioaccumulation and bioconcentration of metals in Scleractinian corals and their algal symbionts from Kharg and Lark coral reefs (Persian Gulf, Iran).},
journal = {The Science of the total environment},
volume = {640-641},
number = {},
pages = {1500-1511},
doi = {10.1016/j.scitotenv.2018.06.029},
pmid = {30021316},
issn = {1879-1026},
mesh = {Animals ; Anthozoa/*metabolism ; *Coral Reefs ; *Environmental Monitoring ; Indian Ocean ; Iran ; Islands ; Metals/analysis/*metabolism ; Microalgae/metabolism ; Symbiosis ; Water Pollutants, Chemical/analysis/*metabolism ; },
abstract = {Metal pollution is nowadays a serious threat worldwide for ecosystem and human health. Despite that, there is still a paucity of data on metal impact on coral reef ecosystems. Herein, the levels of eleven metals (Mn, Zn, Cu, Cr, Co, Ni, V, As, Cd, Hg, Pb) were assessed in surface sediments, seawater samples, Scleractinian corals (tissue and skeleton) and their algal symbionts collected from Kharg and Lark coral reefs in the Persian Gulf, Iran. At Kharg, surface sediments and seawater showed higher concentrations of metals than Lark, attributable to the higher metal loads and petrochemical activities in the area. Sediment quality guidelines indicated Hg as a serious threat to biota both at Kharg and Lark. Accordingly, metals bioaccumulation and bioconcentration was higher in corals from Kharg relatively to Lark Island. Interestingly, as supported by values of BCFs and BSAFs, metal accumulation was higher in coral tissues in respect to skeletons, and in zooxanthellae relatively to coral tissues at both coral reefs. Differential metal bioaccumulation was found among Scleractinian species, indicating that corals have distinct selectivity for assimilating metals from ambient sediments and seawater. Overall, metal accumulation in corals and zooxanthellae is an appropriate tool for environmental monitoring studies in coral reefs. Noteworthy, the use of Porites lutea, among Scleractinian corals, seems to be as a good bioindicator in monitoring studies of metal pollution.},
}
@article {pmid29721778,
year = {2018},
author = {Liu, Z},
title = {Microbes and host dance in harmony or disarray?.},
journal = {Protein & cell},
volume = {9},
number = {5},
pages = {395-396},
pmid = {29721778},
issn = {1674-8018},
mesh = {Animals ; Bacteria/*pathogenicity ; Biological Evolution ; *Host-Pathogen Interactions ; Humans ; *Symbiosis ; },
}
@article {pmid30870733,
year = {2019},
author = {Shinde, S and Prasad, S and Saboo, Y and Kaushick, R and Saini, J and Pal, PK and Ingalhalikar, M},
title = {Predictive markers for Parkinson's disease using deep neural nets on neuromelanin sensitive MRI.},
journal = {NeuroImage. Clinical},
volume = {22},
number = {},
pages = {101748},
doi = {10.1016/j.nicl.2019.101748},
pmid = {30870733},
issn = {2213-1582},
abstract = {Neuromelanin sensitive magnetic resonance imaging (NMS-MRI) has been crucial in identifying abnormalities in the substantia nigra pars compacta (SNc) in Parkinson's disease (PD) as PD is characterized by loss of dopaminergic neurons in the SNc. Current techniques employ estimation of contrast ratios of the SNc, visualized on NMS-MRI, to discern PD patients from the healthy controls. However, the extraction of these features is time-consuming and laborious and moreover provides lower prediction accuracies. Furthermore, these do not account for patterns of subtle changes in PD in the SNc. To mitigate this, our work establishes a computer-based analysis technique that uses convolutional neural networks (CNNs) to create prognostic and diagnostic biomarkers of PD from NMS-MRI. Our technique not only performs with a superior testing accuracy (80%) as compared to contrast ratio-based classification (56.5% testing accuracy) and radiomics classifier (60.3% testing accuracy), but also supports discriminating PD from atypical parkinsonian syndromes (85.7% test accuracy). Moreover, it has the capability to locate the most discriminative regions on the neuromelanin contrast images. These discriminative activations demonstrate that the left SNc plays a key role in the classification in comparison to the right SNc, and are in agreement with the concept of asymmetry in PD. Overall, the proposed technique has the potential to support radiological diagnosis of PD while facilitating deeper understanding into the abnormalities in SNc.},
}
@article {pmid30868162,
year = {2019},
author = {Bruand, C and Meilhoc, E},
title = {NO in plants: pro or anti senescence.},
journal = {Journal of experimental botany},
volume = {},
number = {},
pages = {},
doi = {10.1093/jxb/erz117},
pmid = {30868162},
issn = {1460-2431},
abstract = {Senescence is a regulated process of tissue degeneration which concerns any plant organ and consists in the degradation and remobilization of molecules to other growing tissues. Senescent organs display microscopic changes as well as internal cellular structure modifications and differential gene expression. A large number of factors influencing senescence have been described including age, nutrient supply and environmental interactions. Internal factors such as phytohormones also affect the timing of leaf senescence. A link between the senescence process and nitric oxide (NO) production in senescing tissues has been noticed for many years. Astonishingly, this link proves to be either a positive or a negative correlation depending upon the organ. NO is a gas signaling or a toxic molecule known to have multiple roles in plants; this review discusses the duality of NO roles in the senescence process of two different plant organs, leaves and root nodules.},
}
@article {pmid30867583,
year = {2019},
author = {Dick, GJ},
title = {The microbiomes of deep-sea hydrothermal vents: distributed globally, shaped locally.},
journal = {Nature reviews. Microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41579-019-0160-2},
pmid = {30867583},
issn = {1740-1534},
abstract = {The discovery of chemosynthetic ecosystems at deep-sea hydrothermal vents in 1977 changed our view of biology. Chemosynthetic bacteria and archaea form the foundation of vent ecosystems by exploiting the chemical disequilibrium between reducing hydrothermal fluids and oxidizing seawater, harnessing this energy to fix inorganic carbon into biomass. Recent research has uncovered fundamental aspects of these microbial communities, including their relationships with underlying geology and hydrothermal geochemistry, interactions with animals via symbiosis and distribution both locally in various habitats within vent fields and globally across hydrothermal systems in diverse settings. Although 'black smokers' and symbioses between microorganisms and macrofauna attract much attention owing to their novelty and the insights they provide into life under extreme conditions, habitats such as regions of diffuse flow, subseafloor aquifers and hydrothermal plumes have important roles in the global cycling of elements through hydrothermal systems. Owing to sharp contrasts in physical and chemical conditions between these various habitats and their dynamic, extreme and geographically isolated nature, hydrothermal vents provide a valuable window into the environmental and ecological forces that shape microbial communities and insights into the limits, origins and evolution of microbial life.},
}
@article {pmid30681069,
year = {2019},
author = {Nobbs, A and Kreth, J},
title = {Genetics of sanguinis-Group Streptococci in Health and Disease.},
journal = {Microbiology spectrum},
volume = {7},
number = {1},
pages = {},
doi = {10.1128/microbiolspec.GPP3-0052-2018},
pmid = {30681069},
issn = {2165-0497},
mesh = {Bacterial Adhesion/physiology ; Bacteriocins/metabolism ; Biofilms/growth & development ; Dental Plaque/*microbiology ; Humans ; Microbiota/genetics ; Mouth/*microbiology ; Streptococcal Infections/microbiology/*pathology ; Streptococcus gordonii/*genetics/physiology ; Streptococcus sanguis/*genetics/physiology ; Symbiosis/physiology ; },
abstract = {With the application of increasingly advanced "omics" technologies to the study of our resident oral microbiota, the presence of a defined, health-associated microbial community has been recognized. Within this community, sanguinis-group streptococci, comprising the closely related Streptococcus sanguinis and Streptococcus gordonii, together with Streptococcus parasanguinis, often predominate. Their ubiquitous and abundant nature reflects the evolution of these bacteria as highly effective colonizers of the oral cavity. Through interactions with host tissues and other microbes, and the capacity to readily adapt to prevailing environmental conditions, sanguinis-group streptococci are able to shape accretion of the oral plaque biofilm and promote development of a microbial community that exists in harmony with its host. Nonetheless, upon gaining access to the blood stream, those very same colonization capabilities can confer upon sanguinis-group streptococci the ability to promote systemic disease. This article focuses on the role of sanguinis-group streptococci as the commensurate commensals, highlighting those aspects of their biology that enable the coordination of health-associated biofilm development. This includes the molecular mechanisms, both synergistic and antagonistic, that underpin adhesion to substrata, intercellular communication, and polymicrobial community formation. As our knowledge of these processes advances, so will the opportunities to exploit this understanding for future development of novel strategies to control oral and extraoral disease.},
}
@article {pmid30629913,
year = {2019},
author = {Litvak, Y and Mon, KKZ and Nguyen, H and Chanthavixay, G and Liou, M and Velazquez, EM and Kutter, L and Alcantara, MA and Byndloss, MX and Tiffany, CR and Walker, GT and Faber, F and Zhu, Y and Bronner, DN and Byndloss, AJ and Tsolis, RM and Zhou, H and Bäumler, AJ},
title = {Commensal Enterobacteriaceae Protect against Salmonella Colonization through Oxygen Competition.},
journal = {Cell host & microbe},
volume = {25},
number = {1},
pages = {128-139.e5},
doi = {10.1016/j.chom.2018.12.003},
pmid = {30629913},
issn = {1934-6069},
mesh = {Animals ; Animals, Newborn ; Cecum/microbiology/pathology ; Chickens ; Coinfection ; Enterobacteriaceae/genetics/*growth & development/*physiology ; Escherichia coli ; Female ; Gastrointestinal Microbiome ; Male ; Mice ; Oxygen/*metabolism ; Probiotics ; Salmonella/genetics/*growth & development/pathogenicity ; Salmonella Infections, Animal ; Salmonella enteritidis/growth & development/pathogenicity ; Spores, Bacterial/growth & development ; *Symbiosis ; Virulence Factors ; },
abstract = {Neonates are highly susceptible to infection with enteric pathogens, but the underlying mechanisms are not resolved. We show that neonatal chick colonization with Salmonella enterica serovar Enteritidis requires a virulence-factor-dependent increase in epithelial oxygenation, which drives pathogen expansion by aerobic respiration. Co-infection experiments with an Escherichia coli strain carrying an oxygen-sensitive reporter suggest that S. Enteritidis competes with commensal Enterobacteriaceae for oxygen. A combination of Enterobacteriaceae and spore-forming bacteria, but not colonization with either community alone, confers colonization resistance against S. Enteritidis in neonatal chicks, phenocopying germ-free mice associated with adult chicken microbiota. Combining spore-forming bacteria with a probiotic E. coli isolate protects germ-free mice from pathogen colonization, but the protection is lost when the ability to respire oxygen under micro-aerophilic conditions is genetically ablated in E. coli. These results suggest that commensal Enterobacteriaceae contribute to colonization resistance by competing with S. Enteritidis for oxygen, a resource critical for pathogen expansion.},
}
@article {pmid30516133,
year = {2018},
author = {Chen, EC and Mathieu, S and Hoffrichter, A and Sedzielewska-Toro, K and Peart, M and Pelin, A and Ndikumana, S and Ropars, J and Dreissig, S and Fuchs, J and Brachmann, A and Corradi, N},
title = {Single nucleus sequencing reveals evidence of inter-nucleus recombination in arbuscular mycorrhizal fungi.},
journal = {eLife},
volume = {7},
number = {},
pages = {},
doi = {10.7554/eLife.39813},
pmid = {30516133},
issn = {2050-084X},
mesh = {Cell Nucleus/*genetics/ultrastructure ; Cytoplasm/genetics/ultrastructure ; DNA, Fungal/*genetics ; Genetic Variation ; *Genome, Fungal ; Genotype ; Mycorrhizae/*genetics ; Plants/microbiology ; Polymorphism, Single Nucleotide ; *Recombination, Genetic ; Sequence Analysis, DNA ; Symbiosis ; },
abstract = {Eukaryotes thought to have evolved clonally for millions of years are referred to as ancient asexuals. The oldest group among these are the arbuscular mycorrhizal fungi (AMF), which are plant symbionts harboring hundreds of nuclei within one continuous cytoplasm. Some AMF strains (dikaryons) harbor two co-existing nucleotypes but there is no direct evidence that such nuclei recombine in this life-stage, as is expected for sexual fungi. Here, we show that AMF nuclei with distinct genotypes can undergo recombination. Inter-nuclear genetic exchange varies in frequency among strains, and despite recombination all nuclear genomes have an average similarity of at least 99.8%. The present study demonstrates that AMF can generate genetic diversity via meiotic-like processes in the absence of observable mating. The AMF dikaryotic life-stage is a primary source of nuclear variability in these organisms, highlighting its potential for strain enhancement of these symbionts.},
}
@article {pmid30273387,
year = {2018},
author = {Ruocco, N and Mutalipassi, M and Pollio, A and Costantini, S and Costantini, M and Zupo, V},
title = {First evidence of Halomicronema metazoicum (Cyanobacteria) free-living on Posidonia oceanica leaves.},
journal = {PloS one},
volume = {13},
number = {10},
pages = {e0204954},
pmid = {30273387},
issn = {1932-6203},
mesh = {Alismatales/*microbiology ; Base Sequence ; Cyanobacteria/classification/genetics/*isolation & purification ; Plant Leaves/microbiology ; RNA, Ribosomal, 16S/chemistry/isolation & purification/metabolism ; Seawater/microbiology ; Sequence Alignment ; Sequence Analysis, DNA ; Symbiosis ; },
abstract = {Cyanobacteria contribute to the ecology of various marine environments, also for their symbioses, since some of them are common hosts of sponges and ascidians. They are also emerging as an important source of novel bioactive secondary metabolites in pharmacological (as anticancer drugs) and biotechnological applications. In the present work we isolated a cyanobacteria in a free-living state from leaves of the seagrass Posidonia oceanica leaves. This newly collected strain was then cultivated under two laboratory conditions, and then characterized by combining morphological observation and molecular studies based on 16S rRNA gene sequences analysis. The strain showed 99% pairwise sequence identity with Halomicronema metazoicum ITAC101, never isolated before as a free-living organisms, but firstly described as an endosymbiont of the Mediterranean marine spongae Petrosia ficiformis, under the form of a filamentous strain. Further studies will investigate the actual role of this cyanobacterium in the leaf stratum of P. oceanica leaves, given its demonstrated ability to influence the vitality and the life cycle of other organisms. In fact, its newly demonstrated free-living stage, described in this study, indicate that Phormidium-like cyanobacteria could play important roles in the ecology of benthic and planktonic communities.},
}
@article {pmid30002238,
year = {2018},
author = {Nagy, LG},
title = {Many roads to convergence.},
journal = {Science (New York, N.Y.)},
volume = {361},
number = {6398},
pages = {125-126},
doi = {10.1126/science.aau2409},
pmid = {30002238},
issn = {1095-9203},
mesh = {Conservation of Natural Resources ; Ecosystem ; *Nitrogen ; Phylogeny ; *Symbiosis ; },
}
@article {pmid29471328,
year = {2018},
author = {Morrow, KM and Tedford, AR and Pankey, MS and Lesser, MP},
title = {A member of the Roseobacter clade, Octadecabacter sp., is the dominant symbiont in the brittle star Amphipholis squamata.},
journal = {FEMS microbiology ecology},
volume = {94},
number = {4},
pages = {},
doi = {10.1093/femsec/fiy030},
pmid = {29471328},
issn = {1574-6941},
mesh = {Animals ; Bacteroidetes/genetics/isolation & purification ; Cyanobacteria/genetics/isolation & purification ; DNA, Bacterial/*genetics ; Geologic Sediments/*microbiology ; Phylogeny ; Proteobacteria/genetics/isolation & purification ; RNA, Ribosomal, 16S/genetics ; *Roseobacter/classification/genetics/isolation & purification ; Seawater/*microbiology ; Sequence Analysis, DNA ; Starfish/*microbiology ; Symbiosis ; },
abstract = {Symbiotic associations with subcuticular bacteria (SCB) have been identified and studied in many echinoderms, including the SCB of the brooding brittle star, Amphipholis squamata. Previous studies on the SCB of A. squamata placed the isolated bacterium, designated as AS1, in the genus Vibrio (Gammaproteobacteria), but subsequent studies suggested that the SCB of echinoderms belong to the Alphaproteobacteria. This study examines the taxonomic composition of SCB associated with A. squamata from the Northwest Atlantic using the 16S rRNA gene and next generation sequencing. Results show the presence of a single dominant bacterial type, within the Roseobacter clade, family Rhodobacteraceae, which composes 70%-80% of the A. squamata microbiome. These Rhodobacteraceae sequences were identified as members of the genus Octadecabacter. Additionally, the original isolate, AS1, from the brittle star A. squamata also belongs in the genus Octadecabacter based on Sanger sequencing of cloned 16S rRNA gene sequences. By comparison, adjacent seawater and sediment porewater communities were significantly more diverse, hosting bacteria in the phyla Proteobacteria, Bacteroidetes, Cyanobacteria, Verrucomicrobia and Actinobacteria. Thus, a distinct SCB community is present in A. squamata that is dominated by a member of the genus Octadecabacter and is identical to the original isolate, AS1, from this brittle star.},
}
@article {pmid29390142,
year = {2018},
author = {Zélé, F and Santos, I and Olivieri, I and Weill, M and Duron, O and Magalhães, S},
title = {Endosymbiont diversity and prevalence in herbivorous spider mite populations in South-Western Europe.},
journal = {FEMS microbiology ecology},
volume = {94},
number = {4},
pages = {},
doi = {10.1093/femsec/fiy015},
pmid = {29390142},
issn = {1574-6941},
mesh = {Animals ; Bacteroidetes/classification/genetics/*isolation & purification ; Biological Evolution ; Europe ; Herbivory ; Microbiota/genetics ; Phylogeny ; Prevalence ; RNA, Ribosomal, 16S/genetics ; Rickettsia/classification/genetics/*isolation & purification ; Symbiosis ; Tetranychidae/*microbiology ; Wolbachia/classification/genetics/*isolation & purification ; },
abstract = {Bacterial endosymbionts are known as important players of the evolutionary ecology of their hosts. However, their distribution, prevalence and diversity are still largely unexplored. To this aim, we investigated infections by the most common bacterial reproductive manipulators in herbivorous spider mites of South-Western Europe. Across 16 populations belonging to three Tetranychus species, Wolbachia was the most prevalent (ca. 61%), followed by Cardinium (12%-15%), while only few individuals were infected by Rickettsia (0.9%-3%), and none carried Arsenophonus or Spiroplasma. These endosymbionts are here reported for the first time in Tetranychus evansi and Tetranychus ludeni, and showed variable infection frequencies between and within species, with several cases of coinfections. Moreover, Cardinium was more prevalent in Wolbachia-infected individuals, which suggests facilitation between these symbionts. Finally, sequence comparisons revealed no variation of the Wolbachia wsp and Rickettsia gtlA genes, but some diversity of the Cardinium 16S rRNA, both between and within populations of the three mite species. Some of the Cardinium sequences identified belonged to distantly-related clades, and the lack of association between these sequences and spider mite mitotypes suggests repeated host switching of Cardinium. Overall, our results reveal a complex community of symbionts in this system, opening the path for future studies.},
}
@article {pmid30715337,
year = {2019},
author = {Sinha, A and Li, Z and Sun, L and Carlow, CKS},
title = {Complete Genome Sequence of the Wolbachia wAlbB Endosymbiont of Aedes albopictus.},
journal = {Genome biology and evolution},
volume = {11},
number = {3},
pages = {706-720},
doi = {10.1093/gbe/evz025},
pmid = {30715337},
issn = {1759-6653},
abstract = {Wolbachia, an alpha-proteobacterium closely related to Rickettsia, is a maternally transmitted, intracellular symbiont of arthropods and nematodes. Aedes albopictus mosquitoes are naturally infected with Wolbachia strains wAlbA and wAlbB. Cell line Aa23 established from Ae. albopictus embryos retains only wAlbB and is a key model to study host-endosymbiont interactions. We have assembled the complete circular genome of wAlbB from the Aa23 cell line using long-read PacBio sequencing at 500× median coverage. The assembled circular chromosome is 1.48 megabases in size, an increase of more than 300 kb over the published draft wAlbB genome. The annotation of the genome identified 1,205 protein coding genes, 34 tRNA, 3 rRNA, 1 tmRNA, and 3 other ncRNA loci. The long reads enabled sequencing over complex repeat regions which are difficult to resolve with short-read sequencing. Thirteen percent of the genome comprised insertion sequence elements distributed throughout the genome, some of which cause pseudogenization. Prophage WO genes encoding some essential components of phage particle assembly are missing, while the remainder are found in five prophage regions/WO-like islands or scattered around the genome. Orthology analysis identified a core proteome of 535 orthogroups across all completed Wolbachia genomes. The majority of proteins could be annotated using Pfam and eggNOG analyses, including ankyrins and components of the Type IV secretion system. KEGG analysis revealed the absence of five genes in wAlbB which are present in other Wolbachia. The availability of a complete circular chromosome from wAlbB will enable further biochemical, molecular, and genetic analyses on this strain and related Wolbachia.},
}
@article {pmid30443696,
year = {2018},
author = {Kamaruzaman, NAC and Mašán, P and Velásquez, Y and González-Medina, A and Lindström, A and Braig, HR and Perotti, MA},
title = {Macrocheles species (Acari: Macrochelidae) associated with human corpses in Europe.},
journal = {Experimental & applied acarology},
volume = {76},
number = {4},
pages = {453-471},
doi = {10.1007/s10493-018-0321-4},
pmid = {30443696},
issn = {1572-9702},
mesh = {*Animal Distribution ; Animals ; *Cadaver ; Coleoptera/*physiology ; Female ; Forensic Sciences ; Humans ; Mites/*physiology ; Muscidae/*physiology ; Spain ; Sweden ; *Symbiosis ; },
abstract = {The biology of macrochelid mites might offer new venues for the interpretation of the environmental conditions surrounding human death and decomposition. Three human corpses, one from Sweden and two from Spain, have been analysed for the occurrence of Macrochelidae species. Macrocheles muscaedomesticae (Scopoli) females were associated with a corpse that was found in a popular beach area of southeast Spain. Their arrival coincides with the occurrence of one of their major carrier species, the filth fly Fannia scalaris, the activity of which peaks during mid-summer. Macrocheles glaber (Müller) specimens were collected from a corpse in a shallow grave in a forest in Sweden at the end of summer, concurrent with the arrival of beetles attracted by odours from the corpse. Macrocheles perglaber Filipponi and Pegazzano adults were sampled from a corpse found indoors in the rural surroundings of Granada city, south Spain. The phoretic behaviour of this species is similar to that of M. glaber, but it is more specific to Scarabaeidae and Geotrupidae dung beetles, most of which favour human faeces. Macrocheles muscaedomesticae is known from urban and rural areas and poultry farms, M. glaber from outdoors, particularly the countryside, whereas M. perglaber is known from outdoor, rural, and remote, potentially mountainous locations. Macrocheles muscaedomesticae and M. perglaber are reported for the first time from the Iberian Peninsula. This is the first record of M. perglaber from human remains.},
}
@article {pmid30060596,
year = {2018},
author = {Saccon, E and Vitiello, A and Trevisan, M and Salata, C and Palù, G},
title = {Sixth European Seminar in Virology on Virus⁻Host Interaction at Single Cell and Organism Level.},
journal = {Viruses},
volume = {10},
number = {8},
pages = {},
pmid = {30060596},
issn = {1999-4915},
mesh = {*Host-Pathogen Interactions ; Humans ; Italy ; Organoids ; *Single-Cell Analysis ; Symbiosis ; Transcriptome ; Virus Physiological Phenomena ; Viruses/*genetics/pathogenicity ; },
abstract = {The 6th European Seminar in Virology (EuSeV) was held in Bertinoro, Italy, 22⁻24 June 2018, and brought together international scientists and young researchers working in the field of Virology. Sessions of the meeting included: virus⁻host-interactions at organism and cell level; virus evolution and dynamics; regulation; immunity/immune response; and disease and therapy. This report summarizes lectures by the invited speakers and highlights advances in the field.},
}
@article {pmid30860585,
year = {2019},
author = {Barros-Carvalho, GA and Hungria, M and Lopes, FM and Van Sluys, MA},
title = {Brazilian-adapted soybean Bradyrhizobium strains uncover IS elements with potential impact on biological nitrogen fixation.},
journal = {FEMS microbiology letters},
volume = {},
number = {},
pages = {},
doi = {10.1093/femsle/fnz046},
pmid = {30860585},
issn = {1574-6968},
abstract = {Bradyrhizobium diazoefficiens CPAC 7 and Bradyrhizobium japonicum CPAC 15 are broadly used in commercial inoculants in Brazil, contributing to most of the nitrogen required by the soybean crop. These strains differ in their symbiotic properties: CPAC 7 is more efficient in fixing nitrogen, whereas CPAC 15 is more competitive. Comparative genomics revealed many transposases close to genes associated with symbiosis in the symbiotic island of these strains. Given the importance that Insertion Sequences (ISs) elements have to bacterial genomes, we focused on identifying the local impact of these elements in the genomes of these and other related Bradyrhizobium strains to further understand their phenotypic differences. Analyses were performed using bioinformatics approaches. We found IS elements disrupting and inserted at regulatory regions of genes involved in symbiosis. Further comparative analyses with 21 Bradyrhizobium genomes revealed insertional polymorphism with distinguishing patterns between B. diazoefficiens and B. japonicum lineages. Finally, 13 of these potentially impacted genes are differentially expressed under symbiotic conditions in B. diazoefficiens USDA 110. Thus, IS elements are associated with the diversity of Bradyrhizobium, possibly by providing mechanisms for natural variation of symbiotic effectiveness.},
}
@article {pmid30857919,
year = {2019},
author = {Brinker, P and Fontaine, MC and Beukeboom, LW and Falcao Salles, J},
title = {Host, Symbionts, and the Microbiome: The Missing Tripartite Interaction.},
journal = {Trends in microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.tim.2019.02.002},
pmid = {30857919},
issn = {1878-4380},
abstract = {Symbiosis between microbial associates and a host is a ubiquitous feature of life on earth, modulating host phenotypes. In addition to endosymbionts, organisms harbour a collection of host-associated microbes, the microbiome that can impact important host traits. In this opinion article we argue that the mutual influences of the microbiome and endosymbionts, as well as their combined influence on the host, are still understudied. Focusing on the endosymbiont Wolbachia, we present growing evidence indicating that host phenotypic effects are exerted in interaction with the remainder microbiome and the host. We thus advocate that only through an integrated approach that considers multiple interacting partners and environmental influences will we be able to gain a better understanding of host-microbe associations.},
}
@article {pmid30857310,
year = {2019},
author = {Sańko-Sawczenko, I and Łotocka, B and Mielecki, J and Rekosz-Burlaga, H and Czarnocka, W},
title = {Transcriptomic Changes in Medicago truncatula and Lotus japonicus Root Nodules during Drought Stress.},
journal = {International journal of molecular sciences},
volume = {20},
number = {5},
pages = {},
doi = {10.3390/ijms20051204},
pmid = {30857310},
issn = {1422-0067},
support = {0512/IP1/2015/73//Ministerstwo Nauki i Szkolnictwa Wyzszego/ ; },
abstract = {Drought is one of the major environmental factors limiting biomass and seed yield production in agriculture. In this research, we focused on plants from the Fabaceae family, which has a unique ability for the establishment of symbiosis with nitrogen-fixing bacteria, and are relatively susceptible to water limitation. We have presented the changes in nitrogenase activity and global gene expression occurring in Medicagotruncatula and Lotusjaponicus root nodules during water deficit. Our results proved a decrease in the efficiency of nitrogen fixation, as well as extensive changes in plant and bacterial transcriptomes, shortly after watering cessation. We showed for the first time that not only symbiotic plant components but also Sinorhizobiummeliloti and Mesorhizobiumloti bacteria residing in the root nodules of M. truncatula and L. japonicus, respectively, adjust their gene expression in response to water shortage. Although our results demonstrated that both M. truncatula and L.japonicus root nodules were susceptible to water deprivation, they indicated significant differences in plant and bacterial response to drought between the tested species, which might be related to the various types of root nodules formed by these species.},
}
@article {pmid30834977,
year = {2019},
author = {Kumawat, KC and Sharma, P and Sirari, A and Singh, I and Gill, BS and Singh, U and Saharan, K},
title = {Synergism of Pseudomonas aeruginosa (LSE-2) nodule endophyte with Bradyrhizobium sp. (LSBR-3) for improving plant growth, nutrient acquisition and soil health in soybean.},
journal = {World journal of microbiology & biotechnology},
volume = {35},
number = {3},
pages = {47},
doi = {10.1007/s11274-019-2622-0},
pmid = {30834977},
issn = {1573-0972},
mesh = {Biofilms/growth & development ; Bradyrhizobium/isolation & purification/*physiology ; *Endophytes ; India ; Indoleacetic Acids/metabolism ; Nitrogen/analysis ; *Nutrients ; Oxidoreductases/analysis ; Phosphates/metabolism ; Phosphoric Monoester Hydrolases/analysis ; Phylogeny ; *Plant Development ; Plant Roots/chemistry/microbiology ; Plant Shoots/chemistry/microbiology ; Potassium/analysis ; Pseudomonas aeruginosa/classification/genetics/isolation & purification/*physiology ; RNA, Ribosomal, 16S/genetics ; Siderophores/metabolism ; Soil/chemistry ; Soil Microbiology ; Solubility ; Soybeans/*growth & development/*microbiology ; *Symbiosis ; Virulence ; Zinc/metabolism ; },
abstract = {The present study was aimed to assess the scope of native potential endophyte Pseudomonas aeruginosa (LSE-2) strain (KX925973) with recommended Bradyrhizobium sp. (LSBR-3) (KF906140) for synergistic effect to develop as consortium biofertilizer of soybean. A total of 28 non-rhizobial endophytic bacteria were isolated from cultivated and wild sp. of soybean. All isolates were screened for multifarious PGP traits viz. Indole-3-acetic acid (IAA), phosphate (P) and zinc (Zn) solubilization, siderophore, cell wall degrading enzymes and pathogenicity. Compatible of LSBR-3 and LSE-2 enhanced IAA, P-solubilization, 1-aminocyclopropane-carboxylate deaminase and biofilm formation over the single inoculant treatment. Further, consortium was evaluated in vivo for growth, symbiotic traits, nutrient acquisition, soil quality parameters and yield attributes of soybean. Improvement in growth parameters were recorded with dual inoculant LSBR-3 + LSE-2 as compared to LSBR-3 alone and un-inoculated control treatments. Significantly (p ≥ 0.05) high symbiotic and soil quality parameters (phosphatase and soil dehydrogenase activity) was recorded with LSBR-3 + LSE-2 at vegetative and flowering stage as compared to LSBR-3 alone and un-inoculated control treatments. Single inoculation of LSBR-3 improved grain yield by 4.25% over the un-inoculated control treatment, further, enhancement in yield was recorded with consortium inoculant (LSBR-3 and LSE-2) by 3.47% over the LSBR-3 alone. Application of consortium inoculant (LSBR-3 + LSE-2) gave an additional income of Rs. 5089/ha over the un-inoculated control treatment. The results, thus strongly suggest that endophytic diazotroph LSE-2 can be used as potent bio-inoculant along with LSBR-3 as bio-enhancer for improving soybean productivity in a sustainable system.},
}
@article {pmid30454555,
year = {2018},
author = {Sapountzis, P and Zhukova, M and Shik, JZ and Schiott, M and Boomsma, JJ},
title = {Reconstructing the functions of endosymbiotic Mollicutes in fungus-growing ants.},
journal = {eLife},
volume = {7},
number = {},
pages = {},
pmid = {30454555},
issn = {2050-084X},
support = {323085//European Research Council/International ; ERC Advanced Grant 323085//European Research Council/International ; },
mesh = {Acetates/metabolism ; Animals ; Ants/*microbiology ; Arginine/metabolism ; Biotransformation ; Citrates/metabolism ; Glucose/metabolism ; Intestines/microbiology ; *Symbiosis ; Tenericutes/*physiology ; },
abstract = {Mollicutes, a widespread class of bacteria associated with animals and plants, were recently identified as abundant abdominal endosymbionts in healthy workers of attine fungus-farming leaf-cutting ants. We obtained draft genomes of the two most common strains harbored by Panamanian fungus-growing ants. Reconstructions of their functional significance showed that they are independently acquired symbionts, most likely to decompose excess arginine consistent with the farmed fungal cultivars providing this nitrogen-rich amino-acid in variable quantities. Across the attine lineages, the relative abundances of the two Mollicutes strains are associated with the substrate types that foraging workers offer to fungus gardens. One of the symbionts is specific to the leaf-cutting ants and has special genomic machinery to catabolize citrate/glucose into acetate, which appears to deliver direct metabolic energy to the ant workers. Unlike other Mollicutes associated with insect hosts, both attine ant strains have complete phage-defense systems, underlining that they are actively maintained as mutualistic symbionts.},
}
@article {pmid30037148,
year = {2018},
author = {Cross, ST and Kapuscinski, ML and Perino, J and Maertens, BL and Weger-Lucarelli, J and Ebel, GD and Stenglein, MD},
title = {Co-Infection Patterns in Individual Ixodes scapularis Ticks Reveal Associations between Viral, Eukaryotic and Bacterial Microorganisms.},
journal = {Viruses},
volume = {10},
number = {7},
pages = {},
pmid = {30037148},
issn = {1999-4915},
support = {UL1 TR002535/TR/NCATS NIH HHS/United States ; },
mesh = {Animals ; Bacteria/genetics/isolation & purification ; Borrelia burgdorferi/genetics/isolation & purification ; Coinfection/epidemiology/*microbiology/*virology ; Eukaryota/genetics/isolation & purification ; High-Throughput Nucleotide Sequencing ; Ixodes/genetics/*microbiology/*virology ; Lyme Disease ; Microbiota/genetics ; Orthobunyavirus/genetics/isolation & purification ; Phlebovirus/genetics/isolation & purification ; Prevalence ; Symbiosis ; Tick Infestations/epidemiology/microbiology/virology ; Tick-Borne Diseases/*epidemiology/microbiology/virology ; Viruses/genetics/isolation & purification ; Wisconsin/epidemiology ; },
abstract = {Ixodes scapularis ticks harbor a variety of microorganisms, including eukaryotes, bacteria and viruses. Some of these can be transmitted to and cause disease in humans and other vertebrates. Others are not pathogenic, but may impact the ability of the tick to harbor and transmit pathogens. A growing number of studies have examined the influence of bacteria on tick vector competence but the influence of the tick virome remains less clear, despite a surge in the discovery of tick-associated viruses. In this study, we performed shotgun RNA sequencing on 112 individual adult I. scapularis collected in Wisconsin, USA. We characterized the abundance, prevalence and co-infection rates of viruses, bacteria and eukaryotic microorganisms. We identified pairs of tick-infecting microorganisms whose observed co-infection rates were higher or lower than would be expected, or whose RNA levels were positively correlated in co-infected ticks. Many of these co-occurrence and correlation relationships involved two bunyaviruses, South Bay virus and blacklegged tick phlebovirus-1. These viruses were also the most prevalent microorganisms in the ticks we sampled, and had the highest average RNA levels. Evidence of associations between microbes included a positive correlation between RNA levels of South Bay virus and Borrelia burgdorferi, the Lyme disease agent. These findings contribute to the rationale for experimental studies on the impact of viruses on tick biology and vector competence.},
}
@article {pmid29876848,
year = {2018},
author = {Wang, F and Jing, X and Adams, CA and Shi, Z and Sun, Y},
title = {Decreased ZnO nanoparticle phytotoxicity to maize by arbuscular mycorrhizal fungus and organic phosphorus.},
journal = {Environmental science and pollution research international},
volume = {25},
number = {24},
pages = {23736-23747},
pmid = {29876848},
issn = {1614-7499},
support = {41471395//National Natural Science Foundation of China/ ; 0100229003//Doctoral Foundation of QUST/ ; ZR2018MD006//National Natural Science Foundation of Shandong Province/ ; },
mesh = {Glomeromycota/*physiology ; Mycorrhizae/*physiology ; Nanoparticles/*toxicity ; Phosphorus/*pharmacology ; Plant Roots/drug effects/microbiology/physiology ; Soil Pollutants/*toxicity ; Symbiosis ; Zea mays/*drug effects/microbiology/physiology ; Zinc Oxide/*toxicity ; },
abstract = {ZnO nanoparticles (NPs) are applied in a wide variety of applications and frequently accumulate in the environment, thus posing risks to the environment and human health. Arbuscular mycorrhizal (AM) fungi (AMF) associate symbiotically with roots of most higher plants, helping their host plants acquire phosphorus (P). AMF can reduce the toxicity of ZnO NPs, but the benefits of AMF to host plants highly vary with soil available P. We hypothesize that organic P may help AMF to alleviate ZnO NP phytotoxicity. Here, we investigated the effects of inoculation with Funneliformis mosseae on plant growth and Zn accumulation, using maize grown in soil-sand mix substrates spiked with ZnO NPs (0 or 500 mg kg-1) under different organic P supply levels (0, 20, or 50 mg kg-1). The results showed addition of ZnO NPs inhibited root colonization rate, increased the shoot/root P concentration ratio, and led to significant Zn accumulation in soil and plants. As predicted, AM effects on maize plants all varied with P supply levels, both with or without ZnO NP additions. Organic P interacted synergistically with AMF to promote plant growth and acquisition of P, N, K, Fe, and Cu. AM inoculation reduced the bioavailable Zn released from ZnO NPs and decreased the concentrations and translocation of Zn to maize shoots. In conclusion, ZnO NPs caused excess Zn in soil and plants, posing potential environmental risks. However, our present results first demonstrate that organic P exhibited similar positive effects to AMF and interacted synergistically with AMF to improve plant growth and nutrition, and to decrease Zn accumulation and partitioning in plants, and thus helped diminish the adverse effects induced by ZnO NPs.},
}
@article {pmid29707906,
year = {2018},
author = {Díez-Vives, C and Esteves, AIS and Costa, R and Nielsen, S and Thomas, T},
title = {Detecting signatures of a sponge-associated lifestyle in bacterial genomes.},
journal = {Environmental microbiology reports},
volume = {10},
number = {4},
pages = {433-443},
doi = {10.1111/1758-2229.12655},
pmid = {29707906},
issn = {1758-2229},
mesh = {Adaptation, Biological ; Animals ; Bacteria/*genetics ; *Bacterial Physiological Phenomena ; Databases, Genetic ; Flavobacteriaceae/genetics/physiology ; Genome, Bacterial/*genetics ; Metabolic Networks and Pathways/genetics ; Porifera/*microbiology/*physiology ; Rhodobacteraceae/genetics/physiology ; Sequence Analysis, DNA ; *Symbiosis ; Synechococcus/genetics/physiology ; },
abstract = {Sponges interact with diverse and rich communities of bacteria that are phylogenetically often distinct from their free-living counterparts. Recent genomics and metagenomic studies have indicated that bacterial sponge symbionts also have distinct functional features from free-living bacteria; however, it is unclear, if such genome-derived functional signatures are common and present in different symbiont taxa. We therefore compared here a large set of genomes from cultured (Pseudovibrio, Ruegeria and Aquimarina) and yet-uncultivated (Synechococcus) bacteria found in either sponge-associated or free-living sources. Our analysis revealed only very few genera-specific functions that could be correlated with a sponge-associated lifestyle. Using different sets of sponge-associated and free-living bacteria for each genus, we could however show that the functions identified as 'sponge-associated' are dependent on the reference comparison being made. Using simulation approaches, we show how this influences the robustness of identifying functional signatures and how evolutionary divergence and genomic adaptation can be distinguished. Our results highlight the future need for robust comparative analyses to define genomic signatures of symbiotic lifestyles, whether it is for symbionts of sponges or other host organisms.},
}
@article {pmid30856237,
year = {2019},
author = {Ingraffia, R and Amato, G and Frenda, AS and Giambalvo, D},
title = {Impacts of arbuscular mycorrhizal fungi on nutrient uptake, N2 fixation, N transfer, and growth in a wheat/faba bean intercropping system.},
journal = {PloS one},
volume = {14},
number = {3},
pages = {e0213672},
doi = {10.1371/journal.pone.0213672},
pmid = {30856237},
issn = {1932-6203},
abstract = {Arbuscular mycorrhizal fungi (AMF) can play a key role in natural and agricultural ecosystems affecting plant nutrition, soil biological activity and modifying the availability of nutrients by plants. This research aimed at expanding the knowledge of the role played by AMF in the uptake of macro- and micronutrients and N transfer (using a 15N stem-labelling method) in a faba bean/wheat intercropping system. It also investigates the role of AMF in biological N fixation (using the natural isotopic abundance method) in faba bean grown in pure stand and in mixture. Finally, it examines the role of AMF in driving competition and facilitation between faba bean and wheat. Durum wheat and faba bean were grown in pots (five pots per treatment) as sole crops or in mixture in the presence or absence of AMF. Root colonisation by AMF was greater in faba bean than in wheat and increased when species were mixed compared to pure stand (particularly for faba bean). Mycorrhizal symbiosis positively influenced root biomass, specific root length, and root density and increased the uptake of P, Fe, and Zn in wheat (both in pure stand and in mixture) but not in faba bean. Furthermore, AMF symbiosis increased the percentage of N derived from the atmosphere in the total N biomass of faba bean grown in mixture (+20%) but not in pure stand. Nitrogen transfer from faba bean to wheat was low (2.5-3.0 mg pot-1); inoculation with AMF increased N transfer by 20%. Overall, in terms of above- and belowground growth and uptake of nutrients, mycorrhization favoured the stronger competitor in the mixture (wheat) without negatively affecting the companion species (faba bean). Results of this study confirm the role of AMF in driving biological interactions among neighbouring plants.},
}
@article {pmid30853777,
year = {2018},
author = {Patelunas, AJ and Nishiguchi, MK},
title = {Vascular architecture in the bacteriogenic light organ of Euprymna tasmanica (Cephalopoda: Sepiolidae).},
journal = {Invertebrate biology : a quarterly journal of the American Microscopical Society and the Division of Invertebrate Zoology/ASZ},
volume = {137},
number = {3},
pages = {240-249},
doi = {10.1111/ivb.12223},
pmid = {30853777},
issn = {1077-8306},
abstract = {Symbiosis between southern dumpling squid, Euprymna tasmanica (Cephalopoda: Sepiolidae), and its luminescent symbiont, the bacterium Vibrio fischeri, provides an experimentally tractable system to examine interactions between the eukaryotic host and its bacterial partner. Luminescence emitted by the symbiotic bacteria provides light for the squid in a behavior termed "counter-illumination," which allows the squid to mask its shadow amidst downwelling moonlight. Although this association is beneficial, light generated from the bacteria requires large quantities of oxygen to maintain this energy-consuming reaction. Therefore, we examined the vascular network within the light organ of juveniles of E. tasmanica with and without V. fischeri. Vessel type, diameter, and location of vessels were measured. Although differences between symbiotic and aposymbiotic squid demonstrated that the presence of V. fischeri does not significantly influence the extent of vascular branching at early stages of symbiotic development, these finding do provide an atlas of blood vessel distribution in the organ. Thus, these results provide a framework to understand how beneficial bacteria influence the development of a eukaryotic closed vascular network and provide insight to the evolutionary developmental dynamics that form during mutualistic interactions.},
}
@article {pmid30518125,
year = {2018},
author = {Raimundo, I and Silva, SG and Costa, R and Keller-Costa, T},
title = {Bioactive Secondary Metabolites from Octocoral-Associated Microbes-New Chances for Blue Growth.},
journal = {Marine drugs},
volume = {16},
number = {12},
pages = {},
doi = {10.3390/md16120485},
pmid = {30518125},
issn = {1660-3397},
support = {EXPL/MAR-EST/1664/2013//Fundação para a Ciência e a Tecnologia/ ; PTDC/MAR-BIO/1547/2014//Fundação para a Ciência e a Tecnologia/ ; },
mesh = {Animals ; Anthozoa/*microbiology ; Bacteria/genetics/*metabolism ; Biological Products/isolation & purification/metabolism/*pharmacology ; Biosynthetic Pathways/*genetics ; Fungi/genetics/*metabolism ; Industrial Microbiology/methods ; Microbiota/physiology ; Multigene Family ; Symbiosis ; Technology, Pharmaceutical/methods ; },
abstract = {Octocorals (Cnidaria, Anthozoa Octocorallia) are magnificent repositories of natural products with fascinating and unusual chemical structures and bioactivities of interest to medicine and biotechnology. However, mechanistic understanding of the contribution of microbial symbionts to the chemical diversity of octocorals is yet to be achieved. This review inventories the natural products so-far described for octocoral-derived bacteria and fungi, uncovering a true chemical arsenal of terpenes, steroids, alkaloids, and polyketides with antibacterial, antifungal, antiviral, antifouling, anticancer, anti-inflammatory, and antimalarial activities of enormous potential for blue growth. Genome mining of 15 bacterial associates (spanning 12 genera) cultivated from Eunicella spp. resulted in the identification of 440 putative and classifiable secondary metabolite biosynthetic gene clusters (BGCs), encompassing varied terpene-, polyketide-, bacteriocin-, and nonribosomal peptide-synthase BGCs. This points towards a widespread yet uncharted capacity of octocoral-associated bacteria to synthetize a broad range of natural products. However, to extend our knowledge and foster the near-future laboratory production of bioactive compounds from (cultivatable and currently uncultivatable) octocoral symbionts, optimal blending between targeted metagenomics, DNA recombinant technologies, improved symbiont cultivation, functional genomics, and analytical chemistry are required. Such a multidisciplinary undertaking is key to achieving a sustainable response to the urgent industrial demand for novel drugs and enzyme varieties.},
}
@article {pmid30852466,
year = {2019},
author = {Shi, L and Deng, X and Yang, Y and Jia, Q and Wang, C and Shen, Z and Chen, Y},
title = {A Cr(VI)-tolerant strain, Pisolithus sp1, with a high accumulation capacity of Cr in mycelium and highly efficient assisting Pinus thunbergii for phytoremediation.},
journal = {Chemosphere},
volume = {224},
number = {},
pages = {862-872},
doi = {10.1016/j.chemosphere.2019.03.015},
pmid = {30852466},
issn = {1879-1298},
abstract = {Ectomycorrhizal (ECM) fungi can improve the growth of pine trees and enhance their tolerance to heavy metal stress, and may also be useful during the afforestation and phytoremediation of polluted regions with pine trees. Hebeloma vinosophyllum (Cr(VI)-sensitive strain) and Pisolithus sp1 ((Cr(VI)-tolerant strain) were selected through liquid culture experiment, and were used in symbiosis with Japanese black pine (Pinus thunbergii) in pot experiments, to determine their potential for improving phytoremediation of Cr(VI)-contaminated soils. Our results indicated that Pisolithus sp1 also had a significantly higher accumulation of Cr than H. vinosophyllum in mycelium under the same Cr(VI) treatments in liquid culture experiment. The tolerance index of Pisolithus sp1 ECM seedlings' shoots and roots to Cr(VI) were significantly higher than that of H. vinosophyllum ECM and non-ectomycorrhizal (NM) seedlings while the total accumulated Cr per seedling in Pisolithus sp1 ECM seedlings were 1.50-1.96 and 2.83-27.75 fold higher that of H. vinosophyllum ECM and NM seedlings, respectively, within 0-800 mg kg-1 Cr(VI) treatments in pot experiments. In addition, the significant differences ratios of photosynthetic rate, stomatal conductance, transpiration rate and intercellular CO2 concentration between Pisolithus sp1 ECM and NM seedlings were significantly higher than those between H. vinosophyllum ECM and NM seedlings under 400 and 800 mg kg-1 Cr(VI) treatments. Compared with the control (no plant), and planting NM or H. vinosophyllum ECM seedlings, the planting of Pisolithus sp1 ECM seedlings significantly reduced the percentage content of exchangeable Cr in the soil.},
}
@article {pmid30852185,
year = {2019},
author = {Hudson, J and Kumar, V and Egan, S},
title = {Comparative genome analysis provides novel insight into the interaction of Aquimarina sp. AD1, BL5 and AD10 with their macroalgal host.},
journal = {Marine genomics},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.margen.2019.02.005},
pmid = {30852185},
issn = {1876-7478},
abstract = {The Aquimarina genus is widely distributed throughout the marine environment, however little is understood regarding its ecological role, particularly when in association with eukaryotic hosts. Here, we examine the genomes of two opportunistic pathogens, Aquimarina sp. AD1 and BL5, and a non-pathogenic strain Aquimarina sp. AD10, that were isolated from diseased individuals of the red alga Delisea pulchra. Each strain encodes multiple genes for the degradation of marine carbohydrates and vitamin biosynthesis. These traits are hypothesised to promote nutrient exchange between the Aquimarina strains and their algal host, facilitating a close symbiotic relationship. Moreover, each strain harbours the necessary genes for the assembly of a Type 9 Secretion System (T9SS) and the associated gliding motility apparatus. In addition to these common features, pathogenic strains AD1 and BL5, encode genes for the production of flexirubin type pigments and a number of unique non-ribosomal peptide synthesis (NRPS) gene clusters, suggesting a role for these uncharacterised traits in virulence. This study provides valuable insight into the potential ecological role of Aquimarina in the marine environment and the complex factors driving pathogenesis and symbiosis in this genus.},
}
@article {pmid30850539,
year = {2019},
author = {Wang, L and Delgado-Baquerizo, M and Wang, D and Isbell, F and Liu, J and Feng, C and Liu, J and Zhong, Z and Zhu, H and Yuan, X and Chang, Q and Liu, C},
title = {Diversifying livestock promotes multidiversity and multifunctionality in managed grasslands.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {},
number = {},
pages = {},
doi = {10.1073/pnas.1807354116},
pmid = {30850539},
issn = {1091-6490},
abstract = {Increasing plant diversity can increase ecosystem functioning, stability, and services in both natural and managed grasslands, but the effects of herbivore diversity, and especially of livestock diversity, remain underexplored. Given that managed grazing is the most extensive land use worldwide, and that land managers can readily change livestock diversity, we experimentally tested how livestock diversification (sheep, cattle, or both) influenced multidiversity (the diversity of plants, insects, soil microbes, and nematodes) and ecosystem multifunctionality (including plant biomass production, plant leaf N and P, above-ground insect abundance, nutrient cycling, soil C stocks, water regulation, and plant-microbe symbiosis) in the world's largest remaining grassland. We also considered the potential dependence of ecosystem multifunctionality on multidiversity. We found that livestock diversification substantially increased ecosystem multifunctionality by increasing multidiversity. The link between multidiversity and ecosystem multifunctionality was always stronger than the link between single diversity components and functions. Our work provides insights into the importance of multitrophic diversity to maintain multifunctionality in managed ecosystems and suggests that diversifying livestock could promote both multidiversity and ecosystem multifunctionality in an increasingly managed world.},
}
@article {pmid30850430,
year = {2019},
author = {Pons, I and Renoz, F and Noël, C and Hance, T},
title = {New Insights into the Nature of Symbiotic Associations in Aphids: Infection Process, Biological Effects and Transmission Mode of Cultivable Serratia symbiotica Bacteria.},
journal = {Applied and environmental microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1128/AEM.02445-18},
pmid = {30850430},
issn = {1098-5336},
abstract = {Symbiotic microorganisms are widespread in nature and can play a major role in the ecology and evolution of animals. The aphid-Serratia symbiotica bacterium interaction provides a valuable model to study mechanisms behind these symbiotic associations. The recent discovery of cultivable S. symbiotica strains having the possibility of free-living lifestyle allowed us to simulate their environmental acquisition by aphids to examine the mechanisms involved in this infection pathway. Here, after oral ingestion, we analyzed the infection dynamic of cultivable S. symbiotica during the host's lifetime using qPCR and fluorescence techniques and determined the immediate fitness consequences of these bacteria on their new host. We further examined the transmission behavior and phylogenetic position of cultivable strains. Our study revealed that cultivable S. symbiotica are predisposed to establish a symbiotic association with new aphid host, settling in its gut. We showed that cultivable S. symbiotica colonized the entire aphid digestive tract following infection, after which the bacterium multiplied exponentially during aphid development. Our results further revealed that gut colonization by the bacteria induces a fitness cost to their hosts. Nevertheless, it appeared that the bacteria also offer an immediate protection against parasitoids. Interestingly, cultivable S. symbiotica strains seem to be extracellularly transmitted, possibly through the honeydew; while S. symbiotica is generally considered as a maternally-transmitted bacterium living within aphid body cavity and bringing some benefits to its hosts despite its costs. These findings provide new insights into the nature of symbiosis in aphids and the mechanisms underpinning these interactions.IMPORTANCES. symbiotica is one of the most common symbionts among aphid populations and includes a wide variety of strains whose degree of interdependence on the host may vary considerably. S. symbiotica strains with free-living capacity have recently been isolated from aphids. By using these strains, we established artificial associations by simulating new bacterial acquisitions involved in aphid gut infections to decipher their infection processes and biological effects on their new hosts. Our results showed the early stages involved in this route of infection. So far, S. symbiotica was considered as a maternally-transmitted aphid endosymbiont. Nevertheless, we showed that our cultivable S. symbiotica occupy and replicate in aphid gut and seem to be transmitted over generations through an environmental transmission mechanism. Moreover, cultivable S. symbiotica are both parasites and mutualists given the context, as many of aphid endosymbionts. Our findings give new perception of associations involved in bacterial mutualism in aphids.},
}
@article {pmid30849101,
year = {2019},
author = {Teschima, MM and Garrido, A and Paris, A and Nunes, FLD and Zilberberg, C},
title = {Biogeography of the endosymbiotic dinoflagellates (Symbiodiniaceae) community associated with the brooding coral Favia gravida in the Atlantic Ocean.},
journal = {PloS one},
volume = {14},
number = {3},
pages = {e0213519},
doi = {10.1371/journal.pone.0213519},
pmid = {30849101},
issn = {1932-6203},
abstract = {Zooxanthellate corals live in symbiosis with phototrophic dinoflagellates of the family Symbiodiniaceae, enabling the host coral to dwell in shallow, nutrient-poor marine waters. The South Atlantic Ocean is characterized by low coral diversity with high levels of endemism. However, little is known about coral-dinoflagellate associations in the region. This study examined the diversity of Symbiodiniaceae associated with the scleractinian coral Favia gravida across its distributional range using the ITS-2 marker. This brooding coral endemic to the South Atlantic can be found across a wide range of latitudes and longitudes, including the Mid-Atlantic islands. Even though it occurs primarily in shallower environments, F. gravida is among the few coral species that live in habitats with extreme environmental conditions (high irradiance, temperature, and turbidity) such as very shallow tide pools. In the present study, we show that F. gravida exhibits some degree of flexibility in its symbiotic association with zooxanthellae across its range. F. gravida associates predominantly with Cladocopium C3 (ITS2 type Symbiodinium C3) but also with Symbiodinium A3, Symbiodinium linucheae (ITS2 type A4), Cladocopium C1, Cladocopium C130, and Fugacium F3. Symbiont diversity varied across biogeographic regions (Symbiodinium A3 and S. linucheae were found in the Tropical Eastern Atlantic, Cladocopium C1 in the Mid-Atlantic, and other subtypes in the Southwestern Atlantic) and was affected by local environmental conditions. In addition, Symbiodiniaceae diversity was highest in a southwestern Atlantic oceanic island (Rocas Atoll). Understanding the relationship between corals and their algal symbionts is critical in determining the factors that control the ecological niches of zooxanthellate corals and their symbionts, and identifying host-symbiont pairs that may be more resistant to environmental changes.},
}
@article {pmid30847067,
year = {2019},
author = {Schmidtberg, H and Shukla, SP and Halitschke, R and Vogel, H and Vilcinskas, A},
title = {Symbiont-mediated chemical defense in the invasive ladybird Harmonia axyridis.},
journal = {Ecology and evolution},
volume = {9},
number = {4},
pages = {1715-1729},
doi = {10.1002/ece3.4840},
pmid = {30847067},
issn = {2045-7758},
abstract = {The volatile alkylpyrazines methyl- and methoxypyrazines (MPs) present in the reflex bleeds of coccinellid beetles such as the harlequin ladybird beetle Harmonia axyridis are important semiochemicals that function in antipredatory defense behavior. Pyrazines have also been coadapted from a primarily defensive role into pheromones that function in intraspecific communication, attraction, and aggregation behavior. However, the biosynthesis of MPs in ladybird beetles is poorly understood. Here, we tested the hypothesis that MPs could be produced by microbial symbionts in H. axyridis, which generates four different MPs. The evaluation of tissue-specific MP production showed that MP concentrations were highest in the gut tissue and hemolymph of the beetles rather than the fat body tissue as the presumed site of MP biosynthesis. Furthermore, manipulation of gut microbiota by antibiotic-containing diets resulted in a lower MP content in adult beetles. The analysis of the bacterial community of the digestive tract revealed the presence of bacteria of the genera Serratia and Lactococcus which are reportedly able to produce MPs. In line with the known diet-dependent production of MP in H. axyridis, we determined that the presence or relative abundance of some of the potential MP producers (Enterococcus and Staphylococcus) is also diet-dependent. We hypothesize a potential role of the microbiota in MP production in H. axyridis as a possible example for outsourcing the synthesis of ecologically important semiochemicals to its gut bacteria.},
}
@article {pmid30718370,
year = {2019},
author = {Aichelman, HE and Zimmerman, RC and Barshis, DJ},
title = {Adaptive signatures in thermal performance of the temperate coral Astrangia poculata.},
journal = {The Journal of experimental biology},
volume = {222},
number = {Pt 5},
pages = {},
doi = {10.1242/jeb.189225},
pmid = {30718370},
issn = {1477-9145},
abstract = {Variation in environmental characteristics and divergent selection pressures can drive adaptive differentiation across a species' range. Astrangia poculata is a temperate scleractinian coral that provides unique opportunities to understand the roles of phenotypic plasticity and evolutionary adaptation in coral physiological tolerance limits. This species inhabits hard-bottom ecosystems from the northwestern Atlantic to the Gulf of Mexico and withstands an annual temperature range of up to 20°C. Additionally, A. poculata is facultatively symbiotic and co-occurs in both symbiotic ('brown') and aposymbiotic ('white') states. Here, brown and white A. poculata were collected from Virginia (VA) and Rhode Island (RI), USA, and exposed to heat (18-32°C) and cold (18-6°C) stress, during which respiration of the coral host along with photosynthesis and photochemical efficiency (Fv/Fm) of Breviolum psygmophilum photosymbionts were measured. Thermal performance curves (TPCs) of respiration revealed a pattern of countergradient variation with RI corals exhibiting higher respiration rates overall, and specifically at 6, 15, 18, 22 and 26°C. Additionally, thermal optimum (Topt) analyses show a 3.8°C (brown) and 6.9°C (white) higher Topt in the VA population, corresponding to the warmer in situ thermal environment in VA. In contrast to respiration, no origin effect was detected in photosynthesis rates or Fv/Fm, suggesting a possible host-only signature of adaptation. This study is the first to consider A. poculata's response to both heat and cold stress across symbiotic states and geography, and provides insight into the potential evolutionary mechanisms behind the success of this species along the East Coast of the USA.},
}
@article {pmid30467295,
year = {2018},
author = {Ganesan, K and Chung, SK and Vanamala, J and Xu, B},
title = {Causal Relationship between Diet-Induced Gut Microbiota Changes and Diabetes: A Novel Strategy to Transplant Faecalibacterium prausnitzii in Preventing Diabetes.},
journal = {International journal of molecular sciences},
volume = {19},
number = {12},
pages = {},
doi = {10.3390/ijms19123720},
pmid = {30467295},
issn = {1422-0067},
support = {R201714//Beijing Normal University-Hong Kong Baptist University United International College/ ; },
mesh = {Butyrates/metabolism ; Diabetes Mellitus/immunology/*microbiology/pathology/prevention & control ; Diet/methods ; Dietary Fiber/administration & dosage ; Dysbiosis/immunology/*microbiology/pathology/therapy ; Faecalibacterium prausnitzii/*physiology ; Fecal Microbiota Transplantation/methods ; Feces/microbiology ; Gastrointestinal Microbiome ; Gastrointestinal Tract/microbiology ; Humans ; Probiotics/*therapeutic use ; Symbiosis/*physiology ; },
abstract = {The incidence of metabolic disorders, including diabetes, has elevated exponentially during the last decades and enhanced the risk of a variety of complications, such as diabetes and cardiovascular diseases. In the present review, we have highlighted the new insights on the complex relationships between diet-induced modulation of gut microbiota and metabolic disorders, including diabetes. Literature from various library databases and electronic searches (ScienceDirect, PubMed, and Google Scholar) were randomly collected. There exists a complex relationship between diet and gut microbiota, which alters the energy balance, health impacts, and autoimmunity, further causes inflammation and metabolic dysfunction, including diabetes. Faecalibacterium prausnitzii is a butyrate-producing bacterium, which plays a vital role in diabetes. Transplantation of F. prausnitzii has been used as an intervention strategy to treat dysbiosis of the gut's microbial community that is linked to the inflammation, which precedes autoimmune disease and diabetes. The review focuses on literature that highlights the benefits of the microbiota especially, the abundant of F. prausnitzii in protecting the gut microbiota pattern and its therapeutic potential against inflammation and diabetes.},
}
@article {pmid30844108,
year = {2019},
author = {Szczałba, M and Kopta, T and Gąstoł, M and Sękara, A},
title = {Comprehensive insight into arbuscular mycorrhizal fungi, Trichoderma spp. and plant multilevel interactions with emphasis on biostimulation of horticultural crops.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/jam.14247},
pmid = {30844108},
issn = {1365-2672},
abstract = {Sustainability and a more environment-friendly approach is an emerging issue relevant to crop production. Abiotic stresses like drought, salinity, heat, cold or heavy metal pollution can severely compromise yields, and in this respect, plant protection practices should be highly efficient as well as safe for the environment and people. Among the many ways to achieve high productivity of healthy, safe and tasty food, the use of beneficial microorganisms as biostimulants is one of the most promising. Two types of soil fungi can be considered efficient natural plants stimulants: arbuscular mycorrhizal fungi (AMF) and Trichoderma spp. (TR). Generally, most investigations indicated AMF and TR were effective, as well as safe, for use as natural biopreparations dedicated to horticultural crops, although some reports pointed to their negative impact on plants. This review focuses on the mutual interaction of AMF and TR, as well as complex relationships with plants analysed on a multidimensional level: biochemical, morphological, ecological and agrotechnical. AMF and TR were found to be effective elicitors of root system development, nutrient uptake, plant stress response and production of secondary metabolites. As natural plant stimulants, beneficial fungi are compatible with modern trends of crop management, environmental conservation and functional food production. Herein, we demonstrate the advantages and disadvantages of AMF and TR use in horticulture and their prospects, as well as the points that need further exploring. This article is protected by copyright. All rights reserved.},
}
@article {pmid30843545,
year = {2019},
author = {Deicke, M and Mohr, JF and Roy, S and Herzsprung, P and Bellenger, JP and Wichard, T},
title = {Metallophore profiling of nitrogen-fixing Frankia spp. to understand metal management in the rhizosphere of actinorhizal plants.},
journal = {Metallomics : integrated biometal science},
volume = {},
number = {},
pages = {},
doi = {10.1039/c8mt00344k},
pmid = {30843545},
issn = {1756-591X},
abstract = {Frankia spp. are widespread nitrogen-fixing soil bacteria, which often live in symbiosis with a broad range of hosts. Metal homeostasis plays a crucial role in the success of the symbiosis regarding the acquisition of essential trace metals and detoxification of potentially toxic elements. We have hypothesised that Frankia releases many organic ligands with a broad spectrum of affinity for essential and toxic metals. We coined the term 'ligandosphere' to describe the entirety of excreted metal complexing agents and ligands derived from the dissolved organic matter. Using metal isotope-coded profiling (MICP); metallophores of physiological important and toxic trace metals were identified by the addition of stable metal isotope pairs such as 54Fe/58Fe, 63Cu/65Cu, 66Zn/68Zn or 95Mo/98Mo. Liquid chromatography coupled to a mass spectrometer revealed strong variations of the metallophore profile in between the 14 test-strains. In total, about 83 organic ligands were identified as binding to one of the tested metals. The predicted sum formula of the major Fe binding ligands and MS/MS experiments suggested that several metallophore candidates have a similar molecular backbone. Growth experiments with a hyper-producer of metallophores revealed a positive relationship between metallophore production and the concentration of Cu in the growth medium. The present study provides the first comprehensive overview of the complexity of Frankia's ligandosphere. It opens a path to a deeper understanding of mechanisms that regulate metal homeostasis in frankiae. Deciphering these mechanisms is important since the fitness of actinorhizal plants and their potential in ecological restoration relies heavily on their symbiosis with frankiae.},
}
@article {pmid30843315,
year = {2019},
author = {Yoneyama, K and Xie, X and Yoneyama, K and Nomura, T and Takahashi, I and Asami, T and Mori, N and Akiyama, K and Kusajima, M and Nakashita, H},
title = {Regulation of biosynthesis, perception, and functions of strigolactones for promoting arbuscular mycorrhizal symbiosis and managing root parasitic weeds.},
journal = {Pest management science},
volume = {},
number = {},
pages = {},
doi = {10.1002/ps.5401},
pmid = {30843315},
issn = {1526-4998},
abstract = {Strigolactones (SLs) are carotenoid-derived plant secondary metabolites that play important roles in various aspects of plant growth and development as plant hormones and in the rhizosphere communications with symbiotic microbes and also root parasitic weeds. Therefore, sophisticated regulation of biosynthesis, perception, and functions of SLs is expected to promote symbiosis of beneficial microbes including arbuscular mycorrhizal (AM) fungi and also to retard parasitism by devastating root parasitic weeds. We have developed SL mimics with different skeletons, SL biosynthesis inhibitors acting at different biosynthetic steps, SL perception inhibitors which covalently bind to the SL receptor D14, and SL function inhibitors which bind to the serine residue at the catalytic site. In greenhouse pot tests, TIS108, an azole-type SL biosynthesis inhibitor effectively reduced the numbers of attached root parasites Orobanche minor and Striga hermonthica without affecting their host plants tomato and rice, respectively. The AM colonization resulted in weak but distinctly enhanced plant resistance to pathogens. SL mimics can be used to promote AM symbiosis and to reduce application rate of systemic-acquired resistance inducers that are generally phytotoxic to horticultural crops. This article is protected by copyright. All rights reserved.},
}
@article {pmid30843207,
year = {2019},
author = {Wipf, D and Krajinski, F and Courty, PE},
title = {Trading on the arbuscular mycorrhiza market: from arbuscules to common mycorrhizal networks.},
journal = {The New phytologist},
volume = {},
number = {},
pages = {},
doi = {10.1111/nph.15775},
pmid = {30843207},
issn = {1469-8137},
abstract = {Arbuscular mycorrhizal symbiosis occurs between obligate biotrophic fungi of the phylum Glomeromycota and most of land plants. The exchange of nutrients between host plants and arbuscular mycorrhizal fungi is presumed to be the main benefit for the two symbiotic partners. In this review article, we outline the current concepts of nutrient exchanges within this symbiosis (mechanisms and regulation). First, we focus on phosphorus and nitrogen transfer from the fungal partner to the host plant and on the reciprocal transfer of carbon compounds, with a highlight on a possible interplay between nitrogen and phosphorus nutrition during arbuscular mycorrhizal symbiosis. We further discuss potential mechanisms of regulation of these nutrient exchanges linked to membrane dynamics. The review finally addresses the common mycorrhizal networks formed by arbuscular mycorrhizal fungi, which inter-connect plants from similar and/or different species. Then the best way to integrate this knowledge and the ensuing potential benefits of arbuscular mycorrhiza in a sustainable agriculture is discussed. This article is protected by copyright. All rights reserved.},
}
@article {pmid30842767,
year = {2019},
author = {Wagner, K and Krause, K and Gallegos-Monterrosa, R and Sammer, D and Kovács, ÁT and Kothe, E},
title = {The Ectomycorrhizospheric Habitat of Norway Spruce and Tricholoma vaccinum: Promotion of Plant Growth and Fitness by a Rich Microorganismic Community.},
journal = {Frontiers in microbiology},
volume = {10},
number = {},
pages = {307},
doi = {10.3389/fmicb.2019.00307},
pmid = {30842767},
issn = {1664-302X},
abstract = {The contribution of the mycorrhizospheric microbes in a stand of ectomycorrhizal Norway spruce (Picea abies) featuring mycorrhiza with the basidiomycete Tricholoma vaccinum was addressed by microbiome analysis and in vitro reconstruction of microbial as well as plant-microbe interactions. The protective role of the mycorrhizal fungus with respect to pathogen attack could be validated against Botrytis cinerea and Heterobasidion annosum in co-cultures revealing reduced pathogen growth, higher survival rate of the spruce trees and reduced symptoms on needles upon symbiosis with T. vaccinum. The community structure was shown to yield a high diversity in ECM forming basidiomycetes of Thelephorales and Agaricales associated with a rich bacterial diversity dominated by Rhizobiales with the most abundant Nitrobacter winogradski (3.9%). Isolated bacteria were then used to address plant growth promoting abilities, which included production of the phytohormone indole-3-acetic acid (performed by 74% of the bacterial isolates), siderophores (22%), and phosphate mobilization (23%). Among the isolates, mycorrhiza helper bacteria (MHB) were identified, with Bacillus cereus MRZ-1 inducing hyperbranching in T. vaccinum, supporting tree germination, shoot elongation, and root formation as well as higher mycorrhization rates. Thus, a huge pool of potential MHB and fungal community with widely distributed auxin-production potential extended the ability of T. vaccinum to form ectomycorrhiza. The forest community profited from the mycorrhizal fungus T. vaccinum, with spruce survival enhanced by 33% in microcosms using soil from the native habitat. A higher fungal abundance and diversity in cases where the tree had died during the experiment, showing that decomposition of plant litter from a dead tree supported a different community. T. vaccinum thus actively structured the community of microorganisms in its habitat.},
}
@article {pmid30842763,
year = {2019},
author = {Tipton, L and Darcy, JL and Hynson, NA},
title = {A Developing Symbiosis: Enabling Cross-Talk Between Ecologists and Microbiome Scientists.},
journal = {Frontiers in microbiology},
volume = {10},
number = {},
pages = {292},
doi = {10.3389/fmicb.2019.00292},
pmid = {30842763},
issn = {1664-302X},
abstract = {Like all interactions, the success of cross-discipline collaborations relies on effective communication. Ecology offers theoretical frameworks and lexicons to study microbiomes. Yet some of the terms and concepts borrowed from ecology are being used discordantly by microbiome studies from their traditional definitions. Here we define some of the ecological terms and concepts as they are used in ecology and the study of microbiomes. Where applicable, we have provided the historical context of the terms, highlighted examples from microbiome studies, and considered the research methods involved. We divided these concepts into four sections: Biomes, Diversity, Symbiosis, and Succession. Biomes encompass the interactions within the biotic and abiotic features of an environment. This extends to the term "microbiome," derived from "biome," and includes an environment and all the microbes within it. Diversity encompasses patterns of species richness, abundance, and biogeography, all of which are important to understanding the distribution of microbiomes. Symbiosis emphasizes the relationships between organisms within a community. Symbioses are often misunderstood to be synonymous with mutualism. We discard that implication, in favor of a broader, more historically accurate definition which spans the continuum from parasitism to mutualism. Succession includes classical succession, alternative stable states, community assembly frameworks, and r/K-selection. Our hope is that as microbiome researchers continue to apply ecological terms, and as ecologists continue to gain interest in microbiomes, each will do so in a way that enables cross-talk between them. We recommend initiating these collaborations by using a common lexicon, from which new concepts can emerge.},
}
@article {pmid30707331,
year = {2019},
author = {Rammitsu, K and Yagame, T and Yamashita, Y and Yukawa, T and Isshiki, S and Ogura-Tsujita, Y},
title = {A leafless epiphytic orchid, Taeniophyllum glandulosum Blume (Orchidaceae), is specifically associated with the Ceratobasidiaceae family of basidiomycetous fungi.},
journal = {Mycorrhiza},
volume = {29},
number = {2},
pages = {159-166},
doi = {10.1007/s00572-019-00881-7},
pmid = {30707331},
issn = {1432-1890},
support = {17K07536//Japan Society for the Promotion of Science/ ; 18H02500//Japan Society for the Promotion of Science/ ; },
mesh = {Basidiomycota/classification/*physiology ; DNA, Fungal/analysis ; Mycorrhizae/*physiology ; Orchidaceae/growth & development/*microbiology ; Photosynthesis ; Phylogeny ; Seedlings/growth & development/microbiology ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; },
abstract = {Leafless epiphytes in the Orchidaceae undergo a morphological metamorphosis in which the root has chloroplast-containing cortical cells and is the sole photosynthetic organ for carbon gain. All orchids are entirely dependent on mycorrhizal fungi for their carbon supply during seed germination, and this mycorrhizal association generally persists in adult plants. However, our knowledge of the mycorrhizal association of leafless epiphytic orchids remains limited, and the contribution of the mycorrhizal association to nutrient acquisition in these orchid species is largely unknown. In this study, the mycorrhizal fungi of a leafless epiphytic orchid, Taeniophyllum glandulosum, were identified molecularly using 68 mature plants and 17 seedlings. In total, 187 fungal internal transcribed spacer sequences were obtained, of which 99% were identified as Ceratobasidiaceae. These sequences were classified into five operational taxonomic units (OTUs) based on 97% sequence similarity. The most frequent sequence was OTU1, which accounted for 91% of all Ceratobasidiaceae sequences, although other phylogenetically distinct Ceratobasidiaceae fungi were detected. These results show that T. glandulosum is specifically associated with a particular group of Ceratobasidiaceae. All mycorrhizal fungi found in T. glandulosum seedlings belonged to OTU1, which was also found in adult plants on the same host tree. The mycorrhizal fungi from 13 host tree species were compared, and T. glandulosum was preferentially associated with OTU1 on 11 tree species. In conclusion, T. glandulosum is specifically associated with Ceratobasidiaceae fungi and this specific association remains throughout the orchid life cycle and is found on divergent host tree species.},
}
@article {pmid30303985,
year = {2018},
author = {Guénard, B and Dumont, F and Fréchette, B and Francoeur, A and Lucas, É},
title = {May furtive predation provide enemy free space in ant-tended aphid colonies?.},
journal = {PloS one},
volume = {13},
number = {10},
pages = {e0204019},
pmid = {30303985},
issn = {1932-6203},
mesh = {Animals ; Ants/*physiology ; Aphids/*physiology ; Behavior, Animal ; Coleoptera/*physiology ; Female ; Food Chain ; Predatory Behavior ; Symbiosis ; },
abstract = {In furtive predation, a predator is able to exploit its prey without generating significant defensive behaviors from them. However, in aphidophagous guild, if furtive predator can benefit from dilution effects generated by the aphids, they also suffer from intraguild predation from more mobile and active-searching predators. In this context ant-tended aphid colonies might not only represent an important food source but also potentially an enemy-free space for furtive predators if they remain unharmed by ants while other active predators are being repelled. Here we use the furtive predator Aphidoletes aphidimyza and two distinct instars of an active-searching predator, the Asian ladybeetle Harmonia axyridis, to test hypotheses related to predator persistence within aphid colonies in presence of ants. Our results show that persistence rate over time of the furtive predator was not affected by ant presence while it was strongly reduced for both instars of the active-searching predator. Furthermore, when ran in paired trials within ant-tended aphid colonies, furtive predator persistence rate was significantly higher than for active-searching predators, with these latter always leaving the plants quicker. Finally, we tested the importance of predator mobility in detection susceptibility and aggressive responses in ants using mobile and immobile active-searching predators. While the number of antennal palpations was similar for both treatments indicating similar detection rate, the number of ant attacks was significantly higher on mobile individuals highlighting the importance of movement in triggering aggressive responses in ants. Overall our results indicate that furtive predation represents an efficient strategy to limit ant aggressions, while the exclusion of active-searching predators might create an enemy-free space for furtive predators within ant-tended aphid colonies.},
}
@article {pmid30276936,
year = {2019},
author = {González, AH and Morales Londoño, D and Pille da Silva, E and Nascimento, FXI and de Souza, LF and da Silva, BG and Canei, AD and de Armas, RD and Giachini, AJ and Soares, CRFS},
title = {Bradyrhizobium and Pseudomonas strains obtained from coal-mining areas nodulate and promote the growth of Calopogonium muconoides plants used in the reclamation of degraded areas.},
journal = {Journal of applied microbiology},
volume = {126},
number = {2},
pages = {523-533},
doi = {10.1111/jam.14117},
pmid = {30276936},
issn = {1365-2672},
support = {407769/2016-1//CNPq Projeto Universal/ ; 407769/2016-1//CNPq/ ; //CAPES/ ; },
mesh = {Bradyrhizobium/isolation & purification/metabolism/*physiology ; *Coal Mining ; *Environmental Restoration and Remediation ; Fabaceae/*growth & development/metabolism/microbiology/physiology ; Plant Root Nodulation ; Pseudomonas/isolation & purification/metabolism/*physiology ; Rhizobium/isolation & purification/metabolism/physiology ; Soil ; Symbiosis ; },
abstract = {AIMS: The objective of this work was to isolate and characterize indigenous rhizobia from coal-mining areas able to efficiently nodulate and fix nitrogen in association with Calopogonium mucunoides (calopo).
METHODS AND RESULTS: Isolation, authentication and morphological, biochemical and molecular characterization of the autochthonous rhizobia were performed and their symbiotic efficiency (SE) evaluated. Efficient rhizobial isolates suitable for the inoculation of calopo in coal-mining regions were obtained. A total of 30 isolates were obtained after nodulation authentication, of which five presented high SE with plant-growth promoting traits such as indole-3-acetic acid production, phosphate solubilization and biofilm formation. These isolates were identified as belonging to Bradyrhizobium, Pseudomonas and Rhizobium.
CONCLUSIONS: Bradyrhizobium sp. A2-10 and Pseudomonas sp. A6-05 were able to promote calopo plant growth using soil obtained from coal-mining degraded areas, thus indicating their potential as inoculants aiming at land reclamation.
To our knowledge, this is the first report of Pseudomonas nodule formation in calopo. Furthermore, the results demonstrated that autochthonous rhizobia obtained from degraded soils presented high SE in calopo and possess a wide range of plant-growth promoting traits. Ultimately, they may all contribute to an increased leguminous plant growth under stress conditions. The selected rhizobia strains may be used as inoculants and present a valuable role in the development of strategies aiming to recover coal-mining degraded areas. Bacterial inoculants would greatly reduce the use of often harmful nitrogen fertilizers vastly employed in revegetation programmes of degraded areas.},
}
@article {pmid28762123,
year = {2017},
author = {Zhang, W and Meng, J and Ning, J and Qin, P and Zhou, J and Zou, Z and Wang, Y and Jiang, H and Ahmad, F and Zhao, L and Sun, J},
title = {Differential immune responses of Monochamus alternatus against symbiotic and entomopathogenic fungi.},
journal = {Science China. Life sciences},
volume = {60},
number = {8},
pages = {902-910},
doi = {10.1007/s11427-017-9102-y},
pmid = {28762123},
issn = {1869-1889},
mesh = {Animals ; Coleoptera/*immunology/microbiology ; Fungi/*physiology ; Genes, Fungal ; Host-Pathogen Interactions ; Immunity, Innate ; Signal Transduction ; Species Specificity ; Symbiosis ; Transcriptome ; },
abstract = {Monochamus alternatus, the main vector beetles of invasive pinewood nematode, has established a symbiotic relationship with a native ectotrophic fungal symbiont, Sporothrix sp. 1, in China. The immune response of M. alternatus to S. sp. 1 in the coexistence of beetles and fungi is, however, unknown. Here, we report that immune responses of M. alternatus pupae to infection caused by ectotrophic symbiotic fungus S. sp. 1 and entomopathogenic fungus Beauveria bassiana differ significantly. The S. sp. 1 did not kill the beetles while B. bassiana killed all upon injection. The transcriptome results showed that the numbers of differentially expressed genes in M. alternatus infected with S. sp. 1 were 2-fold less than those infected with B. bassiana at 48 hours post infection. It was noticed that Toll and IMD pathways played a leading role in the beetle's immune system when infected by symbiotic fungus, but upon infection by entomopathogenic fungus, only the Toll pathway gets triggered actively. Furthermore, the beetles could tolerate the infection of symbiotic fungi by retracing their Toll and IMD pathways at 48 h. This study provided a comprehensive sequence resource of M. alternatus transcriptome for further study of the immune interactions between host and associated fungi.},
}
@article {pmid30838204,
year = {2019},
author = {Acuña-Rodríguez, IS and Hansen, H and Gallardo-Cerda, J and Atala, C and Molina-Montenegro, MA},
title = {Antarctic Extremophiles: Biotechnological Alternative to Crop Productivity in Saline Soils.},
journal = {Frontiers in bioengineering and biotechnology},
volume = {7},
number = {},
pages = {22},
doi = {10.3389/fbioe.2019.00022},
pmid = {30838204},
issn = {2296-4185},
abstract = {Salinization of soils is one of the main sources of soil degradation worldwide, particularly in arid and semiarid ecosystems. High salinity results in osmotic stress and it can negatively impact plant grow and survival. Some plant species, however, can tolerate salinity by accumulating osmolytes like proline and maintaining low Na+ concentrations inside the cells. Another mechanism of saline stress tolerance is the association with symbiotic microorganism, an alternative that can be used as a biotechnological tool in susceptible crops. From the immense diversity of plant symbionts, those found in extreme environments such as Antarctica seems to be the ones with most potential since they (and their host) evolved in harsh and stressful conditions. We evaluated the effect of the inoculation with a consortium of plant growth-promoting rhizobacteria (PGPB) and endosymbiotic fungi isolated from an Antarctic plant on saline stress tolerance in different crops. To test this we established 4 treatments: (i) uninoculated plants with no saline stress, (ii) uninoculated plants subjected to saline stress (200 mM NaCl), (iii) plants inoculated with the microorganism consortium with no saline stress, and (iv) inoculated plants subjected to saline stress. First, we assessed the effect of symbiont consortium on survival of four different crops (cayenne, lettuce, onion, and tomato) in order to obtain a more generalized response of this biological interaction. Second, in order to deeply the mechanisms involved in salt tolerance, in lettuce plants we measured the ecophysiological performance (Fv/Fm) and lipid peroxidation to estimate the impact of saline stress on plants. We also measured proline accumulation and NHX1 antiporter gene expression (involved in Na+ detoxification) to search for possible mechanism of stress tolerance. Additionally, root, shoot, and total biomass was also obtained as an indicator of productivity. Overall, plants inoculated with microorganisms from Antarctica increased the fitness related traits in several crops. In fact, three of four crops selected to assess the general response increased its survival under salt conditions compared with those uninoculated plants. On the other hand, saline stress negatively impacted all measured trait, but inoculated plants were significantly less affected. In control osmotic conditions, there were no differences in proline accumulation and lipid peroxidation between inoculation treatments. Interestingly, even in control salinity, Fv/Fm was higher in inoculated plants after 30 and 60 days. Under osmotic stress, Fv/Fm, proline accumulation and NHX1 expression was significantly higher and lipid peroxidation lower in inoculated plants compared to uninoculated individuals. Moreover, inoculated plants exposed to saline stress had a similar final biomass (whole plant) compared to individuals under no stress. We conclude that Antarctic extremophiles can effectively reduce the physiological impact of saline stress in a salt-susceptible crops and also highlight extreme environments such as Antarctica as a key source of microorganism with high biotechnological potential.},
}
@article {pmid30837987,
year = {2019},
author = {Groeger, S and Meyle, J},
title = {Oral Mucosal Epithelial Cells.},
journal = {Frontiers in immunology},
volume = {10},
number = {},
pages = {208},
doi = {10.3389/fimmu.2019.00208},
pmid = {30837987},
issn = {1664-3224},
abstract = {Cellular Phenotype and Apoptosis: The function of epithelial tissues is the protection of the organism from chemical, microbial, and physical challenges which is indispensable for viability. To fulfill this task, oral epithelial cells follow a strongly regulated scheme of differentiation that results in the formation of structural proteins that manage the integrity of epithelial tissues and operate as a barrier. Oral epithelial cells are connected by various transmembrane proteins with specialized structures and functions. Keratin filaments adhere to the plasma membrane by desmosomes building a three-dimensional matrix. Cell-Cell Contacts and Bacterial Influence: It is known that pathogenic oral bacteria are able to affect the expression and configuration of cell-cell junctions. Human keratinocytes up-regulate immune-modulatory receptors upon stimulation with bacterial components. Periodontal pathogens including P. gingivalis are able to inhibit oral epithelial innate immune responses through various mechanisms and to escape from host immune reaction, which supports the persistence of periodontitis and furthermore is able to affect the epithelial barrier function by altering expression and distribution of cell-cell interactions including tight junctions (TJs) and adherens junctions (AJs). In the pathogenesis of periodontitis a highly organized biofilm community shifts from symbiosis to dysbiosis which results in destructive local inflammatory reactions. Cellular Receptors: Cell-surface located toll like receptors (TLRs) and cytoplasmatic nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) belong to the pattern recognition receptors (PRRs). PRRs recognize microbial parts that represent pathogen-associated molecular patterns (PAMPs). A multimeric complex of proteins known as inflammasome, which is a subset of NLRs, assembles after activation and proceeds to pro-inflammatory cytokine release. Cytokine Production and Release: Cytokines and bacterial products may lead to host cell mediated tissue destruction. Keratinocytes are able to produce diverse pro-inflammatory cytokines and chemokines, including interleukin (IL)-1, IL-6, IL-8 and tumor necrosis factor (TNF)-α. Infection by pathogenic bacteria such as Porphyromonas gingivalis (P. gingivalis) and Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) can induce a differentiated production of these cytokines. Immuno-modulation, Bacterial Infection, and Cancer Cells: There is a known association between bacterial infection and cancer. Bacterial components are able to up-regulate immune-modulatory receptors on cancer cells. Interactions of bacteria with tumor cells could support malignant transformation an environment with deficient immune regulation. The aim of this review is to present a set of molecular mechanisms of oral epithelial cells and their reactions to a number of toxic influences.},
}
@article {pmid30486338,
year = {2018},
author = {Amedei, A and Boem, F},
title = {I've Gut A Feeling: Microbiota Impacting the Conceptual and Experimental Perspectives of Personalized Medicine.},
journal = {International journal of molecular sciences},
volume = {19},
number = {12},
pages = {},
doi = {10.3390/ijms19123756},
pmid = {30486338},
issn = {1422-0067},
support = {FAS SALUTE 2014//Regione Toscana/ ; P2016.0808//Ente Cassa di Risparmio di Firenze/ ; },
mesh = {Animals ; Biodiversity ; Biological Therapy ; Disease Susceptibility ; Fecal Microbiota Transplantation ; Feces/microbiology ; *Gastrointestinal Microbiome ; Genomics/methods ; Humans ; Metagenomics/methods ; Microbiota ; Organ Specificity ; *Precision Medicine/methods ; Research ; Symbiosis ; },
abstract = {In recent years, the human microbiota has gained increasing relevance both in research and clinical fields. Increasing studies seem to suggest the centrality of the microbiota and its composition both in the development and maintenance of what we call "health" and in generating and/or favoring (those cases in which the microbiota's complex relational architecture is dysregulated) the onset of pathological conditions. The complex relationships between the microbiota and human beings, which invest core notions of biomedicine such as "health" and "individual," do concern not only problems of an empirical nature but seem to require the need to adopt new concepts and new perspectives in order to be properly analysed and utilized, especially for their therapeutic implementation. In this contribution we report and discuss some of the theoretical proposals and innovations (from the ecological component to the notion of polygenomic organism) aimed at producing this change of perspective. In conclusion, we summarily analyze what impact and what new challenges these new approaches might have on personalized/person centred/precision medicine.},
}
@article {pmid30321239,
year = {2018},
author = {Bonneau, M and Landmann, F and Labbé, P and Justy, F and Weill, M and Sicard, M},
title = {The cellular phenotype of cytoplasmic incompatibility in Culex pipiens in the light of cidB diversity.},
journal = {PLoS pathogens},
volume = {14},
number = {10},
pages = {e1007364},
pmid = {30321239},
issn = {1553-7374},
mesh = {Animals ; Animals, Genetically Modified/genetics/*microbiology ; Bacterial Proteins/genetics/*metabolism ; Culex/genetics/*microbiology ; Cytoplasm/*microbiology/pathology ; Drosophila melanogaster/genetics/*microbiology ; Female ; Gram-Negative Bacterial Infections/microbiology/pathology ; Host Specificity ; Male ; Phenotype ; *Polymorphism, Genetic ; Symbiosis ; Wolbachia/*physiology ; },
abstract = {Wolbachia are maternally inherited endosymbiotic bacteria, widespread among arthropods thanks to host reproductive manipulations that increase their prevalence into host populations. The most commonly observed manipulation is cytoplasmic incompatibility (CI). CI leads to embryonic death in crosses between i) infected males and uninfected females and ii) individuals infected with incompatible Wolbachia strains. CI can be conceptualized as a toxin-antidote system where a toxin deposited by Wolbachia in the sperm would induce embryonic death unless countered by an antidote produced by Wolbachia present in the eggs. In Drosophila melanogaster, transgenic expression of Wolbachia effector cidB revealed its function of CI-inducing toxin. Moreover in Culex pipiens, the diversity of cidB variants present in wPip strains accounts for the diversity in crossing-types. We conducted cytological analyses to determine the CI mechanisms that lead to embryonic death in C. pipiens, and assess whether diversity in crossing-types could be based on variations in these mechanisms. We revealed that paternal chromatin condensation and segregation defects during the first embryonic division are always responsible for embryonic death. The strongest observed defects lead to an exclusion of the paternal chromatin from the first zygotic division, resulting in haploid embryos unable to hatch. The proportion of unhatched haploid embryos, developing with only maternal chromatin, which reflects the frequency of strong defects can be considered as a proxy of CI intensity at the cellular level. We thus studied the putative effect of variations in crossing types and cidB diversification on CI defects intensity. Incompatible crosses involving distinct wPip strains revealed that CI defects intensity depends on the Wolbachia strains hosted by the males and is linked to the diversity of cidB genes harbored in their genomes. These results support that, additionally to its implication in C. pipiens crossing type variability, cidB diversification also influences the strength of CI embryonic defects.},
}
@article {pmid29540638,
year = {2018},
author = {Sharmin, D and Guo, Y and Nishizawa, T and Ohshima, S and Sato, Y and Takashima, Y and Narisawa, K and Ohta, H},
title = {Comparative Genomic Insights into Endofungal Lifestyles of Two Bacterial Endosymbionts, Mycoavidus cysteinexigens and Burkholderia rhizoxinica.},
journal = {Microbes and environments},
volume = {33},
number = {1},
pages = {66-76},
pmid = {29540638},
issn = {1347-4405},
mesh = {Burkholderia/*genetics/physiology ; Burkholderiaceae/*genetics/physiology ; Comparative Genomic Hybridization ; Fungi/*physiology ; Genome, Bacterial ; Metagenome ; Phylogeny ; Sequence Analysis, DNA ; *Symbiosis ; },
abstract = {Endohyphal bacteria (EHB), dwelling within fungal hyphae, markedly affect the growth and metabolic potential of their hosts. To date, two EHB belonging to the family Burkholderiaceae have been isolated and characterized as new taxa, Burkholderia rhizoxinica (HKI 454T) and Mycoavidus cysteinexigens (B1-EBT), in Japan. Metagenome sequencing was recently reported for Mortierella elongata AG77 together with its endosymbiont M. cysteinexigens (Mc-AG77) from a soil/litter sample in the USA. In the present study, we elucidated the complete genome sequence of B1-EBT and compared it with those of Mc-AG77 and HKI 454T. The genomes of B1-EBT and Mc-AG77 contained a higher level of prophage sequences and were markedly smaller than that of HKI 454T. Although the B1-EBT and Mc-AG77 genomes lacked the chitinolytic enzyme genes responsible for invasion into fungal cells, they contained several predicted toxin-antitoxin systems including an insecticidal toxin complex and PIN domain imposing an addiction-like mechanism essential for endohyphal growth control during host colonization. Despite the different host fungi, the alignment of amino acid sequences showed that the HKI 454T genome consisted of 1,265 (32.6%) and 1,221 (31.5%) orthologous coding sequences (CDSs) with those of B1-EBT and Mc-AG77, respectively. This comparative study of three phylogenetically associated endosymbionts has provided insights into their origin and evolution, and suggests the later bacterial invasion and adaptation of B1-EBT to its host metabolism.},
}
@article {pmid29367472,
year = {2018},
author = {Noda, S and Shimizu, D and Yuki, M and Kitade, O and Ohkuma, M},
title = {Host-Symbiont Cospeciation of Termite-Gut Cellulolytic Protists of the Genera Teranympha and Eucomonympha and their Treponema Endosymbionts.},
journal = {Microbes and environments},
volume = {33},
number = {1},
pages = {26-33},
pmid = {29367472},
issn = {1347-4405},
mesh = {Animals ; DNA, Bacterial/genetics ; Evolution, Molecular ; *Gastrointestinal Microbiome ; Isoptera/genetics/*microbiology ; Parabasalidea/genetics/*physiology ; Phylogeny ; RNA, Ribosomal, 16S ; Sequence Analysis, DNA ; *Symbiosis ; Treponema/genetics/*physiology ; },
abstract = {Cellulolytic flagellated protists inhabit the hindgut of termites. They are unique and essential to termites and related wood-feeding cockroaches, enabling host feeding on cellulosic matter. Protists of two genera in the family Teranymphidae (phylum Parabasalia), Eucomonympha and Teranympha, are phylogenetically closely related and harbor intracellular endosymbiotic bacteria from the genus Treponema. In order to obtain a clearer understanding of the evolutionary history of this triplex symbiotic relationship, the molecular phylogenies of the three symbiotic partners, the Teranymphidae protists, their Treponema endosymbionts, and their host termites, were inferred and compared. Strong congruence was observed in the tree topologies of all interacting partners, implying their cospeciating relationships. In contrast, the coevolutionary relationship between the Eucomonympha protists and their endosymbionts was more complex, and evidence of incongruence against cospeciating relationships suggested frequent host switches of the endosymbionts, possibly because multiple Eucomonympha species are present in the same gut community. Similarities in the 16S rRNA and gyrB gene sequences of the endosymbionts were higher among Teranympha spp. (>99.25% and >97.2%, respectively), whereas those between Teranympha and Eucomonympha were lower (<97.1% and <91.9%, respectively). In addition, the endosymbionts of Teranympha spp. formed a phylogenetic clade distinct from those of Eucomonympha spp. Therefore, the endosymbiont species of Teranympha spp., designated here as "Candidatus Treponema teratonymphae", needs to be classified as a species distinct from the endosymbiont species of Eucomonympha spp.},
}
@article {pmid30834262,
year = {2019},
author = {Paço, A and da-Silva, JR and Eliziário, F and Brígido, C and Oliveira, S and Alexandre, A},
title = {traG Gene Is Conserved across Mesorhizobium spp. Able to Nodulate the Same Host Plant and Expressed in Response to Root Exudates.},
journal = {BioMed research international},
volume = {2019},
number = {},
pages = {3715271},
doi = {10.1155/2019/3715271},
pmid = {30834262},
issn = {2314-6141},
abstract = {Evidences for an involvement of the bacterial type IV secretion system (T4SS) in the symbiotic relationship between rhizobia and legumes have been pointed out by several recent studies. However, information regarding this secretion system in Mesorhizobium is still very scarce. The aim of the present study was to investigate the phylogeny and expression of the traG gene, which encodes a substrate receptor of the T4SS. In addition, the occurrence and genomic context of this and other T4SS genes, namely, genes from tra/trb and virB/virD4 complexes, were also analyzed in order to unveil the structural and functional organization of T4SS in mesorhizobia. The location of the T4SS genes in the symbiotic region of the analyzed rhizobial genomes, along with the traG phylogeny, suggests that T4SS genes could be horizontally transferred together with the symbiosis genes. Regarding the T4SS structural organization in Mesorhizobium, the virB/virD4 genes were absent in all chickpea (Cicer arietinum L.) microsymbionts and in the Lotus symbiont Mesorhizobium japonicum MAFF303099T. Interestingly, the presence of genes belonging to another secretion system (T3SS) was restricted to these strains lacking the virB/virD4 genes. The traG gene expression was detected in M. mediterraneum Ca36T and M. ciceri LMS-1 strains when exposed to chickpea root exudates and also in the early nodules formed by M. mediterraneum Ca36T, but not in older nodules. This study contributes to a better understanding of the importance of T4SS in mutualistic symbiotic bacteria.},
}
@article {pmid30833646,
year = {2019},
author = {Hartmann, RM and Schaepe, S and Nübel, D and Petersen, AC and Bertolini, M and Vasilev, J and Küster, H and Hohnjec, N},
title = {Insights into the complex role of GRAS transcription factors in the arbuscular mycorrhiza symbiosis.},
journal = {Scientific reports},
volume = {9},
number = {1},
pages = {3360},
doi = {10.1038/s41598-019-40214-4},
pmid = {30833646},
issn = {2045-2322},
support = {GRK1798//Deutsche Forschungsgemeinschaft (German Research Foundation)/ ; },
abstract = {To improve access to limiting nutrients, the vast majority of land plants forms arbuscular mycorrhizal (AM) symbioses with Glomeromycota fungi. We show here that AM-related GRAS transcription factors from different subgroups are upregulated during a time course of mycorrhization. Based on expression studies in mutants defective in arbuscule branching (ram1-1, with a deleted MtRam1 GRAS transcription factor gene) or in the formation of functional arbuscules (pt4-2, mutated in the phosphate transporter gene MtPt4), we demonstrate that the five AM-related GRAS transcription factor genes MtGras1, MtGras4, MtGras6, MtGras7, and MtRad1 can be differentiated by their dependency on MtRAM1 and MtPT4, indicating that the network of AM-related GRAS transcription factors consists of at least two regulatory modules. One module involves the MtRAM1- and MtPT4-independent transcription factor MtGRAS4 that activates MtGras7. Another module is controlled by the MtRAM1- and MtPT4-dependent transcription factor MtGRAS1. Genome-wide expression profiles of mycorrhized MtGras1 knockdown and ram1-1 roots differ substantially, indicating different targets. Although an MtGras1 knockdown reduces transcription of AM-related GRAS transcription factor genes including MtRam1 and MtGras7, MtGras1 overexpression alone is not sufficient to activate MtGras genes. MtGras1 knockdown roots display normal fungal colonization, with a trend towards the formation of smaller arbuscules.},
}
@article {pmid30833394,
year = {2019},
author = {Moriano-Gutierrez, S and Koch, EJ and Bussan, H and Romano, K and Belcaid, M and Rey, FE and Ruby, EG and McFall-Ngai, MJ},
title = {Critical symbiont signals drive both local and systemic changes in diel and developmental host gene expression.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {},
number = {},
pages = {},
doi = {10.1073/pnas.1819897116},
pmid = {30833394},
issn = {1091-6490},
abstract = {The colonization of an animal's tissues by its microbial partners creates networks of communication across the host's body. We used the natural binary light-organ symbiosis between the squid Euprymna scolopes and its luminous bacterial partner, Vibrio fischeri, to define the impact of colonization on transcriptomic networks in the host. A night-active predator, E. scolopes coordinates the bioluminescence of its symbiont with visual cues from the environment to camouflage against moon and starlight. Like mammals, this symbiosis has a complex developmental program and a strong day/night rhythm. We determined how symbiont colonization impacted gene expression in the light organ itself, as well as in two anatomically remote organs: the eye and gill. While the overall transcriptional signature of light organ and gill were more alike, the impact of symbiosis was most pronounced and similar in light organ and eye, both in juvenile and adult animals. Furthermore, the presence of a symbiosis drove daily rhythms of transcription within all three organs. Finally, a single mutation in V. fischeri-specifically, deletion of the lux operon, which abrogates symbiont luminescence-reduced the symbiosis-dependent transcriptome of the light organ by two-thirds. In addition, while the gills responded similarly to light-organ colonization by either the wild-type or mutant, luminescence was required for all of the colonization-associated transcriptional responses in the juvenile eye. This study defines not only the impact of symbiont colonization on the coordination of animal transcriptomes, but also provides insight into how such changes might impact the behavior and ecology of the host.},
}
@article {pmid30833352,
year = {2019},
author = {Schäper, S and Wendt, H and Bamberger, J and Sieber, V and Schmid, J and Becker, A},
title = {A bifunctional UDP-sugar 4-epimerase supports biosynthesis of multiple cell surface polysaccharides in Sinorhizobium meliloti.},
journal = {Journal of bacteriology},
volume = {},
number = {},
pages = {},
doi = {10.1128/JB.00801-18},
pmid = {30833352},
issn = {1098-5530},
abstract = {Sinorhizobium meliloti produces multiple extracellular glycans, including among others lipopolysaccharides (LPS), and the exopolysaccharides (EPS) succinoglycan (SG) and galactoglucan (GG). These polysaccharides serve cell protective roles. Furthermore, SG and GG promote interaction of S. meliloti with its host Medicago sativa in root nodule symbiosis. ExoB has been suggested to be the sole enzyme catalyzing synthesis of UDP-galactose in S. meliloti (Mol Microbiol 5:1519-30, 1991, doi:10.1111/j.1365-2958.1991.tb00799.x). Accordingly, exoB mutants were previously found to be affected in synthesis of the galactose-containing glycans LPS, SG and GG, and consequently in symbiosis. Here, we report that the S. meliloti Rm2011 uxs1-uxe-apsS-apsH1-apsE-apsH2 (SMb20458-63) gene cluster directs biosynthesis of an arabinose-containing polysaccharide (APS), which contributes to biofilm formation, and is solely or mainly composed of arabinose. Uxe has previously been identified as UDP-xylose 4-epimerase. Collectively, our data from mutational and overexpression analysis of the APS biosynthesis genes, and in vitro enzymatic assays indicate that Uxe functions as UDP-xylose 4- and UDP-glucose 4-epimerase catalyzing UDP-xylose/UDP-arabinose and UDP-glucose/UDP-galactose interconversions, respectively. Overexpression of uxe suppressed the phenotypes of an exoB mutant, evidencing that Uxe can functionally replace ExoB. We suggest that under conditions stimulating expression of the APS biosynthesis operon, Uxe contributes to synthesis of multiple glycans, and thereby to cell protection, biofilm formation, and symbiosis. Furthermore, we show that the C2H2 zinc finger transcriptional regulator MucR counteracts the previously reported CuxR-c-di-GMP-mediated activation of the APS biosynthesis operon. This integrates the c-di-GMP-dependent control of APS production into the opposing regulation of EPS biosynthesis and swimming motility in S. melilotiIMPORTANCE Bacterial extracellular polysaccharides serve important cell protective, structural, and signaling roles. They have particularly attracted attention as adhesives and matrix components promoting biofilm formation, which significantly contributes to resistance against antibiotics. In the root nodule symbiosis between rhizobia and leguminous plants, extracellular polysaccharides have a signaling function. UDP-sugar 4-epimerases are important enzymes in the synthesis of the activated sugar substrates, which are frequently shared between multiple polysaccharide biosynthesis pathways. Thus, these enzymes are potential targets to interfere with these pathways. Our finding of a bifunctional UDP-sugar 4-epimerase in Sinorhizobium meliloti generally advances the knowledge of substrate promiscuity of such enzymes and specifically of the biosynthesis of extracellular polysaccharides involved in biofilm formation and symbiosis in this α-proteobacterium.},
}
@article {pmid30832582,
year = {2019},
author = {Silvestri, A and Fiorilli, V and Miozzi, L and Accotto, GP and Turina, M and Lanfranco, L},
title = {In silico analysis of fungal small RNA accumulation reveals putative plant mRNA targets in the symbiosis between an arbuscular mycorrhizal fungus and its host plant.},
journal = {BMC genomics},
volume = {20},
number = {1},
pages = {169},
doi = {10.1186/s12864-019-5561-0},
pmid = {30832582},
issn = {1471-2164},
support = {60% project//Ministero dell'Istruzione, dell'Università e della Ricerca/ ; },
abstract = {BACKGROUND: Small RNAs (sRNAs) are short non-coding RNA molecules (20-30 nt) that regulate gene expression at transcriptional or post-transcriptional levels in many eukaryotic organisms, through a mechanism known as RNA interference (RNAi). Recent studies have highlighted that they are also involved in cross-kingdom communication: sRNAs can move across the contact surfaces from "donor" to "receiver" organisms and, once in the host cells of the receiver, they can target specific mRNAs, leading to a modulation of host metabolic pathways and defense responses. Very little is known about RNAi mechanism and sRNAs occurrence in Arbuscular Mycorrhizal Fungi (AMF), an important component of the plant root microbiota that provide several benefits to host plants, such as improved mineral uptake and tolerance to biotic and abiotic stress.
RESULTS: Taking advantage of the available genomic resources for the AMF Rhizophagus irregularis we described its putative RNAi machinery, which is characterized by a single Dicer-like (DCL) gene and an unusual expansion of Argonaute-like (AGO-like) and RNA-dependent RNA polymerase (RdRp) gene families. In silico investigations of previously published transcriptomic data and experimental assays carried out in this work provided evidence of gene expression for most of the identified sequences. Focusing on the symbiosis between R. irregularis and the model plant Medicago truncatula, we characterized the fungal sRNA population, highlighting the occurrence of an active sRNA-generating pathway and the presence of microRNA-like sequences. In silico analyses, supported by host plant degradome data, revealed that several fungal sRNAs have the potential to target M. truncatula transcripts, including some specific mRNA already shown to be modulated in roots upon AMF colonization.
CONCLUSIONS: The identification of RNAi-related genes, together with the characterization of the sRNAs population, suggest that R. irregularis is equipped with a functional sRNA-generating pathway. Moreover, the in silico analysis predicted 237 plant transcripts as putative targets of specific fungal sRNAs suggesting that cross-kingdom post-transcriptional gene silencing may occur during AMF colonization.},
}
@article {pmid30832272,
year = {2019},
author = {Chatterjee, S and Yadav, S},
title = {The Origin of Prebiotic Information System in the Peptide/RNA World: A Simulation Model of the Evolution of Translation and the Genetic Code.},
journal = {Life (Basel, Switzerland)},
volume = {9},
number = {1},
pages = {},
doi = {10.3390/life9010025},
pmid = {30832272},
issn = {2075-1729},
abstract = {Information is the currency of life, but the origin of prebiotic information remains a mystery. We propose transitional pathways from the cosmic building blocks of life to the complex prebiotic organic chemistry that led to the origin of information systems. The prebiotic information system, specifically the genetic code, is segregated, linear, and digital, and it appeared before the emergence of DNA. In the peptide/RNA world, lipid membranes randomly encapsulated amino acids, RNA, and peptide molecules, which are drawn from the prebiotic soup, to initiate a molecular symbiosis inside the protocells. This endosymbiosis led to the hierarchical emergence of several requisite components of the translation machine: transfer RNAs (tRNAs), aminoacyl-tRNA synthetase (aaRS), messenger RNAs (mRNAs), ribosomes, and various enzymes. When assembled in the right order, the translation machine created proteins, a process that transferred information from mRNAs to assemble amino acids into polypeptide chains. This was the beginning of the prebiotic information age. The origin of the genetic code is enigmatic; herein, we propose an evolutionary explanation: the demand for a wide range of protein enzymes over peptides in the prebiotic reactions was the main selective pressure for the origin of information-directed protein synthesis. The molecular basis of the genetic code manifests itself in the interaction of aaRS and their cognate tRNAs. In the beginning, aminoacylated ribozymes used amino acids as a cofactor with the help of bridge peptides as a process for selection between amino acids and their cognate codons/anticodons. This process selects amino acids and RNA species for the next steps. The ribozymes would give rise to pre-tRNA and the bridge peptides to pre-aaRS. Later, variants would appear and evolution would produce different but specific aaRS-tRNA-amino acid combinations. Pre-tRNA designed and built pre-mRNA for the storage of information regarding its cognate amino acid. Each pre-mRNA strand became the storage device for the genetic information that encoded the amino acid sequences in triplet nucleotides. As information appeared in the digital languages of the codon within pre-mRNA and mRNA, and the genetic code for protein synthesis evolved, the prebiotic chemistry then became more organized and directional with the emergence of the translation and genetic code. The genetic code developed in three stages that are coincident with the refinement of the translation machines: the GNC code that was developed by the pre-tRNA/pre-aaRS /pre-mRNA machine, SNS code by the tRNA/aaRS/mRNA machine, and finally the universal genetic code by the tRNA/aaRS/mRNA/ribosome machine. We suggest the coevolution of translation machines and the genetic code. The emergence of the translation machines was the beginning of the Darwinian evolution, an interplay between information and its supporting structure. Our hypothesis provides the logical and incremental steps for the origin of the programmed protein synthesis. In order to better understand the prebiotic information system, we converted letter codons into numerical codons in the Universal Genetic Code Table. We have developed a software, called CATI (Codon-Amino Acid-Translator-Imitator), to translate randomly chosen numerical codons into corresponding amino acids and vice versa. This conversion has granted us insight into how the genetic code might have evolved in the peptide/RNA world. There is great potential in the application of numerical codons to bioinformatics, such as barcoding, DNA mining, or DNA fingerprinting. We constructed the likely biochemical pathways for the origin of translation and the genetic code using the Model-View-Controller (MVC) software framework, and the translation machinery step-by-step. While using AnyLogic software, we were able to simulate and visualize the entire evolution of the translation machines, amino acids, and the genetic code.},
}
@article {pmid30830326,
year = {2017},
author = {Hillyer, KE and Dias, D and Lutz, A and Roessner, U and Davy, SK},
title = {13C metabolomics reveals widespread change in carbon fate during coral bleaching.},
journal = {Metabolomics : Official journal of the Metabolomic Society},
volume = {14},
number = {1},
pages = {12},
doi = {10.1007/s11306-017-1306-8},
pmid = {30830326},
issn = {1573-3890},
support = {VUW0902//Marsden Fund/ ; },
abstract = {INTRODUCTION: Rising seawater temperatures are threatening the persistence of coral reefs; where above critical thresholds, thermal stress results in a breakdown of the coral-dinoflagellate symbiosis and the loss of algal symbionts (coral bleaching). As symbiont-derived organic products typically form a major portion of host energy budgets, this has major implications for the fitness and persistence of symbiotic corals.
OBJECTIVES: We aimed to determine change in autotrophic carbon fate within individual compounds and downstream metabolic pathways in a coral symbiosis exposed to varying degrees of thermal stress and bleaching.
METHODS: We applied gas chromatography-mass spectrometry coupled to a stable isotope tracer (13C), to track change in autotrophic carbon fate, in symbiont and host individually, following exposure to elevated water temperature.
RESULTS: Thermal stress resulted in partner-specific changes in carbon fate, which progressed with heat stress duration. We detected modifications to carbohydrate and fatty acid metabolism, lipogenesis, and homeostatic responses to thermal, oxidative and osmotic stress. Despite pronounced photodamage, remaining in hospite symbionts continued to produce organic products de novo and translocate to the coral host. However as bleaching progressed, we observed minimal 13C enrichment of symbiont long-chain fatty acids, also reflected in 13C enrichment of host fatty acid pools.
CONCLUSION: These data have major implications for our understanding of coral symbiosis function during bleaching. Our findings suggest that during early stage bleaching, remaining symbionts continue to effectively translocate a variety of organic products to the host, however under prolonged thermal stress there is likely a reduction in the quality of these products.},
}
@article {pmid30396500,
year = {2018},
author = {Mazzocca, A and Ferraro, G and Misciagna, G and Fais, S},
title = {Moving the systemic evolutionary approach to cancer forward: Therapeutic implications.},
journal = {Medical hypotheses},
volume = {121},
number = {},
pages = {80-87},
doi = {10.1016/j.mehy.2018.09.033},
pmid = {30396500},
issn = {1532-2777},
mesh = {Anti-Bacterial Agents/therapeutic use ; Antineoplastic Agents/*therapeutic use ; *Biological Evolution ; Carcinogenesis ; Electromagnetic Fields ; Humans ; Hydrogen-Ion Concentration ; Inflammation ; Liver Neoplasms/physiopathology/*therapy ; Membrane Potentials ; Organelles ; Phenotype ; Plant Extracts/therapeutic use ; Plants ; Symbiosis/*physiology ; },
abstract = {We have previously presented a new Systemic Evolutionary Theory of Cancer (SETOC) based on the failure of proper endosymbiosis in eukaryotic cells. Here, we propose that the progressive uncoupling of two endosymbiotic subsystems (information and energy) inside the cell, as a consequence of long-term injuries, gives rise to alterations (i) in tissue interactions and (ii) in cell organization. In the first case, we argue that the impairment of both the coherent state and the synergy between intercellular communications underpins the onset of tissue dysplasia, that usually evolves towards cancer development. In the second case, we suggest that the rupture of endosymbiosis drives a sort of cell regression towards a protist-like entity represented by the concept of "de-emergence" postulated in our systemic evolutionary approach to carcinogenesis. This conceptual association of the cancer cell with a protist-like organism could support the development of novel cancer therapeutic approaches. To this end, we propose a paradigm shift in cancer pharmacology since: i) our knowledge of cancer pathophysiology as a complex system is insufficient, despite a vast knowledge of molecular mechanisms underlying cancer; ii) current cancer pharmacology deals only with microvariables (e.g. gene or protein targets), which do not account for the integrated pathophysiology of cancer, rather than with macrovariables (e.g. pH, membrane potential, electromagnetic fields, cell communications and so on) and mesovariables (between micro and macro), such as the interaction between various cellular components including cellular organelles. This paradigm shift should allow cancer pharmacology to move forward from molecular treatments (focusing on single targets) to modular treatments that consider cancer-related processes (i.e. inflammation, coagulation, etc.) or even to a sort of ecosystemic treatment addressing the whole functioning of the "cancer ecosystem". Examples of ecosystems treatment may be natural plant derivatives that act synergistically or pulsed electromagnetic fields which can act on particular biological processes in cancer cells. In addition, we need different working theoretical models on which to base new anticancer pharmacological approaches. Finally, we examine what value our systemic evolutionary approach could add to cancer treatments, in particular in liver cancer as a paradigm for developing potential applications.},
}
@article {pmid29856670,
year = {2018},
author = {Gula, RL and Adams, DK},
title = {Effects of Symbiodinium Colonization on Growth and Cell Proliferation in the Giant Clam Hippopus hippopus.},
journal = {The Biological bulletin},
volume = {234},
number = {2},
pages = {130-138},
doi = {10.1086/698265},
pmid = {29856670},
issn = {1939-8697},
mesh = {Animals ; Bivalvia/cytology/growth & development/*parasitology/*physiology ; Cell Proliferation ; Dinoflagellida/*physiology ; Symbiosis/*physiology ; },
abstract = {Giant clams (subfamily Tridacnidae) house their obligate symbionts, Symbiodinium sp., in a specialized tubular system. Rapid uptake of Symbiodinium has been shown to increase early clam survival, suggesting that symbionts play an essential role in host growth and development. To determine whether symbionts influence development in the giant clam Hippopus hippopus, we compared growth patterns and cell proliferation in two groups of clams inoculated or not inoculated (control) with Symbiodinium sp. Symbiont uptake occurred continuously from days 8 to 26 post-fertilization, with, on average, ∼5% per day colonized. The control treatment grew even without symbionts (1.03 ± 0.41 µm per day, standard error). Inoculated individuals grew significantly faster (2.91 ± 0.37 µm per day) than control individuals (P < 0.001). However, daily shell length measurements did not significantly differ between treatments until day 22, and ∼97% of control individuals metamorphosed by day 24, suggesting a delay in growth effects. Consistent with this, at day 13, clam cell proliferation was not correlated with symbiont abundance in inoculated individuals (P = 0.13), while at day 26, it was (P < 0.01). The proliferating cell pattern also changed from being randomly distributed (P = 0.99) at day 13 to non-randomly distributed (P = 0.002), with increased likelihood of proliferation within ∼25 µm of a symbiont, at day 26. Our results indicate that H. hippopus has a longer Symbiodinium acquisition period than previously recorded, after which proliferation and development are enhanced but during which growth is unaffected by Symbiodinium.},
}
@article {pmid29377516,
year = {2018},
author = {Siegmund, L and Schweikert, M and Fischer, MS and Wöstemeyer, J},
title = {Bacterial Surface Traits Influence Digestion by Tetrahymena pyriformis and Alter Opportunity to Escape from Food Vacuoles.},
journal = {The Journal of eukaryotic microbiology},
volume = {65},
number = {5},
pages = {600-611},
doi = {10.1111/jeu.12504},
pmid = {29377516},
issn = {1550-7408},
mesh = {Escherichia coli/*chemistry/ultrastructure ; Microscopy, Electron, Transmission ; Phagosomes/microbiology ; Surface Properties ; Symbiosis ; Tetrahymena pyriformis/microbiology/*physiology/ultrastructure ; Vacuoles/*microbiology/ultrastructure ; },
abstract = {Endosymbiotic interactions are frequently found in nature, especially in the group of protists. Even though many endosymbioses have been studied in detail, little is known about the mechanistic origins and physiological prerequisites of endosymbiont establishment. A logical step towards the development of endocytobiotic associations is evading digestion and escaping from the host's food vacuoles. Surface properties of bacteria are probably involved in these processes. Therefore, we chemically modified the surface of a transformant strain of Escherichia coli prior to feeding to Tetrahymena pyriformis. N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide allows any substance carrying amino- or carboxyl groups to be bound covalently to the bacterial surface by forming a peptide bond, thus, altering its properties biochemically and biophysically in a predictable manner. The effect of different traits on digestion of T. pyriformis was examined by fluorescence and transmission electron microscopy. The efficiency of digestion differs considerably depending on the coupled substances. Alkaline substances inhibit digestion partially, resulting in incomplete digestion and slightly enhanced escape rates. Increasing hydrophobicity leads to much higher escape frequencies. Both results point to possible mechanisms employed by pathogenic bacteria or potential endosymbionts in evading digestion and transmission to the host's cytoplasm.},
}
@article {pmid30830220,
year = {2019},
author = {Helber, SB and Steinert, G and Wu, YC and Rohde, S and Hentschel, U and Muhando, CA and Schupp, PJ},
title = {Sponges from Zanzibar host diverse prokaryotic communities with potential for natural product synthesis.},
journal = {FEMS microbiology ecology},
volume = {},
number = {},
pages = {},
doi = {10.1093/femsec/fiz026},
pmid = {30830220},
issn = {1574-6941},
abstract = {Sponges are one of the most dominant organisms in marine ecosystems. One reason for their success is their association with microorganisms that are besides the host itself responsible for the chemical defence. Sponge abundances have been increasing on coral reefs in the Western Indian Ocean (WIO) and are predicted to increase further with rising anthropogenic impacts on coral reefs. However, there is a paucity of information on chemical ecology of sponges from the WIO and their prokaryotic community composition. We used a combination of Illumina sequencing and a predictive metagenomic analysis to (1) assess the prokaryotic community composition of sponges from Zanzibar, (2) predict the presence of KEGG metabolic pathways responsible for bioactive compound production and (3) relate their presence to the degree of observed chemical defence in their respective sponge host. We found that sponges from Zanzibar host diverse prokaryotic communities that are host species-specific. Sponge-species and respective specimens that showed strong chemical defences in previous studies were also predicted to be highly enriched in various pathways responsible for secondary metabolite production. Hence, the combined sequencing and predictive metagenomic approach proved to be a useful indicator for the metabolic potential of sponge holobionts.},
}
@article {pmid30828777,
year = {2019},
author = {Vitanović, E and Aldrich, JR and Winterton, SL and Boundy-Mills, K and Lopez, JM and Zalom, FG},
title = {Attraction of the Green Lacewing Chrysoperla comanche (Neuroptera: Chrysopidae) to Yeast.},
journal = {Journal of chemical ecology},
volume = {},
number = {},
pages = {},
doi = {10.1007/s10886-019-01060-w},
pmid = {30828777},
issn = {1573-1561},
abstract = {Many adult Chrysoperla comanche (Stephens) green lacewings were caught in traps baited with live yeast cultures during tests designed to catch olive fruit flies. All 13 yeast species tested were more attractive than the industry-standard dried torula yeast (Cyberlindnera jadinii; syn. Candida utilis). Live C. jadinii culture attracted significantly more lacewings than the inactive dried-pellet form of the same yeast species, demonstrating that volatiles from live yeast cultures attract adults of this lacewing. Odor profiles for two of the highly active yeasts tested herein (Lachancea thermotolerans and Solicoccozyma terrea) were similar to that for Metschnikowia pulcherrima, a yeast species isolated earlier from the gut diverticulum of Chrysoperla rufilabris. A new Metschnikowia species (M. chrysoperlae), along with two new Candida spp. that were recently realigned to one of the Metschnikowia clades (M. picachoensis and M. pimensis), were also identified from the diverticulum of C. comanche. Thus, one clade of Metschnikowia yeasts that commonly occur in floral nectar appears to exhibit mutualistic symbioses with Chrysoperla green lacewings. Both male and female C. comanche adults were attracted in the present study, and we speculate that males have exploited this symbiosis by offering Metschnikowia-laden regurgitant, including attractive volatiles, to females ('mating trophallaxis') as a nuptial gift.},
}
@article {pmid30828341,
year = {2019},
author = {Fernandez-Göbel, TF and Deanna, R and Muñoz, NB and Robert, G and Asurmendi, S and Lascano, R},
title = {Redox Systemic Signaling and Induced Tolerance Responses During Soybean-Bradyrhizobium japonicum Interaction: Involvement of Nod Factor Receptor and Autoregulation of Nodulation.},
journal = {Frontiers in plant science},
volume = {10},
number = {},
pages = {141},
doi = {10.3389/fpls.2019.00141},
pmid = {30828341},
issn = {1664-462X},
abstract = {The symbiotic relationship between legumes and nitrogen-fixing rhizobia induces local and systemic responses, which ultimately lead to nodule formation. The autoregulation of nodulation (AON) is a systemic mechanism related to innate immunity that controls nodule development and involves different components ranging from hormones, peptides, receptors to small RNAs. Here, we characterized a rapid systemic redox changes induced during soybean-Bradyrhizobium japonicum symbiotic interaction. A transient peak of reactive oxygen species (ROS) generation was found in soybean leaves after 30 min of root inoculation with B. japonicum. The ROS response was accompanied by changes in the redox state of glutathione and by activation of antioxidant enzymes. Moreover, the ROS peak and antioxidant enzyme activation were abolished in leaves by the addition, in either root or leaf, of DPI, an NADPH oxidase inhibitor. Likewise, these systemic redox changes primed the plant increasing its tolerance to photooxidative stress. With the use of non-nodulating nfr5-mutant and hyper-nodulating nark-mutant soybean plants, we subsequently studied the systemic redox changes. The nfr5-mutant lacked the systemic redox changes after inoculation, whereas the nark-mutant showed a similar redox systemic signaling than the wild type plants. However, neither nfr5- nor nark-mutant exhibited tolerance to photooxidative stress condition. Altogether, these results demonstrated that (i) the early redox systemic signaling during symbiotic interaction depends on a Nod factor receptor, and that (ii) the induced tolerance response depends on the AON mechanisms.},
}
@article {pmid30827917,
year = {2019},
author = {Decelle, J and Stryhanyuk, H and Gallet, B and Veronesi, G and Schmidt, M and Balzano, S and Marro, S and Uwizeye, C and Jouneau, PH and Lupette, J and Jouhet, J and Maréchal, E and Schwab, Y and Schieber, NL and Tucoulou, R and Richnow, H and Finazzi, G and Musat, N},
title = {Algal Remodeling in a Ubiquitous Planktonic Photosymbiosis.},
journal = {Current biology : CB},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.cub.2019.01.073},
pmid = {30827917},
issn = {1879-0445},
abstract = {Photosymbiosis between single-celled hosts and microalgae is common in oceanic plankton, especially in oligotrophic surface waters. However, the functioning of this ecologically important cell-cell interaction and the subcellular mechanisms allowing the host to accommodate and benefit from its microalgae remain enigmatic. Here, using a combination of quantitative single-cell structural and chemical imaging techniques (FIB-SEM, nanoSIMS, Synchrotron X-ray fluorescence), we show that the structural organization, physiology, and trophic status of the algal symbionts (the haptophyte Phaeocystis) significantly change within their acantharian hosts compared to their free-living phase in culture. In symbiosis, algal cell division is blocked, photosynthesis is enhanced, and cell volume is increased by up to 10-fold with a higher number of plastids (from 2 to up to 30) and thylakoid membranes. The multiplication of plastids can lead to a 38-fold increase of the total plastid volume in a cell. Subcellular mapping of nutrients (nitrogen and phosphorous) and their stoichiometric ratios shows that symbiotic algae are impoverished in phosphorous and suggests a higher investment in energy-acquisition machinery rather than in growth. Nanoscale imaging also showed that the host supplies a substantial amount of trace metals (e.g., iron and cobalt), which are stored in algal vacuoles at high concentrations (up to 660 ppm). Sulfur mapping reveals a high concentration in algal vacuoles that may be a source of antioxidant molecules. Overall, this study unveils an unprecedented morphological and metabolic transformation of microalgae following their integration into a host, and it suggests that this widespread symbiosis is a farming strategy wherein the host engulfs and exploits microalgae.},
}
@article {pmid30540238,
year = {2019},
author = {Altamia, MA and Shipway, JR and Concepcion, GP and Haygood, MG and Distel, DL},
title = {Thiosocius teredinicola gen. nov., sp. nov., a sulfur-oxidizing chemolithoautotrophic endosymbiont cultivated from the gills of the giant shipworm, Kuphus polythalamius.},
journal = {International journal of systematic and evolutionary microbiology},
volume = {69},
number = {3},
pages = {638-644},
doi = {10.1099/ijsem.0.003143},
pmid = {30540238},
issn = {1466-5034},
abstract = {A chemolithoautotrophic sulfur-oxidizing, diazotrophic, facultatively heterotrophic, endosymbiotic bacterium, designated as strain 2141T, was isolated from the gills of the giant shipworm Kuphus polythalamius (Teredinidae: Bivalvia). Based on its 16S rRNA sequence, the endosymbiont falls within a clade that includes the as-yet-uncultivated thioautotrophic symbionts of a marine ciliate and hydrothermal vent gastropods, uncultivated marine sediment bacteria, and a free-living sulfur-oxidizing bacterium ODIII6, all of which belong to the Gammaproteobacteria. The endosymbiont is Gram-negative, rod-shaped and has a single polar flagellum when grown in culture. This bacterium can be grown chemolithoautotrophically on a chemically defined medium supplemented with either hydrogen sulfide, thiosulfate, tetrathionate or elemental sulfur. The closed-circular genome has a DNA G+C content of 60.1 mol% and is 4.79 Mbp in size with a large nitrogenase cluster spanning nearly 40 kbp. The diazotrophic capability was confirmed by growing the strain on chemolithoautotrophic thiosulfate-based medium without a combined source of fixed nitrogen. The bacterium is also capable of heterotrophic growth on organic acids such as acetate and propionate. The pH, temperature and salinity optima for chemolithoautotrophic growth on thiosulfate were found to be 8.5, 34 °C and 0.2 M NaCl, respectively. To our knowledge, this is the first report of pure culture of a thioautotrophic animal symbiont. The type strain of Thiosocius teredinicola is PMS-2141T.STBD.0c.01aT (=DSM 108030T).},
}
@article {pmid30515998,
year = {2019},
author = {Timmis, K and Jebok, F and Rohde, M and Molinari, G},
title = {Microbiome yarns: The Global Phenotype-Genotype Survey: Episode I: all my worldly goods, including my microbiome, I thee endow.},
journal = {Microbial biotechnology},
volume = {12},
number = {1},
pages = {11-24},
doi = {10.1111/1751-7915.13341},
pmid = {30515998},
issn = {1751-7915},
mesh = {*Biological Variation, Individual ; *Gastrointestinal Microbiome ; *Genotype ; Humans ; *Microbiota ; *Phenotype ; *Symbiosis ; },
}
@article {pmid30328280,
year = {2019},
author = {Thomashow, LS and LeTourneau, MK and Kwak, YS and Weller, DM},
title = {The soil-borne legacy in the age of the holobiont.},
journal = {Microbial biotechnology},
volume = {12},
number = {1},
pages = {51-54},
doi = {10.1111/1751-7915.13325},
pmid = {30328280},
issn = {1751-7915},
mesh = {Agriculture/*methods ; *Plant Development ; Plant Diseases/microbiology/*prevention & control ; Plants/immunology/*microbiology ; *Soil Microbiology ; Symbiosis ; },
abstract = {Future efforts to increase agricultural productivity will focus on crops as functional units comprised of plants and their associated microflora in the context of the various environments in which they are grown. It is suggested that future efforts to increase agricultural productivity will focus on crops as functional units comprised of plants and their associated beneficial microorganisms in the context in which they are grown. Scientists, industry, and farmers must work closely together to develop, adapt, and apply new technologies to a wide range of cropping systems. Consumer education is needed help grow public awareness that 'plant probiotics' offer a safe and environmentally friendly alternative to dependence on the use of chemical pesticides.},
}
@article {pmid30279284,
year = {2018},
author = {Rowley, CA and Anderson, CJ and Kendall, MM},
title = {Ethanolamine Influences Human Commensal Escherichia coli Growth, Gene Expression, and Competition with Enterohemorrhagic E. coli O157:H7.},
journal = {mBio},
volume = {9},
number = {5},
pages = {},
pmid = {30279284},
issn = {2150-7511},
support = {R01 AI118732/AI/NIAID NIH HHS/United States ; R21 AI130439/AI/NIAID NIH HHS/United States ; T32 AI007046/AI/NIAID NIH HHS/United States ; T32 GM007267/GM/NIGMS NIH HHS/United States ; },
mesh = {Escherichia coli/*drug effects/*genetics/growth & development ; Escherichia coli O157/*drug effects/*genetics/growth & development ; Ethanolamine/*pharmacology ; Gastrointestinal Tract/microbiology ; Gene Expression ; Host Microbial Interactions/drug effects ; Host-Pathogen Interactions/drug effects ; Humans ; Microbial Interactions/*drug effects ; Microbiota/drug effects ; Signal Transduction ; Symbiosis ; Virulence ; },
abstract = {A core principle of bacterial pathogenesis is that pathogens preferentially utilize metabolites that commensal bacteria do not in order to sidestep nutritional competition. The metabolite ethanolamine (EA) is well recognized to play a central role in host adaptation for diverse pathogens. EA promotes growth and influences virulence during host infection. Although genes encoding EA utilization have been identified in diverse bacteria (nonpathogenic and pathogenic), a prevailing idea is that commensal bacteria do not utilize EA to enhance growth, and thus, EA is a noncompetitive metabolite for pathogens. Here, we show that EA augments growth of two human commensal strains of Escherichia coli Significantly, these commensal strains grow more rapidly than, and even outcompete, the pathogen enterohemorrhagic E. coli O157:H7 specifically when EA is provided as the sole nitrogen source. Moreover, EA-dependent signaling is similarly conserved in the human commensal E. coli strain HS and influences expression of adhesins. These findings suggest a more extensive role for EA utilization in bacterial physiology and host-microbiota-pathogen interactions than previously appreciated.IMPORTANCE The microbiota protects the host from invading pathogens by limiting access to nutrients. In turn, bacterial pathogens selectively exploit metabolites not readily used by the microbiota to establish infection. Ethanolamine has been linked to pathogenesis of diverse pathogens by serving as a noncompetitive metabolite that enhances pathogen growth as well as a signal that modulates virulence. Although ethanolamine is abundant in the gastrointestinal tract, the prevailing idea is that commensal bacteria do not utilize EA, and thus, EA utilization has been particularly associated with pathogenesis. Here, we provide evidence that two human commensal Escherichia coli isolates readily utilize ethanolamine to enhance growth, modulate gene expression, and outgrow the pathogen enterohemorrhagic E. coli These data indicate a more complex role for ethanolamine in host-microbiota-pathogen interactions.},
}
@article {pmid30261054,
year = {2018},
author = {Carpinone, EM and Li, Z and Mills, MK and Foltz, C and Brannon, ER and Carlow, CKS and Starai, VJ},
title = {Identification of putative effectors of the Type IV secretion system from the Wolbachia endosymbiont of Brugia malayi.},
journal = {PloS one},
volume = {13},
number = {9},
pages = {e0204736},
pmid = {30261054},
issn = {1932-6203},
support = {R01 AI100913/AI/NIAID NIH HHS/United States ; },
mesh = {Animals ; *Bacterial Proteins/biosynthesis/genetics ; Brugia malayi/*microbiology ; Gene Expression Regulation, Bacterial/*physiology ; Saccharomyces cerevisiae/genetics/metabolism ; *Symbiosis ; *Type IV Secretion Systems/genetics/metabolism ; *Wolbachia/genetics/metabolism ; },
abstract = {Wolbachia is an unculturable, intracellular bacterium that persists within an extremely broad range of arthropod and parasitic nematode hosts, where it is transmitted maternally to offspring via vertical transmission. In the filarial nematode Brugia malayi, a causative agent of human lymphatic filariasis, Wolbachia is an endosymbiont, and its presence is essential for proper nematode development, survival, and pathogenesis. While the elucidation of Wolbachia:nematode interactions that promote the bacterium's intracellular persistence is of great importance, research has been hampered due to the fact that Wolbachia cannot be cultured in the absence of host cells. The Wolbachia endosymbiont of B. malayi (wBm) has an active Type IV secretion system (T4SS). Here, we have screened 47 putative T4SS effector proteins of wBm for their ability to modulate growth or the cell biology of a typical eukaryotic cell, Saccharomyces cerevisiae. Five candidates strongly inhibited yeast growth upon expression, and 6 additional proteins showed toxicity in the presence of zinc and caffeine. Studies on the uptake of an endocytic vacuole-specific fluorescent marker, FM4-64, identified 4 proteins (wBm0076 wBm00114, wBm0447 and wBm0152) involved in vacuole membrane dynamics. The WAS(p)-family protein, wBm0076, was found to colocalize with yeast cortical actin patches and disrupted actin cytoskeleton dynamics upon expression. Deletion of the Arp2/3-activating protein, Abp1p, provided resistance to wBm0076 expression, suggesting a role for wBm0076 in regulating eukaryotic actin dynamics and cortical actin patch formation. Furthermore, wBm0152 was found to strongly disrupt endosome:vacuole cargo trafficking in yeast. This study provides molecular insight into the potential role of the T4SS in the Wolbachia endosymbiont:nematode relationship.},
}
@article {pmid30181250,
year = {2018},
author = {Tazi, A and Araujo, JR and Mulet, C and Arena, ET and Nigro, G and Pédron, T and Sansonetti, PJ},
title = {Disentangling Host-Microbiota Regulation of Lipid Secretion by Enterocytes: Insights from Commensals Lactobacillus paracasei and Escherichia coli.},
journal = {mBio},
volume = {9},
number = {5},
pages = {},
pmid = {30181250},
issn = {2150-7511},
mesh = {Animals ; Chylomicrons/blood ; Diet, High-Fat ; Enterocytes/*metabolism ; Escherichia coli/*physiology ; Female ; Gastrointestinal Microbiome ; *Host Microbial Interactions ; Lactobacillus paracasei/*physiology ; *Lipid Metabolism ; Lipids/biosynthesis ; Metabolic Networks and Pathways ; Mice ; Mice, Inbred C57BL ; Symbiosis ; TOR Serine-Threonine Kinases/physiology ; Weight Gain ; },
abstract = {The gut microbiota contributes to nutrients absorption and metabolism by enterocytes, but the molecular mechanisms involved remain poorly understood, and most conclusions are inferred from studies comparing germfree and conventional animals colonized with diverse bacterial species. We selected two model commensal microorganisms, Escherichia coli and Lactobacillus paracasei, to assess the role of the small-intestinal microbiota in modulating lipid absorption and metabolism by the epithelium. Using an integrated approach encompassing cellular and murine models and combining metabolic parameters measurement, lipid droplet imaging, and gene expression analysis, we demonstrated that under homeostatic conditions, L. paracasei promotes fat storage in enterocytes, whereas E. coli enhances lipid catabolism and reduces chylomicron circulating levels. The Akt/mammalian target of sirolimus (mTOR) pathway is inhibited by both bacterial species in vitro, indicating that several regulatory pathways are involved in the distinct intracellular lipid outcomes associated with each bacterial species. Moreover, soluble bacterial factors partially reproduce the effects observed with live microorganisms. However, reduction of chylomicron circulating levels in E. coli-colonized animals is lost under high-fat-diet conditions, whereas it is potentiated by L. paracasei colonization accompanied by resistance to hypercholesterolemia and excess body weight gain.IMPORTANCE The specific contribution of each bacterial species within a complex microbiota to the regulation of host lipid metabolism remains largely unknown. Using two model commensal microorganisms, L. paracasei and E. coli, we demonstrated that both bacterial species impacted host lipid metabolism in a diet-dependent manner and, notably, that L. paracasei-colonized mice but not E. coli-colonized mice resisted high-fat-diet-induced body weight gain. In addition, we set up cellular models of fatty acid absorption and secretion by enterocytes cocultured with bacteria and showed that, in vitro, both L. paracasei and E. coli inhibited lipid secretion, through increased intracellular fat storage and enhanced lipid catabolism, respectively.},
}
@article {pmid29756204,
year = {2018},
author = {Bowman, EA and Arnold, AE},
title = {Distributions of ectomycorrhizal and foliar endophytic fungal communities associated with Pinus ponderosa along a spatially constrained elevation gradient.},
journal = {American journal of botany},
volume = {105},
number = {4},
pages = {687-699},
doi = {10.1002/ajb2.1072},
pmid = {29756204},
issn = {1537-2197},
mesh = {Altitude ; Ecosystem ; Endophytes/physiology ; Mycorrhizae/*physiology ; Pinus ponderosa/*microbiology ; Plant Leaves/microbiology ; Plant Roots/microbiology ; Soil Microbiology ; Symbiosis ; },
abstract = {PREMISE OF THE STUDY: Understanding distributions of plant-symbiotic fungi is important for projecting responses to environmental change. Many coniferous trees host ectomycorrhizal fungi (EM) in association with roots and foliar endophytic fungi (FE) in leaves. We examined how EM and FE associated with Pinus ponderosa each vary in abundance, diversity, and community structure over a spatially constrained elevation gradient that traverses four plant communities, 4°C in mean annual temperature, and 15 cm in mean annual precipitation.
METHODS: We sampled 63 individuals of Pinus ponderosa in 10 sites along a 635 m elevation gradient that encompassed a geographic distance of 9.8 km. We used standard methods to characterize each fungal group (amplified and sequenced EM from root tips; isolated and sequenced FE from leaves).
KEY RESULTS: Abundance and diversity of EM were similar across sites, but community composition and distributions of the most common EM differed with elevation (i.e., with climate, soil chemistry, and plant communities). Abundance and composition of FE did not differ with elevation, but diversity peaked in mid-to-high elevations.
CONCLUSIONS: Our results suggest relatively tight linkages between EM and climate, soil chemistry, and plant communities. That FE appear less linked with these factors may speak to limitations of a culture-based approach, but more likely reflects the small spatial scale encompassed by our study. Future work should consider comparable methods for characterizing these functional groups, and additional transects to understand relationships of EM and FE to environmental factors that are likely to shift as a function of climate change.},
}
@article {pmid29604609,
year = {2018},
author = {Upson, JL and Zess, EK and Białas, A and Wu, CH and Kamoun, S},
title = {The coming of age of EvoMPMI: evolutionary molecular plant-microbe interactions across multiple timescales.},
journal = {Current opinion in plant biology},
volume = {44},
number = {},
pages = {108-116},
doi = {10.1016/j.pbi.2018.03.003},
pmid = {29604609},
issn = {1879-0356},
support = {//Biotechnology and Biological Sciences Research Council/United Kingdom ; },
mesh = {Microbial Interactions/*physiology ; Plant Diseases/microbiology ; Plants/*metabolism/*microbiology ; Symbiosis/physiology ; },
abstract = {Plant-microbe interactions are great model systems to study co-evolutionary dynamics across multiple timescales. However, mechanistic research on plant-microbe interactions has often been conducted with little consideration of evolutionary concepts and methods. Conversely, evolutionary research has rarely integrated the range of mechanisms and models from the molecular plant-microbe interactions field. In recent years, the incipient field of evolutionary molecular plant-microbe interactions (EvoMPMI) has emerged to bridge this gap. Here, we report on some of the recent advances in EvoMPMI. In particular, we highlight new systems to study microbe interactions with early diverging land plants, and new findings from studies of adaptive evolution in pathogens and plants. By linking mechanistic and evolutionary research, EvoMPMI promises to expand our understanding of plant-microbe interactions.},
}
@article {pmid29260261,
year = {2018},
author = {Abinandan, S and Subashchandrabose, SR and Venkateswarlu, K and Megharaj, M},
title = {Microalgae-bacteria biofilms: a sustainable synergistic approach in remediation of acid mine drainage.},
journal = {Applied microbiology and biotechnology},
volume = {102},
number = {3},
pages = {1131-1144},
doi = {10.1007/s00253-017-8693-7},
pmid = {29260261},
issn = {1432-0614},
mesh = {Acids/*metabolism ; Bacteria/*metabolism ; *Biodegradation, Environmental ; *Biofilms ; Biofuels ; Biomass ; Metals, Heavy/metabolism ; Microalgae/*metabolism ; Microbial Consortia ; Mining ; Symbiosis ; },
abstract = {Microalgae and bacteria offer a huge potential in delving interest to study and explore various mechanisms under extreme environments. Acid mine drainage (AMD) is one such environment which is extremely acidic containing copious amounts of heavy metals and poses a major threat to the ecosystem. Despite its extreme conditions, AMD is the habitat for several microbes and their activities. The use of various chemicals in prevention of AMD formation and conventional treatment in a larger scale is not feasible under different geological conditions. It implies that microbe-mediated approach is a viable and sustainable alternative technology for AMD remediation. Microalgae in biofilms play a pivotal role in such bioremediation as they maintain mutualism with heterotrophic bacteria. Synergistic approach of using microalgae-bacteria biofilms provides supportive metabolites from algal biomass for growth of bacteria and mediates remediation of AMD. However, by virtue of their physiology and capabilities of metal removal, non-acidophilic microalgae can be acclimated for use in AMD remediation. A combination of selective acidophilic and non-acidophilic microalgae together with bacteria, all in the form of biofilms, may be very effective for bioremediation of metal-contaminated waters. The present review critically examines the nature of mutualistic interactions established between microalgae and bacteria in biofilms and their role in removal of metals from AMDs, and consequent biomass production for the yield of biofuel. Integration of microalgal-bacterial consortia in fuel cells would be an attractive emerging approach of microbial biotechnology for AMD remediation.},
}
@article {pmid28941124,
year = {2018},
author = {Pellissier, L and Albouy, C and Bascompte, J and Farwig, N and Graham, C and Loreau, M and Maglianesi, MA and Melián, CJ and Pitteloud, C and Roslin, T and Rohr, R and Saavedra, S and Thuiller, W and Woodward, G and Zimmermann, NE and Gravel, D},
title = {Comparing species interaction networks along environmental gradients.},
journal = {Biological reviews of the Cambridge Philosophical Society},
volume = {93},
number = {2},
pages = {785-800},
doi = {10.1111/brv.12366},
pmid = {28941124},
issn = {1469-185X},
mesh = {Animals ; *Biodiversity ; Environment ; *Food Chain ; Plants/*classification ; Species Specificity ; Symbiosis ; },
abstract = {Knowledge of species composition and their interactions, in the form of interaction networks, is required to understand processes shaping their distribution over time and space. As such, comparing ecological networks along environmental gradients represents a promising new research avenue to understand the organization of life. Variation in the position and intensity of links within networks along environmental gradients may be driven by turnover in species composition, by variation in species abundances and by abiotic influences on species interactions. While investigating changes in species composition has a long tradition, so far only a limited number of studies have examined changes in species interactions between networks, often with differing approaches. Here, we review studies investigating variation in network structures along environmental gradients, highlighting how methodological decisions about standardization can influence their conclusions. Due to their complexity, variation among ecological networks is frequently studied using properties that summarize the distribution or topology of interactions such as number of links, connectance, or modularity. These properties can either be compared directly or using a procedure of standardization. While measures of network structure can be directly related to changes along environmental gradients, standardization is frequently used to facilitate interpretation of variation in network properties by controlling for some co-variables, or via null models. Null models allow comparing the deviation of empirical networks from random expectations and are expected to provide a more mechanistic understanding of the factors shaping ecological networks when they are coupled with functional traits. As an illustration, we compare approaches to quantify the role of trait matching in driving the structure of plant-hummingbird mutualistic networks, i.e. a direct comparison, standardized by null models and hypothesis-based metaweb. Overall, our analysis warns against a comparison of studies that rely on distinct forms of standardization, as they are likely to highlight different signals. Fostering a better understanding of the analytical tools available and the signal they detect will help produce deeper insights into how and why ecological networks vary along environmental gradients.},
}
@article {pmid30826731,
year = {2019},
author = {Koehler, L and Flemming, FE and Schrallhammer, M},
title = {Towards an ecological understanding of the killer trait - A reproducible protocol for testing its impact on freshwater ciliates.},
journal = {European journal of protistology},
volume = {68},
number = {},
pages = {108-120},
doi = {10.1016/j.ejop.2019.02.002},
pmid = {30826731},
issn = {1618-0429},
abstract = {Paramecium strains with the ability to kill other paramecia often harbour intracellular bacteria belonging to the genera Caedibacter or Caedimonas. Central structures of this killer trait are refractile bodies (R-bodies) produced by the endosymbionts. Once ingested by a sensitive Paramecium, R-bodies presumably act as delivery system for an unidentified toxin which causes the death of endosymbiont-free paramecia while those infected gain resistance from their symbionts. The killer trait is therefore considered as competitive advantage for the hosts of R-body producers. While its effectiveness against paramecia is well documented, the effects on other aquatic ciliates are much less studied. In order to address the broadness of the killer trait, a reproducible killer test assay considering the effects on predatory ciliates (Climacostomum virens and Dileptus jonesi) as well as potential bacterivorous Paramecium competitors (Dexiostoma campyla, Euplotes aediculatus, Euplotes woodruffi, and Spirostomum teres) as possibly susceptible species was established. All used organisms were molecularly characterized to increase traceability and reproducibility. The absence of any lethal effects in both predators and competitors after exposure to killer paramecia strongly suggests a narrow action range for the killer trait. Thus, R-body producing bacteria provide their host with a complex, costly strategy to outcompete symbiont-free congeners only.},
}
@article {pmid30825941,
year = {2019},
author = {Tang, MJ and Zhu, Q and Zhang, FM and Zhang, W and Yuan, J and Sun, K and Xu, FJ and Dai, CC},
title = {Enhanced nitrogen and phosphorus activation with an optimized bacterial community by endophytic fungus Phomopsis liquidambari in paddy soil.},
journal = {Microbiological research},
volume = {221},
number = {},
pages = {50-59},
doi = {10.1016/j.micres.2019.02.005},
pmid = {30825941},
issn = {1618-0623},
abstract = {The endophytic fungus Phomopsis liquidambari play a key role in habitat adaptation of rice (Oryza sativa L.) with potential multiple beneficial. However, our previous published work on this subject remains incomplete. Here, we performed a soil nutrient (nitrogen and phosphorus) transformation with related functional genes and elucidated how rhizosphere microbiota vary their response to P. liquidambari interaction throughout the plant's life cycle under field conditions by Illumina Miseq sequencing platforms in a nutrient-limited paddy soil. Our results showed that P. liquidambari symbiosis decreased the nitrogen and phosphorus loss by 24.59% and 17.46% per pot, respectively. Additionally, we suggest that the application of P. liquidambari altered the activation of soil nitrogen and phosphorus functional genes to accelerate nutrient turnover in the rice rhizosphere. High-throughput sequencing with co-occurrence network and species-related network analysis further revealed that P. liquidambari colonization influenced the patterns of microbiota shift in the rhizosphere, especially during the heading stages. This led to an optimized microbial community through the promotion and inhibition of indigenous soil microbes with a higher level of available nutrient supplies. Our study strongly proposes rice-P. liquidambari symbiosis as a useful candidate for improving N and P acquisition and utilization.},
}
@article {pmid30824056,
year = {2019},
author = {Das, DR and Horváth, B and Kundu, A and Kaló, P and DasGupta, M},
title = {Functional conservation of CYCLOPS in crack entry legume Arachis hypogaea.},
journal = {Plant science : an international journal of experimental plant biology},
volume = {281},
number = {},
pages = {232-241},
doi = {10.1016/j.plantsci.2018.12.003},
pmid = {30824056},
issn = {1873-2259},
abstract = {Root nodule symbiosis in legumes is established following interaction of compatible rhizobia that activates an array of genes, commonly known as symbiotic-pathway, resulting in nodule development. In model legumes, bacterial entry mainly occurs through infection thread involving the expression of transcription factor CYCLOPS/IPD3. Here we show the functional analysis of AhCYCLOPS in Arachis hypogaea where bacteria invade roots through epidermal cracks. Exploiting significant cross-species domain conservation, trans-complementation experiments involving ectopic expression of AhCYCLOPS in transgenic hairy-roots of Medicago truncatula ipd3 mutants resulted in functional complementation of Medicago nodules. Moreover, native promoter of AhCYCLOPS was sufficient for this cross-species complementation irrespective of the different modes of infection of roots by rhizobia and nodule ontology. To unravel the role of AhCYCLOPS during 'crack-entry' nodulation in A. hypogaea, RNAi of AhCYCLOPS was performed which resulted in delayed nodule inception followed by drastic reduction in nodule number on transgenic hairy-roots. The infection zone of a significant number of RNAi nodules showed presence of infected cells with enlarged nucleus and rod shaped undifferentiated bacteria. Expression analysis showed downregulation of several nodulation responsible effectors endorsing the compromised condition of RNAi roots. Together, the results indicated that AhCYCLOPS plays an important role in A. hypogaea nodule development.},
}
@article {pmid30824024,
year = {2019},
author = {Ferrol, N and Azcón-Aguilar, C and Pérez-Tienda, J},
title = {Review: Arbuscular mycorrhizas as key players in sustainable plant phosphorus acquisition: An overview on the mechanisms involved.},
journal = {Plant science : an international journal of experimental plant biology},
volume = {280},
number = {},
pages = {441-447},
doi = {10.1016/j.plantsci.2018.11.011},
pmid = {30824024},
issn = {1873-2259},
abstract = {Phosphorus (P) is a poorly available macronutrient essential for plant growth and development and consequently for successful crop yield and ecosystem productivity. To cope with P limitations plants have evolved strategies for enhancing P uptake and/or improving P efficiency use. The universal 450-million-yr-old arbuscular mycorrhizal (AM) (fungus-root) symbioses are one of the most successful and widespread strategies to maximize access of plants to available P. AM fungi biotrophically colonize the root cortex of most plant species and develop an extraradical mycelium which overgrows the nutrient depletion zone of the soil surrounding plant roots. This hyphal network is specialized in the acquisition of low mobility nutrients from soil, particularly P. During the last years, molecular biology techniques coupled to novel physiological approaches have provided fascinating contributions to our understanding of the mechanisms of symbiotic P transport. Mycorrhiza-specific plant phosphate transporters, which are required not only for symbiotic P transfer but also for maintenance of the symbiosis, have been identified. The present review provides an overview of the contribution of AM fungi to plant P acquisition and an update of recent findings on the physiological, molecular and regulatory mechanisms of P transport in the AM symbiosis.},
}
@article {pmid30823538,
year = {2019},
author = {Gil, R and Latorre, A},
title = {Unity Makes Strength: A Review on Mutualistic Symbiosis in Representative Insect Clades.},
journal = {Life (Basel, Switzerland)},
volume = {9},
number = {1},
pages = {},
doi = {10.3390/life9010021},
pmid = {30823538},
issn = {2075-1729},
support = {BFU2015-64322-C2-1-R//Ministerio de Economía, Industria y Competitividad, Gobierno de España/ ; PROMETEO/2018/133//Generalitat Valenciana/ ; },
abstract = {Settled on the foundations laid by zoologists and embryologists more than a century ago, the study of symbiosis between prokaryotes and eukaryotes is an expanding field. In this review, we present several models of insect⁻bacteria symbioses that allow for the detangling of most known features of this distinctive way of living, using a combination of very diverse screening approaches, including molecular, microscopic, and genomic techniques. With the increasing the amount of endosymbiotic bacteria genomes available, it has been possible to develop evolutionary models explaining the changes undergone by these bacteria in their adaptation to the intracellular host environment. The establishment of a given symbiotic system can be a root cause of substantial changes in the partners' way of life. Furthermore, symbiont replacement and/or the establishment of bacterial consortia are two ways in which the host can exploit its interaction with environmental bacteria for endosymbiotic reinvigoration. The detailed study of diverse and complex symbiotic systems has revealed a great variety of possible final genomic products, frequently below the limit considered compatible with cellular life, and sometimes with unanticipated genomic and population characteristics, raising new questions that need to be addressed in the near future through a wider exploration of new models and empirical observations.},
}
@article {pmid30819893,
year = {2019},
author = {Maire, J and Vincent-Monégat, C and Balmand, S and Vallier, A and Hervé, M and Masson, F and Parisot, N and Vigneron, A and Anselme, C and Perrin, J and Orlans, J and Rahioui, I and Da Silva, P and Fauvarque, MO and Mengin-Lecreulx, D and Zaidman-Rémy, A and Heddi, A},
title = {Weevil pgrp-lb prevents endosymbiont TCT dissemination and chronic host systemic immune activation.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {},
number = {},
pages = {},
doi = {10.1073/pnas.1821806116},
pmid = {30819893},
issn = {1091-6490},
abstract = {Long-term intracellular symbiosis (or endosymbiosis) is widely distributed across invertebrates and is recognized as a major driving force in evolution. However, the maintenance of immune homeostasis in organisms chronically infected with mutualistic bacteria is a challenging task, and little is known about the molecular processes that limit endosymbiont immunogenicity and host inflammation. Here, we investigated peptidoglycan recognition protein (PGRP)-encoding genes in the cereal weevil Sitophilus zeamais's association with Sodalis pierantonius endosymbiont. We discovered that weevil pgrp-lb generates three transcripts via alternative splicing and differential regulation. A secreted isoform is expressed in insect tissues under pathogenic conditions through activation of the PGRP-LC receptor of the immune deficiency pathway. In addition, cytosolic and transmembrane isoforms are permanently produced within endosymbiont-bearing organ, the bacteriome, in a PGRP-LC-independent manner. Bacteriome isoforms specifically cleave the tracheal cytotoxin (TCT), a peptidoglycan monomer released by endosymbionts. pgrp-lb silencing by RNAi results in TCT escape from the bacteriome to other insect tissues, where it chronically activates the host systemic immunity through PGRP-LC. While such immune deregulations did not impact endosymbiont load, they did negatively affect host physiology, as attested by a diminished sexual maturation of adult weevils. Whereas pgrp-lb was first described in pathogenic interactions, this work shows that, in an endosymbiosis context, specific bacteriome isoforms have evolved, allowing endosymbiont TCT scavenging and preventing chronic endosymbiont-induced immune responses, thus promoting host homeostasis.},
}
@article {pmid30819117,
year = {2019},
author = {Fortin, M and Meunier, J and Laverré, T and Souty-Grosset, C and Richard, FJ},
title = {Joint effects of group sex-ratio and Wolbachia infection on female reproductive success in the terrestrial isopod Armadillidium vulgare.},
journal = {BMC evolutionary biology},
volume = {19},
number = {1},
pages = {65},
doi = {10.1186/s12862-019-1391-6},
pmid = {30819117},
issn = {1471-2148},
support = {FPA 2023 - 0224/ 532524-1-FR-2012-1-ERA//Education, Audiovisual and Culture Executive Agency. the funding body had no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript./ ; },
abstract = {BACKGROUND: In species that reproduce with sexual reproduction, males and females often have opposite strategies to maximize their own fitness. For instance, males are typically expected to maximize their number of mating events, whereas an excessive number of mating events can be costly for females. Although the risk of sexual harassment by males and resulting costs for females are expected to increase with the proportion of males, it remains unknown whether and how parasitic distorters of a host population's sex-ratio can shape this effect on the fitness of females. Here, we addressed this question using Armadillidium vulgare and its parasite Wolbachia that alters the sex-ratio of a population. We set up Wolbachia-free and Wolbachia-infected females in experimental groups exhibiting 100, 80, 50% or 20% females for 1 year, during which we measured changes in survival, fertility and fecundity.
RESULTS: Wolbachia infection shaped the effects of both population sex-ratio and reproductive season on female fecundity. Compared to Wolbachia-free females, Wolbachia-infected females were less likely to be gravid in populations exhibiting an excess of females and did not exhibit the otherwise negative effect of seasons on this likelihood. Group sex-ratio and Wolbachia infection have independent effects on other measured traits. Male-biased populations had females both exhibiting the lowest survival rate after 6 months and producing the smallest number of offspring, independent of Wolbachia infection. Conversely, Wolbachia-infected females had the lowest likelihood of producing at least one offspring, independent of group sex-ratio. Wolbachia infection had no effect on female survival rate.
CONCLUSIONS: We demonstrated that male-biased sex-ratio and the presence of Wolbachia are costly for females due to sexual harassment by males and bacterial infection, respectively. Interestingly, Wolbachia infection triggers another negative effect. This effect does not come from an excess of males and its associated sexual harassment of females but instead from a lack of males and the associated risk for females of remaining unmated. Overall, these findings highlight the importance of social pressures and infection on female fitness and provide insights into our general understanding of the joint and opposite effects of these two parameters in the evolution of reproductive strategies.},
}
@article {pmid30273494,
year = {2019},
author = {Kang, W and Xu, L and Jiang, Z and Shi, S},
title = {Genetic diversity and symbiotic efficiency difference of endophytic rhizobia of Medicago sativa.},
journal = {Canadian journal of microbiology},
volume = {65},
number = {1},
pages = {68-83},
doi = {10.1139/cjm-2018-0158},
pmid = {30273494},
issn = {1480-3275},
mesh = {Endophytes/*genetics/physiology ; *Genetic Variation ; Medicago sativa/*microbiology ; Rhizobium/*genetics/physiology ; Sinorhizobium meliloti/genetics ; *Symbiosis ; },
abstract = {Research on rhizobium diversity has paved the way for diversification of rhizobial germplasm resources. Seventy-three endophytic bacterial isolates were collected from seven tissues of five alfalfa cultivars in three geographic locations in Gansu, China. Restriction fragment length polymorphism (RFLP) fingerprinting of 16S rRNA and analysis of concatenated sequence of three housekeeping genes (atpD, glnII, and recA) and two symbiotic genes (nodC and nifH) were used for strain identification. Results showed that the endophytic strains were genetically diverse at different taxonomic levels, and Ensifer meliloti (31) and Agrobacterium radiobacter (12) are common Medicago sativa endophytic bacteria in Gansu, China. The nifH genes (97%-98% sequence identity) of E. meliloti strains were more diverse than the nodC genes (99%-100% sequence identity), even though the strains evolved from a common ancestor. The degree of dispersion of symbiotic phenotypes of E. meliloti strains on M. sativa 'Gannong No. 3', 'Gannong No. 9', and 'Qingshui' was much less than that on M. sativa 'Longzhong' and 'WL168HQ'. This suggested that the symbiotic efficiency of E. meliloti strains on the former three alfalfa cultivars was similar but on the latter two was discrepant. Their symbiotic efficiency differed primarily according to alfalfa cultivars and, to a lesser extent, to the tested strains, indicating the difference in the sensitivity of different alfalfa cultivars to rhizobial strains.},
}
@article {pmid28249626,
year = {2018},
author = {Fogel, D and Fuentes, JL and Soto, LM and López, C},
title = {Association between an ectoparasitic copepod (Caligus sp.) and the monogenean Udonella cf. caligorum Johnston 1835 on a catfish population.},
journal = {Journal of helminthology},
volume = {92},
number = {2},
pages = {250-253},
doi = {10.1017/S0022149X17000153},
pmid = {28249626},
issn = {1475-2697},
mesh = {Animals ; Catfishes/*physiology ; Copepoda/anatomy & histology/*parasitology ; Ectoparasitic Infestations/epidemiology/parasitology ; Fertility ; *Host-Parasite Interactions ; Lakes/parasitology ; Symbiosis ; Trematoda/*physiology ; Venezuela/epidemiology ; },
abstract = {We analysed the association between a monogenean (Udonella cf. caligorum Johnston 1835) and its copepod host (Caligus sp.) living on a wild population of Arius herzbergii Bloch, 1794 in a north-eastern coastal lagoon from Venezuela. This study characterized infestation levels and analysed the effects of monogeneans on the fecundity and hatching success of the copepod host, as well as damage to its egg capsules and genital complex. A total of 218 Caligus specimens were analysed (94 males, 110 females and 14 immature stages) in which a total of 1017 monogeneans were found. These included 311 mature stages and 706 egg capsules. Monogenean stages were found attached to the cephalothorax, abdomen, genital complex and egg capsules of the copepods. No significant differences were found in fecundity and egg hatching when infested and non-infested ovigerous females were compared. No damage was observed on egg capsules or genital areas of infested ovigerous females. Our results suggest that this association, at the level of prevalence and intensity observed, is closer to commensalism than parasitism. The importance of considering that the nature of interaction is dynamic and changing with environmental conditions and time scale is highlighted.},
}
@article {pmid30816051,
year = {2019},
author = {Abdelhameed, RE and Metwally, RA},
title = {Alleviation of cadmium stress by arbuscular mycorrhizal symbiosis.},
journal = {International journal of phytoremediation},
volume = {},
number = {},
pages = {1-9},
doi = {10.1080/15226514.2018.1556584},
pmid = {30816051},
issn = {1549-7879},
abstract = {Owing to the realization of the harmful effect of cadmium on the environment and plants and as the plants are sessile organisms, they need to increase the protective mechanisms to cope with Cd stress. Inoculation the plant with soil microbes at the place of their growing is an important strategy to support the plants against stresses. In this study, trigonella plants were inoculated with arbuscular mycorrhizal (AM) fungi under different CdCl2 concentrations (0, 2.25, and 6.25 mM). AM inoculation increased growth parameters, chlorophyll, and protein contents. Root colonization was significantly increased at low Cd concentration (2.25 mM) and decreased at high one (6.25 mM). Also, with AM fungal inoculation, the translocation factor of trigonella plants significantly decreased as compared to non-AM ones at both low and high Cd concentrations. In addition, it was clearly that malondialdehyde content of trigonella plants increased significantly at both Cd concentrations and with AM fungal inoculation its content decreased compared to those of non-AM ones. AM inoculation significantly increased antioxidant enzymes activities compared to non-AM ones. Consequently, this study showed a tolerance strategy of AM trigonella plants against Cd stress, thus mycorrhizal symbiosis becomes a promising and suitable as phytostabilizers of Cd stressed soil.},
}
@article {pmid30814981,
year = {2019},
author = {Cherni, AE and Perret, X},
title = {Deletion of rRNA Operons of Sinorhizobium fredii Strain NGR234 and Impact on Symbiosis With Legumes.},
journal = {Frontiers in microbiology},
volume = {10},
number = {},
pages = {154},
doi = {10.3389/fmicb.2019.00154},
pmid = {30814981},
issn = {1664-302X},
abstract = {During their lifecycle, from free-living soil bacteria to endosymbiotic nitrogen-fixing bacteroids of legumes, rhizobia must colonize, and cope with environments where nutrient concentrations and compositions vary greatly. Bacterial colonization of legume rhizospheres and of root surfaces is subject to a fierce competition for plant exudates. By contrast root nodules offer to rhizobia sheltered nutrient-rich environments within which the cells that successfully propagated via infection threads can rapidly multiply. To explore the effects on symbiosis of a slower rhizobia growth and metabolism, we deleted one or two copies of the three functional rRNA operons of the promiscuous Sinorhizobium fredii strain NGR234 and examined the impact of these mutations on free-living and symbiotic lifestyles. Strains with two functional rRNA operons (NGRΔrRNA1 and NGRΔrRNA3) grew almost as rapidly as NGR234, and NGRΔrRNA1 was as proficient as the parent strain on all of the five legume species tested. By contrast, the NGRΔrRNA1,3 double mutant, which carried a single rRNA operon and grew significantly slower than NGR234, had a reduced symbiotic proficiency on Cajanus cajan, Macroptilium atropurpureum, Tephrosia vogelii, and Vigna unguiculata. In addition, while NGRΔrRNA1 and NGR234 equally competed for nodulation of V. unguiculata, strain NGRΔrRNA1,3 was clearly outcompeted by wild-type. Surprisingly, on Leucaena leucocephala, NGRΔrRNA1,3 was the most proficient strain and competed equally NGR234 for nodule occupation. Together, these results indicate that for strains with otherwise identical repertoires of symbiotic genes, a faster growth on roots and/or inside plant tissues may contribute to secure access to nodules of some hosts. By contrast, other legumes such as L. leucocephala appear as less selective and capable of providing symbiotic environments susceptible to accommodate strains with a broader spectrum of competences.},
}
@article {pmid30814906,
year = {2019},
author = {Montoya, QV and Martiarena, MJS and Danilo Augusto Polezel, and Akazu, S and Rodrigues, A},
title = {More pieces to a huge puzzle: Two new Escovopsis species from fungus gardens of attine ants.},
journal = {MycoKeys},
volume = {},
number = {46},
pages = {97-118},
doi = {10.3897/mycokeys.46.30951},
pmid = {30814906},
issn = {1314-4049},
abstract = {Escovopsis (Ascomycota: Hypocreales, Hypocreaceae) is the only known parasite of the mutualistic fungi cultivated by fungus-growing ants (Formicidae: Myrmicinae: Attini: Attina, the "attines"). Despite its ecological role, the taxonomy and systematics of Escovopsis have been poorly addressed. Here, based on morphological and phylogenetic analyses with three molecular markers (internal transcribed spacer, large subunit ribosomal RNA and the translation elongation factor 1-alpha), we describe Escovopsisclavatus and E.multiformis as new species isolated from fungus gardens of Apterostigma ant species. Our analysis shows that E.clavatus and E.multiformis belong to the most derived Escovopsis clade, whose main character is the presence of conidiophores with vesicles. Nevertheless, the most outstanding feature of both new species is the presence of a swollen region in the central hypha of the conidiophore named swollen cell, which is absent in all previously described Escovopsis species. The less derived Escovopsis clades lack vesicles and their phylogenetic position within the Hypocreaceae still remains unclear. Considering the high genetic diversity in Escovopsis, the description of these new species adds barely two pieces to a huge taxonomic puzzle; however, this discovery is an important piece for building the systematics of this group of fungi.},
}
@article {pmid30814067,
year = {2019},
author = {Lin, MF and Takahashi, S and Forêt, S and Davy, SK and Miller, DJ},
title = {Transcriptomic analyses highlight the likely metabolic consequences of colonization of a cnidarian host by native or non-native Symbiodinium species.},
journal = {Biology open},
volume = {},
number = {},
pages = {},
doi = {10.1242/bio.038281},
pmid = {30814067},
issn = {2046-6390},
abstract = {Reef-building corals and some other cnidarians form symbiotic relationships with members of the dinoflagellates family Symbiodinaceae. As Symbiodinaceae is a highly diverse taxon, the physiological interactions between its members and their hosts are assumed to differ between associations. The presence of different symbiont types is known to affect expression levels of specific host genes, but knowledge of the effects on the transcriptome more broadly remains limited. In the present study transcriptome profiling was conducted on the tropical corallimorpharian, Ricordea yuma, following the establishment of symbiosis with either the "homologous" symbiont Symbiodinium goreaui (also known as Cladocopium goreaui; ITS2 type C1) or "heterologous" symbionts (predominantly S. trenchii , which is also known as Durusdinium trenchii; ITS2 type D1a) isolated from a different corallimorpharian host (Rhodactis indosinensis). Transcriptomic analyses showed that genes encoding host glycogen biosynthesis pathway components are more highly induced during colonization by the homologous symbiont than by the heterologous symbiont. Similar patterns were also observed for several other genes thought to facilitate symbiotic nutrient exchange, including those involved in lipid translocation / storage and metabolite transport. The gene expression results presented here imply that colonization by homologous or heterologous Symbiodinium types may have very different metabolic consequences for the Ricordea host, supporting the notion that even though some cnidarians may be able to form novel symbioses after bleaching, the metabolic performance of these may be compromised.},
}
@article {pmid30813886,
year = {2019},
author = {Bykov, RА and Yudina, MA and Gruntenko, NE and Zakharov, IK and Voloshina, MA and Melashchenko, ES and Danilova, MV and Mazunin, IO and Ilinsky, YY},
title = {Prevalence and genetic diversity of Wolbachia endosymbiont and mtDNA in Palearctic populations of Drosophila melanogaster.},
journal = {BMC evolutionary biology},
volume = {19},
number = {Suppl 1},
pages = {48},
doi = {10.1186/s12862-019-1372-9},
pmid = {30813886},
issn = {1471-2148},
abstract = {BACKGROUND: Maternally inherited Wolbachia symbionts infect D. melanogaster populations worldwide. Infection rates vary greatly. Genetic diversity of Wolbachia in D. melanogaster can be subdivided into several closely related genotypes coinherited with certain mtDNA lineages. mtDNA haplotypes have the following global distribution pattern: mtDNA clade I is mostly found in North America, II and IV in Africa, III in Europe and Africa, V in Eurasia, VI is global but very rare, and VIII is found in Asia. The wMel Wolbachia genotype is predominant in D. melanogaster populations. However, according to the hypothesis of global Wolbachia replacement, the wMelCS genotype was predominant before the XX century when it was replaced by the wMel genotype. Here we analyse over 1500 fly isolates from the Palearctic region to evaluate the prevalence, genetic diversity and distribution pattrern of the Wolbachia symbiont, occurrence of mtDNA variants, and finally to discuss the Wolbachia genotype global replacement hypothesis.
RESULTS: All studied Palearctic populations of D. melanogaster were infected with Wolbachia at a rate of 33-100%. We did not observe any significant correlation between infection rate and longitude or latitude. Five previously reported Wolbachia genotypes were found in Palearctic populations with a predominance of the wMel variant. The mtDNA haplotypes of the I_II_III clade and V clade were prevalent in Palearctic populations. To test the recent Wolbachia genotype replacement hypothesis, we examined three genomic regions of CS-like genotypes. Low genetic diversity was observed, only two haplotypes of the CS genotypes with a 'CCG' variant predominance were found.
CONCLUSION: The results of our survey of Wolbachia infection prevalence and genotype diversity in Palearctic D. melanogaster populations confirm previous studies. Wolbachia is ubiquitous in the Palearctic region. The wMel genotype is dominant with local occurrence of rare genotypes. Together with variants of the V mtDNA clade, the variants of the 'III+' clade are dominant in both infected and uninfected flies of Palearctic populations. Based on our data on Wolbachia and mtDNA in different years in some Palearctic localities, we can conclude that flies that survive the winter make the predominant symbiont contribution to the subsequent generation. A comprehensive overview of mtDNA and Wolbachia infection of D. melanogaster populations worldwide does not support the recent global Wolbachia genotype replacement hypothesis. However, we cannot exclude wMelCS genotype rate fluctuations in the past.},
}
@article {pmid30629155,
year = {2019},
author = {Sazama, EJ and Ouellette, SP and Wesner, JS},
title = {Bacterial Endosymbionts Are Common Among, but not Necessarily Within, Insect Species.},
journal = {Environmental entomology},
volume = {48},
number = {1},
pages = {127-133},
doi = {10.1093/ee/nvy188},
pmid = {30629155},
issn = {1938-2936},
mesh = {Animals ; Insecta/*microbiology ; Linear Models ; Rickettsiales ; *Symbiosis ; Wolbachia ; },
abstract = {Bacterial endosymbionts, particularly Wolbachia (Rickettsiales: Rickettsiaceae), Rickettsia (Rickettsiales: Rickettsiaceae), and Cardinium (Bacteroidales: Bacteroidaceae), are commonly found in several arthropod groups, including insects. Most estimates of the global infection rate of Wolbachia (52% [95% credible intervals: 44-60]) show that these bacteria infect more than half of all insect species. Other endosymbionts, such as Rickettsia (24% [confidence intervals [CIs] 20-42]) and Cardinium (13% [CIs 13-55]), infect a smaller but still substantial proportion of insect species. In spite of these observations, it is unclear what proportion of individuals within those species are infected. Here, we used published databases to estimate the proportion of individuals that are infected with either Wolbachia, Rickettsia, or Cardinium. We found that the majority (69%) of Wolbachia-infected species have less than half of their individuals infected with Wolbachia, indicating that although the bacterium may be common among species, it is not common within species. The same was true for Rickettsia (81%) and Cardinium (87%). This discrepancy was consistent across orders, in which less than 10% of individuals were typically infected, even though more than 50% of species within orders were infected. For example, according to our model, nearly 50% of beetle (Coleoptera) species are infected with Wolbachia (i.e., contain at least one individual that has tested positive for Wolbachia), but less than 5% of all individuals are infected. These results add to the growing knowledge base about endosymbionts in insects and should guide future sampling efforts and investigations on the role that these bacteria play in populations.},
}
@article {pmid30613848,
year = {2019},
author = {Ye, S and Bhattacharjee, M and Siemann, E},
title = {Thermal Tolerance in Green Hydra: Identifying the Roles of Algal Endosymbionts and Hosts in a Freshwater Holobiont Under Stress.},
journal = {Microbial ecology},
volume = {77},
number = {2},
pages = {537-545},
doi = {10.1007/s00248-018-01315-1},
pmid = {30613848},
issn = {1432-184X},
mesh = {Animals ; Chlorophyta/*physiology ; Fresh Water/chemistry/parasitology ; Hot Temperature ; Hydra/*parasitology/physiology ; Stress, Physiological ; *Symbiosis ; },
abstract = {It has been proposed that holobionts (host-symbiont units) could swap endosymbionts, rapidly alter the hologenome (host plus symbiont genome), and increase their stress tolerance. However, experimental tests of individual and combined contributions of hosts and endosymbionts to holobiont stress tolerance are needed to test this hypothesis. Here, we used six green hydra (Hydra viridissima) strains to tease apart host (hydra) and symbiont (algae) contributions to thermal tolerance. Heat shock experiments with (1) hydra with their original symbionts, (2) aposymbiotic hydra (algae removed), (3) novel associations (a single hydra strain hosting different algae individually), and (4) control hydra (aposymbiotic hydra re-associated with their original algae) showed high variation in thermal tolerance in each group. Relative tolerances of strains were the same within original, aposymbiotic, and control treatments, but reversed in the novel associations group. Aposymbiotic hydra had similar or higher thermal tolerance than hydra with algal symbionts. Selection on the holobiont appears to be stronger than on either partner alone, suggesting endosymbiosis could become an evolutionary trap under climate change. Our results suggest that green hydra thermal tolerance is strongly determined by the host, with a smaller, non-positive role for the algal symbiont. Once temperatures exceed host tolerance limits, swapping symbionts is unlikely to allow these holobionts to persist. Rather, increases in host tolerance through in situ adaptation or migration of pre-adapted host strains appear more likely to increase local thermal tolerance. Overall, our results indicate green hydra is a valuable system for studying aquatic endosymbiosis under changing environmental conditions, and demonstrate how the host and the endosymbiont contribute to holobiont stress tolerance.},
}
@article {pmid30250094,
year = {2018},
author = {Neff, EP},
title = {How the sparrow got its house.},
journal = {Lab animal},
volume = {47},
number = {10},
pages = {268},
doi = {10.1038/s41684-018-0167-8},
pmid = {30250094},
issn = {1548-4475},
mesh = {Animals ; Humans ; *Sparrows ; Symbiosis ; },
}
@article {pmid29946784,
year = {2019},
author = {Sakoda, S and Aisu, K and Imagami, H and Matsuda, Y},
title = {Comparison of Actinomycete Community Composition on the Surface and Inside of Japanese Black Pine (Pinus thunbergii) Tree Roots Colonized by the Ectomycorrhizal Fungus Cenococcum geophilum.},
journal = {Microbial ecology},
volume = {77},
number = {2},
pages = {370-379},
doi = {10.1007/s00248-018-1221-1},
pmid = {29946784},
issn = {1432-184X},
mesh = {Actinobacteria/classification/genetics/*isolation & purification/physiology ; Ascomycota/classification/genetics/*isolation & purification/physiology ; Biodiversity ; Mycorrhizae/classification/genetics/*isolation & purification/physiology ; Phylogeny ; Pinus/growth & development/*microbiology ; Plant Roots/growth & development/microbiology ; Soil Microbiology ; Symbiosis ; Trees/growth & development/microbiology ; },
abstract = {Various bacteria are associated with ectomycorrhizal roots, which are symbiotic complexes formed between plant roots and fungi. Among these associated bacteria, actinomycetes have received attention for their ubiquity and diverse roles in forest ecosystems. Here, to examine the association of actinomycetes with ectomycorrhizal root tips, we compared the bacterial and actinomycete communities on the surface and inside of root tips of coastal Japanese black pine (Pinus thunbergii) colonized by the fungus Cenococcum geophilum. Next-generation sequences of 16S rDNA of bacteria communities using the Ion Torrent Personal Genome Machine showed that the number of bacterial classes in the surface of C. geophilum ECM roots was significantly higher than that in non-ECM roots. The bacterial community structure of surface, inside, and non-ECM roots was significantly discriminated each other. For an isolation method, a total of 762 and 335 actinomycete isolates were obtained from the surface and inside of the roots, respectively. In addition, the isolation ratio of actinomycetes in these root tips varied depending on the age of the tree and the season. Identification of the isolates based on partial 16S rDNA sequencing revealed that the isolates belonged to nine genera of the order Actinomycetales. On the surface of the roots, most of the isolates belonged to genus Streptomyces (90.4%); inside of the roots, most of the isolates belonged to genus Actinoallomurus (40.0%), which is a relatively new taxon. Our results suggest that actinomycetes as well as bacteria are ubiquitously associated with C. geophilum ectomycorrhizal roots of P. thunbergii, although their communities can vary either surface or inside of individual root tips.},
}
@article {pmid29386628,
year = {2018},
author = {Achlatis, M and Pernice, M and Green, K and Guagliardo, P and Kilburn, MR and Hoegh-Guldberg, O and Dove, S},
title = {Single-cell measurement of ammonium and bicarbonate uptake within a photosymbiotic bioeroding sponge.},
journal = {The ISME journal},
volume = {12},
number = {5},
pages = {1308-1318},
pmid = {29386628},
issn = {1751-7370},
mesh = {Ammonium Compounds/*metabolism ; Animals ; Bicarbonates/*metabolism ; Coral Reefs ; Dinoflagellida/*metabolism ; Ecosystem ; Porifera/*metabolism ; Single-Cell Analysis ; *Symbiosis ; },
abstract = {Some of the most aggressive coral-excavating sponges host intracellular dinoflagellates from the genus Symbiodinium, which are hypothesized to provide the sponges with autotrophic energy that powers bioerosion. Investigations of the contribution of Symbiodinium to host metabolism and particularly inorganic nutrient recycling are complicated, however, by the presence of alternative prokaryotic candidates for this role. Here, novel methods are used to study nutrient assimilation and transfer within and between the outer-layer cells of the Indopacific bioeroding sponge Cliona orientalis. Combining stable isotope labelling, transmission electron microscopy (TEM) and nanoscale secondary ion mass spectrometry (NanoSIMS), we visualize and measure metabolic activity at the individual cell level, tracking the fate of 15N-ammonium and 13C-bicarbonate within the intact holobiont. We found strong uptake of both inorganic sources (especially 13C-bicarbonate) by Symbiodinium cells. Labelled organic nutrients were translocated from Symbiodinium to the Symbiodinium-hosting sponge cells within 6 h, and occasionally to other sponge cells within 3 days. By contrast, prokaryotic symbionts were not observed to participate in inorganic nutrient assimilation in the outer layers of the sponge. Our findings strongly support the metabolic interaction between the sponge and dinoflagellates, shedding light on the ecological advantages and adaptive capacity of photosymbiotic bioeroding sponges in oligotrophic marine habitats.},
}
@article {pmid30811772,
year = {2019},
author = {Pringle, EG},
title = {Convergence, constraint and the potential for mutualism between ants and gut microbes.},
journal = {Molecular ecology},
volume = {28},
number = {4},
pages = {699-702},
doi = {10.1111/mec.14998},
pmid = {30811772},
issn = {1365-294X},
abstract = {Ants are a hugely diverse family of eusocial insects that dominate terrestrial ecosystems all over the planet. Did mutualistic gut microbes help ants to achieve their diversity and ecological dominance? Initial studies suggested the potential for widespread convergence in ant gut bacterial communities based on dietary niche, but it now seems possible that dedicated bacterial symbionts are restricted to a minority of ant lineages (Russell et al.,). Nevertheless, as most ants are omnivores, the evidence so far has suggested a broad, positive correlation between the evolution of dietary specialization and ant investment in nutrient-provisioning gut bacteria. In this issue of Molecular Ecology, Sapountzis et al. () and Rubin et al. () examine the evolution of gut bacterial communities in two iconic ant taxa-the attine fungus farmers and the Pseudomyrmex plant bodyguards, respectively-in a comparative context. By comparing gut bacteria between ant species of differing dietary specialization within each taxon, these studies demonstrate a hint of convergence in the midst of widespread apparent constraints. These results raise numerous interesting questions about the nature of these apparent constraints and whether they are causes or consequences of varying investment by ants to mutualism with their gut microbes.},
}
@article {pmid30811604,
year = {2019},
author = {Carotenuto, G and Volpe, V and Russo, G and Politi, M and Sciascia, I and de Almeida-Engler, J and Genre, A},
title = {Local endoreduplication as a feature of intracellular fungal accommodation in arbuscular mycorrhizas.},
journal = {The New phytologist},
volume = {},
number = {},
pages = {},
doi = {10.1111/nph.15763},
pmid = {30811604},
issn = {1469-8137},
abstract = {The intracellular accommodation of arbuscular mycorrhizal (AM) fungi is a paradigmatic feature of this plant symbiosis that depends on the activation of a dedicated signaling pathway and the extensive reprogramming of host cells, including striking changes in nuclear size and transcriptional activity. By combining targeted sampling of early root colonization sites, detailed confocal imaging, flow cytometry and gene expression analyses, we demonstrate that local, recursive events of endoreduplication are triggered in the Medicago truncatula root cortex during AM colonization. AM colonization induces an increase in ploidy levels and the activation of endocycle specific markers. This response anticipates the progression of fungal colonization and is limited to arbusculated and neighboring cells in the cortical tissue. Furthermore, endoreduplication is not induced in M. truncatula mutants for symbiotic signaling pathway genes. On this basis, we propose endoreduplication as part of the host cell prepenetration responses that anticipate AM fungal accommodation in the root cortex. This article is protected by copyright. All rights reserved.},
}
@article {pmid30809766,
year = {2019},
author = {Kutschera, U and Hoppe, T},
title = {Plasmodial slime molds and the evolution of microbial husbandry.},
journal = {Theory in biosciences = Theorie in den Biowissenschaften},
volume = {},
number = {},
pages = {},
doi = {10.1007/s12064-019-00285-3},
pmid = {30809766},
issn = {1611-7530},
abstract = {Detailed analyses into the life cycle of the soil-dwelling microbe Dictyostelium discoideum led to the conclusion that this "social amoeba" practices some form of "non-monoculture farming" via the transfer of bacteria to novel environments. Herein, we show that in myxomycetes (plasmodial slime molds or myxogastrids) a similar "farming symbiosis" has evolved. Based on laboratory studies of two representative species in the genera Fuligo and Didymium, the sexual life cycle of these enigmatic microbes that feed on bacteria was reconstructed, with reference to plasmo- and karyogamy. We document that the spores carry and transfer bacteria and hence may inoculate new habitats. The significance of this finding with respect to Ernst Haeckel's work on myxomycetes and his concept of ecology are addressed.},
}
@article {pmid30809447,
year = {2019},
author = {Siozios, S and Pilgrim, J and Darby, AC and Baylis, M and Hurst, GDD},
title = {The draft genome of strain cCpun from biting midges confirms insect Cardinium are not a monophyletic group and reveals a novel gene family expansion in a symbiont.},
journal = {PeerJ},
volume = {7},
number = {},
pages = {e6448},
doi = {10.7717/peerj.6448},
pmid = {30809447},
issn = {2167-8359},
abstract = {Background: It is estimated that 13% of arthropod species carry the heritable symbiont Cardinium hertigii. 16S rRNA and gyrB sequence divides this species into at least four groups (A-D), with the A group infecting a range of arthropods, the B group infecting nematode worms, the C group infecting Culicoides biting midges, and the D group associated with the marine copepod Nitocra spinipes. To date, genome sequence has only been available for strains from groups A and B, impeding general understanding of the evolutionary history of the radiation. We present a draft genome sequence for a C group Cardinium, motivated both by the paucity of genomic information outside of the A and B group, and the importance of Culicoides biting midge hosts as arbovirus vectors.
Methods: We reconstructed the genome of cCpun, a Cardinium strain from group C that naturally infects Culicoides punctatus, through Illumina sequencing of infected host specimens.
Results: The draft genome presented has high completeness, with BUSCO scores comparable to closed group A Cardinium genomes. Phylogenomic analysis based on concatenated single copy core proteins do not support Cardinium from arthropod hosts as a monophyletic group, with nematode Cardinium strains nested within the two groups infecting arthropod hosts. Analysis of the genome of cCpun revealed expansion of a variety of gene families classically considered important in symbiosis (e.g., ankyrin domain containing genes), and one set-characterized by DUF1703 domains-not previously associated with symbiotic lifestyle. This protein group encodes putative secreted nucleases, and the cCpun genome carried at least 25 widely divergent paralogs, 24 of which shared a common ancestor in the C group. The genome revealed no evidence in support of B vitamin provisioning to its haematophagous host, and indeed suggests Cardinium may be a net importer of biotin.
Discussion: These data indicate strains of Cardinium within nematodes cluster within Cardinium strains found in insects. The draft genome of cCpun further produces new hypotheses as to the interaction of the symbiont with the midge host, in particular the biological role of DUF1703 nuclease proteins that are predicted as being secreted by cCpun. In contrast, the coding content of this genome provides no support for a role for the symbiont in provisioning the host with B vitamins.},
}
@article {pmid30809207,
year = {2019},
author = {Chakravarti, LJ and Negri, AP and van Oppen, MJH},
title = {Thermal and Herbicide Tolerances of Chromerid Algae and Their Ability to Form a Symbiosis With Corals.},
journal = {Frontiers in microbiology},
volume = {10},
number = {},
pages = {173},
doi = {10.3389/fmicb.2019.00173},
pmid = {30809207},
issn = {1664-302X},
abstract = {Reef-building corals form an obligate symbiosis with photosynthetic microalgae in the family Symbiodiniaceae that meet most of their energy requirements. This symbiosis is under threat from the unprecedented rate of ocean warming as well as the simultaneous pressure of local stressors such as poor water quality. Only 1°C above mean summer sea surface temperatures (SSTs) on the Great Barrier Reef (GBR) can trigger the loss of Symbiodiniaceae from the host, and very low concentrations of the most common herbicide, diuron, can disrupt the photosynthetic activity of microalgae. In an era of rapid environmental change, investigation into the assisted evolution of the coral holobiont is underway in an effort to enhance the resilience of corals. Apicomplexan-like microalgae were discovered in 2008 and the Phylum Chromerida (chromerids) was created. Chromerids have been isolated from corals and contain a functional photosynthetic plastid. Their discovery therefore opens a new avenue of research into the use of alternative/additional photosymbionts of corals. However, only two studies to-date have investigated the symbiotic nature of Chromera velia with corals and thus little is known about the coral-chromerid relationship. Furthermore, the response of chromerids to environmental stressors has not been examined. Here we tested the performance of four chromerid strains and the common dinoflagellate symbiont Cladocopium goreaui (formerly Symbiodinium goreaui, ITS2 type C1) in response to elevated temperature, diuron and their combined exposure. Three of the four chromerid strains exhibited high thermal tolerances and two strains showed exceptional herbicide tolerances, greater than observed for any photosynthetic microalgae, including C. goreaui. We also investigated the onset of symbiosis between the chromerids and larvae of two common GBR coral species under ambient and stress conditions. Levels of colonization of coral larvae with the chromerid strains were low compared to colonization with C. goreaui. We did not observe any overall negative or positive larval fitness effects of the inoculation with chromerid algae vs. C. goreaui. However, we cannot exclude the possibility that chromerid algae may have more important roles in later coral life stages and recommend this be the focus of future studies.},
}
@article {pmid30808908,
year = {2019},
author = {Ren, CG and Kong, CC and Yan, K and Xie, ZH},
title = {Transcriptome analysis reveals the impact of arbuscular mycorrhizal symbiosis on Sesbania cannabina expose to high salinity.},
journal = {Scientific reports},
volume = {9},
number = {1},
pages = {2780},
doi = {10.1038/s41598-019-39463-0},
pmid = {30808908},
issn = {2045-2322},
abstract = {Arbuscular mycorrhiza can improve the salt-tolerance of host plant. A systematic study of mycorrhizal plant responses to salt stress may provide insights into the acquired salt tolerance. Here, the transcriptional profiles of mycorrhizal Sesbania cannabina shoot and root under saline stress were obtained by RNA-Seq. Using weighted gene coexpression network analysis and pairwise comparisons, we identified coexpressed modules, networks and hub genes in mycorrhizal S. cannabina in response to salt stress. In total, 10,371 DEGs were parsed into five coexpression gene modules. One module was positively correlated with both salt treatment and arbuscular mycorrhizal (AM) inoculation, and associated with photosynthesis and ROS scavenging in both enzymatic and nonenzymatic pathways. The hub genes in the module were mostly transcription factors including WRKY, MYB, ETHYLENE RESPONSE FACTOR, and TCP members involved in the circadian clock and might represent central regulatory components of acquired salinity tolerance in AM S. cannabina. The expression patterns of 12 genes involved in photosynthesis, oxidation-reduction processes, and several transcription factors revealed by qRT-PCR confirmed the RNA-Seq data. This large-scale assessment of Sesbania genomic resources will help in exploring the molecular mechanisms underlying plant-AM fungi interaction in salt stress responses.},
}
@article {pmid29752729,
year = {2018},
author = {Goheen, JR and Augustine, DJ and Veblen, KE and Kimuyu, DM and Palmer, TM and Porensky, LM and Pringle, RM and Ratnam, J and Riginos, C and Sankaran, M and Ford, AT and Hassan, AA and Jakopak, R and Kartzinel, TR and Kurukura, S and Louthan, AM and Odadi, WO and Otieno, TO and Wambua, AM and Young, HS and Young, TP},
title = {Conservation lessons from large-mammal manipulations in East African savannas: the KLEE, UHURU, and GLADE experiments.},
journal = {Annals of the New York Academy of Sciences},
volume = {1429},
number = {1},
pages = {31-49},
doi = {10.1111/nyas.13848},
pmid = {29752729},
issn = {1749-6632},
mesh = {Africa, Eastern ; Animals ; *Animals, Wild ; *Conservation of Natural Resources ; *Ecosystem ; Grassland ; *Herbivory ; Mammals ; Symbiosis ; },
abstract = {African savannas support an iconic fauna, but they are undergoing large-scale population declines and extinctions of large (>5 kg) mammals. Long-term, controlled, replicated experiments that explore the consequences of this defaunation (and its replacement with livestock) are rare. The Mpala Research Centre in Laikipia County, Kenya, hosts three such experiments, spanning two adjacent ecosystems and environmental gradients within them: the Kenya Long-Term Exclosure Experiment (KLEE; since 1995), the Glade Legacies and Defaunation Experiment (GLADE; since 1999), and the Ungulate Herbivory Under Rainfall Uncertainty experiment (UHURU; since 2008). Common themes unifying these experiments are (1) evidence of profound effects of large mammalian herbivores on herbaceous and woody plant communities; (2) competition and compensation across herbivore guilds, including rodents; and (3) trophic cascades and other indirect effects. We synthesize findings from the past two decades to highlight generalities and idiosyncrasies among these experiments, and highlight six lessons that we believe are pertinent for conservation. The removal of large mammalian herbivores has dramatic effects on the ecology of these ecosystems; their ability to rebound from these changes (after possible refaunation) remains unexplored.},
}
@article {pmid30805248,
year = {2019},
author = {Zhang, X and Ye, L and Kang, Z and Zou, J and Zhang, X and Li, X},
title = {Mycorrhization of Quercus acutissima with Chinese black truffle significantly altered the host physiology and root-associated microbiomes.},
journal = {PeerJ},
volume = {7},
number = {},
pages = {e6421},
doi = {10.7717/peerj.6421},
pmid = {30805248},
issn = {2167-8359},
abstract = {Background: Our aim was to explore how the ectomycorrhizae of an indigenous tree, Quercus acutissima, with a commercial truffle, Chinese black truffle (Tuber indicum), affects the host plant physiology and shapes the associated microbial communities in the surrounding environment during the early stage of symbiosis.
Methods: To achieve this, changes in root morphology and microscopic characteristics, plant physiology indices, and the rhizosphere soil properties were investigated when six-month-old ectomycorrhizae were synthesized. Meanwhile, next-generation sequencing technology was used to analyze the bacterial and fungal communities in the root endosphere and rhizosphere soil inoculated with T. indicum or not.
Results: The results showed that colonization by T. indicum significantly improved the activity of superoxide dismutase in roots but significantly decreased the root activity. The biomass, leaf chlorophyll content and root peroxidase activity did not obviously differ. Ectomycorrhization of Q. acutissima with T. indicum affected the characteristics of the rhizosphere soil, improving the content of organic matter, total nitrogen, total phosphorus and available nitrogen. The bacterial and fungal community composition in the root endosphere and rhizosphere soil was altered by T. indicum colonization, as was the community richness and diversity. The dominant bacteria in all the samples were Proteobacteria and Actinobacteria, and the dominant fungi were Eukaryota_norank, Ascomycota, and Mucoromycota. Some bacterial communities, such as Streptomyces, SM1A02, and Rhizomicrobium were more abundant in the ectomycorrhizae or ectomycorrhizosphere soil. Tuber was the second-most abundant fungal genus, and Fusarium was present at lower amounts in the inoculated samples.
Discussion: Overall, the symbiotic relationship between Q. acutissima and T. indicum had an obvious effect on host plant physiology, soil properties, and microbial community composition in the root endosphere and rhizosphere soil, which could improve our understanding of the symbiotic relationship between Q. acutissima and T. indicum, and may contribute to the cultivation of truffle.},
}
@article {pmid30803810,
year = {2019},
author = {Puozaa, DK and Jaiswal, SK and Dakora, FD},
title = {Phylogeny and distribution of Bradyrhizobium symbionts nodulating cowpea (Vigna unguiculata L. Walp) and their association with the physicochemical properties of acidic African soils.},
journal = {Systematic and applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.syapm.2019.02.004},
pmid = {30803810},
issn = {1618-0984},
abstract = {In the N2-fixing symbiosis, the choice of a symbiotic partner is largely influenced by the host plant, the rhizobial symbiont, as well as soil factors. Understanding the soil environment conducive for the survival and multiplication of root-nodule bacteria is critical for microbial ecology. In this study, we collected cowpea-nodules from acidic soils in Ghana and South Africa, and nodule DNA isolates were characterized using 16S-23S rRNA-RFLP, phylogenetic analysis of housekeeping and symbiotic genes, and bradyrhizobial community structure through canonical correspondence analysis (CCA). The CCA ordination plot results showed that arrow of soil pH was overlapping on CCA2 axis and was the most important to the ordination. The test nodule DNA isolates from Ghana were positively influenced by soil Zn, Na and K while nodule DNA isolates from South Africa were influenced by P. The amplified 16S-23S rRNA region yielded single polymorphic bands of varying lengths (573-1298bp) that were grouped into 28 ITS types. The constructed ITS-dendrogram placed all the nodule DNA isolates in five major clusters at low cut-off of approx. 0.1 Jaccard's similarity coefficient. The phylogenetic analysis of 16S rRNA and housekeeping genes (glnII, gyrB, and atpD) formed distinct Bradyrhizobium groups in the phylogenetic trees. It revealed the presence of highly diverse bradyrhizobia (i.e. Bradyrhizobium vignae, Bradyrhizobium elkanii, Bradyrhizobium iriomotense, Bradyrhizobium pachyrhizi, and Bradyrhizobium yuanmingense) together with novel/unidentified bradyrhizobia in the acidic soils from Ghana and South Africa. Discrepancies noted in the phylogenies of some nodule DNA isolates could be attributed to horizontal gene transfer or recombination.},
}
@article {pmid30803109,
year = {2019},
author = {Obando, M and Correa-Galeote, D and Castellano-Hinojosa, A and Gualpa, J and Hidalgo, A and de Dios Alché, J and Bedmar, E and Cassán, F},
title = {Analysis of the denitrification pathway and greenhouse gases emissions in Bradyrhizobium sp. strains used as biofertilizers in South America.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/jam.14233},
pmid = {30803109},
issn = {1365-2672},
abstract = {AIMS: Greenhouse gases are considered potential atmospheric pollutants, with agriculture being one of the main emission sources. The practice of inoculating soybean seeds with Bradyrhizobium sp. might contribute to nitrous oxide (N2 O) emissions. We analyzed this capacity in five of the most used strains of Bradyrhizobium sp. in South America.
METHODS AND RESULTS: We analyzed the denitrification pathway and N2 O production by B. japonicum E109 and CPAC15, B. diazoefficiens CPAC7, and B. elkanii SEMIA 587 and SEMIA 5019, both in free-living conditions and symbiosis with soybean. The in silico analysis indicated the absence of nosZ genes in B. japonicum and the presence of all denitrification genes in B. diazoefficiens strains, as well as the absence of nirK, norC and nosZ genes in B. elkanii. The in planta analysis confirmed the N2 O production under saprophytic conditions or symbiosis with soybean roots nodules. In the last case up to 26·1 and 18·4 times higher in plants inoculated with SEMIA5019 and E109 respectively, than in those inoculated with USDA110.
CONCLUSIONS: The strains E109, SEMIA 5019, CPAC15 and SEMIA 587 showed the highest N2 O production both as free-living cells and in symbiotic conditions in comparison with USDA110 and CPAC7, which do have the nosZ gene. Although norC and nosZ could not be identified in silico or in vitro in SEMIA 587 and SEMIA 5019, these strains showed capacity to produce N2 O in our experimental conditions.
This is the first report to analyze and confirm the incomplete denitrification capacity and N2 O production in four of the five most used strains of Bradyrhizobium sp. for soybean inoculation in South America. This article is protected by copyright. All rights reserved.},
}
@article {pmid30673440,
year = {2018},
author = {Na, F and Carrillo, JD and Mayorquin, JS and Ndinga-Muniania, C and Stajich, JE and Stouthamer, R and Huang, YT and Lin, YT and Chen, CY and Eskalen, A},
title = {Two Novel Fungal Symbionts Fusarium kuroshium sp. nov. and Graphium kuroshium sp. nov. of Kuroshio Shot Hole Borer (Euwallacea sp. nr. fornicatus) Cause Fusarium Dieback on Woody Host Species in California.},
journal = {Plant disease},
volume = {102},
number = {6},
pages = {1154-1164},
doi = {10.1094/PDIS-07-17-1042-RE},
pmid = {30673440},
issn = {0191-2917},
mesh = {Animals ; Ascomycota/*genetics/physiology ; California ; Coleoptera/*microbiology/physiology ; DNA, Fungal/genetics/isolation & purification ; Fusarium/*genetics/physiology ; Persea/microbiology ; Phylogeny ; Plant Diseases/*microbiology ; *Symbiosis ; },
abstract = {Shot hole borer (SHB)-Fusarium dieback (FD) is a new pest-disease complex affecting numerous tree species in California and is vectored by two distinct, but related ambrosia beetles (Euwallacea sp. nr. fornicatus) called polyphagous shot hole borer (PSHB) and Kuroshio shot hole borer (KSHB). These pest-disease complexes cause branch dieback and tree mortality on numerous wildland and landscape tree species, as well as agricultural tree species, primarily avocado. The recent discovery of KSHB in California initiated an investigation of fungal symbionts associated with the KSHB vector. Ten isolates of Fusarium sp. and Graphium sp., respectively, were recovered from the mycangia of adult KSHB females captured in three different locations within San Diego County and compared with the known symbiotic fungi of PSHB. Multigene phylogenetic analyses of the internal transcribed spacer region (ITS), translation elongation factor-1 alpha (TEF1-α), and RNA polymerase II subunit (RPB1, RPB2) regions as well as morphological comparisons revealed that two novel fungal associates Fusarium kuroshium sp. nov. and Graphium kuroshium sp. nov. obtained from KSHB were related to, but distinct from the fungal symbionts F. euwallaceae and G. euwallaceae associated with PSHB in California. Pathogenicity tests on healthy, young avocado plants revealed F. kuroshium and G. kuroshium to be pathogenic. Lesion lengths from inoculation of F. kuroshium were found to be significantly shorter compared with those caused by F. euwallaceae, while no difference in symptom severity was detected between Graphium spp. associated with KSHB and PSHB. These findings highlight the pest disease complexes of KSHB-FD and PSHB-FD as distinct, but collective threats adversely impacting woody hosts throughout California.},
}
@article {pmid30183712,
year = {2018},
author = {Kim, HT and Lee, JM},
title = {Organellar genome analysis reveals endosymbiotic gene transfers in tomato.},
journal = {PloS one},
volume = {13},
number = {9},
pages = {e0202279},
pmid = {30183712},
issn = {1932-6203},
mesh = {Base Sequence ; Cell Nucleus/genetics ; DNA, Mitochondrial/chemistry/*genetics ; Evolution, Molecular ; Genome, Mitochondrial/*genetics ; Genome, Plant/genetics ; Lycopersicon esculentum/classification/*genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; Solanum/*genetics ; Symbiosis/*genetics ; },
abstract = {We assembled three complete mitochondrial genomes (mitogenomes), two of Solanum lycopersicum and one of Solanum pennellii, and analyzed their intra- and interspecific variations. The mitogenomes were 423,596-446,257 bp in length. Despite numerous rearrangements between the S. lycopersicum and S. pennellii mitogenomes, over 97% of the mitogenomes were similar to each other. These mitogenomes were compared with plastid and nuclear genomes to investigate genetic material transfers among DNA-containing organelles in tomato. In all mitogenomes, 9,598 bp of plastome sequences were found. Numerous nuclear copies of mitochondrial DNA (NUMTs) and plastid DNA (NUPTs) were observed in the S. lycopersicum and S. pennellii nuclear genomes. Several long organellar DNA fragments were tightly clustered in the nuclear genome; however, the NUMT and NUPT locations differed between the two species. Our results demonstrate the recent occurrence of frequent endosymbiotic gene transfers in tomato genomes.},
}
@article {pmid30177306,
year = {2018},
author = {Noë, R and Kiers, ET},
title = {Mycorrhizal Markets, Firms, and Co-ops.},
journal = {Trends in ecology & evolution},
volume = {33},
number = {10},
pages = {777-789},
doi = {10.1016/j.tree.2018.07.007},
pmid = {30177306},
issn = {1872-8383},
mesh = {Mycorrhizae/*physiology ; Plants/*microbiology ; *Symbiosis ; },
abstract = {The nutrient exchange mutualism between arbuscular mycorrhizal fungi (AMFs) and their host plants qualifies as a biological market, but several complications have hindered its appropriate use. First, fungal 'trading agents' are hard to identify because AMFs are potentially heterokaryotic, that is, they may contain large numbers of polymorphic nuclei. This means it is difficult to define and study a fungal 'individual' acting as an independent agent with a specific trading strategy. Second, because nutrient exchanges occur via communal structures (arbuscules), this temporarily reduces outbidding competition and transaction costs and hence resembles exchanges among divisions of firms, rather than traditional trade on markets. We discuss how fungal nuclei may coordinate their trading strategies, but nevertheless retain some independence, similar to human co-operatives (co-ops).},
}
@article {pmid29856048,
year = {2018},
author = {Peterson, BF and Scharf, ME},
title = {Metatranscriptomic Techniques for Identifying Cellulases in Termites and their Symbionts.},
journal = {Methods in molecular biology (Clifton, N.J.)},
volume = {1796},
number = {},
pages = {85-101},
doi = {10.1007/978-1-4939-7877-9_7},
pmid = {29856048},
issn = {1940-6029},
support = {K12 GM000708/GM/NIGMS NIH HHS/United States ; },
mesh = {Animals ; Cellulases/*genetics ; Computational Biology ; Dissection ; Isoptera/*enzymology/*genetics ; Metagenomics/*methods ; Molecular Sequence Annotation ; RNA/isolation & purification ; Sonication ; Symbiosis/*genetics ; Transcriptome/*genetics ; },
abstract = {Characterizing symbiotic communities, like that of the termite hindgut, is essential for understanding their functionality and capabilities. However, the same complexity that allows termites to digest wood so efficiently also makes them difficult to study. With the expansion in technology and sequencing strategies the feasibility of sequencing entire consortiums or microecosystems is now possible. Here we present an adapted library preparation strategy which allows for the detection and measurement of expressed genes from all three domains of life in a single sample simultaneously. This technique effectively captures the transcriptome contributions by the various members of the consortium regardless of their taxonomic identity, which can then be annotated using custom-built databases and reciprocal BLASTing. Joining the universality of this library prep strategy with the power of bioinformatics allows for the identification of cellulases and other genes encoding carbohydrate active enzymes from complex communities using metatranscriptomics.},
}
@article {pmid29346623,
year = {2018},
author = {Fakhour, S and Ambroise, J and Renoz, F and Foray, V and Gala, JL and Hance, T},
title = {A large-scale field study of bacterial communities in cereal aphid populations across Morocco.},
journal = {FEMS microbiology ecology},
volume = {94},
number = {3},
pages = {},
doi = {10.1093/femsec/fiy003},
pmid = {29346623},
issn = {1574-6941},
mesh = {Animals ; Aphids/classification/*microbiology/physiology ; Bacteria/classification/genetics/*isolation & purification ; Bacterial Physiological Phenomena ; Biological Evolution ; Edible Grain/parasitology ; Host Specificity ; *Microbiota ; Morocco ; Symbiosis ; },
abstract = {Insects are frequently associated with bacteria that can have significant ecological and evolutionary impacts on their hosts. To date, few studies have examined the influence of environmental factors to microbiome composition of aphids. The current work assessed the diversity of bacterial communities of five cereal aphid species (Sitobion avenae, Rhopalosiphum padi, R. maidis, Sipha maydis and Diuraphis noxia) collected across Morocco, covering a wide range of environmental conditions. We aimed to test whether symbiont combinations are host or environment specific. Deep 16S rRNA sequencing enabled us to identify 17 bacterial operational taxonomic units (OTUs). The obligate symbiont Buchnera aphidicola was represented by five OTUs with multiple haplotypes in many single samples. Facultative endosymbionts were presented by a high prevalence of Regiella insecticola and Serratia symbiotica in S. avenae and Si. maydis, respectively. In addition to these symbiotic partners, Pseudomonas, Acinetobacter, Pantoea, Erwinia and Staphyloccocus were also identified in aphids, suggesting that the aphid microbiome is not limited to the presence of endosymbiotic bacteria. Beside a significant association between host species and bacterial communities, an inverse correlation was also found between altitude and α-diversity. Overall, our results support that symbiont combinations are mainly host specific.},
}
@article {pmid29327416,
year = {2018},
author = {Masson, V and Arafah, K and Voisin, S and Bulet, P},
title = {Comparative Proteomics Studies of Insect Cuticle by Tandem Mass Spectrometry: Application of a Novel Proteomics Approach to the Pea Aphid Cuticular Proteins.},
journal = {Proteomics},
volume = {18},
number = {3-4},
pages = {},
doi = {10.1002/pmic.201700368},
pmid = {29327416},
issn = {1615-9861},
mesh = {Animals ; Anopheles/metabolism ; Aphids/*physiology ; Bees/metabolism ; Bombyx/metabolism ; Insect Proteins/*metabolism ; Larva ; Medicago truncatula ; Proteome/*analysis ; Symbiosis ; Tandem Mass Spectrometry/*methods ; },
abstract = {The cuticle is a biological composite material consisting principally of N-acetylglucosamine polymer embedded in cuticular proteins (CPs). CPs have been studied and characterized by mass spectrometry in several cuticular structures and in many arthropods. Such analyses were carried out by protein extraction using SDS followed by electrophoresis, allowing detection and identification of numerous CPs. To build a repertoire of cuticular structures from Bombyx mori, Apis mellifera and Anopheles gambiae the use of SDS and electrophoresis was avoided. Using the combination of hexafluoroisopropanol and of a surfactant compatible with MS, a high number of CPs was identified in An. gambiae wings, legs and antennae, and in the thoracic integument cuticle of Ap. mellifera pupae. The exoskeleton analysis of B. mori larvae allowed to identify 85 CPs from a single larva. Finally, the novel proteomics approach was tested on cuticles left behind after the molt from the fourth instar of Acyrthosiphon pisum. Analysis of these cast cuticles allowed to identify 100 Ac. pisum CPs as authentic cuticle constituents. These correspond to 68% of the total putative CPs previously annotated for this pea aphid. While this paper analyzes only the recovered cuticular proteins, peptides from many other proteins were also detected.},
}
@article {pmid29098686,
year = {2018},
author = {Rose, NH and Bay, RA and Morikawa, MK and Palumbi, SR},
title = {Polygenic evolution drives species divergence and climate adaptation in corals.},
journal = {Evolution; international journal of organic evolution},
volume = {72},
number = {1},
pages = {82-94},
doi = {10.1111/evo.13385},
pmid = {29098686},
issn = {1558-5646},
mesh = {Animals ; Anthozoa/chemistry/*genetics/*physiology ; Chlorophyll A/analysis ; Gene Flow ; Heat-Shock Response ; Polymorphism, Single Nucleotide ; Quantitative Trait Loci ; Symbiosis ; },
abstract = {Closely related species often show substantial differences in ecological traits that allow them to occupy different environmental niches. For few of these systems is it clear what the genomic basis of adaptation is and whether a few loci of major effect or many genome-wide differences drive species divergence. Four cryptic species of the tabletop coral Acropora hyacinthus are broadly sympatric in American Samoa; here we show that two common species have differences in key environmental traits such as microhabitat distributions and thermal stress tolerance. We compared gene expression patterns and genetic polymorphism between these two species using RNA-Seq. The vast majority of polymorphisms are shared between species, but the two species show widespread differences in allele frequencies and gene expression, and tend to host different symbiont types. We find that changes in gene expression are related to changes in the frequencies of many gene regulatory variants, but that many of these differences are consistent with the action of genetic drift. However, we observe greater genetic divergence between species in amino acid replacement polymorphisms compared to synonymous variants. These findings suggest that polygenic evolution plays a major role in driving species differences in ecology and resilience to climate change.},
}
@article {pmid28740238,
year = {2017},
author = {Kim, Y and Lee, YS and Yang, JY and Lee, SH and Park, YY and Kweon, MN},
title = {The resident pathobiont Staphylococcus xylosus in Nfkbiz-deficient skin accelerates spontaneous skin inflammation.},
journal = {Scientific reports},
volume = {7},
number = {1},
pages = {6348},
pmid = {28740238},
issn = {2045-2322},
mesh = {Adaptor Proteins, Signal Transducing/*deficiency ; Animals ; CD4-Positive T-Lymphocytes/immunology ; Cephalexin/therapeutic use ; Dermatitis/drug therapy/genetics/microbiology/*pathology ; Disease Models, Animal ; Enrofloxacin/therapeutic use ; Humans ; Immunoglobulin E/blood ; Mice ; Nuclear Proteins/*deficiency ; Sequence Analysis, DNA ; Skin/microbiology/*pathology ; Staphylococcal Infections/*diagnosis/drug therapy/genetics/pathology ; Staphylococcus/classification/*isolation & purification/pathogenicity ; Symbiosis ; },
abstract = {IκBζ, which is encoded by the Nfkbiz gene, is a member of the nuclear IκB family of proteins that act as transcriptional regulators via association with NF-κB. Nfkbiz-deficient (Nfkbiz -/-) mice develop spontaneous dermatitis; however, the underlying mechanism has yet to be elucidated. In our study, we found higher skin pathology scores and more serum IgE antibodies and trans-epidermal water loss in Nfkbiz -/- than in Nfkbiz-sufficient (Nfkbiz +/-) mice. There was also greater expansion of IFN-γ-, IL-17A-, and IL-22-secreting CD4+ T cells and of IL-17A-secreting γδ+ T cells in the skin of Nfkbiz -/- mice than in with Nfkbiz +/- mice. Pyrosequencing analysis showed decreased diversity of resident bacteria and markedly expanded Staphylococcus (S.) xylosus in the skin of Nfkbiz -/- mice. Oral administration of antibiotics including cephalexin and enrofloxacin ameliorated skin inflammation. Topical application of S. xylosus also resulted in the expansion of IL-17A-secreting CD4+ T cells along with high levels of pro-inflammatory cytokines and chemokines in the skin of Nfkbiz -/- mice. The expansion of commensal S. xylosus may be one cause of skin dysbiosis in Nfkbiz -/- mice and suggests that the Nfkbiz gene may play a regulatory role in the microbiota-skin immunity axis.},
}
@article {pmid30797940,
year = {2019},
author = {Pfeiffer, JM and Breinholt, JW and Page, LM},
title = {Unioverse: A phylogenomic resource for reconstructing the evolution of freshwater mussels (Bivalvia, Unionoida).},
journal = {Molecular phylogenetics and evolution},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.ympev.2019.02.016},
pmid = {30797940},
issn = {1095-9513},
abstract = {Freshwater mussels (order Unionoida) are a diverse radiation of parasitic bivalves that require temporary larval encystment on vertebrate hosts to complete metamorphosis to their free-living phase. The freshwater mussel-fish symbiosis represents a useful relationship for understanding eco-evolutionary dynamics in freshwater ecosystems but the practicality of this promising model system is undermined by the absence of a stable freshwater mussel phylogeny. Inadequate character sampling is the primary analytical impediment obfuscating a coherent phylogeny of freshwater mussels, specifically the lack of nuclear molecular markers appropriate for reconstructing supraspecific relationships and testing macroevolutionary hypotheses. The objective of this study is to develop a phylogenomic resource, specifically an anchored hybrid enrichment probe set, capable of capturing hundreds of molecular markers from taxa distributed across the entirety of freshwater mussel biodiversity. Our freshwater mussel specific anchored hybrid enrichment probe set, called Unioverse, successfully captures hundreds of nuclear protein-coding loci from all major lineages of the Unionoida and will facilitate more data-rich and taxonomically inclusive reconstructions of freshwater mussel evolution. We demonstrate the utility of this resource at three disparate evolutionary scales by estimating a backbone phylogeny of the Bivalvia with a focus on the order Unionoida, reconstructing the subfamily-level relationships of the Unionidae, and recovering the systematic position of the phylogenetically unstable genus Plectomerus.},
}
@article {pmid30797939,
year = {2019},
author = {Steinová, J and Škaloud, P and Yahr, R and Bestová, H and Muggia, L},
title = {Reproductive and dispersal strategies shape the diversity of mycobiont-photobiont association in Cladonia lichens.},
journal = {Molecular phylogenetics and evolution},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.ympev.2019.02.014},
pmid = {30797939},
issn = {1095-9513},
abstract = {Ecological preferences, partner compatibility, or partner availability are known to be important factors shaping obligate and intimate lichen symbioses. We considered a complex of Cladonia species, traditionally differentiated by the extent of sexual reproduction and the type of vegetative propagules, to assess if the reproductive and dispersal strategies affect mycobiont-photobiont association patterns. In total 85 lichen thalli from 72 European localities were studied, two genetic markers for both Cladonia mycobionts and Asterochloris photobionts were analysed. Variance partitioning analysis by multiple regression on distance matrices was performed to describe and partition variance in photobiont genetic diversity. Asexually reproducing Cladonia in our study were found to be strongly specific to their photobionts, associating with only two closely related Asterochloris species. In contrast, sexually reproducing lichens associated with seven unrelated Asterochloris lineages, thus being photobiont generalists. The reproductive mode had the largest explanatory power, explaining 44% of the total photobiont variability. Reproductive and dispersal strategies are the key factors shaping photobiont diversity in this group of Cladonia lichens. A strict photobiont specialisation observed in two studied species may steer both evolutionary flexibility and responses to ecological changes of these organisms, and considerably limit their distribution ranges.},
}
@article {pmid30796304,
year = {2019},
author = {Chomicki, G and Renner, SS},
title = {Climate and symbioses with ants modulate leaf/stem scaling in epiphytes.},
journal = {Scientific reports},
volume = {9},
number = {1},
pages = {2624},
doi = {10.1038/s41598-019-39853-4},
pmid = {30796304},
issn = {2045-2322},
support = {RE 603/20//Deutsche Forschungsgemeinschaft (German Research Foundation)/ ; RE 603/23-1//Deutsche Forschungsgemeinschaft (German Research Foundation)/ ; RE 603/20//Deutsche Forschungsgemeinschaft (German Research Foundation)/ ; RE 603/23-1//Deutsche Forschungsgemeinschaft (German Research Foundation)/ ; },
abstract = {In most seed plants, leaf size is isometrically related to stem cross-sectional area, a relationship referred to as Corner's rule. When stems or leaves acquire a new function, for instance in ant-plant species with hollow stems occupied by ants, their scaling is expected to change. Here we use a lineage of epiphytic ant-plants to test how the evolution of ant-nesting structures in species with different levels of symbiotic dependence has impacted leaf/stem scaling. We expected that leaf size would correlate mostly with climate, while stem diameter would change with domatium evolution. Using a trait dataset from 286 herbarium specimens, field and greenhouse observations, climatic data, and a range of phylogenetic-comparative analyses, we detected significant shifts in leaf/stem scaling, mirroring the evolution of specialized symbioses. Our analyses support both predictions, namely that stem diameter change is tied to symbiosis evolution (ant-nesting structures), while leaf size is independently correlated with rainfall variables. Our study highlights how independent and divergent selective pressures can alter allometry. Because shifts in scaling relationships can impact the costs and benefits of mutualisms, studying allometry in mutualistic interactions may shed unexpected light on the stability of cooperation among species.},
}
@article {pmid30796064,
year = {2019},
author = {Newton, ILG and Slatko, BE},
title = {Symbiosis Comes of age at the 10th Biennial Meeting of Wolbachia Researchers.},
journal = {Applied and environmental microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1128/AEM.03071-18},
pmid = {30796064},
issn = {1098-5336},
abstract = {Wolbachia pipientis is an alpha-proteobacterial, obligate intracellular microbe and arguably the most successful infection on our planet, colonizing 40-60% of insect species. Wolbachia are also present in most, but not all, filarial nematodes where they are obligate mutualists and are the targets for anti-filarial drug discovery. Although Wolbachia are related to important human pathogens they do not infect mammals, but instead are well known for their reproductive manipulations of insect populations, inducing the following phenotypes: male-killing, feminization, parthenogenesis induction, or cytoplasmic incompatibility (CI). The most common of these, CI, results in a sperm-egg incompatibility and increases the relative fecundity of infected females in a population. In the last decade, Wolbachia have also been shown to provide a benefit to insects, where the infection can inhibit RNA virus replication within the host. Wolbachia cannot be cultivated outside of host cells and no genetic tools are available in the symbiont, limiting approaches available to its study. This means that many questions fundamental to our understanding of Wolbachia basic biology remained unknown for decades. The tenth biennial international Wolbachia conference, "Wolbachia Evolution, Ecology, Genomics and Cell Biology: A Chronicle of the Most Ubiquitous Symbiont", was held on June 17-22, 2018, Salem, MA USA. In the review below we highlight the new science presented at the meeting, link it to prior efforts to answer these questions across the Wolbachia genus, and the importance to the field of symbiosis. The topics covered in this review are based on the presentations at the conference.},
}
@article {pmid30790227,
year = {2019},
author = {Afonso, J and Pinto, T and Simões-Sousa, S and Schmitt, F and Longatto-Filho, A and Pinheiro, C and Marques, H and Baltazar, F},
title = {Clinical significance of metabolism-related biomarkers in non-Hodgkin lymphoma - MCT1 as potential target in diffuse large B cell lymphoma.},
journal = {Cellular oncology (Dordrecht)},
volume = {},
number = {},
pages = {},
doi = {10.1007/s13402-019-00426-2},
pmid = {30790227},
issn = {2211-3436},
support = {SFRH/BPD/116784/2016//Funda??o para a Ci?ncia e a Tecnologia/ ; POCI-01-0145-FEDER-007038//Funda??o para a Ci?ncia e a Tecnologia/ ; NORTE-01-0145-FEDER- 000013//Programa Operacional Regional do Norte de Portugal (Norte 2020)/ ; },
abstract = {PURPOSE: Increased glycolytic activity with accumulation of extracellular lactate is regarded as a hallmark of cancer. In lymphomas, FDG-PET has undeniable diagnostic and prognostic value, corroborating that these tumours are avid for glucose. However, the role of glycolytic metabolism-related molecules in lymphoma is not well known. Here, we aimed to evaluate the clinical and prognostic significance of a panel of glycolytic metabolism-related molecules in primary non-Hodgkin lymphomas (NHL) and to test in vitro the putative therapeutic impact of lactate transport inhibition.
METHODS: We assessed, by immunohistochemistry, the expression of the metabolism-related molecules MCT1, MCT2, MCT4, CD147, GLUT1, LDHA and CAIX in both tumour and stroma compartments of tissue sections obtained from 104 NHL patients. In addition, the lymphoma-derived cell lines OZ and DOHH-2 were used to evaluate the effect of AZD3965 on their viability and on apoptosis induction, as well as on extracellular lactate accumulation.
RESULTS: We found that expression of MCT1 in the NHL tumour compartment was significantly associated with a poor clinicopathological profile. We also found that MCT4 and CAIX were present in the stromal compartment and correlated with an aggressive phenotype, while MCT1 was absent in this compartment. In addition, we found that AZD3965-mediated disruption of MCT1 activity led to inhibited NHL cell viability and extracellular lactate accumulation, while increasing apoptotic cell death.
CONCLUSIONS: Our results indicate that elevated glycolytic activity is associated with NHL aggressiveness, pointing at metabolic cooperation, mediated by MCT1 and MCT4, between tumour cells and their surrounding stroma. MCT1 may serve as a target to treat NHL (diffuse large B cell lymphoma) patients with high MCT1/low MCT4 expressing tumours. Further (pre-)clinical studies are required to allow the design of novel therapeutic strategies aimed at e.g. reprogramming the tumour microenvironment.},
}
@article {pmid30789995,
year = {2019},
author = {Martinez, AFC and de Almeida, LG and Moraes, LAB and Cônsoli, FL},
title = {Microbial Diversity and Chemical Multiplicity of Culturable, Taxonomically Similar Bacterial Symbionts of the Leaf-Cutting Ant Acromyrmex coronatus.},
journal = {Microbial ecology},
volume = {},
number = {},
pages = {},
doi = {10.1007/s00248-019-01341-7},
pmid = {30789995},
issn = {1432-184X},
support = {2011/50877-0//Funda??o de Amparo ? Pesquisa do Estado de S?o Paulo/ ; 2014/21584-3//Funda??o de Amparo ? Pesquisa do Estado de S?o Paulo/ ; },
abstract = {Insects are a highly diverse group, exploit a wide range of habitats, and harbor bacterial symbionts of largely unknown diversity. Insect-associated bacterial symbionts are underexplored but promising sources of bioactive compounds. The community of culturable bacteria associated with the leaf-cutting ant Acromyrmex coronatus (Fabricius) and the diversity of their metabolites produced were investigated. Forty-six phylotypes belonging to Actinobacteria, Firmicutes, and Proteobacteria were identified. The chemical profiles of 65 isolates were further analyzed by LC-MS/MS, and principal components analysis (PCA) was used to group the isolates according to their chemical profiles. Historically, selection of bacterial strains for drug discovery has been based on phenotypic and/or genotypic traits. Use of such traits may well impede the discovery of new compounds; in this study, several indistinguishable phylotypes cultured in identical nutritional and environmental conditions produced completely different chemical profiles. Our data also demonstrated the wide chemical diversity to be explored in insect-associated symbionts.},
}
@article {pmid30788565,
year = {2019},
author = {Londoño, DMM and Meyer, E and González, D and Hernández, AG and Soares, CRFS and Lovato, PE},
title = {Landrace maize varieties differ from conventional and genetically modified hybrid maize in response to inoculation with arbuscular mycorrhizal fungi.},
journal = {Mycorrhiza},
volume = {},
number = {},
pages = {},
doi = {10.1007/s00572-019-00883-5},
pmid = {30788565},
issn = {1432-1890},
support = {Finance Code 001//Capes/ ; Finance Code 001//Capes/ ; Finance Code 001//Capes/ ; Finance Code 001//Capes/ ; 403720/2013-3//CNPq/ ; Bolsa Produtividade//CNPq/ ; Bolsa Produtividade//CNPq/ ; },
abstract = {Land area planted with genetically modified (GM) crops has grown rapidly, and Brazil has the second largest area with those plants. There is, however, limited information on the possible effects of that technology on non-target organisms, especially root symbionts, such as arbuscular mycorrhizal fungi (AMF). We evaluated AMF symbiosis development in five maize genotypes: one landrace, two conventional hybrids (DKB 240 and Formula), and two GM hybrids (DKB 240-VT Pro and Formula TL). We evaluated symbiosis response in two separate experiments: one in autumn and the other in summer. Plants were inoculated with Rhizophagus clarus (Rc) and Gigaspora margarita (Gm) and compared to plants without inoculation. We evaluated root colonization, spore number, and plant biomass and phosphorous accumulation 30 and 60 days after inoculation. There were no consistent effects of GM crops, but AMF species and maize genotype affected symbiosis development. Formula genotype (isoline and GM) had a negative response to inoculation, with a decrease of around 30% in biomass and P concentration in Rc-inoculated plants. The maize landrace had a positive response, with increases of 17% and 14% in the same variables. DKB genotype (isoline and GM) showed negative, positive, and neutral effects. The results show that plant genetic identity is a determinant factor in symbiosis performance, suggesting that plants selected in low P availability can make better use of mycorrhizal symbiosis. Given the role that AMF play in different ecosystem processes, use of landrace maize may contribute to agrobiodiversity conservation.},
}
@article {pmid30787909,
year = {2019},
author = {Alex, A and Antunes, A},
title = {Whole-Genome Comparisons Among the Genus Shewanella Reveal the Enrichment of Genes Encoding Ankyrin-Repeats Containing Proteins in Sponge-Associated Bacteria.},
journal = {Frontiers in microbiology},
volume = {10},
number = {},
pages = {5},
doi = {10.3389/fmicb.2019.00005},
pmid = {30787909},
issn = {1664-302X},
abstract = {The bacterial members of the genus Shewanella are widely distributed and inhabit both freshwater and marine environments. Some members of Shewanella have gained considerable attention due to its ability to survive in redox-stratified environments. However, a gap of knowledge exists on the key genomic features of the sponge-associated Shewanella sp. involving the successful host-bacteria interaction, as sponge-symbiotic Shewanella are largely underrepresented in the public repositories. With the aim of identifying the genomic signatures of sponge-Shewanella association, we generated a high-quality genome data of a sponge-associated, Shewanella sp. OPT22, isolated from the intertidal marine sponge Ophlitaspongia papilla and performed comprehensive comparative analyses of 68 genome strains of the genus Shewanella including two previously reported genomes of sponge-associated bacteria, Shewanella spongiae KCTC 22492 and Shewanella sp. Alg231_23. The 16S rRNA-based phylogenetic reconstruction showed the well-supported affiliation of OPT22 and KCTC 22492 with previously reported sponge-associated bacteria, affirming the "sponge-specific" nature of these two bacterial strains isolated from different marine sponge species from the Atlantic and Pacific (East Sea) Oceans, respectively. The genome comparison of the 68 strains of Shewanella inhabiting different habitats revealed the unusual/previously unreported abundance of genes encoding for ankyrin-repeat containing proteins (ANKs) in the genomes of the two sponge-associated strains, OPT22 (ANKs; n = 45) and KCTC 22492 (ANKs; n = 52), which might be involved in sponge-Shewanella interactions. Focused analyses detected the syntenic organization of the gene cluster encoding major secretion system (type III/IV/VI) components and the presence of effector homologs in OPT22 and KCTC 22492 that seem to play a role in the virulence of the sponge bacteria. The genomic island (GI) of Shewanella sp. OPT22 was identified to localize a gene cluster encoding T4SS components and ANK (n = 1), whereas S. spongiae KCTC 22492 harbored a total of seven ANKs within multiple GIs. GIs may play a pivotal role in the dissemination of symbioses-related genes (ANKs) through the horizontal gene transfer, contributing to the diversification and adaptation of sponge-associated Shewanella. Overall, the genome analyses of Shewanella isolates from marine sponges revealed genomic repertoires that might be involved in establishing successful symbiotic relationships with the sponge hosts.},
}
@article {pmid30387176,
year = {2019},
author = {Zhang, R and Huang, Z and Yu, G and Zhang, Z},
title = {Characterization of microbiota diversity of field-collected Haemaphysalis longicornis (Acari: Ixodidae) with regard to sex and blood meals.},
journal = {Journal of basic microbiology},
volume = {59},
number = {2},
pages = {215-223},
doi = {10.1002/jobm.201800372},
pmid = {30387176},
issn = {1521-4028},
support = {2017GSF221017//Key Research and Development project of Shandong Province/ ; },
mesh = {Animals ; Bacteria/*classification/genetics ; *Biodiversity ; Cattle ; China ; Coxiella/classification/genetics/isolation & purification ; DNA, Bacterial/analysis/genetics ; Feeding Behavior ; Female ; Goats ; Host Specificity ; Ixodidae/*microbiology ; Male ; *Microbiota/physiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Sex Factors ; Symbiosis ; },
abstract = {Haemaphysalis longicornis is a prominent tick species in China, and the major vector of an emerging tick-borne disease: severe fever with thrombocytopenia syndrome (SFTS). Microbiome diversity of ticks is influenced by several factors. In this study, we investigated microbiome diversity in field-collected female and male H. longicornis ticks and compared the microbial composition of fed and unfed ticks and of those feeding on different hosts using barcode sequencing of V3-V4 region of 16S RNA gene. Regardless of sex, host, and feeding status; the highest abundance among all samples was found for the genus Coxiella. The relative numbers of Coxiella sequences decreased with the length of the blood feeding, whereas the numbers of Staphylococcus and Corynebacterium increased gradually. The dominance of Coxiella across all samples indicates that it is an obligate symbiont of H. longicornis. Overall, higher microbiome richness was detected in male ticks than in female ticks. Fed ticks showed a more diverse microbe composition than unfed ticks, and ticks fed on goats exhibited the highest diversity. These findings of this study can serve as a basis for future studies of microbiota biology and interactions between the microbes and pathogens of H. longicornis.},
}
@article {pmid30270751,
year = {2018},
author = {Xia, C and Li, N and Zhang, Y and Li, C and Zhang, X and Nan, Z},
title = {Role of Epichloë Endophytes in Defense Responses of Cool-Season Grasses to Pathogens: A Review.},
journal = {Plant disease},
volume = {102},
number = {11},
pages = {2061-2073},
doi = {10.1094/PDIS-05-18-0762-FE},
pmid = {30270751},
issn = {0191-2917},
mesh = {Cyclopentanes/metabolism ; *Disease Resistance ; *Endophytes ; Epichloe/*physiology ; Host-Pathogen Interactions ; Oxylipins/metabolism ; Plant Breeding ; Plant Diseases/immunology/microbiology/*prevention & control ; Plant Growth Regulators/*metabolism ; Plant Leaves/immunology/microbiology ; Poaceae/immunology/*microbiology ; Salicylates/metabolism ; Signal Transduction ; Symbiosis ; },
abstract = {Various cool-season grasses are infected by Epichloë endophyte, and this symbiotic relationship is always of benefit to the host grass due to an increased resistance to abiotic and biotic stresses. Fungal diseases adversely affect the yield, quality, and economic benefits of rangelands, which affects the production of animal husbandry. Therefore, it is imperative to breed resistant cultivars and to better understand the role of fungal endophytes in order to protect grasses against pathogens. The present review introduces research regarding how these endophytes affect the growth of pathogens in vitro and how they change the resistance of host plants to plant diseases. From the perspective of physical defense, changes in physiological indexes, and secretion of chemical compounds, we summarize the potential mechanisms by which endophytes are able to enhance the disease resistance of a host grass. Through these, we aim to establish a solid theoretical foundation for plant disease control and disease resistance breeding by application of fungal endophytes. A broader understanding of fungal endophyte effects on hosts could create a new opportunity for managing or introducing fungal symbioses in both agronomic or non-agronomic ecosystems.},
}
@article {pmid30065090,
year = {2018},
author = {Fast, D and Duggal, A and Foley, E},
title = {Monoassociation with Lactobacillus plantarum Disrupts Intestinal Homeostasis in Adult Drosophila melanogaster.},
journal = {mBio},
volume = {9},
number = {4},
pages = {},
pmid = {30065090},
issn = {2150-7511},
mesh = {Animals ; Cell Proliferation ; Drosophila melanogaster/*microbiology/*physiology ; Gastrointestinal Tract/*microbiology/*pathology ; *Homeostasis ; Lactobacillus plantarum/*growth & development ; Longevity ; Stem Cells/physiology ; Symbiosis ; },
abstract = {Adult Drosophila melanogaster raised in the absence of symbiotic bacteria have fewer intestinal stem cell divisions and a longer life span than their conventionally reared counterparts. However, we do not know if increased stem cell divisions are essential for symbiont-dependent regulation of longevity. To determine if individual symbionts cause aging-dependent death in Drosophila, we examined the impacts of common symbionts on host longevity. We found that monoassociation of adult Drosophila with Lactobacillus plantarum, a widely reported fly symbiont and member of the probiotic Lactobacillus genus, curtails adult longevity relative to germfree counterparts. The effects of Lactobacillus plantarum on life span were independent of intestinal aging. Instead, we found that association with Lactobacillus plantarum causes an extensive intestinal pathology within the host, characterized by loss of stem cells, impaired epithelial renewal, and a gradual erosion of epithelial ultrastructure. Our study uncovers an unknown aspect of Lactobacillus plantarum-Drosophila interactions and establishes a simple model to characterize symbiont-dependent disruption of intestinal homeostasis.IMPORTANCE Under homeostatic conditions, gut bacteria provide molecular signals that support the organization and function of the host intestine. Sudden shifts in the composition or distribution of gut bacterial communities impact host receipt of bacterial cues and disrupt tightly regulated homeostatic networks. We used the Drosophila melanogaster model to determine the effects of prominent fly symbionts on host longevity and intestinal homeostasis. We found that monoassociation with Lactobacillus plantarum leads to a loss of intestinal progenitor cells, impaired epithelial renewal, and disruption of gut architecture as flies age. These observations uncover a novel phenotype caused by monoassociation of a germfree host with a common symbiont and establish a simple model to characterize symbiont-dependent loss of intestinal homeostasis.},
}
@article {pmid30785204,
year = {2019},
author = {Cognato, AI and Smith, SM and Li, Y and Pham, TH and Hulcr, J},
title = {Genetic Variability Among Xyleborus glabratus Populations Native to Southeast Asia (Coleoptera: Curculionidae: Scolytinae: Xyleborini) and the Description of Two Related Species.},
journal = {Journal of economic entomology},
volume = {},
number = {},
pages = {},
doi = {10.1093/jee/toz026},
pmid = {30785204},
issn = {1938-291X},
abstract = {The redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is native to Southeast Asia, where it specializes on Lauraceae trees. It forms a symbiosis with the ambrosia fungus Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva, which can act as a pathogen in living host trees. The beetle and fungus were recently introduced into the United States, where they have killed millions of native Lauraceae trees and threaten the avocado industry. These introduced populations have limited genetic variation. In the native range, the fungi are genetically variable, but the native genetic variability of the beetles is unknown. It is important to assess the beetle's native genetic variation because different lineages may vary in the capacity to vector this fungus, which may affect disease etiology. Here, we analyzed genetic variation in several Chinese, Taiwanese, and Vietnamese populations of X. glabratus using mitochondrial (COI) and nuclear DNA (CAD) markers. Phylogenetic analysis revealed nine COI haplotypes and four CAD genotypes. Uncorrected 'p' distance for intrapopulation comparisons ranged from 0 to 0.1 and 0 to 0.013 and interpopulation comparisons ranged from 0.137 to 0.168 and 0.015 to 0.032 for COI and CAD, respectively. Two populations exceeded the range of intraspecific nucleotide differences for both genes. Given that individuals from these populations also exhibited consistent morphological differences, they are described as two new species: Xyleborus insidiosus Cognato & Smith, n. sp. and Xyleborus mysticulus Cognato & Smith, n. sp. Xyleborus glabratus was redescribed and a lectotype was designated to facilitate its recognition in light of these new species. These results indicate that X. glabratus is genetically variable and is related to two morphologically similar species. Whether these new species and X. glabratus lineages associate with different fungal strains is unknown. Given that the biology and host colonization of these new species are unknown, preventing their introduction to other regions is prudent.},
}
@article {pmid30784795,
year = {2019},
author = {Simón-Grao, S and Nieves, M and Martínez-Nicolás, JJ and Alfosea-Simón, M and Cámara-Zapata, JM and Fernández-Zapata, JC and García-Sánchez, F},
title = {Arbuscular mycorrhizal symbiosis improves tolerance of Carrizo citrange to excess boron supply by reducing leaf B concentration and toxicity in the leaves and roots.},
journal = {Ecotoxicology and environmental safety},
volume = {173},
number = {},
pages = {322-330},
doi = {10.1016/j.ecoenv.2019.02.030},
pmid = {30784795},
issn = {1090-2414},
abstract = {This study explores the possibility of using mycorrhization as a novel technique for diminishing the negative effects of boron (B) in the nutrient solution on seedlings of Carrizo citrange rootstock plants. For this, an experiment was planned for studying the physiological (gas exchange and chlorophyll fluorescence parameters), morphological (vegetative growth parameters), nutritional (organic solutes, carbohydrates) and oxidative stress responses of seedlings that were either mycorrhized (+AM, Rhizophagus irregularis; previously known as Glomus intraradices) or not mycorrhized (-AM), and irrigated with water containing different concentrations of B (0.5, 5 and 10 mg L-1). It was observed that an excess of B in the nutrient solution decreased the vegetative growth in both +AM and -AM plants, but this decrease was greater in -AM plants. Mycorrhized plants (+AM) under high B concentration accumulated less B in the leaves, and had a smaller reduction of net assimilation rate of CO2 and lower MDA concentration than non-mycorrhized plants. Thus, it can be concluded that mycorrhization increased the tolerance to high boron concentration in the irrigation water of citrange Carrizo seedlings by reducing both the B concentration in the plant tissue and the B toxicity in the physiological processes. The study of organic solutes and carbohydrates also pointed to a different response model between +AM and -AM plants that could be related to the different tolerance observed between these plants.},
}
@article {pmid30781289,
year = {2006},
author = {Clarke, BB and White, JF and Hurley, RH and Torres, MS and Sun, S and Huff, DR},
title = {Endophyte-Mediated Suppression of Dollar Spot Disease in Fine Fescues.},
journal = {Plant disease},
volume = {90},
number = {8},
pages = {994-998},
doi = {10.1094/PD-90-0994},
pmid = {30781289},
issn = {0191-2917},
abstract = {In 1989, a close association was found between single-plant progenies of strong creeping red fescue infected with the endophyte Epichloë festucae and enhanced suppression of dollar spot, a widespread foliar disease of turfgrass caused by Sclerotinia homoeocarpa. From this limited observation, extensive field evaluations were conducted on a wide range of fine fescue germplasm obtained throughout the United States and Europe to determine the frequency and magnitude of this association. In five field trials established between 1985 and 1991, endophyte-infected Chewings, hard, blue, and strong creeping red fescue cultivars, selections, and crosses consistently exhibited endophyte-mediated suppression of dollar spot, when compared with closely related endophyte-free entries. Endophyte-infected Chewings and hard fescue cultivars and selections also had greater turf density and supported less foliar mycelium of S. homoeocarpa than endophyte-free entries.},
}
@article {pmid30780965,
year = {2006},
author = {Petit, E and Gubler, WD},
title = {Influence of Glomus intraradices on Black Foot Disease Caused by Cylindrocarpon macrodidymum on Vitis rupestris Under Controlled Conditions.},
journal = {Plant disease},
volume = {90},
number = {12},
pages = {1481-1484},
doi = {10.1094/PD-90-1481},
pmid = {30780965},
issn = {0191-2917},
abstract = {We examined the influence of an arbuscular-mycorrhizal fungus, Glomus intraradices (INVAM CA 501), on black foot disease caused by the fungus Cylindrocarpon macrodidymum on Vitis rupestris cv. St. George under controlled conditions. Mycorrhizal or nonmycorrhizal grape rootings were inoculated with the pathogen. Eight months following inoculation with the pathogen, we evaluated disease severity, vine growth, and mycorrhizal colonization. Mycorrhizal plants developed significantly less leaf and root symptoms than nonmycorrhizal plants (P = 0.04 and P < 0.0001, respectively). Only nonmycorrhizal grape rootings inoculated with the pathogen had significantly less dry root and leaf weights compared with the noninoculated control (P = 0.0021 and P = 0.0017, respectively). Mycorrhizal colonization was high (48.3% for the noninfected control and 54.5% for plants infected with C. macrodidymum) and not significantly affected by inoculation with C. macrodidymum (P = 0.2256). Thus, V. rupestris preinoculated with G. intraradices were less susceptible to black foot disease than nonmycorrhizal plants. Results from this study suggest that preplant applications of G. intraradices may help prevent black foot disease in the nursery and in the vineyard.},
}
@article {pmid30779767,
year = {2019},
author = {Vangelisti, A and Mascagni, F and Giordani, T and Sbrana, C and Turrini, A and Cavallini, A and Giovannetti, M and Natali, L},
title = {Arbuscular mycorrhizal fungi induce the expression of specific retrotransposons in roots of sunflower (Helianthus annuus L.).},
journal = {PloS one},
volume = {14},
number = {2},
pages = {e0212371},
doi = {10.1371/journal.pone.0212371},
pmid = {30779767},
issn = {1932-6203},
abstract = {Retrotransposon expression during arbuscular mycorrhizal (AM) fungal colonisation of sunflower roots (Helianthus annuus) was analysed using Illumina RNA-Seq, in order to verify whether mycorrhizal symbiosis can activate retrotransposable elements. Illumina cDNA libraries were produced from RNAs isolated from the roots of sunflower plants at 4 and 16 days after inoculation with the AM fungus Rhizoglomus irregulare and from their respective control plants. Illumina reads were mapped to a library of reverse transcriptase-encoding sequences, putatively belonging to long terminal repeat retrotransposons of Gypsy and Copia superfamilies. Forty-six different reverse transcriptase sequences were transcribed, although at a low rate, in mycorrhizal or control roots and only four were significantly over-expressed at day 16, compared with control roots. Almost all expressed or over-expressed sequences belonged to low-copy elements, mostly, of the Copia superfamily. A meta-analysis, using publicly available Illumina cDNA libraries obtained from sunflower plants treated with different hormones and chemicals, mimicking stimuli produced by abiotic and biotic stresses, was also conducted. Such analyses indicated that the four reverse transcriptase sequences over-expressed in mycorrhizal roots were explicitly induced only by AM symbiosis, showing the specificity of AM stimuli compared to that of other fungal/plant interactions.},
}
@article {pmid30778241,
year = {2019},
author = {Neumann, C and Blume, J and Roy, U and Teh, PP and Vasanthakumar, A and Beller, A and Liao, Y and Heinrich, F and Arenzana, TL and Hackney, JA and Eidenschenk, C and Gálvez, EJC and Stehle, C and Heinz, GA and Maschmeyer, P and Sidwell, T and Hu, Y and Amsen, D and Romagnani, C and Chang, HD and Kruglov, A and Mashreghi, MF and Shi, W and Strowig, T and Rutz, S and Kallies, A and Scheffold, A},
title = {c-Maf-dependent Treg cell control of intestinal TH17 cells and IgA establishes host-microbiota homeostasis.},
journal = {Nature immunology},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41590-019-0316-2},
pmid = {30778241},
issn = {1529-2916},
abstract = {Foxp3+ regulatory T cells (Treg cells) are crucial for the maintenance of immune homeostasis both in lymphoid tissues and in non-lymphoid tissues. Here we demonstrate that the ability of intestinal Treg cells to constrain microbiota-dependent interleukin (IL)-17-producing helper T cell (TH17 cell) and immunoglobulin A responses critically required expression of the transcription factor c-Maf. The terminal differentiation and function of several intestinal Treg cell populations, including RORγt+ Treg cells and follicular regulatory T cells, were c-Maf dependent. c-Maf controlled Treg cell-derived IL-10 production and prevented excessive signaling via the kinases PI(3)K (phosphatidylinositol-3-OH kinase) and Akt and the metabolic checkpoint kinase complex mTORC1 (mammalian target of rapamycin) and expression of inflammatory cytokines in intestinal Treg cells. c-Maf deficiency in Treg cells led to profound dysbiosis of the intestinal microbiota, which when transferred to germ-free mice was sufficient to induce exacerbated intestinal TH17 responses, even in a c-Maf-competent environment. Thus, c-Maf acts to preserve the identity and function of intestinal Treg cells, which is essential for the establishment of host-microbe symbiosis.},
}
@article {pmid30777812,
year = {2019},
author = {Green, RT and East, AK and Karunakaran, R and Downie, JA and Poole, PS},
title = {Transcriptomic analysis of Rhizobium leguminosarum bacteroids in determinate and indeterminate nodules.},
journal = {Microbial genomics},
volume = {},
number = {},
pages = {},
doi = {10.1099/mgen.0.000254},
pmid = {30777812},
issn = {2057-5858},
abstract = {Two common classes of nitrogen-fixing legume root nodules are those that have determinate or indeterminate meristems, as in Phaseolus bean and pea, respectively. In indeterminate nodules, rhizobia terminally differentiate into bacteroids with endoreduplicated genomes, whereas bacteroids from determinate nodules are less differentiated and can regrow. We used RNA sequencing to compare bacteroid gene expression in determinate and indeterminate nodules using two Rhizobium leguminosarum strains whose genomes differ due to replacement of the symbiosis (Sym) plasmid pRP2 (strain Rlp4292) with pRL1 (strain RlvA34), thereby switching symbiosis hosts from Phaseolus bean (determinate nodules) to pea (indeterminate nodules). Both bacteroid types have gene expression patterns typical of a stringent response, a stressful environment and catabolism of dicarboxylates, formate, amino acids and quaternary amines. Gene expression patterns were indicative that bean bacteroids were more limited for phosphate, sulphate and iron than pea bacteroids. Bean bacteroids had higher levels of expression of genes whose products are predicted to be associated with metabolite detoxification or export. Pea bacteroids had increased expression of genes associated with DNA replication, membrane synthesis and the TCA (tricarboxylic acid) cycle. Analysis of bacteroid-specific transporter genes was indicative of distinct differences in sugars and other compounds in the two nodule environments. Cell division genes were down-regulated in pea but not bean bacteroids, while DNA synthesis was increased in pea bacteroids. This is consistent with endoreduplication of pea bacteroids and their failure to regrow once nodules senesce.},
}
@article {pmid30777183,
year = {2019},
author = {Buckley, KM and Schuh, NW and Heyland, A and Rast, JP},
title = {Analysis of immune response in the sea urchin larva.},
journal = {Methods in cell biology},
volume = {150},
number = {},
pages = {333-355},
doi = {10.1016/bs.mcb.2018.10.009},
pmid = {30777183},
issn = {0091-679X},
abstract = {Sea urchin larvae deploy a complex immune system in the context of relatively simple morphology. Several types of phagocytic or granular immune cells respond rapidly to microbes and microbial components within the body cavity. Many of these cells also respond to microbial disturbances in the gut lumen. In the course of immune response, hundreds of genes are up- and downregulated, many of which have homologs involved in immunity in other species. Thus, the larval sea urchin provides an experimentally advantageous model for investigating the response to immune challenge at the level of cell behavior and gene regulatory networks. Importantly, the morphological simplicity and optical clarity of these larvae allow studies to be carried out within the intact animal. Here, we outline techniques to probe and visualize the immune system of the feeding sea urchin larva, particularly for quantifying gene expression and cell migration as the animal responds to both pathogens and symbionts. Techniques addressed in this chapter include (1) exposure of larvae to microbes and microbial products in sea water and by blastocoelar microinjection, (2) time-lapse imaging of immune response, (3) isolation of culturable bacteria associated with feeding larvae, (4) quantification of larval associations with isolated bacterial strains and (5) preparation of secreted products from isolated bacteria for testing in larval culture.},
}
@article {pmid30729921,
year = {2019},
author = {Simo, G and Kanté, ST and Madinga, J and Kame, G and Farikou, O and Ilombe, G and Geiger, A and Lutumba, P and Njiokou, F},
title = {Molecular identification of Wolbachia and Sodalis glossinidius in the midgut of Glossina fuscipes quanzensis from the Democratic Republic of Congo.},
journal = {Parasite (Paris, France)},
volume = {26},
number = {},
pages = {5},
doi = {10.1051/parasite/2019005},
pmid = {30729921},
issn = {1776-1042},
mesh = {Animals ; Coinfection/microbiology ; DNA, Bacterial/genetics ; Democratic Republic of the Congo ; Digestive System/*microbiology ; Enterobacteriaceae/*genetics/isolation & purification ; Fructose-Bisphosphate Aldolase/genetics ; High-Throughput Nucleotide Sequencing ; Insect Vectors/microbiology ; Polymerase Chain Reaction ; Symbiosis ; Tsetse Flies/*microbiology ; Wolbachia/*genetics/isolation & purification ; },
abstract = {During the last 30 years, investigations on the microbiome of different tsetse species have generated substantial data on the bacterial flora of these cyclical vectors of African trypanosomes, with the overarching goal of improving the control of trypanosomiases. It is in this context that the presence of Wolbachia and Sodalis glossinidius was studied in wild populations of Glossina fuscipes quanzensis from the Democratic Republic of Congo. Tsetse flies were captured with pyramidal traps. Of the 700 Glossina f. quanzensis captured, 360 were dissected and their midguts collected and analyzed. Sodalis glossinidius and Wolbachia were identified by PCR. The Wolbachia-positive samples were genetically characterized with five molecular markers. PCR revealed 84.78% and 15.55% midguts infected by Wolbachia and S. glossinidius, respectively. The infection rates varied according to capture sites. Of the five molecular markers used to characterize Wolbachia, only the fructose bis-phosphate aldolase gene was amplified for about 60% of midguts previously found with Wolbachia infections. The sequencing results confirmed the presence of Wolbachia and revealed the presence of S. glossinidius in the midgut of Glossina f. quanzensis. A low level of midguts were naturally co-infected by both bacteria. The data generated in this study open a framework for investigations aimed at understanding the contribution of these symbiotic microorganisms to the vectorial competence of Glossina fuscipes quanzensis.},
}
@article {pmid30406145,
year = {2018},
author = {Kallala, N and M'sehli, W and Jelali, K and Kais, Z and Mhadhbi, H},
title = {Inoculation with Efficient Nitrogen Fixing and Indoleacetic Acid Producing Bacterial Microsymbiont Enhance Tolerance of the Model Legume Medicago truncatula to Iron Deficiency.},
journal = {BioMed research international},
volume = {2018},
number = {},
pages = {9134716},
pmid = {30406145},
issn = {2314-6141},
mesh = {*Adaptation, Physiological ; Antioxidants/metabolism ; Biomass ; Cell Membrane/metabolism ; Chlorophyll/metabolism ; Electrolytes/metabolism ; Indoleacetic Acids/*metabolism ; Iron/deficiency ; Malondialdehyde/metabolism ; Medicago truncatula/*microbiology/*physiology ; *Nitrogen Fixation ; Plant Root Nodulation ; Plant Roots/metabolism ; Plant Shoots/metabolism ; Siderophores/metabolism ; Sinorhizobium/*physiology ; *Symbiosis ; },
abstract = {The aim of this study was to assess the effect of symbiotic bacteria inoculation on the response of Medicago truncatula genotypes to iron deficiency. The present work was conducted on three Medicago truncatula genotypes: A17, TN8.20, and TN1.11. Three treatments were performed: control (C), direct Fe deficiency (DD), and induced Fe deficiency by bicarbonate (ID). Plants were nitrogen-fertilized (T) or inoculated with two bacterial strains: Sinorhizobium meliloti TII7 and Sinorhizobium medicae SII4. Biometric, physiological, and biochemical parameters were analyzed. Iron deficiency had a significant lowering effect on plant biomass and chlorophyll content in all Medicago truncatula genotypes. TN1.11 showed the highest lipid peroxidation and leakage of electrolyte under iron deficiency conditions, which suggest that TN1.11 was more affected than A17 and TN8.20 by Fe starvation. Iron deficiency affected symbiotic performance indices of all Medicago truncatula genotypes inoculated with both Sinorhizobium strains, mainly nodules number and biomass as well as nitrogen-fixing capacity. Nevertheless, inoculation with Sinorhizobium strains mitigates the negative effect of Fe deficiency on plant growth and oxidative stress compared to nitrogen-fertilized plants. The highest auxin producing strain, TII7, preserves relatively high growth and root biomass and length when inoculated to TN8.20 and A17. On the other hand, both TII7 and SII4 strains improve the performance of sensitive genotype TN1.11 through reduction of the negative effect of iron deficiency on chlorophyll and plant Fe content. The bacterial inoculation improved Fe-deficient plant response to oxidative stress via the induction of the activities of antioxidant enzymes.},
}
@article {pmid30240129,
year = {2019},
author = {Sun, K and Cao, W and Hu, LY and Fu, WQ and Gong, JH and Kang, N and Dai, CC},
title = {Symbiotic fungal endophyte Phomopsis liquidambari-rice system promotes nitrogen transformation by influencing below-ground straw decomposition in paddy soil.},
journal = {Journal of applied microbiology},
volume = {126},
number = {1},
pages = {191-203},
doi = {10.1111/jam.14111},
pmid = {30240129},
issn = {1365-2672},
support = {31570491//National Nature Science Foundation of China/ ; //State Key Laboratory of Soil and Sustainable Agriculture/ ; //Nanjing Institute of Soil Science/ ; Y412201435//Chinese Academy of Science/ ; },
mesh = {Ammonia/metabolism ; Archaea/metabolism ; Ascomycota/*physiology ; Bacteria/metabolism ; Biodegradation, Environmental ; Ecosystem ; Endophytes/*physiology ; Nitrogen/*metabolism ; Oryza/growth & development/metabolism/*microbiology ; Oxidation-Reduction ; Plant Stems/metabolism/microbiology ; Soil/chemistry ; Soil Microbiology ; *Symbiosis ; },
abstract = {AIMS: To explore if and how symbiotic Phomopsis liquidambari-rice system influences below-ground straw decomposition and then nitrogen(N) transformation in response to environmental N levels.
METHODS AND RESULTS: Litter bag experiments were utilized to trace the decay process during rice growth phases (seedling (T1), tillering (T2), heading (T3) and maturing (T4) stage), with (E+) and without endophyte (E-), under low (LN), medium (MN) and high nitrogen (HN) supply. Litter, soil and plant samples were collected to evaluate the decay process, N transformations, plant quality and relative abundance of soil ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB) and P. liquidambari. The results showed that straw decomposition increased by 19·76% (LN, T2 stage), 14·05% (MN, T3 stage) and 16·88% (MN, T4 stage) in E+ pots when compared with E- pots. Further analysis revealed that no significant endophyte × N interaction was found for straw decay rate and that the decay rate was reduced by a higher N supply (LN, 37·16 ± 0·65%; MN, 32·27 ± 1·72%; HN, 29·44 ± 1·22%) at the T1 stage, whereas straw decay rate and N release increased by 9·38 and 11·16%, respectively, mainly by endophyte colonization at the T4 stage. The abundance of AOA and AOB were altered, corresponding with the decay rate. Soil mineral N, straw mineral N and plant quality were shown to increase in E+ pots, depending on environmental N conditions and growth phase. The yield increased by 2·98% for E+ plants under MN level.
CONCLUSIONS: Symbiotic P. liquidambari-rice system promoted below-ground straw decomposition and N transformation, depending on environmental N levels and plant growth phase.
This study provides evidence that fungal endophyte-plant systems are able to promote N transformation by increasing straw decomposition. A reasonable combination of N inputs could enhance its advantage in agriculture ecosystems.},
}
@article {pmid29396918,
year = {2018},
author = {Queller, DC},
title = {Nancy A. Moran - Recipient of the 2017 Molecular Ecology Prize.},
journal = {Molecular ecology},
volume = {27},
number = {1},
pages = {35-37},
doi = {10.1111/mec.14447},
pmid = {29396918},
issn = {1365-294X},
mesh = {Animals ; Aphids/physiology ; *Awards and Prizes ; Ecology/*history ; History, 20th Century ; History, 21st Century ; Symbiosis ; },
}
@article {pmid28775301,
year = {2017},
author = {Erwin, PM and Rhodes, RG and Kiser, KB and Keenan-Bateman, TF and McLellan, WA and Pabst, DA},
title = {High diversity and unique composition of gut microbiomes in pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales.},
journal = {Scientific reports},
volume = {7},
number = {1},
pages = {7205},
pmid = {28775301},
issn = {2045-2322},
mesh = {Animals ; *Biodiversity ; *Gastrointestinal Microbiome ; Metagenome ; Metagenomics/methods ; Phylogeny ; *Sperm Whale ; Symbiosis ; *Whales ; },
abstract = {Mammals host diverse bacterial and archaeal symbiont communities (i.e. microbiomes) that play important roles in digestive and immune system functioning, yet cetacean microbiomes remain largely unexplored, in part due to sample collection difficulties. Here, fecal samples from stranded pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales were used to characterize the gut microbiomes of two closely-related species with similar diets. 16S rRNA gene sequencing revealed diverse microbial communities in kogiid whales dominated by Firmicutes and Bacteroidetes. Core symbiont taxa were affiliated with phylogenetic lineages capable of fermentative metabolism and sulfate respiration, indicating potential symbiont contributions to energy acquisition during prey digestion. The diversity and phylum-level composition of kogiid microbiomes differed from those previously reported in toothed whales, which exhibited low diversity communities dominated by Proteobacteria and Actinobacteria. Community structure analyses revealed distinct gut microbiomes in K. breviceps and K. sima, driven by differential relative abundances of shared taxa, and unique microbiomes in kogiid hosts compared to other toothed and baleen whales, driven by differences in symbiont membership. These results provide insight into the diversity, composition and structure of kogiid gut microbiomes and indicate that host identity plays an important role in structuring cetacean microbiomes, even at fine-scale taxonomic levels.},
}
@article {pmid28769037,
year = {2017},
author = {Smolentseva, O and Gusarov, I and Gautier, L and Shamovsky, I and DeFrancesco, AS and Losick, R and Nudler, E},
title = {Mechanism of biofilm-mediated stress resistance and lifespan extension in C. elegans.},
journal = {Scientific reports},
volume = {7},
number = {1},
pages = {7137},
pmid = {28769037},
issn = {2045-2322},
support = {R01 GM018568/GM/NIGMS NIH HHS/United States ; /HHMI/Howard Hughes Medical Institute/United States ; },
mesh = {Adaptation, Biological/genetics ; Animal Feed ; Animals ; *Biofilms ; Biomarkers ; Caenorhabditis elegans/*microbiology/*physiology ; HSP70 Heat-Shock Proteins/genetics/metabolism ; Host-Pathogen Interactions ; Intestinal Mucosa/metabolism/microbiology ; *Longevity ; *Stress, Physiological ; Symbiosis ; },
abstract = {Bacteria naturally form communities of cells known as biofilms. However the physiological roles of biofilms produced by non-pathogenic microbiota remain largely unknown. To assess the impact of a biofilm on host physiology we explored the effect of several non-pathogenic biofilm-forming bacteria on Caenorhabditis elegans. We show that biofilm formation by Bacillus subtilis, Lactobacillus rhamnosus and Pseudomonas fluorescens induces C. elegans stress resistance. Biofilm also protects against pathogenic infection and prolongs lifespan. Total mRNA analysis identified a set of host genes that are upregulated in response to biofilm formation by B. subtilis. We further demonstrate that mtl-1 is responsible for the biofilm-mediated increase in oxidative stress resistance and lifespan extension. Induction of mtl-1 and hsp-70 promotes biofilm-mediated thermotolerance. ilys-2 activity accounts for biofilm-mediated resistance to Pseudomonas aeruginosa killing. These results reveal the importance of non-pathogenic biofilms for host physiology and provide a framework to study commensal biofilms in higher organisms.},
}
@article {pmid30775775,
year = {2019},
author = {Liang, J and Klingl, A and Lin, YY and Boul, E and Thomas-Oates, J and Marín, M},
title = {A sub-compatible rhizobium strain reveals infection duality in Lotus.},
journal = {Journal of experimental botany},
volume = {},
number = {},
pages = {},
doi = {10.1093/jxb/erz057},
pmid = {30775775},
issn = {1460-2431},
abstract = {Lotus species develop infection threads to guide rhizobia into nodule cells. However, there is evidence that some species have a genetic repertoire to allow other modes of infection. Conducting confocal and electron microscopy, quantification of marker gene expression, and phenotypic analysis of transgenic roots infected with mutant rhizobia we elucidated the infection mechanism used by Rhizobium leguminosarum Norway to colonise Lotus burttii. R. leguminosarum Norway induces a distinct host transcriptional response compared to Mesorhizobium loti. It infects L.burttii utilising an epidermal and trans-cellular infection thread-independent mechanism at high frequency. The entry into plant cells occurs directly from the apoplast and is primarily mediated by "peg"-like structures, the formation of which is dependent on the production of Nod factor by the rhizobia. These results demonstrate that Lotus species can exhibit duality in their infection mechanisms depending on the rhizobial strain that they encounter. This is especially relevant in the context of interactions in the rhizosphere where legumes do not encounter single strains, but complex rhizobial communities. Additionally, our findings support a perception mechanism at the nodule cell entry interface reinforcing the idea that there are successive checkpoints during rhizobial infection.},
}
@article {pmid30772337,
year = {2019},
author = {Mishra, N and Damle, G and Dhas, Y and Banerjee, J},
title = {Association of vitamin D deficiency with insulin resistance in middle-aged type 2 diabetics.},
journal = {Clinica chimica acta; international journal of clinical chemistry},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.cca.2019.02.014},
pmid = {30772337},
issn = {1873-3492},
abstract = {BACKGROUND: Vitamin D deficiency contributes to the pathophysiology of insulin resistance (IR) and type 2 diabetes mellitus (T2DM). We investigated the association of 25-hydroxyvitamin D [25(OH)D] with IR and β-cell function in middle-aged participants.
METHODS: We enrolled 90 controls and 90 T2DM patients of both genders aged 30-50 y. Serum 25(OH)D, fasting plasma insulin (FPI), fasting plasma glucose (FPG), HbA1c, and lipid profile were measured by standard methods. Insulin resistance and sensitivity were assessed by triglyceride glucose (TyG) index, homeostatic model assessment (HOMA-IR), and quantitative insulin sensitivity check index (QUICKI), and β-cell function by HOMA-B.
RESULTS: 25(OH)D deficiency was reported as 40% in control and 70% in T2DM patients. 25(OH)D concentration was positively associated with age, blood pressure, T2DM duration, FPG, HbA1c, TyG index, and HOMA-IR and negatively associated with HOMA-B and QUICKI among all the participants (p ≤.001). Participants with severe 25(OH)D deficiency (<10 ng/ml) were 38.927 times higher odds of being T2DM, while, those with moderate deficiency (10-19n g/ml) and insufficiency (20-29 ng/ml) were 15 times and 13 times higher odds of being T2DM, respectively.
CONCLUSION: Sufficient 25(OH)D concentration may lower the risk of development of IR and T2DM in middle-aged control and diabetic participants.},
}
@article {pmid30772172,
year = {2019},
author = {Yu, H and Bao, H and Zhang, Z and Cao, Y},
title = {Immune Signaling Pathway during Terminal Bacteroid Differentiation in Nodules.},
journal = {Trends in plant science},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.tplants.2019.01.010},
pmid = {30772172},
issn = {1878-4372},
abstract = {Plant innate immunity plays an important role in regulating symbiotic associations with rhizobia, including during rhizobial infection, rhizobial colonization, and bacteroid differentiation in leguminous plants. Here we propose that an immune signaling pathway similar to plant pattern-triggered immunity (PTI) is required for the regulation of bacteroid differentiation in Medicago truncatula nodules.},
}
@article {pmid30765781,
year = {2019},
author = {Yoshida, T and Furihata, HY and To, TK and Kakutani, T and Kawabe, A},
title = {Genome defense against integrated organellar DNA fragments from plastids into plant nuclear genomes through DNA methylation.},
journal = {Scientific reports},
volume = {9},
number = {1},
pages = {2060},
doi = {10.1038/s41598-019-38607-6},
pmid = {30765781},
issn = {2045-2322},
support = {201508708//MEXT | Japan Society for the Promotion of Science (JSPS)/ ; 18K14758//MEXT | Japan Society for the Promotion of Science (JSPS)/ ; S1511023//Ministry of Education, Culture, Sports, Science and Technology (MEXT)/ ; },
abstract = {Nuclear genomes are always faced with the modification of themselves by insertions and integrations of foreign DNAs and intrinsic parasites such as transposable elements. There is also substantial number of integrations from symbiotic organellar genomes to their host nuclear genomes. Such integration might have acted as a beneficial mutation during the evolution of symbiosis, while most of them have more or less deleterious effects on the stability of current genomes. Here we report the pattern of DNA substitution and methylation on organellar DNA fragments integrated from plastid into plant nuclear genomes. The genome analyses of 17 plants show homology-dependent DNA substitution bias. A certain number of these sequences are DNA methylated in the nuclear genome. The intensity of DNA methylation also decays according to the increase of relative evolutionary times after being integrated into nuclear genomes. The methylome data of epigenetic mutants shows that the DNA methylation of organellar DNA fragments in nuclear genomes are mainly dependent on the methylation maintenance machinery, while other mechanisms may also affect on the DNA methylation level. The DNA methylation on organellar DNA fragments may contribute to maintaining the genome stability and evolutionary dynamics of symbiotic organellar and their host's genomes.},
}
@article {pmid30765481,
year = {2019},
author = {Zhou, D and Li, Y and Wang, X and Xie, F and Chen, D and Ma, B and Li, Y},
title = {Mesorhizobium huakuii HtpG interaction with nsLTP AsE246 is required for symbiotic nitrogen fixation.},
journal = {Plant physiology},
volume = {},
number = {},
pages = {},
doi = {10.1104/pp.18.00336},
pmid = {30765481},
issn = {1532-2548},
abstract = {Plant non-specific lipid transfer proteins (nsLTPs) are involved in a number of biological processes including root nodule symbiosis. However, the role of nsLTPs in legume-rhizobium symbiosis remains poorly understood, and no rhizobia proteins that interact with nsLTPs have been reported to date. In this study, we used a bacteria two-hybrid system and identified the HtpG protein from Mesorhizobium huakuii that interacts with the nsLTP AsE246. The interaction between HtpG and AsE246 was confirmed by far-western blotting and bimolecular fluorescence complementation. Our results indicated that the HSP90 domain of HtpG mediates the HtpG-AsE246 interaction. Immunofluorescence assay showed that HtpG was co-localized with AsE246 in infected nodule cells and symbiosome membranes. Expression of the htpG gene was relatively higher in young nodules and was highly expressed in the infection zones. Further investigaton showed that htpG expression affects lipid abundance and profiles in root nodules and plays an essential role in nodule development and nitrogen fixation. Our findings provide further insights into the functional mechanisms behind the transport of symbiosome lipids via nsLTPs in root nodules.},
}
@article {pmid30422992,
year = {2018},
author = {Grobler, Y and Yun, CY and Kahler, DJ and Bergman, CM and Lee, H and Oliver, B and Lehmann, R},
title = {Whole genome screen reveals a novel relationship between Wolbachia levels and Drosophila host translation.},
journal = {PLoS pathogens},
volume = {14},
number = {11},
pages = {e1007445},
pmid = {30422992},
issn = {1553-7374},
support = {/Howard Hughes Medical Institute/Howard Hughes Medical Institute/United States ; P30 CA016087/CA/NCI NIH HHS/United States ; P40 OD018537/OD/NIH HHS/United States ; },
mesh = {Animals ; Culicidae ; Drosophila/genetics/microbiology ; Drosophila melanogaster/*genetics/microbiology ; Genome ; Host Microbial Interactions/*genetics ; Host-Pathogen Interactions/genetics ; Humans ; In Situ Hybridization, Fluorescence/methods ; Mosquito Vectors ; RNA Interference ; Symbiosis ; Viruses/genetics ; Whole Genome Sequencing/methods ; Wolbachia/*genetics ; },
abstract = {Wolbachia is an intracellular bacterium that infects a remarkable range of insect hosts. Insects such as mosquitos act as vectors for many devastating human viruses such as Dengue, West Nile, and Zika. Remarkably, Wolbachia infection provides insect hosts with resistance to many arboviruses thereby rendering the insects ineffective as vectors. To utilize Wolbachia effectively as a tool against vector-borne viruses a better understanding of the host-Wolbachia relationship is needed. To investigate Wolbachia-insect interactions we used the Wolbachia/Drosophila model that provides a genetically tractable system for studying host-pathogen interactions. We coupled genome-wide RNAi screening with a novel high-throughput fluorescence in situ hybridization (FISH) assay to detect changes in Wolbachia levels in a Wolbachia-infected Drosophila cell line JW18. 1117 genes altered Wolbachia levels when knocked down by RNAi of which 329 genes increased and 788 genes decreased the level of Wolbachia. Validation of hits included in depth secondary screening using in vitro RNAi, Drosophila mutants, and Wolbachia-detection by DNA qPCR. A diverse set of host gene networks was identified to regulate Wolbachia levels and unexpectedly revealed that perturbations of host translation components such as the ribosome and translation initiation factors results in increased Wolbachia levels both in vitro using RNAi and in vivo using mutants and a chemical-based translation inhibition assay. This work provides evidence for Wolbachia-host translation interaction and strengthens our general understanding of the Wolbachia-host intracellular relationship.},
}
@article {pmid30332402,
year = {2018},
author = {Pang, R and Chen, M and Yue, L and Xing, K and Li, T and Kang, K and Liang, Z and Yuan, L and Zhang, W},
title = {A distinct strain of Arsenophonus symbiont decreases insecticide resistance in its insect host.},
journal = {PLoS genetics},
volume = {14},
number = {10},
pages = {e1007725},
pmid = {30332402},
issn = {1553-7404},
mesh = {Animals ; Asia ; Bacteria/genetics ; DNA, Bacterial/genetics ; Enterobacteriaceae/*genetics ; Hemiptera ; Insecta/genetics ; Insecticide Resistance/*genetics/physiology ; Insecticides ; Polymorphism, Single Nucleotide/genetics ; Symbiosis/genetics ; },
abstract = {Symbiotic bacteria are important drivers of phenotypic diversity in insects. One of the widespread symbionts to have emerged belongs to the genus Arsenophonus, however, its biological functions in most host insects remain entirely unknown. Here we report two distinct Arsenophonus strains in the brown planthopper (BPH), Nilaparvata lugens, a major pest insect in Asian countries that causes significant economic damage through rice crop destruction. Genomic resequencing data suggested that one Arsenophonus strain (S-type) negatively affected the insecticide resistance of the host. Indeed, replacement of the resident Arsenophonus with the S-type Arsenophonus significantly decreased host insecticide resistance. Transcriptome and metabolome analysis revealed down-regulation of xenobiotic metabolism and increased amino acid accumulation in the S-type Arsenophonus infected host. This study demonstrates how a symbiont-mediated phenotypic change can occur. The results of this study will aid in developing strategies that work through imposing an ecological disadvantage on insect pests, which will be of great value for pest control in agricultural industry.},
}
@article {pmid29267881,
year = {2018},
author = {Britstein, M and Saurav, K and Teta, R and Sala, GD and Bar-Shalom, R and Stoppelli, N and Zoccarato, L and Costantino, V and Steindler, L},
title = {Identification and chemical characterization of N-acyl-homoserine lactone quorum sensing signals across sponge species and time.},
journal = {FEMS microbiology ecology},
volume = {94},
number = {2},
pages = {},
doi = {10.1093/femsec/fix182},
pmid = {29267881},
issn = {1574-6941},
mesh = {Acyl-Butyrolactones/*metabolism ; Animals ; Humans ; Indian Ocean ; Porifera/*microbiology ; Quorum Sensing/*physiology ; Signal Transduction ; Symbiosis ; },
abstract = {Marine sponges form symbiotic relationships with complex microbial communities, yet little is known about the mechanisms by which these microbes regulate their behavior through gene expression. Many bacterial communities regulate gene expression using chemical signaling termed quorum sensing. While a few previous studies have shown presence of N-acyl-homoserine lactone (AHL)-based quorum sensing in marine sponges, the chemical identity of AHL signals has been published for only two sponge species. In this study, we screened for AHLs in extracts from 15 sponge species (109 specimens in total) from the Mediterranean and Red Sea, using a wide-range AHL biosensor. This is the first time that AHL presence was examined over time in sponges. We detected the presence of AHL in 46% of the sponge species and found that AHL signals differ for certain sponge species in time and across sponge individuals. Furthermore, for the Mediterranean sponge species Sarcotragus fasciculatus, we identified 14 different AHLs. The constant presence of specific AHL molecules in all specimens, together with varying signaling molecules between the different specimens, makes Sa. fasciculatus a good model to further investigate the function of quorum sensing in sponge-associated bacteria. This study extends the knowledge of AHL-based quorum sensing in marine sponges.},
}
@article {pmid30763666,
year = {2019},
author = {Cao-Pham, AH and Hiong, KC and Boo, MV and Choo, CYL and Pang, CZ and Wong, WP and Neo, ML and Chew, SF and Ip, YK},
title = {Molecular characterization, cellular localization, and light-enhanced expression of Beta-Na+/H+ Exchanger-like in the whitish inner mantle of the giant clam, Tridacna squamosa, denote its role in light-enhanced shell formation.},
journal = {Gene},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.gene.2019.02.009},
pmid = {30763666},
issn = {1879-0038},
abstract = {The fluted giant clam, Tridacna squamosa, lives in symbiosis with photosynthetic zooxanthellae, and can engage in light-enhanced growth and shell formation. Light-enhanced shell formation necessitates the elimination of excess H+ from the extrapallial fluid adjacent to the shell. This study aimed to clone Na+/H+Exchanger (NHE) from the whitish inner mantle adjacent to the extrapallial fluid of T. squamosa, to determine its cellular and subcellular localization, and to evaluate the effect of light exposure on its mRNA expression level and protein abundance therein. The complete coding cDNA sequence of NHE obtained was identified as a homolog of beta NHE (βNHE-like). It consisted of 2925 bp, encoding for a polypeptide of 974 amino acids and 107.1 kDa, and was expressed predominantly in the inner mantle. There, βNHE-like was localized in the apical membrane of the seawater-facing epithelium by immunofluorescence microscopy. After exposure to light for 12 h, the seawater-facing epithelium of the inner mantle displayed consistently stronger immunostaining than that of the control exposed to 12 h of darkness. Western blotting confirmed that light exposure significantly enhanced the protein abundance of βNHE-like in the inner mantle. These results denote that some of the excess H+ generated during light-enhanced shell formation can be excreted through the light-dependent βNHE-like of the seawater-facing epithelium to minimize the impact on the whole-body pH. Importantly, the excreted H+ could dehydrate exogenous HCO3-, and facilitate the absorption of inorganic carbon through the seawater-facing epithelium dedicated for light-enhanced shell formation due to its close proximity with the shell-facing epithelium. NUCLEOTIDE SYMBOL COMBINATIONS: Pairs: R = A/G; W = A/T; Y = C/T. Triples: D = A/G/T.},
}
@article {pmid30763358,
year = {2019},
author = {Abi Khattar, Z and Lanois, A and Hadchity, L and Gaudriault, S and Givaudan, A},
title = {Spatiotemporal expression of the putative MdtABC efflux pump of Phtotorhabdus luminescens occurs in a protease-dependent manner during insect infection.},
journal = {PloS one},
volume = {14},
number = {2},
pages = {e0212077},
doi = {10.1371/journal.pone.0212077},
pmid = {30763358},
issn = {1932-6203},
abstract = {Photorhabdus luminescens is an enterobacterium establishing a mutualistic symbiosis with nematodes, that also kills insects after septicaemia and connective tissue colonization. The role of the bacterial mdtABC genes encoding a putative multidrug efflux system from the resistance/nodulation/cell division family was investigated. We showed that a mdtA mutant and the wild type had similar levels of resistance to antibiotics, antimicrobial peptides, metals, detergents and bile salts. The mdtA mutant was also as pathogenic as the wild-type following intrahaemocoel injection in Locusta migratoria, but had a slightly attenuated phenotype in Spodoptera littoralis. A transcriptional fusion of the mdtA promoter (PmdtA) and the green fluorescent protein (gfp) encoding gene was induced by copper in bacteria cultured in vitro. The PmdtA-gfp fusion was strongly induced within bacterial aggregates in the haematopoietic organ during late stages of infection in L. migratoria, whereas it was only weakly expressed in insect plasma throughout infection. A medium supplemented with haematopoietic organ extracts induced the PmdtA-gfp fusion ex vivo, suggesting that site-specific mdtABC expression resulted from insect signals from the haematopoietic organ. Finally, we showed that protease inhibitors abolished ex vivo activity of the PmdtA-gfp fusion in the presence of haematopoietic organ extracts, suggesting that proteolysis by-products play a key role in upregulating the putative MdtABC efflux pump during insect infection with P. luminescens.},
}
@article {pmid30761784,
year = {2018},
author = {Kuzmin, MD and Pashkova, TM and Kartashova, OL and Pashinina, OA and Popova, LP},
title = {[Biological properties of microorganisms isolated from the urine of patients with urolithiasis].},
journal = {Urologiia (Moscow, Russia : 1999)},
volume = {},
number = {4},
pages = {14-18},
pmid = {30761784},
issn = {1728-2985},
abstract = {AIM: To define persistent properties and antibiotic resistance of microorganisms isolated from the urine of adult patient undergoing surgery for urolithiasis.
MATERIALS AND METHODS: Urine specimens were obtained from the renal pelvis and urinary bladder during percutaneous nephrolithotripsy. Microorganisms that were isolated from the urine were examined for their persistent properties (anti-lysozyme activity, the ability of biofilm formation) and antibiotic resistance using photometric and bacteriological methods.
RESULTS: Strains of microorganisms isolated from the urine of patients with urolithiasis have high anti-lysozyme activity and the ability of biofilm formation, and variable antibiotic resistance. These properties should be taken into account when selecting an empirical antibiotic therapy for preventing infectious-inflammatory complications after percutaneous nephrolithotripsy.
CONCLUSION: The high level of resistance of microorganisms isolated from the urine of patients with urolithiasis to the studied antibiotics, their ability to inactivate lysozyme and form biofilms may be the cause of the development of postoperative complications.},
}
@article {pmid30761341,
year = {2018},
author = {Pushpakumara, BLDU and Gunawardana, D},
title = {Preliminary data on the presence of an alternate vanadium nitrogenase in a culturable cyanobiont of Azolla pinnata R. Brown: Implications on Chronic Kidney Disease of an unknown etiology (CKDu).},
journal = {Data in brief},
volume = {21},
number = {},
pages = {2590-2597},
doi = {10.1016/j.dib.2018.11.073},
pmid = {30761341},
issn = {2352-3409},
abstract = {In a recent paper titled "How a taxonomically-ambiguous cyanobiont and vanadate assist in the phytoremediation of cadmium by Azolla pinnata: implications for CKDu" (Atugoda et al., 2018) [1] it was shown by us, that plant health and phytoremediation capacities, of Azolla pinnata R. Brown, were elevated in the presence of vanadate, a vanadium containing ion. This highlighted a possibility, that either the major or minor cyanobionts of Azolla pinnata, could possess a vanadium dependent nitrogenase enzyme, as an alternate nitrogenase, in addition to the molybdenum counterpart. In this data article, we report the isolation of a minor cyanobiont which we name as Fischerella uthpalarensis. We grew Fischerella uthpalarensis, exclusively in N-free media, with only molybdenum (Mo+ V-), with only vanadium (V+ Mo-) and with neither (negative control), to find out the growth patterns in the relevant media. While F. uthpalarensis grew as green colored consistencies, increasing gradually in turbidity, for 4 weeks in culture, both, in the presence of molybdenum (Mo+ V-), as well as vanadium (V+ Mo-), the negative control, showed no, or very little growth. This alludes to the presence of dual nitrogenases in Fischerella uthpalarensis. An attempt was also made by us to unravel the vnf genes, responsible for the V-nitrogenase. However, it was not possible to PCR amplify the vnf genes, from both, the unculturable major (using total DNA from the Azolla-Nostoc azollae symbiosis) and minor (DNA directly from the cultured F. uthpalarensis) cyanobionts. This is the first time, to our knowledge, that an endosymbiotic cyanobacterium inside a plant compartment, has been shown to contain two possible nitrogenase systems.},
}
@article {pmid30760820,
year = {2019},
author = {Karimi, E and Keller-Costa, T and Slaby, BM and Cox, CJ and da Rocha, UN and Hentschel, U and Costa, R},
title = {Genomic blueprints of sponge-prokaryote symbiosis are shared by low abundant and cultivatable Alphaproteobacteria.},
journal = {Scientific reports},
volume = {9},
number = {1},
pages = {1999},
doi = {10.1038/s41598-019-38737-x},
pmid = {30760820},
issn = {2045-2322},
support = {PTDC/BIA-MIC/3865/2012//Ministry of Education and Science | Fundação para a Ciência e a Tecnologia (Portuguese Science and Technology Foundation)/ ; PTDC/MAR-BIO/1547/2014//Ministry of Education and Science | Fundação para a Ciência e a Tecnologia (Portuguese Science and Technology Foundation)/ ; },
abstract = {Marine sponges are early-branching, filter-feeding metazoans that usually host complex microbiomes comprised of several, currently uncultivatable symbiotic lineages. Here, we use a low-carbon based strategy to cultivate low-abundance bacteria from Spongia officinalis. This approach favoured the growth of Alphaproteobacteria strains in the genera Anderseniella, Erythrobacter, Labrenzia, Loktanella, Ruegeria, Sphingorhabdus, Tateyamaria and Pseudovibrio, besides two likely new genera in the Rhodobacteraceae family. Mapping of complete genomes against the metagenomes of S. officinalis, seawater, and sediments confirmed the rare status of all the above-mentioned lineages in the marine realm. Remarkably, this community of low-abundance Alphaproteobacteria possesses several genomic attributes common to dominant, presently uncultivatable sponge symbionts, potentially contributing to host fitness through detoxification mechanisms (e.g. heavy metal and metabolic waste removal, degradation of aromatic compounds), provision of essential vitamins (e.g. B6 and B12 biosynthesis), nutritional exchange (especially regarding the processing of organic sulphur and nitrogen) and chemical defence (e.g. polyketide and terpenoid biosynthesis). None of the studied taxa displayed signs of genome reduction, indicative of obligate mutualism. Instead, versatile nutrient metabolisms along with motility, chemotaxis, and tight-adherence capacities - also known to confer environmental hardiness - were inferred, underlying dual host-associated and free-living life strategies adopted by these diverse sponge-associated Alphaproteobacteria.},
}
@article {pmid30760639,
year = {2019},
author = {Liu, J and Liu, J and Liu, J and Cui, M and Huang, Y and Tian, Y and Chen, A and Xu, G},
title = {The potassium transporter SlHAK10 is involved in mycorrhizal potassium uptake.},
journal = {Plant physiology},
volume = {},
number = {},
pages = {},
doi = {10.1104/pp.18.01533},
pmid = {30760639},
issn = {1532-2548},
abstract = {Most terrestrial plants form a root symbiosis with arbuscular mycorrhizal (AM) fungi, which receive fixed carbon from the plant and enhance the plant's uptake of mineral nutrients. AM symbiosis improves the phosphorous and nitrogen nutrition of host plants; however, little is known about the role of AM symbiosis in potassium (K+) nutrition. Here, we report that inoculation with the AM fungus Rhizophagus irregularis improved tomato (Solanum lycopersicum) plant growth and K+ acquisition, and K+ deficiency has a negative effect on root growth and AM colonization. Based on its homology to a Lotus japonicus AM-induced K+ transporter, we identified a mycorrhiza-specific tomato K+ transporter, SlHAK10 (Solanum lycopersicum High-affinity Potassium Transporter 10), that was exclusively expressed in arbuscule-containing cells. SlHAK10 could restore a yeast K+ uptake-defective mutant in the low-affinity concentration range. Loss of function of SlHAK10 led to a significant decrease in mycorrhizal K+ uptake and AM colonization rate under low K+ conditions, but did not affect arbuscule development. Overexpressing SlHAK10 from the constitutive CaMV35S promoter or the AM-specific pSmPT4 promoter (Solanum melongena Phosphate Transporter 4) not only improved plant growth and K+ uptake, but also increased AM colonization efficiency and soluble sugar content in roots supplied with low K+. Our results indicate that tomato plants have a SlHAK10-mediated mycorrhizal K+ uptake pathway and that improved plant K+ nutrition could increase carbohydrate accumulation in roots, which facilitates AM fungal colonization.},
}
@article {pmid30759832,
year = {2019},
author = {Jia, T and Wang, J and Chang, W and Fan, X and Sui, X and Song, F},
title = {Proteomics Analysis of E. angustifolia Seedlings Inoculated with Arbuscular Mycorrhizal Fungi under Salt Stress.},
journal = {International journal of molecular sciences},
volume = {20},
number = {3},
pages = {},
doi = {10.3390/ijms20030788},
pmid = {30759832},
issn = {1422-0067},
support = {31570635//National Natural Science Foundation of China/ ; 201504409//Special Fund for Forest Scientific Research in the Public Welfare/ ; JC201306//Excellent Youth Foundation of Heilongjiang Scientific Committee/ ; 2016//100 Discipline Young Scholars Project of the Heilongjiang University/ ; },
abstract = {To reveal the mechanism of salinity stress alleviation by arbuscular mycorrhizal fungi (AMF), we investigated the growth parameter, soluble sugar, soluble protein, and protein abundance pattern of E. angustifolia seedlings that were cultured under salinity stress (300 mmol/L NaCl) and inoculated by Rhizophagus irregularis (RI). Furthermore, a label-free quantitative proteomics approach was used to reveal the stress-responsive proteins in the leaves of E. angustifolia. The result indicates that the abundance of 75 proteins in the leaves was significantly influenced when E. angustifolia was inoculated with AMF, which were mainly involved in the metabolism, signal transduction, and reactive oxygen species (ROS) scavenging. Furthermore, we identified chorismate mutase, elongation factor mitochondrial, peptidyl-prolyl cis-trans isomerase, calcium-dependent kinase, glutathione S-transferase, glutathione peroxidase, NADH dehydrogenase, alkaline neutral invertase, peroxidase, and other proteins closely related to the salt tolerance process. The proteomic results indicated that E. angustifolia seedlings inoculated with AMF increased the secondary metabolism level of phenylpropane metabolism, enhanced the signal transduction of Ca2+ and ROS scavenging ability, promoted the biosynthesis of protein, accelerated the protein folding, and inhibited the degradation of protein under salt stress. Moreover, AMF enhanced the synthesis of ATP and provided sufficient energy for plant cell activity. This study implied that symbiosis of halophytes and AMF has potential as an application for the improvement of saline-alkali soils.},
}
@article {pmid30759803,
year = {2019},
author = {Crespo-Rivas, JC and Navarro-Gómez, P and Alias-Villegas, C and Shi, J and Zhen, T and Niu, Y and Cuéllar, V and Moreno, J and Cubo, T and Vinardell, JM and Ruiz-Sainz, JE and Acosta-Jurado, S and Soto, MJ},
title = {Sinorhizobium fredii HH103 RirA Is Required for Oxidative Stress Resistance and Efficient Symbiosis with Soybean.},
journal = {International journal of molecular sciences},
volume = {20},
number = {3},
pages = {},
doi = {10.3390/ijms20030787},
pmid = {30759803},
issn = {1422-0067},
support = {P11-CVI-7500//Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía/ ; BIO2013-42801-P//Ministerio de Economía, Industria y Competitividad, Gobierno de España/ ; BIO2016-78409-R//Ministerio de Economía, Industria y Competitividad, Gobierno de España/ ; },
abstract = {Members of Rhizobiaceae contain a homologue of the iron-responsive regulatory protein RirA. In different bacteria, RirA acts as a repressor of iron uptake systems under iron-replete conditions and contributes to ameliorate cell damage during oxidative stress. In Rhizobium leguminosarum and Sinorhizobium meliloti, mutations in rirA do not impair symbiotic nitrogen fixation. In this study, a rirA mutant of broad host range S. fredii HH103 has been constructed (SVQ780) and its free-living and symbiotic phenotypes evaluated. No production of siderophores could be detected in either the wild-type or SVQ780. The rirA mutant exhibited a growth advantage under iron-deficient conditions and hypersensitivity to hydrogen peroxide in iron-rich medium. Transcription of rirA in HH103 is subject to autoregulation and inactivation of the gene upregulates fbpA, a gene putatively involved in iron transport. The S. fredii rirA mutant was able to nodulate soybean plants, but symbiotic nitrogen fixation was impaired. Nodules induced by the mutant were poorly infected compared to those induced by the wild-type. Genetic complementation reversed the mutant's hypersensitivity to H₂O₂, expression of fbpA, and symbiotic deficiency in soybean plants. This is the first report that demonstrates a role for RirA in the Rhizobium-legume symbiosis.},
}
@article {pmid30759337,
year = {2016},
author = {Abdurashytov, SF and Volkohon, VV},
title = {NEW ARBUSCULAR MYCORRHIZAL FUNGI ASSOCIATIONS FROM SOILS OF CRIMEAN STEPPE.},
journal = {Mikrobiolohichnyi zhurnal (Kiev, Ukraine : 1993)},
volume = {78},
number = {1},
pages = {63-70},
pmid = {30759337},
issn = {1028-0987},
abstract = {The primary selection ofarbuscular mycorrhizal (AM)fungifrom soils of Crimean Steppe was conducted The most effective associations P3, P5, S1, S3, S8 and S9 were identified using morphological characteristics of Sorgum sudanense roots colonization and spores surface appearance. It was shown that AMfitngiform Arum-type symbiosis contain well- established spores' kinds specific to individual associations. The molecular identification was performed in addition to the morphological data. AMfungi associations P3, P5, S1, S3, S8 and S9 were identified as Rhizophagus genus while SI association as Funneliformis genus.},
}
@article {pmid30276423,
year = {2019},
author = {Abdelkrim, S and Jebara, SH and Saadani, O and Chiboub, M and Abid, G and Mannai, K and Jebara, M},
title = {Heavy metal accumulation in Lathyrus sativus growing in contaminated soils and identification of symbiotic resistant bacteria.},
journal = {Archives of microbiology},
volume = {201},
number = {1},
pages = {107-121},
doi = {10.1007/s00203-018-1581-4},
pmid = {30276423},
issn = {1432-072X},
mesh = {Bacillus/growth & development/isolation & purification/metabolism ; Biodegradation, Environmental ; Cadmium/metabolism ; Copper/metabolism ; Fabaceae/microbiology ; Lathyrus/*growth & development/*microbiology ; Lead/metabolism ; Metals, Heavy/*metabolism ; Plant Roots/microbiology ; Pseudomonas/growth & development/isolation & purification/metabolism ; Rhizobium/growth & development/isolation & purification/metabolism ; Root Nodules, Plant/*microbiology ; Sinorhizobium meliloti/growth & development/isolation & purification/metabolism ; Soil ; Soil Microbiology ; Soil Pollutants/*metabolism ; Symbiosis ; Zinc/metabolism ; },
abstract = {In this study, two populations of leguminous plants Lathyrus sativus were grown in four soils that were collected from sites differently contaminated by heavy metals. Evaluations included basic soil properties, concentrations of major nutrients and four metals (copper, zinc, lead and cadmium) in these soils. Investigation of Lathyrus sativus response to contamination showed that the increase of heavy metal concentration in soils affected biomass of plant, number of nodules and plant metal uptake. Heavy metal tolerance of 46 isolated bacteria from the root nodules was evaluated and demonstrated that the maximum concentration of Cd, Pb, Cu and Zn tolerated by strains were 0.8, 2.5, 0.2, and 0.5 mM, respectively. Twenty-two isolates were tested for their effects on plant biomass production and nodule formation and showed that only R. leguminosarum nodulated Lathyrus sativus, while some bacteria improved the shoot and root dry biomass. Sequences of their 16S rDNA gene fragments were also obtained and evaluated for tentative identification of the isolates which revealed different bacterial genera represented by Rhizobium sp, Rhizobium leguminosarum, Sinorhizobium meliloti, Pseudomonas sp, Pseudomonas fluorescens, Luteibacter sp, Variovorax sp, Bacillus simplex and Bacillus megaterium. The existence of Pb- and Cd-resistant genes (PbrA and CadA) in these bacteria was determined by PCR, and it showed high homology with PbrA and CadA genes from other bacteria. The tested resistant population was able to accumulate high concentrations of Pb and Cd in all plant parts and, therefore, can be classified as a strong metal accumulator with suitable potential for phytoremediation of Pb and Cd polluted sites. Heavy metal resistant and efficient bacteria isolated from root nodules were chosen with Lathyrus sativus to form symbiotic associations for eventual bioremediation program, which could be tested to remove pollutants from contaminated sites.},
}
@article {pmid30759164,
year = {2019},
author = {Hassing, B and Winter, D and Becker, Y and Mesarich, CH and Eaton, CJ and Scott, B},
title = {Analysis of Epichloë festucae small secreted proteins in the interaction with Lolium perenne.},
journal = {PloS one},
volume = {14},
number = {2},
pages = {e0209463},
doi = {10.1371/journal.pone.0209463},
pmid = {30759164},
issn = {1932-6203},
abstract = {Epichloë festucae is an endophyte of the agriculturally important perennial ryegrass. This species systemically colonises the aerial tissues of this host where its growth is tightly regulated thereby maintaining a mutualistic symbiotic interaction. Recent studies have suggested that small secreted proteins, termed effectors, play a vital role in the suppression of host defence responses. To date only a few effectors with important roles in mutualistic interactions have been described. Here we make use of the fully assembled E. festucae genome and EffectorP to generate a suite of 141 effector candidates. These were analysed with respect to their genome location and expression profiles in planta and in several symbiosis-defective mutants. We found an association between effector candidates and a class of transposable elements known as MITEs, but no correlation with other dynamic features of the E. festucae genome, such as transposable element-rich regions. Three effector candidates and a small GPI-anchored protein were chosen for functional analysis based on their high expression in planta compared to in culture and their differential regulation in symbiosis defective E. festucae mutants. All three candidate effector proteins were shown to possess a functional signal peptide and two could be detected in the extracellular medium by western blotting. Localization of the effector candidates in planta suggests that they are not translocated into the plant cell, but rather, are localized in the apoplastic space or are attached to the cell wall. Deletion and overexpression of the effector candidates, as well as the putative GPI-anchored protein, did not affect the plant growth phenotype or restrict growth of E. festucae mutants in planta. These results indicate that these proteins are either not required for the interaction at the observed life stages or that there is redundancy between effectors expressed by E. festucae.},
}
@article {pmid30744248,
year = {1998},
author = {Schwencke, J and Bureau, JM and Crosnier, MT and Brown, S},
title = {Cytometric determination of genome size and base composition of tree species of three genera of Casuarinaceae.},
journal = {Plant cell reports},
volume = {18},
number = {3-4},
pages = {346-349},
doi = {10.1007/s002990050584},
pmid = {30744248},
issn = {1432-203X},
abstract = {The genome size and base composition of diploid plant species from three genera of the Casuarinaceae family were determined by flow cytometry. Casuarina glauca Sieb. ex Spring. and Gymnostoma deplancheana (Miq.) L. Johnson showed a small genome with 2C = 0.70 pg, 58.6% AT, 40.5% GC for the first species and 2C = 0.75 pg, 58.7% AT, 40.5% GC for the second. Allocasuarina verticillata (Lam.) L. Johnson had a larger genome: 2C = 1.90 pg, 59.3% AT, 41.1% GC. One haploid genome of C. glauca is therefore about 340×106 base pairs. In leaves, roots or bark of these three species, polysomaty was virtually absent: a maximum frequency of 4C nuclei of only 0.08 was found in bark of C. glauca. The genome sizes of C. glauca and G. deplancheana are among the smallest described for higher plants. Small genome size, diploidy and the absence of polysomaty are advantageous traits for facilitating molecular approaches to improvement of these actinorhizal plants and developing the study of their symbiotic interactions with Frankia.},
}
@article {pmid30683856,
year = {2019},
author = {Ellegaard, KM and Engel, P},
title = {Genomic diversity landscape of the honey bee gut microbiota.},
journal = {Nature communications},
volume = {10},
number = {1},
pages = {446},
doi = {10.1038/s41467-019-08303-0},
pmid = {30683856},
issn = {2041-1723},
mesh = {Age Factors ; Animals ; Bees/*microbiology ; Bifidobacterium/classification/*genetics/isolation & purification ; *Biological Variation, Individual ; DNA, Bacterial/genetics ; Firmicutes/classification/*genetics/isolation & purification ; Gammaproteobacteria/classification/*genetics/isolation & purification ; Gastrointestinal Microbiome/*genetics ; Genetic Variation ; Metagenomics ; Microbial Consortia/genetics ; Phylogeny ; Symbiosis/physiology ; },
abstract = {The structure and distribution of genomic diversity in natural microbial communities is largely unexplored. Here, we used shotgun metagenomics to assess the diversity of the honey bee gut microbiota, a community consisting of few bacterial phylotypes. Our results show that most phylotypes are composed of sequence-discrete populations, which co-exist in individual bees and show age-specific abundance profiles. In contrast, strains present within these sequence-discrete populations were found to segregate into individual bees. Consequently, despite a conserved phylotype composition, each honey bee harbors a distinct community at the functional level. While ecological differentiation seems to facilitate coexistence at higher taxonomic levels, our findings suggest that, at the level of strains, priority effects during community assembly result in individualized profiles, despite the social lifestyle of the host. Our study underscores the need to move beyond phylotype-level characterizations to understand the function of this community, and illustrates its potential for strain-level analysis.},
}
@article {pmid30129423,
year = {2018},
author = {Woodruff, GC and Phillips, PC},
title = {Field studies reveal a close relative of C. elegans thrives in the fresh figs of Ficus septica and disperses on its Ceratosolen pollinating wasps.},
journal = {BMC ecology},
volume = {18},
number = {1},
pages = {26},
pmid = {30129423},
issn = {1472-6785},
support = {R01 GM-102511/NH/NIH HHS/United States ; F32 GM115209/GM/NIGMS NIH HHS/United States ; 5F32GM115209-03/NH/NIH HHS/United States ; PE13557//Japan Society for the Promotion of Science/International ; R01 GM102511/GM/NIGMS NIH HHS/United States ; },
mesh = {*Animal Distribution ; Animals ; Caenorhabditis/*physiology ; Ficus/*physiology ; Fruit/physiology ; Japan ; *Pollination ; *Symbiosis ; Wasps/*physiology ; },
abstract = {BACKGROUND: Biotic interactions are ubiquitous and require information from ecology, evolutionary biology, and functional genetics in order to be understood. However, study systems that are amenable to investigations across such disparate fields are rare. Figs and fig wasps are a classic system for ecology and evolutionary biology with poor functional genetics; Caenorhabditis elegans is a classic system for functional genetics with poor ecology. In order to help bridge these disciplines, here we describe the natural history of a close relative of C. elegans, Caenorhabditis inopinata, that is associated with the fig Ficus septica and its pollinating Ceratosolen wasps.
RESULTS: To understand the natural context of fig-associated Caenorhabditis, fresh F. septica figs from four Okinawan islands were sampled, dissected, and observed under microscopy. C. inopinata was found in all islands where F. septica figs were found. C.i nopinata was routinely found in the fig interior and almost never observed on the outside surface. C. inopinata was only found in pollinated figs, and C. inopinata was more likely to be observed in figs with more foundress pollinating wasps. Actively reproducing C. inopinata dominated early phase figs, whereas late phase figs with emerging wasp progeny harbored C. inopinata dauer larvae. Additionally, C. inopinata was observed dismounting from Ceratosolen pollinating wasps that were placed on agar plates. C. inopinata was not found on non-pollinating, parasitic Philotrypesis wasps. Finally, C. inopinata was only observed in F. septica figs among five Okinawan Ficus species sampled.
CONCLUSION: These are the first detailed field observations of C. inopinata, and they suggest a natural history where this species proliferates in early phase F. septica figs and disperses from late phase figs on Ceratosolen pollinating fig wasps. While consistent with other examples of nematode diversification in the fig microcosm, the fig and wasp host specificity of C. inopinata is highly divergent from the life histories of its close relatives and frames hypotheses for future investigations. This natural co-occurrence of the fig/fig wasp and C. inopinata study systems sets the stage for an integrated research program that can help to explain the evolution of interspecific interactions.},
}
@article {pmid30753553,
year = {2019},
author = {Gautrat, P and Mortier, V and Laffont, C and De Keyser, A and Fromentin, J and Frugier, F and Goormachtig, S},
title = {Unraveling new molecular players involved in the autoregulation of nodulation in Medicago truncatula.},
journal = {Journal of experimental botany},
volume = {},
number = {},
pages = {},
doi = {10.1093/jxb/ery465},
pmid = {30753553},
issn = {1460-2431},
abstract = {The number of legume root nodules resulting from a symbiosis with rhizobia is tightly controlled by the plant. Certain members of the CLAVATA3/Embryo Surrounding Region (CLE) peptide family, specifically MtCLE12 and MtCLE13 in Medicago truncatula, act in the systemic autoregulation of nodulation (AON) pathway that negatively regulates the number of nodules. Little is known about the molecular pathways that operate downstream of the AON-related CLE peptides. Here, by means of a transcriptome analysis, we show that roots ectopically expressing MtCLE13 deregulate only a limited number of genes, including three down-regulated genes encoding lysin motif receptor-like kinases (LysM-RLKs), among which are the nodulation factor (NF) receptor NF Perception gene (NFP) and two up-regulated genes, MtTML1 and MtTML2, encoding Too Much Love (TML)-related Kelch-repeat containing F-box proteins. The observed deregulation was specific for the ectopic expression of nodulation-related MtCLE genes and depended on the Super Numeric Nodules (SUNN) AON RLK. Moreover, overexpression and silencing of these two MtTML genes demonstrated that they play a role in the negative regulation of nodule numbers. Hence, the identified MtTML genes are the functional counterpart of the Lotus japonicus TML gene shown to be central in the AON pathway. Additionally, we propose that the down-regulation of a subset of LysM-RLK-encoding genes, among which is NFP, might contribute to the restriction of further nodulation once the first nodules have been formed.},
}
@article {pmid30753410,
year = {2019},
author = {Plouznikoff, K and Asins, MJ and de Boulois, HD and Carbonell, EA and Declerck, S},
title = {Genetic analysis of tomato root colonization by arbuscular mycorrhizal fungi.},
journal = {Annals of botany},
volume = {},
number = {},
pages = {},
doi = {10.1093/aob/mcy240},
pmid = {30753410},
issn = {1095-8290},
abstract = {Background and Aims: Arbuscular mycorrhizal fungi (AMF) play an important role in plant nutrition and protection against pests and diseases, as well as in soil structuration, nutrient cycling and, generally speaking, in sustainable agriculture, particularly under drought, salinity and low input or organic agriculture. However, little is known about the genetics of the AMF-plant association in tomato. The aim of this study was the genetic analysis of root AMF colonization in tomato via the detection of the quantitative trait loci (QTLs) involved.
Methods: A population of 130 recombinant inbred lines derived from the wild species Solanum pimpinellifolium, genotyped for 1899 segregating, non-redundant single nucleotide polymorphisms (SNPs) from the SolCAP tomato panel, was characterized for intensity, frequency and arbuscular abundance of AMF colonization to detect the QTLs involved and to analyse the genes within their peaks (2-2.6 Mbp).
Key Results: The three AMF colonization parameters were highly correlated (0.78-0.97) and the best one, with the highest heritability (0.23), corresponded to colonization intensity. A total of eight QTLs in chromosomes 1, 3, 4, 5, 6, 8, 9 and 10 were detected. Seven of them simultaneously affected intensity and arbuscule abundance. The allele increasing the expression of the trait usually came from the wild parent in accordance with the parental means, and several epistatic interactions were found relevant for breeding purposes. SlCCaMK and SlLYK13 were found among the candidate genes. Carbohydrate transmembrane transporter activity, lipid metabolism and transport, metabolic processes related to nitrogen and phosphate-containing compounds, regulation of carbohydrates, and other biological processes involved in the plant defence were found to be over-represented within the QTL peaks.
Conclusions: Intensity is genetically the best morphological measure of tomato root AMF colonization. Wild alleles can improve AMF colonization, and the gene contents of AMF colonization QTLs might be important for explaining the establishment and functioning of the AMF-plant symbiosis.},
}
@article {pmid29906776,
year = {2018},
author = {Trinh, CS and Jeong, CY and Lee, WJ and Truong, HA and Chung, N and Han, J and Hong, SW and Lee, H},
title = {Paenibacillus pabuli strain P7S promotes plant growth and induces anthocyanin accumulation in Arabidopsis thaliana.},
journal = {Plant physiology and biochemistry : PPB},
volume = {129},
number = {},
pages = {264-272},
doi = {10.1016/j.plaphy.2018.06.001},
pmid = {29906776},
issn = {1873-2690},
mesh = {Anthocyanins/*metabolism ; Arabidopsis/*growth & development/metabolism/microbiology ; Chlorophyll/metabolism ; Gene Expression Regulation, Plant ; Paenibacillus/*metabolism ; Plant Roots/*microbiology ; Reverse Transcriptase Polymerase Chain Reaction ; Seedlings/growth & development ; Symbiosis ; },
abstract = {In this study, a novel plant growth-promoting rhizobacteria (PGPR), the bacterial strain Paenibacillus pabuli P7S (PP7S), showed promising plant growth-promoting effects. Furthermore, it induced anthocyanin accumulation in Arabidopsis. When co-cultivated with PP7S, there was a significant increase in anthocyanin content and biomass of Arabidopsis seedlings compared with those of the control. The quantitative reverse transcription-polymerase chain reaction analysis revealed higher expression of many key genes regulating anthocyanin and flavonoid biosynthesis pathways in PP7S-treated seedlings when compared with that of the control. Furthermore, higher expression of pathogen-related genes and microbe-associated molecular pattern genes was also observed in response to PP7S, indicating that the PGPR triggered the induced systemic response (ISR) in A. thaliana. These results suggest that PP7S promotes plant growth in A. thaliana and increases anthocyanin biosynthesis by triggering specific ISRs in plant.},
}
@article {pmid29105020,
year = {2018},
author = {Pentimone, I and Lebrón, R and Hackenberg, M and Rosso, LC and Colagiero, M and Nigro, F and Ciancio, A},
title = {Identification of tomato miRNAs responsive to root colonization by endophytic Pochonia chlamydosporia.},
journal = {Applied microbiology and biotechnology},
volume = {102},
number = {2},
pages = {907-919},
doi = {10.1007/s00253-017-8608-7},
pmid = {29105020},
issn = {1432-0614},
mesh = {Apoptosis ; Endophytes/physiology ; Gene Expression Profiling ; Gene Expression Regulation, Plant ; Hypocreales/*physiology ; Lycopersicon esculentum/*genetics/microbiology ; MicroRNAs/*genetics ; Plant Roots/*microbiology ; Real-Time Polymerase Chain Reaction ; Symbiosis/*genetics ; },
abstract = {The molecular mechanisms active during the endophytic phase of the fungus Pochonia chlamydosporia are still poorly understood. In particular, few data are available on the links between the endophyte and the root response, as modulated by noncoding small RNAs. In this study, we describe the microRNAs (miRNAs) that are differentially expressed (DE) in the roots of tomato, colonized by P. chlamydosporia. A genome-wide NGS expression profiling of small RNAs in roots, either colonized or not by the fungus, showed 26 miRNAs upregulated in inoculated roots. Their predicted target genes are involved in the plant information processing system, which recognizes, percepts, and transmits signals, with higher representations in processes such as apoptosis and plant defense regulation. RNAseq data showed that predicted miRNA target genes were downregulated in tomato roots after 4, 7, 10, and 21 days post P. chlamydosporia inoculation. The differential expression of four miRNAs was further validated using qPCR analysis. The P. chlamydosporia endophytic lifestyle in tomato roots included an intricate network of miRNAs and targets. Data provide a first platform of DE tomato miRNAs after P. chlamydosporia colonization. They indicated that several miRNAs are involved in the host response to the fungus, playing important roles for its recognition as a symbiotic microorganism, allowing endophytism by modulating the host defense reaction. Data also indicated that endophytism affects tRNA fragmentation. This is the first study on miRNAs induced by P. chlamydosporia endophytism and related development regulation effects in Solanum lycopersicum.},
}
@article {pmid30742016,
year = {2019},
author = {Ohbayashi, T and Futahashi, R and Terashima, M and Barrière, Q and Lamouche, F and Takeshita, K and Meng, XY and Mitani, Y and Sone, T and Shigenobu, S and Fukatsu, T and Mergaert, P and Kikuchi, Y},
title = {Comparative cytology, physiology and transcriptomics of Burkholderia insecticola in symbiosis with the bean bug Riptortus pedestris and in culture.},
journal = {The ISME journal},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41396-019-0361-8},
pmid = {30742016},
issn = {1751-7370},
support = {15H05638//Ministry of Education, Culture, Sports, Science and Technology (MEXT)/ ; 14J03996//MEXT | Japan Society for the Promotion of Science (JSPS)/ ; 20170267//MEXT | Japan Society for the Promotion of Science (JSPS)/ ; },
abstract = {In the symbiosis of the bean bug Riptortus pedestris with Burkholderia insecticola, the bacteria occupy an exclusive niche in the insect midgut and favor insect development and reproduction. In order to understand how the symbiotic bacteria stably colonize the midgut crypts and which services they provide to the host, we compared the cytology, physiology, and transcriptomics of free-living and midgut-colonizing B. insecticola. The analyses revealed that midgut-colonizing bacteria were smaller in size and had lower DNA content, they had increased stress sensitivity, lost motility, and an altered cell surface. Transcriptomics revealed what kinds of nutrients are provided by the bean bug to the Burkholderia symbiont. Transporters and metabolic pathways of diverse sugars such as rhamnose and ribose, and sulfur compounds like sulfate and taurine were upregulated in the midgut-colonizing symbionts. Moreover, pathways enabling the assimilation of insect nitrogen wastes, i.e. allantoin and urea, were also upregulated. The data further suggested that the midgut-colonizing symbionts produced all essential amino acids and B vitamins, some of which are scarce in the soybean food of the host insect. Together, these findings suggest that the Burkholderia symbiont is fed with specific nutrients and also recycles host metabolic wastes in the insect gut, and in return, the bacterial symbiont provides the host with essential nutrients limited in the insect food, contributing to the rapid growth and enhanced reproduction of the bean bug host.},
}
@article {pmid30740571,
year = {2018},
author = {Wang, Y and Li, N and Chen, T and Gong, Y},
title = {Generation and characterization of expressed sequence tags (ESTs) from coralloid root cDNA library of Cycas debaoensis.},
journal = {Plant diversity},
volume = {40},
number = {5},
pages = {245-252},
doi = {10.1016/j.pld.2018.09.002},
pmid = {30740571},
issn = {2468-2659},
abstract = {A normalized full-length cDNA library was constructed from the coralloid roots of Cycas debaoensis by the DSN (duplex-specific nuclease) normalization method combined with the SMART (Switching Mechanism At 5' end of the RNA Transcript) technique. The titer of the original cDNA library was about 1.5 × 106 cfu·mL-1 and the average insertion size was about 1 kb with a high recombination rate (97%). The 5011 high-quality expressed sequence tags (ESTs) were obtained from 5393 randomly picked cDNA clones. Clustering and assembly of ESTs resulted in 2984 unique sequences, consisting of 618 contigs and 2366 singlets. EST sequence annotation revealed that 2333 and 1901 unigenes were functionally annotated in the NCBI non-redundant database and Swiss-Prot protein database, respectively. Functional analysis demonstrated that 1495 (50.1%) unigenes were associated with 4082 Gene Ontology (GO) terms. A total of 847 unigenes were grouped into 22 Cluster of Orthologous Groups (COG) functional categories. Based on the EST dataset, 22 ESTs that encoded putative receptor-like protein kinase (RLK) genes were screened. Furthermore, a total of 94 simple sequence repeats (SSRs) were discovered, of which 20 loci were successfully amplified in C. debaoensis. This study is the first EST analysis for the coralloid roots of C. debaoensis and provides a valuable genomic resource for novel gene discovery, gene expression and comparative genomics, conservation and management studies as well as applications in C. debaoensis and related cycad species.},
}
@article {pmid30740120,
year = {2018},
author = {Nogales, A and Santos, ES and Abreu, MM and Arán, D and Victorino, G and Pereira, HS and Lopes, CM and Viegas, W},
title = {Mycorrhizal Inoculation Differentially Affects Grapevine's Performance in Copper Contaminated and Non-contaminated Soils.},
journal = {Frontiers in plant science},
volume = {9},
number = {},
pages = {1906},
doi = {10.3389/fpls.2018.01906},
pmid = {30740120},
issn = {1664-462X},
abstract = {Plant inoculation with arbuscular mycorrhizal fungi (AMF) is increasingly employed to enhance productivity and sustainability in agricultural ecosystems. In the present study, the potential benefits of AMF inoculation on young grapevines replanted in pots containing vineyard soil with high Cu concentration were evaluated. For this purpose, one-year-old cv. Touriga Nacional grapevines grafted onto 1103P rootstocks were further inoculated with Rhizoglomus irregulare or Funneliformis mosseae, or left non-inoculated, and maintained in a sterilized substrate under greenhouse conditions for three months. After this time, half of the plants were transplanted to containers filled with an Arenosol from a vineyard which had been artificially contaminated or not with 300 mg kg-1 of Cu. At the end of the growing season, soil nutrient concentration, soil dehydrogenase activity and mycorrhizal colonization rate were analyzed. Grapevine performance was assessed by measuring several vegetative growth and physiological parameters as well as nutrient concentrations in leaves and roots. In the non-contaminated soil, R. irregulare- and F. mosseae-inoculated plants had significantly greater root biomass than the non-inoculated ones. However, the opposite effect was observed in the Cu-contaminated soil, where non-inoculated plants performed better regarding shoot and root development. Concerning nutrient levels, an increase in Cu, Mg and Mn concentrations was observed in the roots of plants growing in the contaminated soil, although only Mn was translocated to leaves. This led to a large increase in leaf Mn concentrations, which was significantly higher in non-inoculated and F. mosseae- inoculated plants than in the R. irregulare- inoculated ones. Copper contamination induced a general decrease in leaf N, P and Fe concentrations as well as chlorosis symptoms. The largest decrease in N and P was observed in F. mosseae- inoculated plants, with 73 and 31.2%, respectively. However, these plants were the ones with the least decrease in Fe concentration (10% vs. almost 30% in the other two inoculation treatments). In conclusion, this study indicates that soil Cu levels can modify the outcome of AMF inoculations in young grapevines, disclosing new AMF-plant associations potentially relevant in vineyards with a tradition of Cu-based fungicide application.},
}
@article {pmid30321327,
year = {2018},
author = {Chouvenc, T and Elliott, ML and Šobotník, J and Efstathion, CA and Su, NY},
title = {The Termite Fecal Nest: A Framework for the Opportunistic Acquisition of Beneficial Soil Streptomyces (Actinomycetales: Streptomycetaceae).},
journal = {Environmental entomology},
volume = {47},
number = {6},
pages = {1431-1439},
doi = {10.1093/ee/nvy152},
pmid = {30321327},
issn = {1938-2936},
mesh = {Animals ; Antifungal Agents/analysis ; Feces/microbiology ; Female ; Isoptera/*microbiology ; Male ; *Soil Microbiology ; Streptomyces/chemistry/*isolation & purification ; Symbiosis ; },
abstract = {Mutualistic associations between insects and microorganisms must imply gains for both partners, and the emphasis has mostly focused on coevolved host-symbiont systems. However, some insect hosts may have evolved traits that allow for various means of association with opportunistic microbial communities, especially when the microbes are omnipresent in their environment. It was previously shown that colonies of the subterranean termite Coptotermes formosanus Shiraki (Blattodea: Rhinotermitidae) build nests out of fecal material that host a community of Streptomyces Waksman and Henrici (Actinomycetales: Streptomycetaceae). These Actinobacteria produce an array of bioactive metabolites that provides a level of protection for termites against certain entomopathogenic fungi. How C. formosanus acquires and maintains this association remains unknown. This study shows that the majority of Streptomyces isolates found in field termite fecal nest materials are identical to Streptomyces isolates from soils surrounding the nests and are not vertically inherited. A survey of Streptomyces communities from C. formosanus fecal nest materials sampled at 20 locations around the world revealed that all nests are reliably associated with a diverse Streptomyces community. The C. formosanus fecal nest material therefore provides a nutritional framework that can recruit beneficial Streptomyces from the soil environment, in the absence of long-term coevolutionary processes. A diverse Streptomyces community is reliably present in soils, and subterranean termite colonies can acquire such facultative symbionts each social cycle into their fecal nest. This association probably emerged as an exaptation from the existing termite nest structure and benefits both the termite and the opportunistic colonizing bacteria.},
}
@article {pmid30178231,
year = {2018},
author = {Morel, F and Jacquier, H and Desroches, M and Fihman, V and Kumanski, S and Cambau, E and Decousser, JW and Berçot, B},
title = {Use of Andromas and Bruker MALDI-TOF MS in the identification of Neisseria.},
journal = {European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology},
volume = {37},
number = {12},
pages = {2273-2277},
pmid = {30178231},
issn = {1435-4373},
mesh = {Biological Specimen Banks ; Humans ; Neisseria/*classification/isolation & purification ; Neisseria gonorrhoeae/isolation & purification ; Neisseria meningitidis/isolation & purification ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/*instrumentation/*methods ; Symbiosis ; },
abstract = {Through the past decade, MALDI-TOF MS has been recognized as a fast and robust tool for identification of most bacteria in clinical microbiology. However, the accuracy of this method to identify Neisseria species is still debated, and few data are available about commensal Neisseria species identification. In this study, we assessed two MALDI-TOF MS systems (Bruker Biotyper and Andromas) for the identification of 88, 18, and 29 isolates of Neisseria gonorrhoeae, Neisseria meningitidis, and commensal Neisseria species, respectively. All 88 isolates of N. gonorrhoeae were correctly identified using both systems, and most N. meningitidis and commensal Neisseria species were well identified: only 1/18 isolates of N. meningitidis was misidentified using Bruker Biotyper, and 1 isolate of Neisseria polysaccharea was misidentified as N. meningitidis using both systems. These results strengthen the possibility to use MALDI-TOF MS as a single method for Neisseria identification in routine, with excellent performance for N. gonorrhoeae identification. However, results should be interpreted prudently for N. meningitdis and commensal Neisseria species when isolated from genital and oropharyngeal samples where these both species can coexist.},
}
@article {pmid29479025,
year = {2018},
author = {},
title = {[Symposium].},
journal = {Nihon saikingaku zasshi. Japanese journal of bacteriology},
volume = {73},
number = {1},
pages = {6-20},
doi = {10.3412/jsb.73.6},
pmid = {29479025},
issn = {1882-4110},
mesh = {Animals ; Antibiosis ; Clostridium ; Fungi/pathogenicity ; *Gastrointestinal Microbiome/genetics/physiology ; Gastrointestinal Tract/metabolism/*microbiology ; Host Microbial Interactions/physiology ; Humans ; Infant, Newborn ; Microbiology/*organization & administration ; Parkinson Disease ; Societies, Scientific/*organization & administration ; Symbiosis ; alpha-Synuclein ; },
}
@article {pmid29479020,
year = {2018},
author = {},
title = {[Luncheon Seminar].},
journal = {Nihon saikingaku zasshi. Japanese journal of bacteriology},
volume = {73},
number = {1},
pages = {154-155},
doi = {10.3412/jsb.73.154},
pmid = {29479020},
issn = {1882-4110},
mesh = {Bacteria/genetics ; Gastrointestinal Microbiome ; Genome, Bacterial/genetics ; Humans ; Japan/epidemiology ; Microbiology/*organization & administration ; Phylogeny ; Publishing ; Research Personnel ; Serotyping ; Societies, Scientific/*organization & administration ; Symbiosis ; Syphilis/epidemiology ; Whole Genome Sequencing ; },
}
@article {pmid29330177,
year = {2018},
author = {Zhu, YX and Song, YL and Zhang, YK and Hoffmann, AA and Zhou, JC and Sun, JT and Hong, XY},
title = {Incidence of Facultative Bacterial Endosymbionts in Spider Mites Associated with Local Environments and Host Plants.},
journal = {Applied and environmental microbiology},
volume = {84},
number = {6},
pages = {},
pmid = {29330177},
issn = {1098-5336},
mesh = {Animals ; Bacteroidetes/*physiology ; China ; Environment ; Lycopersicon esculentum/growth & development ; Soybeans/growth & development ; Spiroplasma/*physiology ; *Symbiosis ; Tetranychidae/*microbiology/physiology ; Wolbachia/*physiology ; Zea mays/growth & development ; },
abstract = {Spider mites are frequently associated with multiple endosymbionts whose infection patterns often exhibit spatial and temporal variation. However, the association between endosymbiont prevalence and environmental factors remains unclear. Here, we surveyed endosymbionts in natural populations of the spider mite, Tetranychus truncatus, in China, screening 935 spider mites from 21 localities and 12 host plant species. Three facultative endosymbiont lineages, Wolbachia, Cardinium, and Spiroplasma, were detected at different infection frequencies (52.5%, 26.3%, and 8.6%, respectively). Multiple endosymbiont infections were observed in most local populations, and the incidence of individuals with the Wolbachia-Spiroplasma coinfection was higher than expected from the frequency of each infection within a population. Endosymbiont infection frequencies exhibited associations with environmental factors: Wolbachia infection rates increased at localities with higher annual mean temperatures, while Cardinium and Spiroplasma infection rates increased at localities from higher altitudes. Wolbachia was more common in mites from Lycopersicon esculentum and Glycine max compared to those from Zea mays This study highlights that host-endosymbiont interactions may be associated with environmental factors, including climate and other geographically linked factors, as well as the host's food plant.IMPORTANCE The aim of this study was to examine the incidence of endosymbiont distribution and the infection patterns in spider mites. The main findings are that multiple endosymbiont infections were more common than expected and that endosymbiont infection frequencies were associated with environmental factors. This work highlights that host-endosymbiont interactions need to be studied within an environmental and geographic context.},
}
@article {pmid29250734,
year = {2018},
author = {Martín-Vivaldi, M and Soler, JJ and Martínez-García, Á and Arco, L and Juárez-García-Pelayo, N and Ruiz-Rodríguez, M and Martínez-Bueno, M},
title = {Acquisition of Uropygial Gland Microbiome by Hoopoe Nestlings.},
journal = {Microbial ecology},
volume = {76},
number = {1},
pages = {285-297},
pmid = {29250734},
issn = {1432-184X},
support = {CGL2009-14006//Ministerio de Ciencia e Innovación/ ; CGL2010-19233-C03-01//Ministerio de Ciencia e Innovación/ ; CGL2010-19233-C03-03//Ministerio de Ciencia e Innovación/ ; CGL2013-48193-C3-1-P//Ministerio de Ciencia e Innovación/ ; CGL2013-48193-C3-2-P//Ministerio de Ciencia e Innovación/ ; P09-RNM-4557//Agencia de Innovación y Desarrollo de Andalucía/ ; Predoctoral grant P09-RNM-4557//Agencia de Innovación y Desarrollo de Andalucía/ ; },
mesh = {Animals ; Bacteria/*classification/genetics ; Bacterial Load ; Bacterial Physiological Phenomena ; Biodiversity ; Biological Coevolution ; Birds/*microbiology/physiology ; DNA, Bacterial/genetics ; Exocrine Glands/*microbiology ; Female ; Microbiota/*physiology ; Molecular Typing ; Nesting Behavior/*physiology ; Phylogeny ; Spain ; Symbiosis ; },
abstract = {Mutualistic symbioses between animals and bacteria depend on acquisition of appropriate symbionts while avoiding exploitation by non-beneficial microbes. The mode of acquisition of symbionts would determine, not only the probability of encountering but also evolutionary outcomes of mutualistic counterparts. The microbiome inhabiting the uropygial gland of the European hoopoe (Upupa epops) includes a variety of bacterial strains, some of them providing antimicrobial benefits. Here, the mode of acquisition and stability of this microbiome is analyzed by means of Automated rRNA Intergenic Spacer Analysis and two different experiments. The first experiment impeded mothers' access to their glands, thus avoiding direct transmission of microorganisms from female to offspring secretions. The second experiment explored the stability of the microbiomes by inoculating glands with secretions from alien nests. The first experiment provoked a reduction in similarity of microbiomes of mother and nestlings. Interestingly, some bacterial strains were more often detected when females had not access to their glands, suggesting antagonistic effects among bacteria from different sources. The second experiment caused an increase in richness of the microbiome of receivers in terms of prevalence of Operational Taxonomic Units (OTUs) that reduced differences in microbiomes of donors and receivers. That occurred because OTUs that were present in donors but not in receivers incorporated to the microbiome of the latter, which provoked that cross-inoculated nestlings got similar final microbiomes that included the most prevalent OTUs. The results are therefore consistent with a central role of vertical transmission in bacterial acquisition by nestling hoopoes and support the idea that the typical composition of the hoopoe gland microbiome is reached by the incorporation of some bacteria during the nestling period. This scenario suggests the existence of a coevolved core microbiome composed by a mix of specialized vertically transmitted strains and facultative symbionts able to coexist with them. The implications of this mixed mode of transmission for the evolution of the mutualism are discussed.},
}
@article {pmid28320556,
year = {2017},
author = {Gutierrez, AC and Tornesello-Galván, J and Manfrino, RG and Hipperdinger, M and Falvo, M and D'Alessandro, C and López Lastra, CC},
title = {[Organization and preservation of the collection of pathogenic and fungal symbionts of insects and other arthropods from CEPAVE (CONICET-UNLP), La Plata, Argentina].},
journal = {Revista Argentina de microbiologia},
volume = {49},
number = {2},
pages = {183-188},
doi = {10.1016/j.ram.2016.09.007},
pmid = {28320556},
issn = {0325-7541},
mesh = {Animals ; Argentina ; *Arthropods/microbiology ; *Ascomycota/isolation & purification ; *Insecta/microbiology ; Preservation, Biological ; *Symbiosis ; },
abstract = {The collection of fungal pathogens and symbionts of insects and other arthropods of the Centro de Estudios Parasitológicos y de Vectores, La Plata, Argentina, is unique because it preserves in vivo and in vitro cultures of fungal pathogens. This culture collection is open for research, teaching, consulting services, and strain deposit. It contains 421 strains belonging to 23 genera (16 Ascomycota, 4 Entomophthoromycotina, 2 Glomeromycota and 1 Oomycota), and the cultures are preserved by different methods such as cryopreservation in freezer at -20°C and -70°C, paper, distilled water and lyophilization. Fungi were isolated from insects, other arthropods, and soil (by using insect baits and selective media). Species were identified by morphological features and in a few strains by molecular taxonomy (PCR of rDNA). This collection is a reference center for species identification/certifications, research and teaching purposes, strain deposit, transference and consultancy services, and its overall goal is to preserve the fungal germplasm and ex situ diversity. Most of the strains are native of Argentina. The collection was originated in 1988 and is registered in the Latin American Federation for Culture Collections and in the World Federation of Culture Collections.},
}
@article {pmid30737512,
year = {2019},
author = {Ivanov, S and Austin, J and Berg, RH and Harrison, MJ},
title = {Extensive membrane systems at the host-arbuscular mycorrhizal fungus interface.},
journal = {Nature plants},
volume = {5},
number = {2},
pages = {194-203},
doi = {10.1038/s41477-019-0364-5},
pmid = {30737512},
issn = {2055-0278},
abstract = {During arbuscular mycorrhizal (AM) symbiosis, cells within the root cortex develop a matrix-filled apoplastic compartment in which differentiated AM fungal hyphae called arbuscules reside. Development of the compartment occurs rapidly, coincident with intracellular penetration and rapid branching of the fungal hypha, and it requires much of the plant cell's secretory machinery to generate the periarbuscular membrane that delimits the compartment. Despite recent advances, our understanding of the development of the periarbuscular membrane and the transfer of molecules across the symbiotic interface is limited. Here, using electron microscopy and tomography, we reveal that the periarbuscular matrix contains two types of membrane-bound compartments. We propose that one of these arises as a consequence of biogenesis of the periarbuscular membrane and may facilitate movement of molecules between symbiotic partners. Additionally, we show that the arbuscule contains massive arrays of membrane tubules located between the protoplast and the cell wall. We speculate that these tubules may provide the absorptive capacity needed for nutrient assimilation and possibly water absorption to enable rapid hyphal expansion.},
}
@article {pmid30737510,
year = {2019},
author = {Limpens, E},
title = {Extracellular membranes in symbiosis.},
journal = {Nature plants},
volume = {5},
number = {2},
pages = {131-132},
doi = {10.1038/s41477-019-0370-7},
pmid = {30737510},
issn = {2055-0278},
}
@article {pmid30734808,
year = {2019},
author = {Abreu, I and Mihelj, P and Raimunda, D},
title = {Transition metal transporters in rhizobia: tuning the inorganic micronutrient requirements to different living styles.},
journal = {Metallomics : integrated biometal science},
volume = {},
number = {},
pages = {},
doi = {10.1039/c8mt00372f},
pmid = {30734808},
issn = {1756-591X},
abstract = {A group of bacteria known as rhizobia are key players in symbiotic nitrogen fixation (SNF) in partnership with legumes. After a molecular exchange, the bacteria end surrounded by a plant membrane forming symbiosomes, organelle-like structures, where they differentiate to bacteroids and fix nitrogen. This symbiotic process is highly dependent on dynamic nutrient exchanges between the partners. Among these are transition metals (TM) participating as inorganic and organic cofactors of fundamental enzymes. While the understanding of how plant transporters facilitate TMs to the very near environment of the bacteroid is expanding, our knowledge on how bacteroid transporters integrate to TM homeostasis mechanisms in the plant host is still limited. This is significantly relevant considering the low solubility and scarcity of TMs in soils, and the in crescendo gradient of TM bioavailability rhizobia faces during the infection and bacteroid differentiation processes. In the present work, we review the main metal transporter families found in rhizobia, their role in free-living conditions and, when known, in symbiosis. We focus on discussing those transporters which could play a significant role in TM-dependent biochemical and physiological processes in the bacteroid, thus paving the way towards an optimized SNF.},
}
@article {pmid30733794,
year = {2018},
author = {Satyanarayana, SDV and Krishna, MSR and Pavan Kumar, P and Jeereddy, S},
title = {In silico structural homology modeling of nif A protein of rhizobial strains in selective legume plants.},
journal = {Journal, genetic engineering & biotechnology},
volume = {16},
number = {2},
pages = {731-737},
doi = {10.1016/j.jgeb.2018.06.006},
pmid = {30733794},
issn = {2090-5920},
abstract = {Symbiosis is a complex genetic regulatory biological evolution which is highly specific pertaining to plant species and microbial strains. Biological nitrogen fixation in legumes is a functional combination of nodulation by nod genes and regulation by nif, fix genes. Three rhizobial strains (Rhizobium leguminosarum, Bradyrhizobium japonicum, and Mesorhizobium ciceri) that we considered for in silico analysis of nif A are proved to be the best isolates with respect to N2 fixing for ground nut, chick pea and soya bean (in vitro) out of 47 forest soil samples. An attempt has been made to understand the structural characteristics and variations of nif genes that may reveal the factors influencing the nitrogen fixation. The primary, secondary and tertiary structure of nif A protein was analyzed by using multiple bioinformatics tools such as chou-Fasman, GOR, ExPasy ProtParam tools, Prosa -web. Literature shows that the homology modeling of nif A protein have not been explored yet which insisted the immediate development for better understanding of nif A structure and its influence on biological nitrogen fixation. In the present predicted 3D structure, the nif A protein was analyzed by three different software tools (Phyre2, Swiss model, Modeller) and validated accordingly which can be considered as an acceptable model. However further in silico studies are suggested to determine the specific factors responsible for nitrogen fixing in the present three rhizobial strains.},
}
@article {pmid30727226,
year = {2012},
author = {Eskalen, A and Gonzalez, A and Wang, DH and Twizeyimana, M and Mayorquin, JS and Lynch, SC},
title = {First Report of a Fusarium sp. and Its Vector Tea Shot Hole Borer (Euwallacea fornicatus) Causing Fusarium Dieback on Avocado in California.},
journal = {Plant disease},
volume = {96},
number = {7},
pages = {1070},
doi = {10.1094/PDIS-03-12-0276-PDN},
pmid = {30727226},
issn = {0191-2917},
abstract = {Per capita consumption of avocado in the United States has nearly doubled between 2000 and 2010. The California avocado industry supplies almost 40% of U.S. demand and the remaining 60% is supplied by imports from Latin America and New Zealand. The Tea Shot Hole Borer (TSHB) is an ambrosia beetle from Asia that forms a symbiosis with a new, yet undescribed Fusarium sp. and is a serious problem for the Israeli avocado industry (3). The beetle also causes severe damage on the branches of tea (Camelia sinensis) in Sri Lanka and India (1). In California, TSHB was first reported on black locust (Robinia pseudoacacia) in 2003, but there are no records of fungal damage (4). In 2012, nine backyard avocado trees (cvs. Hass, Bacon, Fuerte, and Nabal) exhibiting branch dieback were observed throughout the residential neighborhoods of South Gate, Downey, and Pico Rivera in Los Angeles County. Upon inspection, symptoms of white powdery exudate, either dry or surrounded by wet discoloration of the outer bark in association with a single beetle exit hole, were found on the trunk and main branches of the tree. Examination of the cortex and wood under the exit hole revealed brown discolored necrosis. The TSHB was also found within galleries that were 1 to 4 cm long going against the grain. Symptomatic cortex and sapwood tissues were plated onto potato dextrose agar amended with 0.01% tetracycline (PDA-tet). The TSHB was dissected and plated onto PDA-tet after surface disinfestation following methods described by Kajimura and Hijii (2). After 5 days of incubation at room temperature, regular fungal colonies with aerial mycelia and reddish brown margins were produced. Single spore isolations were used to establish pure culture of the fungus. Fifty conidia were hyaline, clavate with a rounded apex, and initially aseptate (4.1 to 12.0 × 2.4 to 4.1 μm) becoming one- to three-septate (7.6 to 15.1 × 2.8 to 4.5 μm, 9.2 to 17.2 × 3.4 to 4.8 μm, and 13.5 to 17.6 × 4.3 to 4.7 μm, respectively). Identity of the fungal isolates was determined by amplification of the rDNA genes with primers ITS4/5 and EF1/2, respectively. Sequences were deposited into GenBank under Accession Nos. JQ723753, JQ723760, JQ723756, and JQ723763. A BLASTn search revealed 100% similarity to Fusarium sp. (Accession Nos. JQ038020 and JQ038013). Detached green shoots of healthy 1-year-old avocado were wounded to a depth of 1 to 2 mm and 5-mm mycelial plugs from 5-day-old cultures (UCR 1781 and UCR 1837) were placed mycelial side down onto the freshly wounded surfaces and then wrapped with Parafilm. Control shoots were inoculated with sterile agar plugs and five replicates per treatment were used. Shoots were incubated at 25 ± 1°C in moist chambers for 3 weeks. Lesions were observed on all inoculated shoots except for the control. Mean lesion lengths were 10.7 and 12.8 cm for UCR1781 and UCR1837, respectively, and were significantly different (P ≤ 0.05) from the control. Both isolates were reisolated from 100% of symptomatic tissues of inoculated shoots to complete Koch's postulates. This experiment was conducted twice and similar results were obtained. To our knowledge, this is the first report of Fusarium sp. and its vector E. fornicatus causing Fusarium dieback on Avocado in California. References: (1) W. Danthanarayana. Tea Quarterly 39:61, 1968. (2) H. Kajimura and N. Hijii. Ecol. Res. 7:107, 1992; (3) Mendel et al., Phytoparasitica, DOI 10.1007/s12600-012-0223-7, 2012. (4) R. J. Rabaglia. Annals Entomol. Soc. Amer. 99:1034, 2006.},
}
@article {pmid30731202,
year = {2019},
author = {Chujo, T and Lukito, Y and Eaton, CJ and Dupont, PY and Johnson, LJ and Winter, D and Cox, MP and Scott, B},
title = {Complex epigenetic regulation of alkaloid biosynthesis and host interaction by heterochromatin protein I in a fungal endophyte-plant symbiosis.},
journal = {Fungal genetics and biology : FG & B},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.fgb.2019.02.001},
pmid = {30731202},
issn = {1096-0937},
abstract = {Epichloë festucae forms mutualistic symbiotic interactions with grasses of the Lolium and Festuca genera. Protection from insect and mammalian herbivory are the best-documented host benefits of these associations. The two main classes of anti-mammalian alkaloids synthesized by E. festucae are the ergot alkaloids and indole diterpenes, of which ergovaline and lolitrems are the principal terminal products. Synthesis of both metabolites require multiple gene products encoded by clusters of 11 genes located at the subtelomeric regions of chromosomes I and III respectively. These loci are essentially unexpressed in axenic culture but among the most highly expressed genes in planta. We show here that heterochromatin 1 protein (HepA) is an important component of the regulatory machinery that maintains these loci in a silent state in culture. Deletion of this gene led to derepression of eas and ltm gene expression under non-symbiotic culture conditions. Although there was no obvious culture phenotype, RNAseq analysis revealed that around 1000 genes were differentially expressed in the ΔhepA mutant compared to wild type with just one-third upregulated. Inoculation of the ΔhepA mutants into seedlings of Lolium perenne led to a severe host interaction phenotype characterized by a reduction in tiller length but an increase in tiller number. Hyphae within the leaves of these associations were much more abundant in the intercellular spaces of the leaves and aberrantly colonized the vascular bundles. This physiological change was accompanied by a dramatic change in the transcriptome with around 900 genes differentially expressed, with two thirds of these upregulated. This major physiological change was accompanied by a decrease in ltm gene expression and loss of the ability to synthesize lolitrems. These results show that HepA has an important role in controlling the chromatin state of these sub-telomeric secondary metabolite genes, including their symbiosis-specific regulation.},
}
@article {pmid30730567,
year = {2019},
author = {Li, C and Zhou, J and Wang, X and Liao, H},
title = {A purple acid phosphatase, GmPAP33, participates in arbuscule degeneration during AM symbiosis in soybean.},
journal = {Plant, cell & environment},
volume = {},
number = {},
pages = {},
doi = {10.1111/pce.13530},
pmid = {30730567},
issn = {1365-3040},
abstract = {Arbuscules are the central structures of the symbiotic association between terrestrial plants and arbuscular mycorrhizal (AM) fungi. However, arbuscules are also ephemeral structures, and following development, these structures are soon digested and ultimately disappear. Currently, little is known regarding the mechanism underlying the digestion of senescent arbuscules. Here, biochemical and functional analyses were integrated to test the hypothesis that a purple acid phosphatase, GmPAP33, controls the hydrolysis of phospholipids during arbuscule degeneration. The expression of GmPAP33 was enhanced by AM fungal inoculation independent of the P conditions in soybean roots. Promoter-GUS reporter assays revealed that the expression of GmPAP33 was mainly localized to arbuscule-containing cells during symbiosis. The recombinant GmPAP33 exhibited high hydrolytic activity toward phospholipids, phosphatidylcholine and phosphatidic acid. Furthermore, soybean plants overexpressing GmPAP33 exhibited increased percentages of large arbuscules and improved yield and P content compared to wild-type plants when inoculated with AM fungi. Mycorrhizal RNAi plants had high phospholipid levels and a large percentage of small arbuscules. These results in combination with the subcellular localization of GmPAP33 at the plasma membrane indicate that GmPAP33 participates in arbuscule degeneration during AM symbiosis via involvement in phospholipid hydrolysis.},
}
@article {pmid30729580,
year = {2019},
author = {},
title = {Kalliope Papadopoulou.},
journal = {The New phytologist},
volume = {221},
number = {4},
pages = {1701-1702},
doi = {10.1111/nph.15622},
pmid = {30729580},
issn = {1469-8137},
}
@article {pmid30727955,
year = {2019},
author = {Détrée, C and Haddad, I and Demey-Thomas, E and Vinh, J and Lallier, FH and Tanguy, A and Mary, J},
title = {Global host molecular perturbations upon in situ loss of bacterial endosymbionts in the deep-sea mussel Bathymodiolus azoricus assessed using proteomics and transcriptomics.},
journal = {BMC genomics},
volume = {20},
number = {1},
pages = {109},
doi = {10.1186/s12864-019-5456-0},
pmid = {30727955},
issn = {1471-2164},
abstract = {BACKGROUND: Colonization of deep-sea hydrothermal vents by most invertebrates was made efficient through their adaptation to a symbiotic lifestyle with chemosynthetic bacteria, the primary producers in these ecosystems. Anatomical adaptations such as the establishment of specialized cells or organs have been evidenced in numerous deep-sea invertebrates. However, very few studies detailed global inter-dependencies between host and symbionts in these ecosystems. In this study, we proposed to describe, using a proteo-transcriptomic approach, the effects of symbionts loss on the deep-sea mussel Bathymodiolus azoricus' molecular biology. We induced an in situ depletion of symbionts and compared the proteo-transcriptome of the gills of mussels in three conditions: symbiotic mussels (natural population), symbiont-depleted mussels and aposymbiotic mussels.
RESULTS: Global proteomic and transcriptomic results evidenced a global disruption of host machinery in aposymbiotic organisms. We observed that the total number of proteins identified decreased from 1118 in symbiotic mussels to 790 in partially depleted mussels and 761 in aposymbiotic mussels. Using microarrays we identified 4300 transcripts differentially expressed between symbiont-depleted and symbiotic mussels. Among these transcripts, 799 were found differentially expressed in aposymbiotic mussels and almost twice as many in symbiont-depleted mussels as compared to symbiotic mussels. Regarding apoptotic and immune system processes - known to be largely involved in symbiotic interactions - an overall up-regulation of associated proteins and transcripts was observed in symbiont-depleted mussels.
CONCLUSION: Overall, our study showed a global impairment of host machinery and an activation of both the immune and apoptotic system following symbiont-depletion. One of the main assumptions is the involvement of symbiotic bacteria in the inhibition and regulation of immune and apoptotic systems. As such, symbiotic bacteria may increase their lifespan in gill cells while managing the defense of the holobiont against putative pathogens.},
}
@article {pmid30722538,
year = {2013},
author = {Eskalen, A and Stouthamer, R and Lynch, SC and Rugman-Jones, PF and Twizeyimana, M and Gonzalez, A and Thibault, T},
title = {Host Range of Fusarium Dieback and Its Ambrosia Beetle (Coleoptera: Scolytinae) Vector in Southern California.},
journal = {Plant disease},
volume = {97},
number = {7},
pages = {938-951},
doi = {10.1094/PDIS-11-12-1026-RE},
pmid = {30722538},
issn = {0191-2917},
abstract = {The polyphagous shot hole borer (PSHB) is an invasive ambrosia beetle that forms a symbiosis with a new, as-yet-undescribed Fusarium sp., together causing Fusarium dieback on avocado and other host plants in California and Israel. In California, PSHB was first reported on black locust in 2003 but there were no records of fungal damage until 2012, when a Fusarium sp. was recovered from the tissues of several backyard avocado trees infested with PSHB in Los Angeles County. The aim of this study was to determine the plant host range of the beetle-fungus complex in two heavily infested botanical gardens in Los Angeles County. Of the 335 tree species observed, 207 (62%), representing 58 plant families, showed signs and symptoms consistent with attack by PSHB. The Fusarium sp. was recovered from 54% of the plant species attacked by PSHB, indicated by the presence of the Fusarium sp. at least at the site of the entry hole. Trees attacked by PSHB included 11 species of California natives, 13 agriculturally important species, and many common street trees. Survey results also revealed 19 tree species that function as reproductive hosts for PSHB. Additionally, approximately a quarter of all tree individuals planted along the streets of southern California belong to a species classified as a reproductive host. These data suggest the beetle-disease complex potentially may establish in a variety of plant communities locally and worldwide.},
}
@article {pmid30648935,
year = {2019},
author = {Soto, W and Travisano, M and Tolleson, AR and Nishiguchi, MK},
title = {Symbiont evolution during the free-living phase can improve host colonization.},
journal = {Microbiology (Reading, England)},
volume = {165},
number = {2},
pages = {174-187},
doi = {10.1099/mic.0.000756},
pmid = {30648935},
issn = {1465-2080},
abstract = {For micro-organisms cycling between free-living and host-associated stages, where reproduction occurs in both of these lifestyles, an interesting inquiry is whether evolution during the free-living stage can be positively pleiotropic to microbial fitness in a host environment. To address this topic, the squid host Euprymna tasmanica and the marine bioluminescent bacterium Vibrio fischeri were utilized. Microbial ecological diversification in static liquid microcosms was used to simulate symbiont evolution during the free-living stage. Thirteen genetically distinct V. fischeri strains from a broad diversity of ecological sources (e.g. squid light organs, fish light organs and seawater) were examined to see if the results were reproducible in many different genetic settings. Genetic backgrounds that are closely related can be predisposed to considerable differences in how they respond to similar selection pressures. For all strains examined, new mutations with striking and facilitating effects on host colonization arose quickly during microbial evolution in the free-living stage, regardless of the ecological context under consideration for a strain's genetic background. Microbial evolution outside a host environment promoted host range expansion, improved host colonization for a micro-organism, and diminished the negative correlation between biofilm formation and motility.},
}
@article {pmid30420273,
year = {2019},
author = {Ueki, T and Fujie, M and Romaidi, and Satoh, N},
title = {Symbiotic bacteria associated with ascidian vanadium accumulation identified by 16S rRNA amplicon sequencing.},
journal = {Marine genomics},
volume = {43},
number = {},
pages = {33-42},
doi = {10.1016/j.margen.2018.10.006},
pmid = {30420273},
issn = {1876-7478},
mesh = {Animals ; Bacteria/*classification/genetics ; Japan ; Phylogeny ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S/analysis ; Sequence Analysis, RNA ; Species Specificity ; *Symbiosis ; Urochordata/microbiology/*physiology ; Vanadium/metabolism ; },
abstract = {Ascidians belonging to Phlebobranchia accumulate vanadium to an extraordinary degree (≤ 350 mM). Vanadium levels are strictly regulated and vary among ascidian species; thus, they represent well-suited models for studies on vanadium accumulation. No comprehensive study on metal accumulation and reduction in marine organisms in relation to their symbiotic bacterial communities has been published. Therefore, we performed comparative 16S rRNA amplicon sequence analyses on samples from three tissues (branchial sac, intestine, and intestinal lumen) involved in vanadium absorption, isolated from two vanadium-rich (Ascidia ahodori and Ascidia sydneiensis samea) and one vanadium-poor species (Styela plicata). For each sample, the abundance of every bacteria and an abundance value normalized to their abundance in seawater were calculated and compared. Two bacterial genera, Pseudomonas and Ralstonia, were extremely abundant in the branchial sacs of vanadium-rich ascidians. Two bacterial genera, Treponema and Borrelia, were abundant and enriched in the intestinal content of vanadium-rich ascidians. The results suggest that specific selective forces maintain the bacterial population in the three ascidian tissues examined, which contribute to successful vanadium accumulation. This study furthers the understanding of the relationship between bacterial communities and metal accumulation in marine life.},
}
@article {pmid30398151,
year = {2018},
author = {Rolig, AS and Sweeney, EG and Kaye, LE and DeSantis, MD and Perkins, A and Banse, AV and Hamilton, MK and Guillemin, K},
title = {A bacterial immunomodulatory protein with lipocalin-like domains facilitates host-bacteria mutualism in larval zebrafish.},
journal = {eLife},
volume = {7},
number = {},
pages = {},
pmid = {30398151},
issn = {2050-084X},
support = {P01 HD022486/HD/NICHD NIH HHS/United States ; P50 GM098911/GM/NIGMS NIH HHS/United States ; P01HD22486//Eunice Kennedy Shriver National Institute of Child Health and Human Development/International ; P50GM098911/GM/NIGMS NIH HHS/United States ; F32DK098884/DK/NIDDK NIH HHS/United States ; },
mesh = {Aeromonas/*genetics ; Animals ; Host-Pathogen Interactions/*genetics/immunology ; Immunity, Innate/*genetics ; Intestines/immunology/microbiology ; Larva/immunology/microbiology ; Lipocalins/genetics/immunology ; Protein Domains/genetics ; Symbiosis/*genetics/immunology ; Zebrafish/immunology/microbiology ; },
abstract = {Stable mutualism between a host and its resident bacteria requires a moderated immune response to control bacterial population size without eliciting excessive inflammation that could harm both partners. Little is known about the specific molecular mechanisms utilized by bacterial mutualists to temper their hosts' responses and protect themselves from aggressive immune attack. Using a gnotobiotic larval zebrafish model, we identified an Aeromonas secreted immunomodulatory protein, AimA. AimA is required during colonization to prevent intestinal inflammation that simultaneously compromises both bacterial and host survival. Administration of exogenous AimA prevents excessive intestinal neutrophil accumulation and protects against septic shock in models of both bacterially and chemically induced intestinal inflammation. We determined the molecular structure of AimA, which revealed two related calycin-like domains with structural similarity to the mammalian immune modulatory protein, lipocalin-2. As a secreted bacterial protein required by both partners for optimal fitness, AimA is an exemplar bacterial mutualism factor.},
}
@article {pmid30223906,
year = {2018},
author = {Bredon, M and Dittmer, J and Noël, C and Moumen, B and Bouchon, D},
title = {Lignocellulose degradation at the holobiont level: teamwork in a keystone soil invertebrate.},
journal = {Microbiome},
volume = {6},
number = {1},
pages = {162},
pmid = {30223906},
issn = {2049-2618},
mesh = {Animals ; Bacteria/enzymology/genetics/isolation & purification ; Bacterial Physiological Phenomena ; Bacterial Proteins/genetics/metabolism ; Gastrointestinal Microbiome ; Isopoda/*metabolism/*microbiology/physiology ; Lignin/*metabolism ; Phylogeny ; Soil/parasitology ; *Symbiosis ; },
abstract = {BACKGROUND: Woodlice are recognized as keystone species in terrestrial ecosystems due to their role in the decomposition of organic matter. Thus, they contribute to lignocellulose degradation and nutrient cycling in the environment together with other macroarthropods. Lignocellulose is the main component of plants and is composed of cellulose, lignin and hemicellulose. Its digestion requires the action of multiple Carbohydrate-Active enZymes (called CAZymes), typically acting together as a cocktail with complementary, synergistic activities and modes of action. Some invertebrates express a few endogenous lignocellulose-degrading enzymes but in most species, an efficient degradation and digestion of lignocellulose can only be achieved through mutualistic associations with endosymbionts. Similar to termites, it has been suspected that several bacterial symbionts may be involved in lignocellulose degradation in terrestrial isopods, by completing the CAZyme repertoire of their hosts.
RESULTS: To test this hypothesis, host transcriptomic and microbiome shotgun metagenomic datasets were obtained and investigated from the pill bug Armadillidium vulgare. Many genes of bacterial and archaeal origin coding for CAZymes were identified in the metagenomes of several host tissues and the gut content of specimens from both laboratory lineages and a natural population of A. vulgare. Some of them may be involved in the degradation of cellulose, hemicellulose, and lignin. Reconstructing a lignocellulose-degrading microbial community based on the prokaryotic taxa contributing relevant CAZymes revealed two taxonomically distinct but functionally redundant microbial communities depending on host origin. In parallel, endogenous CAZymes were identified from the transcriptome of the host and their expression in digestive tissues was demonstrated by RT-qPCR, demonstrating a complementary enzyme repertoire for lignocellulose degradation from both the host and the microbiome in A. vulgare.
CONCLUSIONS: Our results provide new insights into the role of the microbiome in the evolution of terrestrial isopods and their adaptive radiation in terrestrial habitats.},
}
@article {pmid30223892,
year = {2018},
author = {Sitaraman, R},
title = {Prokaryotic horizontal gene transfer within the human holobiont: ecological-evolutionary inferences, implications and possibilities.},
journal = {Microbiome},
volume = {6},
number = {1},
pages = {163},
pmid = {30223892},
issn = {2049-2618},
mesh = {Bacteria/classification/*genetics/isolation & purification ; Bacterial Physiological Phenomena ; *Biological Evolution ; *Gene Transfer, Horizontal ; Humans ; *Microbiota ; *Symbiosis ; },
abstract = {The ubiquity of horizontal gene transfer in the living world, especially among prokaryotes, raises interesting and important scientific questions regarding its effects on the human holobiont i.e., the human and its resident bacterial communities considered together as a unit of selection. Specifically, it would be interesting to determine how particular gene transfer events have influenced holobiont phenotypes in particular ecological niches and, conversely, how specific holobiont phenotypes have influenced gene transfer events. In this synthetic review, we list some notable and recent discoveries of horizontal gene transfer among the prokaryotic component of the human microbiota, and analyze their potential impact on the holobiont from an ecological-evolutionary viewpoint. Finally, the human-Helicobacter pylori association is presented as an illustration of these considerations, followed by a delineation of unresolved questions and avenues for future research.},
}
@article {pmid30153277,
year = {2018},
author = {Diplock, N and Johnston, K and Mellon, A and Mitchell, L and Moore, M and Schneider, D and Taylor, A and Whitney, J and Zegar, K and Kioko, J and Kiffner, C},
title = {Large mammal declines and the incipient loss of mammal-bird mutualisms in an African savanna ecosystem.},
journal = {PloS one},
volume = {13},
number = {8},
pages = {e0202536},
pmid = {30153277},
issn = {1932-6203},
mesh = {Animals ; *Birds ; *Ecosystem ; Grassland ; Humans ; *Mammals ; Symbiosis/*physiology ; Tanzania/epidemiology ; },
abstract = {Over the past half-century, large mammal populations have declined substantially throughout East Africa, mainly due to habitat loss and unsustainable direct exploitation. While it has been acknowledged that the loss of large mammals can have direct and cascading effects on community composition and ecosystem characteristics, limited quantitative work has been done on how declines of large herbivore populations impacts the abundance of mutualistic symbionts. Using a space-for-time observational approach, we quantified the large mammal community alongside the densities, host preferences and behaviors of mutualistic red-billed oxpeckers (Buphagus erythrorhynchus), and yellow-billed oxpeckers (Buphagus africanus) in northern Tanzania. At the landscape scale, mammal community composition was substantially less diverse in highly human-dominated areas when compared with more protected areas, with an observed complete loss of large wild mammal species in two study areas. Mirroring this trend, oxpecker densities were lowest in the least protected areas, and highest in fully protected areas. Using resource selection functions implemented via generalized linear models at different scales, we found that oxpeckers (1) were predominantly (67% of red-billed oxpeckers; 70% of yellow-billed oxpeckers) feeding on larger (between 500kg and 1500kg) ungulate host species within the mammal community, (2) usually preferred feeding on larger individuals (adults and males) within a specific host species population, and (3) preferred hosts that were more tolerant of their presence. In particular, cattle were especially intolerant of oxpecker presence and were relatively effective in displacing oxpeckers. We found little evidence that oxpecker feeding was parasitic across all host species; wound feeding was only observed on giraffe, comprising 6% and 4% of feeding behavior in red-billed and yellow-billed oxpeckers respectively. Thus, a loss of large-bodied and oxpecker tolerant host species is a likely explanation for declines of oxpecker populations in human dominated landscapes, which may have further cascading effects.},
}
@article {pmid29297160,
year = {2018},
author = {Janashia, I and Choiset, Y and Jozefiak, D and Déniel, F and Coton, E and Moosavi-Movahedi, AA and Chanishvili, N and Haertlé, T},
title = {Beneficial Protective Role of Endogenous Lactic Acid Bacteria Against Mycotic Contamination of Honeybee Beebread.},
journal = {Probiotics and antimicrobial proteins},
volume = {10},
number = {4},
pages = {638-646},
pmid = {29297160},
issn = {1867-1314},
mesh = {Animals ; Antibiosis ; Bees/*microbiology ; Fungi/classification/growth & development/*isolation & purification/physiology ; Lactobacillales/genetics/*physiology ; Symbiosis ; },
abstract = {The purpose of this article is to reveal the role of the lactic acid bacteria (LAB) in the beebread transformation/preservation, biochemical properties of 25 honeybee endogenous LAB strains, particularly: antifungal, proteolytic, and amylolytic activities putatively expressed in the beebread environment have been studied. Seventeen fungal strains isolated from beebread samples were identified and checked for their ability to grow on simulated beebread substrate (SBS) and then used to study mycotic propagation in the presence of LAB. Fungal strains identified as Aspergillus niger (Po1), Candida sp. (BB01), and Z. rouxii (BB02) were able to grow on SBS. Their growth was partly inhibited when co-cultured with the endogenous honeybee LAB strains studied. No proteolytic or amylolytic activities of the studied LAB were detected using pollen, casein starch based media as substrates. These findings suggest that some honeybee LAB symbionts are involved in maintaining a safe microbiological state in the host honeybee colonies by inhibiting beebread mycotic contaminations, starch, and protein predigestion in beebread by LAB is less probable. Honeybee endogenous LAB use pollen as a growth substrate and in the same time restricts fungal propagation, thus showing host beneficial action preserving larval food. This study also can have an impact on development of novel methods of pollen preservation and its processing as a food ingredient.},
}
@article {pmid29249193,
year = {2017},
author = {Schwartz, WJ},
title = {Embodied Clocks.},
journal = {Journal of biological rhythms},
volume = {32},
number = {6},
pages = {503-504},
doi = {10.1177/0748730417748381},
pmid = {29249193},
issn = {1552-4531},
mesh = {Animals ; Circadian Clocks/*physiology ; Decapodiformes/*microbiology/*physiology/radiation effects ; Light ; Models, Biological ; *Symbiosis ; Vibrio/*physiology ; },
}
@article {pmid29228264,
year = {2018},
author = {Porter, SS and Faber-Hammond, JJ and Friesen, ML},
title = {Co-invading symbiotic mutualists of Medicago polymorpha retain high ancestral diversity and contain diverse accessory genomes.},
journal = {FEMS microbiology ecology},
volume = {94},
number = {1},
pages = {},
doi = {10.1093/femsec/fix168},
pmid = {29228264},
issn = {1574-6941},
mesh = {Animals ; Biological Evolution ; California ; Ecosystem ; Europe ; Genome, Bacterial/genetics ; *Introduced Species ; Medicago/*microbiology ; Rhizobium/genetics ; Root Nodules, Plant/*microbiology ; Sinorhizobium/*classification/genetics/*isolation & purification ; Symbiosis/genetics ; },
abstract = {Exotic, invasive plants and animals can wreak havoc on ecosystems by displacing natives and altering environmental conditions. However, much less is known about the identities or evolutionary dynamics of the symbiotic microbes that accompany invasive species. Most leguminous plants rely upon symbiotic rhizobium bacteria to fix nitrogen and are incapable of colonizing areas devoid of compatible rhizobia. We compare the genomes of symbiotic rhizobia in a portion of the legume's invaded range with those of the rhizobium symbionts from across the legume's native range. We show that in an area of California the legume Medicago polymorpha has invaded, its Ensifer medicae symbionts: (i) exhibit genome-wide patterns of relatedness that together with historical evidence support host-symbiont co-invasion from Europe into California, (ii) exhibit population genomic patterns consistent with the introduction of the majority of deep diversity from the native range, rather than a genetic bottleneck during colonization of California and (iii) harbor a large set of accessory genes uniquely enriched in binding functions, which could play a role in habitat invasion. Examining microbial symbiont genome dynamics during biological invasions is critical for assessing host-symbiont co-invasions whereby microbial symbiont range expansion underlies plant and animal invasions.},
}
@article {pmid29192362,
year = {2018},
author = {Bidartondo, MI and Hijri, M},
title = {The Ninth International Conference on Mycorrhiza in Prague: across mycorrhizal symbioses from molecules to global scales.},
journal = {Mycorrhiza},
volume = {28},
number = {2},
pages = {203-205},
doi = {10.1007/s00572-017-0804-x},
pmid = {29192362},
issn = {1432-1890},
mesh = {Congresses as Topic ; Czech Republic ; Mycorrhizae/*physiology ; *Symbiosis ; },
}
@article {pmid30726794,
year = {2019},
author = {Matsuoka, JI and Ishizuna, F and Ogawa, T and Hidaka, M and Siarot, L and Aono, T},
title = {Localization of the reb operon expression is inconsistent with that of the R-body production in the stem nodules formed by Azorhizobium caulinodans mutants having a deletion of praR.},
journal = {The Journal of general and applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.2323/jgam.2018.09.003},
pmid = {30726794},
issn = {1349-8037},
abstract = {Azorhizobium caulinodans, a kind of rhizobia, has a reb operon encoding pathogenic R-body components, whose expression is usually repressed by a transcription factor PraR. Mutation on praR induced a high expression of reb operon and the formation of aberrant nodules, in which both morphologically normal and shrunken host cells were observed. Histochemical GUS analyses of praR mutant expressing reb operon-uidA fusion revealed that the bacterial cells within the normal host cells highly expressed the reb operon, but rarely produced R-bodies. On the other hand, the bacterial cells within the shrunken host cells frequently produced R-bodies but rarely expressed the reb operon. This suggests that R-body production is not only regulated at the transcriptional level, but by other regulatory mechanisms as well.},
}
@article {pmid30726789,
year = {2019},
author = {Hashami, SZ and Nakamura, H and Ohkama-Ohtsu, N and Kojima, K and Djedidi, S and Fukuhara, I and Haidari, MD and Sekimoto, H and Yokoyama, T},
title = {Evaluation of Immune Responses Induced by Simultaneous Inoculations of Soybean (Glycine max [L.] Merr.) with Soil Bacteria and Rhizobia.},
journal = {Microbes and environments},
volume = {},
number = {},
pages = {},
doi = {10.1264/jsme2.ME18110},
pmid = {30726789},
issn = {1347-4405},
abstract = {Legumes form root nodules and fix atmospheric nitrogen by establishing symbiosis with rhizobia. However, excessive root nodules are harmful to plants because of the resulting overconsumption of energy from photosynthates. The delay of an inoculation of the soybean super-nodulation mutant NOD1-3 with Bradyrhizobium diazoefficiens USDA110T by 5 d after an inoculation with several soil bacteria confirmed that one bacterial group significantly decreased root nodules throughout the study period. Moreover, no significant changes were observed in nitrogen fixation by root nodules between an inoculation with USDA 110T only and co-inoculation treatments. To clarify the potential involvement of PR proteins in the restriction of nodule formation in the plants tested, the relative expression levels of PR-1, PR-2, PR-5, and PDF1.2 in NOD1-3 roots were measured using real-time PCR. One group of soil bacteria (Gr.3), which markedly reduced nodule numbers, significantly induced the expression of PR-1, PR-5 and PDF1.2 genes by day 5 after the inoculation. By days 7, 10, and 20 after the inoculation, the expression levels of PR-2 and PR-5 were lower than those with the uninoculated treatment. Inoculations with this group of soil bacteria resulted in lower root nodule numbers than with other tested soil bacteria exerting weak inhibitory effects on nodulation, and were accompanied by the induction of plant defense-related genes. Thus, PR genes appear to play important roles in the mechanisms that suppresses nodule formation on soybean roots.},
}
@article {pmid30723470,
year = {2019},
author = {Cohen, IR and Efroni, S},
title = {The Immune System Computes the State of the Body: Crowd Wisdom, Machine Learning, and Immune Cell Reference Repertoires Help Manage Inflammation.},
journal = {Frontiers in immunology},
volume = {10},
number = {},
pages = {10},
doi = {10.3389/fimmu.2019.00010},
pmid = {30723470},
issn = {1664-3224},
abstract = {Here, we outline an overview of the mammalian immune system that updates and extends the classical clonal selection paradigm. Rather than focusing on strict self-not-self discrimination, we propose that the system orchestrates variable inflammatory responses that maintain the body and its symbiosis with the microbiome while eliminating the threat from pathogenic infectious agents and from tumors. The paper makes four points: The immune system classifies healthy and pathologic states of the body-including both self and foreign elements-by deploying individual lymphocytes as cellular computing machines; immune cells transform input signals from the body into an output of specific immune reactions.Rather than independent clonal responses, groups of individually activated immune-system cells co-react in lymphoid organs to make collective decisions through a type of self-organizing swarm intelligence or crowd wisdom.Collective choices by swarms of immune cells, like those of schools of fish, are modified by relatively small numbers of individual regulators responding to shifting conditions-such collective inflammatory responses are dynamically responsive.Self-reactive autoantibody and T-cell receptor (TCR) repertoires shared by healthy individuals function in a biological version of experience-based supervised machine learning. Immune system decisions are primed by formative experience with training sets of self-antigens encountered during lymphocyte development; these initially trained T cell and B cell repertoires form a Wellness Profile that then guides immune responses to test sets of antigens encountered later. This experience-based machine learning strategy is analogous to that deployed by supervised machine-learning algorithms. We propose experiments to test these ideas. This overview of the immune system bears clinical implications for monitoring wellness and for treating autoimmune disease, cancer, and allograft reactions.},
}
@article {pmid30517219,
year = {2018},
author = {Farias, CP and Carvalho, RC and Resende, FML and Azevedo, LCB},
title = {Consortium of five fungal isolates conditioning root growth and arbuscular mycorrhiza in soybean, corn, and sugarcane.},
journal = {Anais da Academia Brasileira de Ciencias},
volume = {90},
number = {4},
pages = {3649-3660},
doi = {10.1590/0001-3765201820180161},
pmid = {30517219},
issn = {1678-2690},
mesh = {Mycorrhizae/*physiology ; Plant Roots/*growth & development/microbiology ; Saccharum/*growth & development/microbiology ; Soybeans/*growth & development/microbiology ; Symbiosis ; Zea mays/*growth & development/microbiology ; },
abstract = {Plant growth and arbuscular mycorrhizal colonization were studied in sugarcane, corn and soybean by applying five plant growth promoting fungi: Beauveria bassiana, Metarhizium anisopliae, Pochonia chlamydosporia, Purpureocillium lilacinum, and Trichoderma asperella. Sugarcane, corn and soybean were grown in pots under two treatments: (1) inoculation with the fungal consortium and (2) control without inoculation. In the inoculated treatment, fungal spore suspension were applied to the seeds and shoots were sprayed every 28 days. Means were analyzed by analysis of variance and Tukey's test at 5% probability level. The experiment was arranged in a completely randomized design, with six replications. Fungi consortium mediate root growth in soybean and corn, and arbuscular mycorrhizal colonization in soybean and sugarcane. These findings are probably caused by the fungi producing phytohormones and inducing the plants to synthesize phytohormones: auxins for root growth; and jasmonic, abscisic, and salicylic acids with a role in the regulation of mycorrhizal colonization. These effects are important when seeking conservation strategies in agriculture and livestock production, since Fungi consortium can better mediate soil resource acquisition, promoting greater absorption of nutrients and water.},
}
@article {pmid30195930,
year = {2019},
author = {St John, E and Liu, Y and Podar, M and Stott, MB and Meneghin, J and Chen, Z and Lagutin, K and Mitchell, K and Reysenbach, AL},
title = {A new symbiotic nanoarchaeote (Candidatus Nanoclepta minutus) and its host (Zestosphaera tikiterensis gen. nov., sp. nov.) from a New Zealand hot spring.},
journal = {Systematic and applied microbiology},
volume = {42},
number = {1},
pages = {94-106},
doi = {10.1016/j.syapm.2018.08.005},
pmid = {30195930},
issn = {1618-0984},
mesh = {Desulfurococcaceae/*classification/genetics ; Genome, Archaeal ; Hot Springs/*microbiology ; New Zealand ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; },
abstract = {Three thermophilic Nanoarchaeota-Crenarchaeota symbiotic systems have been described. We obtained another stable anaerobic enrichment culture at 80°C, pH 6.0 from a New Zealand hot spring. The nanoarchaeote (Ncl-1) and its host (NZ3T) were isolated in co-culture and their genomes assembled. The small (∼200nm) flagellated cocci were often attached to larger cocci. Based on 16S rRNA gene similarity (88.4%) and average amino acid identity (52%), Ncl-1 is closely related to Candidatus Nanopusillus acidilobi. Their genomes both encode for archaeal flagella and partial glycolysis and gluconeogenesis pathways, but lack ATP synthase genes. Like Nanoarchaeum equitans, Ncl-1 has a CRISPR-Cas system. Ncl-1 also relies on its crenarchaeotal host for most of its biosynthetic needs. The host NZ3T was isolated and grows on proteinaceous substrates but not on sugars, alcohols, or fatty acids. NZ3T requires thiosulfate and grows best at 82°C, pH 6.0. NZ3T is most closely related to the Desulfurococcaceae, Ignisphaera aggregans (∼92% 16S rRNA gene sequence similarity, 45% AAI). Based on phylogenetic, physiological and genomic data, Ncl-1 and NZ3T represent novel genera in the Nanoarchaeota and the Desulfurococcaceae, respectively, with the proposed names Candidatus Nanoclepta minutus and Zestosphaera tikiterensis gen. nov., sp. nov., type strain NZ3T (=DSMZ 107634T=OCM 1213T).},
}
@article {pmid29924971,
year = {2018},
author = {Gefen, T and Geva-Zatorsky, N},
title = {What Came First: The Microbiota or the Tr(egg) Cells?.},
journal = {Immunity},
volume = {48},
number = {6},
pages = {1072-1074},
doi = {10.1016/j.immuni.2018.06.005},
pmid = {29924971},
issn = {1097-4180},
mesh = {Bacteria ; Immunity ; *Microbiota ; Symbiosis ; *T-Lymphocytes, Regulatory ; },
abstract = {Studies have shown that gut commensals facilitate the differentiation of peripheral regulatory T cells (pTregs) via their metabolic products. In this issue of Immunity, Campbell et al. (2018) demonstrate a reciprocal effect of pTregs on the metabolic functions of specific gut commensals that affects their overall energy harvest capacity.},
}
@article {pmid29536599,
year = {2018},
author = {Correia, M and Heleno, R and Vargas, P and Rodríguez-Echeverría, S},
title = {Should I stay or should I go? Mycorrhizal plants are more likely to invest in long-distance seed dispersal than non-mycorrhizal plants.},
journal = {Ecology letters},
volume = {21},
number = {5},
pages = {683-691},
doi = {10.1111/ele.12936},
pmid = {29536599},
issn = {1461-0248},
mesh = {*Mycorrhizae ; Plants ; *Seed Dispersal ; Seeds ; Symbiosis ; },
abstract = {Seed dispersal and mycorrhizal associations are key mutualisms for the functioning and regeneration of plant communities; however, these processes have seldom been explored together. We hypothesised that obligatory mycorrhizal plants will be less likely to have long-distance dispersal (LDD) syndromes since the probability of finding suitable mycorrhizal partners is likely to decrease with distance to the mother plant. We contrasted the mycorrhizal status and LDD syndromes for 1960 European plant species, using phylogenetically corrected log-linear models. Contrary to our expectation, having specialised structures for LDD is more frequent in obligate mycorrhizal plants than in non-mycorrhizal plants, revealing that lack of compatible mutualists does not constrain investment in LDD structures in the European Flora. Ectomycorrhizal plants associated with wind-dispersing fungi are also more likely to have specialised structures for wind dispersal. Habitat specificity and narrower niche of non-mycorrhizal plants might explain the smaller investment in specialised structures for seed dispersal.},
}
@article {pmid29234159,
year = {2018},
author = {Zug, R and Hammerstein, P},
title = {Evolution of reproductive parasites with direct fitness benefits.},
journal = {Heredity},
volume = {120},
number = {3},
pages = {266-281},
pmid = {29234159},
issn = {1365-2540},
mesh = {Animals ; Biological Evolution ; Female ; Fertility ; *Genetic Fitness ; Male ; *Models, Genetic ; Parasites/*physiology ; *Reproduction ; *Symbiosis ; },
abstract = {Maternally inherited symbionts such as Wolbachia have long been seen mainly as reproductive parasites, with deleterious effects on host fitness. It is becoming clear, however, that, frequently, these symbionts also have beneficial effects on host fitness, either along with reproductive parasitism or not. Using the examples of cytoplasmic incompatibility (CI) and male-killing (MK), we here analyze the effect of direct fitness benefits on the evolution of reproductive parasites. By means of a simple theoretical framework, we synthesize and extend earlier modeling approaches for CI and MK, which usually ignore fitness benefits. Moreover, our framework is not restricted to a particular mechanism underlying the fitness benefit (e.g., protection against pathogens). We derive invasion conditions and equilibrium frequencies for the different infection scenarios. Our results demonstrate the importance of a symbiont's "effective fecundity" (i.e., the product of the relative fecundity of an infected female and her transmission efficiency) for a symbiont's invasion success. In particular, we adopt the concept of effective fecundity to scenarios where CI and MK co-occur in one host population. We confirm that direct fitness benefits substantially facilitate the invasion and spread of infections (for example, by lowering or removing the invasion threshold) or even make invasion possible in the first place (for example, if reproductive parasitism is weak or absent). Finally, we discuss the role of direct fitness benefits in long-term evolutionary dynamics of reproductive phenotypes and highlight their potential to resolve genetic conflicts between maternally inherited symbionts and their hosts.},
}
@article {pmid28611430,
year = {2017},
author = {Tsao, HF and Scheikl, U and Volland, JM and Köhsler, M and Bright, M and Walochnik, J and Horn, M},
title = {'Candidatus Cochliophilus cryoturris' (Coxiellaceae), a symbiont of the testate amoeba Cochliopodium minus.},
journal = {Scientific reports},
volume = {7},
number = {1},
pages = {3394},
pmid = {28611430},
issn = {2045-2322},
support = {I 1628//Austrian Science Fund FWF/Austria ; },
mesh = {Amebiasis/*microbiology ; Amoebida/*classification/isolation & purification ; Coxiellaceae/*physiology ; *Phylogeny ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S ; *Symbiosis ; },
abstract = {Free-living amoebae are well known for their role in controlling microbial community composition through grazing, but some groups, namely Acanthamoeba species, also frequently serve as hosts for bacterial symbionts. Here we report the first identification of a bacterial symbiont in the testate amoeba Cochliopodium. The amoeba was isolated from a cooling tower water sample and identified as C. minus. Fluorescence in situ hybridization and transmission electron microscopy revealed intracellular symbionts located in vacuoles. 16S rRNA-based phylogenetic analysis identified the endosymbiont as member of a monophyletic group within the family Coxiellaceae (Gammaprotebacteria; Legionellales), only moderately related to known amoeba symbionts. We propose to tentatively classify these bacteria as 'Candidatus Cochliophilus cryoturris'. Our findings add both, a novel group of amoeba and a novel group of symbionts, to the growing list of bacteria-amoeba relationships.},
}
@article {pmid30721680,
year = {2019},
author = {Jenkins, B and Richards, TA},
title = {Symbiosis: Wolf Lichens Harbour a Choir of Fungi.},
journal = {Current biology : CB},
volume = {29},
number = {3},
pages = {R88-R90},
doi = {10.1016/j.cub.2018.12.034},
pmid = {30721680},
issn = {1879-0445},
abstract = {Identification of the fungus Tremella as a consistent fourth component of wolf lichens further challenges the conventional view of lichen symbiosis as a mutualistic interaction between two players.},
}
@article {pmid30721677,
year = {2019},
author = {King, KC},
title = {Defensive symbionts.},
journal = {Current biology : CB},
volume = {29},
number = {3},
pages = {R78-R80},
doi = {10.1016/j.cub.2018.11.028},
pmid = {30721677},
issn = {1879-0445},
abstract = {Interactions in nature vary from competitive to neutral to symbiotic. An interesting case of symbiosis is seen when one organism provides protection to the other-a relationship termed 'defensive symbiosis'. Kayla King highlights this interesting type of relationship, which can be found throughout the tree of life.},
}
@article {pmid30719639,
year = {2019},
author = {Cornejo Ulloa, P and van der Veen, MH and Krom, BP},
title = {Review: modulation of the oral microbiome by the host to promote ecological balance.},
journal = {Odontology},
volume = {},
number = {},
pages = {},
doi = {10.1007/s10266-019-00413-x},
pmid = {30719639},
issn = {1618-1255},
abstract = {The indivisible relationship between the human host and its oral microbiome has been shaped throughout the millennia, by facing various changes that have forced the adaptation of oral microorganisms to new environmental conditions. In this constant crosstalk between the human host and its microbiome, a bidirectional relationship has been established. The microorganisms provide the host with functions it cannot perform on its own and at the same time the host provides its microbes with a suitable environment for their growth and development. These host factors can positively affect the microbiome, promoting diversity and balance between different species, resulting in a state of symbiosis and absence of pathology. In contrast, other host factors can negatively influence the composition of the oral microbiome and drive the interaction towards a dysbiotic state, where the balance tilts towards a harmful relationship between the host and its microbiome. The aim of this review is to describe the role host factors play in cultivating and maintaining a healthy oral ecology and discuss mechanisms that can prevent its drift towards dysbiosis.},
}
@article {pmid30716127,
year = {2019},
author = {Piquet, B and Shillito, B and Lallier, FH and Duperron, S and Andersen, AC},
title = {High rates of apoptosis visualized in the symbiont-bearing gills of deep-sea Bathymodiolus mussels.},
journal = {PloS one},
volume = {14},
number = {2},
pages = {e0211499},
doi = {10.1371/journal.pone.0211499},
pmid = {30716127},
issn = {1932-6203},
abstract = {Symbiosis between Bathymodiolus and Gammaproteobacteria allows these deep-sea mussels to live in toxic environments such as hydrothermal vents and cold seeps. The quantity of endosymbionts within the gill-bacteriocytes appears to vary according to the hosts environment; however, the mechanisms of endosymbiont population size regulation remain obscure. We investigated the possibility of a control of endosymbiont density by apoptosis, a programmed cell death, in three mussel species. Fluorometric TUNEL and active Caspase-3-targeting antibodies were used to visualize and quantify apoptotic cells in mussel gills. To control for potential artefacts due to depressurization upon specimen recovery from the deep-sea, the apoptotic rates between mussels recovered unpressurised, versus mussels recovered in a pressure-maintaining device, were compared in two species from hydrothermal vents on the Mid-Atlantic Ridge: Bathymodiolus azoricus and B. puteoserpentis. Results show that pressurized recovery had no significant effect on the apoptotic rate in the gill filaments. Apoptotic levels were highest in the ciliated zone and in the circulating hemocytes, compared to the bacteriocyte zone. Apoptotic gill-cells in B. aff. boomerang from cold seeps off the Gulf of Guinea show similar distribution patterns. Deep-sea symbiotic mussels have much higher rates of apoptosis in their gills than the coastal mussel Mytilus edulis, which lacks chemolithoautotrophic symbionts. We discuss how apoptosis might be one of the mechanisms that contribute to the adaptation of deep-sea mussels to toxic environments and/or to symbiosis.},
}
@article {pmid30715218,
year = {2019},
author = {Schoenherr, AP and Rizzo, E and Jackson, N and Manosalva, P and Gomez, SK},
title = {Mycorrhiza-Induced Resistance in Potato Involves Priming of Defense Responses Against Cabbage Looper (Noctuidae: Lepidoptera).},
journal = {Environmental entomology},
volume = {},
number = {},
pages = {},
doi = {10.1093/ee/nvy195},
pmid = {30715218},
issn = {1938-2936},
abstract = {Most plants form mutualistic associations with arbuscular mycorrhizal (AM) fungi that are ubiquitous in soils. Through this symbiosis, plants can withstand abiotic and biotic stresses. The underlying molecular mechanisms involved in mediating mycorrhiza-induced resistance against insects needs further research, and this is particularly true for potato (Solanum tuberosum L. (Solanales: Solanaceae)), which is the fourth most important crop worldwide. In this study, the tripartite interaction between potato, the AM fungus Rhizophagus irregularis (Glomerales: Glomeraceae), and cabbage looper (Trichoplusia ni Hübner) (Lepidoptera: Noctuidae) was examined to determine whether potato exhibits mycorrhiza-induced resistance against this insect. Plant growth, insect fitness, AM fungal colonization of roots, and transcript levels of defense-related genes were measured in shoots and roots after 5 and 8 d of herbivory on mycorrhizal and nonmycorrhizal plants. AM fungal colonization of roots did not have an effect on potato growth, but root colonization levels increased by herbivory. Larval weight gain was reduced after 8 d of feeding on mycorrhizal plants compared with nonmycorrhizal plants. Systemic upregulation of Allene Oxide Synthase 1 (AOS1), 12-Oxo-Phytodienoate Reductase 3 (OPR3) (jasmonic acid pathway), Protease Inhibitor Type I (PI-I) (anti-herbivore defense), and Phenylalanine Ammonia Lyase (PAL) transcripts (phenylpropanoid pathway) was found during the tripartite interaction. Together, these findings suggest that potato may exhibit mycorrhiza-induced resistance to cabbage looper by priming anti-herbivore defenses aboveground. This study illustrates how mycorrhizal potato responds to herbivory by a generalist-chewing insect and serves as the basis for future studies involving tripartite interactions with other pests.},
}
@article {pmid30712873,
year = {2019},
author = {Kobayashi, T and Voisin, B and Kim, DY and Kennedy, EA and Jo, JH and Shih, HY and Truong, A and Doebel, T and Sakamoto, K and Cui, CY and Schlessinger, D and Moro, K and Nakae, S and Horiuchi, K and Zhu, J and Leonard, WJ and Kong, HH and Nagao, K},
title = {Homeostatic Control of Sebaceous Glands by Innate Lymphoid Cells Regulates Commensal Bacteria Equilibrium.},
journal = {Cell},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.cell.2018.12.031},
pmid = {30712873},
issn = {1097-4172},
abstract = {Immune cells and epithelium form sophisticated barrier systems in symbiotic relationships with microbiota. Evidence suggests that immune cells can sense microbes through intact barriers, but regulation of microbial commensalism remain largely unexplored. Here, we uncovered spatial compartmentalization of skin-resident innate lymphoid cells (ILCs) and modulation of sebaceous glands by a subset of RORγt+ ILCs residing within hair follicles in close proximity to sebaceous glands. Their persistence in skin required IL-7 and thymic stromal lymphopoietin, and localization was dependent on the chemokine receptor CCR6. ILC subsets expressed TNF receptor ligands, which limited sebocyte growth by repressing Notch signaling pathway. Consequently, loss of ILCs resulted in sebaceous hyperplasia with increased production of antimicrobial lipids and restricted commensalism of Gram-positive bacterial communities. Thus, epithelia-derived signals maintain skin-resident ILCs that regulate microbial commensalism through sebaceous gland-mediated tuning of the barrier surface, highlighting an immune-epithelia circuitry that facilitates host-microbe symbiosis.},
}
@article {pmid30626871,
year = {2019},
author = {Pacheco, AR and Moel, M and Segrè, D},
title = {Costless metabolic secretions as drivers of interspecies interactions in microbial ecosystems.},
journal = {Nature communications},
volume = {10},
number = {1},
pages = {103},
doi = {10.1038/s41467-018-07946-9},
pmid = {30626871},
issn = {2041-1723},
support = {5R01DE024468/NH/NIH HHS/United States ; R01GM121950/NH/NIH HHS/United States ; P30DK036836/NH/NIH HHS/United States ; },
mesh = {*Computer Simulation ; *Microbial Consortia ; *Microbial Interactions ; Microbiota ; *Models, Biological ; Species Specificity ; Symbiosis ; },
abstract = {Metabolic exchange mediates interactions among microbes, helping explain diversity in microbial communities. As these interactions often involve a fitness cost, it is unclear how stable cooperation can emerge. Here we use genome-scale metabolic models to investigate whether the release of "costless" metabolites (i.e. those that cause no fitness cost to the producer), can be a prominent driver of intermicrobial interactions. By performing over 2 million pairwise growth simulations of 24 species in a combinatorial assortment of environments, we identify a large space of metabolites that can be secreted without cost, thus generating ample cross-feeding opportunities. In addition to providing an atlas of putative interactions, we show that anoxic conditions can promote mutualisms by providing more opportunities for exchange of costless metabolites, resulting in an overrepresentation of stable ecological network motifs. These results may help identify interaction patterns in natural communities and inform the design of synthetic microbial consortia.},
}
@article {pmid30205594,
year = {2018},
author = {Wu, Q and Sun, J and Chen, J and Zhang, H and Guo, YW and Wang, H},
title = {Terpenoids from Marine Soft Coral of the Genus Lemnalia: Chemistry and Biological Activities.},
journal = {Marine drugs},
volume = {16},
number = {9},
pages = {},
pmid = {30205594},
issn = {1660-3397},
support = {No. 81773628, No. 81741165, No. 41776139//National Natural Science Foundation of China/ ; No. 2017YFE0103100//National Key Research and Development Program/ ; No. LY16H300008, No. LY16H300007//National Natural Science Foundation of Zhejiang Province/ ; Jianwei Chen//Zhejiang Postdoctoral Foundation/ ; 2017M620254//China Postdoctoral Science Foundation/ ; },
mesh = {Animals ; Anthozoa/genetics/*metabolism/microbiology ; Anti-Inflammatory Agents/chemistry/isolation & purification/metabolism/*pharmacology ; Antineoplastic Agents/chemistry/isolation & purification/metabolism/*pharmacology ; Biological Products/chemistry/isolation & purification/metabolism/*pharmacology ; Biosynthetic Pathways/genetics ; Cell Line, Tumor/drug effects ; Humans ; Molecular Structure ; Oceans and Seas ; Symbiosis ; Terpenes/chemistry/isolation & purification/metabolism/*pharmacology ; },
abstract = {Lemnalia is one of the most widely-distributed marine soft coral in tropical oceans and is known to produce novel terpenoids with a broad spectrum of biological activities. This review provides the first comprehensive overview of terpenoids produced by soft coral Lemnalia since their first discovery in 1974.},
}
@article {pmid30198488,
year = {2018},
author = {Krapivin, VA and Bagrov, SV and Varfolomeeva, MA},
title = {Effect of tidal level on abundance of symbionts in the White Sea blue mussel.},
journal = {Diseases of aquatic organisms},
volume = {130},
number = {2},
pages = {131-144},
doi = {10.3354/dao03259},
pmid = {30198488},
issn = {0177-5103},
mesh = {Animals ; *Mytilus edulis/parasitology ; *Symbiosis ; *Tidal Waves ; *Trematoda ; },
abstract = {In the White Sea, the blue mussel Mytilus edulis occupies a wide range of biotopes and is associated with numerous symbiotic organisms. At some sites, mussel cover spreads continuously from the intertidal to the subtidal zone. We checked whether the patterns of infection by different associated organisms differed among the upper subtidal, zero-depth and lower intertidal zones at 3 sites in the Kandalaksha Gulf and the Onega Bay of the White Sea. Organisms belonging to 13 taxa were found in mantle cavities and tissues of blue mussels. Parasitic green algae, a sporocyst and metacercariae of 5 species of digenean trematodes occupied mussel tissues; commensal ciliates, rhabdocoelans and some free-living invertebrates were found in mantle cavities. Quantitative composition of symbiotic communities of mussels was not the same at different tidal levels: Urastoma cyprinae (commensal rhabdocoelans) were more abundant in the subtidal and zero-depth zones, while encysted metacercariae of Renicola roscovita and Himasthla sp. were more abundant at the zero-depth and intertidal zones. We suggested several hypotheses to explain this heterogeneity.},
}
@article {pmid30189599,
year = {2018},
author = {Gemperlein, K and Zaburannyi, N and Garcia, R and La Clair, JJ and Müller, R},
title = {Metabolic and Biosynthetic Diversity in Marine Myxobacteria.},
journal = {Marine drugs},
volume = {16},
number = {9},
pages = {},
pmid = {30189599},
issn = {1660-3397},
support = {German Center for Infection Research//Deutsches Zentrum für Infektionsforschung/ ; X//Xenobe Research Institute/ ; },
mesh = {Animals ; Aquatic Organisms/*metabolism ; *Biodiversity ; Biological Products/isolation & purification/metabolism/*pharmacology ; Biosynthetic Pathways/genetics ; Computer Simulation ; Genome, Bacterial/genetics ; Myxococcales/genetics/*metabolism ; Phylogeny ; Porifera/*microbiology ; Soil Microbiology ; Symbiosis ; },
abstract = {Prior to 2005, the vast majority of characterized myxobacteria were obtained from terrestrial habitats. Since then, several species of halotolerant and even obligate marine myxobacteria have been described. Chemical analyses of extracts from these organisms have confirmed their ability to produce secondary metabolites with unique chemical scaffolds. Indeed, new genera of marine-derived myxobacteria, particularly Enhygromyxa, have been shown to produce novel chemical scaffolds that differ from those observed in soil myxobacteria. Further studies have shown that marine sponges and terrestrial myxobacteria are capable of producing similar or even identical secondary metabolites, suggesting that myxobacterial symbionts may have been the true producers. Recent in silico analysis of the genome sequences available from six marine myxobacteria disclosed a remarkably versatile biosynthetic potential. With access to ever-advancing tools for small molecule and genetic evaluation, these studies suggest a bright future for expeditions into this yet untapped resource for secondary metabolites.},
}
@article {pmid30110359,
year = {2018},
author = {Moir, ML and Renton, M and Hoffmann, BD and Leng, MC and Lach, L},
title = {Development and testing of a standardized method to estimate honeydew production.},
journal = {PloS one},
volume = {13},
number = {8},
pages = {e0201845},
pmid = {30110359},
issn = {1932-6203},
mesh = {Animals ; *Hemiptera/anatomy & histology/growth & development ; Introduced Species ; *Models, Biological ; North America ; Species Specificity ; Symbiosis ; },
abstract = {Honeydew production by Hemiptera is an ecologically important process that facilitates mutualisms and increases nutrient cycling. Accurate estimates of the amount of honeydew available in a system are essential for quantifying food web dynamics, energy flow, and the potential growth of sooty mould that inhibits plant growth. Despite the importance of honeydew, there is no standardized method to estimate its production when intensive laboratory testing is not feasible. We developed two new models to predict honeydew production, one based on insect body mass and taxonomic family, and one based on body mass and life stage. We tested the accuracy of both models' predictions for a diverse range of honeydew-producing hemipteran families (Aphididae, Pseudococcidae, Coccidae, Psyllidae, Aleyrodidae, Delphacidae, Cicadellidae). The method based on body mass and family provided more accurate estimates of honeydew production, due to large variation in honeydew production among families. We apply our methodology to a case study, the recalculation of honeydew available to invasive red imported fire ant (Solenopsis invicta) in the United States. We find that the amount of honeydew may be an order of magnitude lower than that previously estimated (2.16 versus 21.6 grams of honeydew per day) and discuss possible reasons for the difference. We anticipate that being able to estimate honeydew production based on minimal biological information will have applications to agriculture, invasion biology, forestry, and carbon farming.},
}
@article {pmid30102395,
year = {2018},
author = {Manzano-Marín, A and Coeur d'acier, A and Clamens, AL and Orvain, C and Cruaud, C and Barbe, V and Jousselin, E},
title = {A Freeloader? The Highly Eroded Yet Large Genome of the Serratia symbiotica Symbiont of Cinara strobi.},
journal = {Genome biology and evolution},
volume = {10},
number = {9},
pages = {2178-2189},
pmid = {30102395},
issn = {1759-6653},
mesh = {Animals ; Aphids/*microbiology/physiology ; Biological Evolution ; Buchnera/*genetics/isolation & purification/physiology ; Enterobacteriaceae/*genetics/isolation & purification/physiology ; *Genome, Bacterial ; Metabolic Networks and Pathways ; Serratia/*genetics/isolation & purification/physiology ; *Symbiosis ; },
abstract = {Genome reduction is pervasive among maternally inherited bacterial endosymbionts. This genome reduction can eventually lead to serious deterioration of essential metabolic pathways, thus rendering an obligate endosymbiont unable to provide essential nutrients to its host. This loss of essential pathways can lead to either symbiont complementation (sharing of the nutrient production with a novel co-obligate symbiont) or symbiont replacement (complete takeover of nutrient production by the novel symbiont). However, the process by which these two evolutionary events happen remains somewhat enigmatic by the lack of examples of intermediate stages of this process. Cinara aphids (Hemiptera: Aphididae) typically harbor two obligate bacterial symbionts: Buchnera and Serratia symbiotica. However, the latter has been replaced by different bacterial taxa in specific lineages, and thus species within this aphid lineage could provide important clues into the process of symbiont replacement. In the present study, using 16S rRNA high-throughput amplicon sequencing, we determined that the aphid Cinara strobi harbors not two, but three fixed bacterial symbionts: Buchnera aphidicola, a Sodalis sp., and S. symbiotica. Through genome assembly and genome-based metabolic inference, we have found that only the first two symbionts (Buchnera and Sodalis) actually contribute to the hosts' supply of essential nutrients while S. symbiotica has become unable to contribute towards this task. We found that S. symbiotica has a rather large and highly eroded genome which codes only for a few proteins and displays extensive pseudogenization. Thus, we propose an ongoing symbiont replacement within C. strobi, in which a once "competent" S. symbiotica does no longer contribute towards the beneficial association. These results suggest that in dual symbiotic systems, when a substitute cosymbiont is available, genome deterioration can precede genome reduction and a symbiont can be maintained despite the apparent lack of benefit to its host.},
}
@article {pmid30078596,
year = {2018},
author = {Mowbray, CA and Niranji, SS and Cadwell, K and Bailey, R and Watson, KA and Hall, J},
title = {Gene expression of AvBD6-10 in broiler chickens is independent of AvBD6, 9, and 10 peptide potency.},
journal = {Veterinary immunology and immunopathology},
volume = {202},
number = {},
pages = {31-40},
doi = {10.1016/j.vetimm.2018.06.007},
pmid = {30078596},
issn = {1873-2534},
mesh = {Animals ; Avian Proteins/*genetics/immunology ; Bacteria ; Chickens/*immunology ; Gastrointestinal Tract/*immunology/microbiology ; Interleukin-1beta/immunology ; Interleukin-6/immunology ; Kidney/immunology ; Liver/immunology ; Symbiosis/immunology ; Transcriptome ; beta-Defensins/*genetics/immunology ; },
abstract = {The Avian β-defensin (AvBD) gene cluster contains fourteen genes; within this, two groups (AvBD6/7 and AvBD8 -10) encode charged peptides of >+5 (AvBD6/7), indicative of potent microbial killing activities, and ≤+4 (AvBD8-10), suggestive of reduced antimicrobial activities. Chicken broiler gut tissues are constantly exposed to microbes in the form of commensal bacteria. This study examined whether tissue expression patterns of AvBD6-10 reflected microbial exposure and the encoded peptides a functional antimicrobial hierarchy. Gut AvBD6-10 gene expression was observed in hatch to day 21 birds, although the AvBD8-10 profiles were eclipsed by those detected in the liver and kidney tissues. In vitro challenges of chicken CHCC-OU2 cells using the gut commensal Lactobacillus johnsonii (104 CFU) did not significantly affect AvBD8-10 gene expression patterns, although upregulation (P < 0.05) of IL-Iβ gene expression was observed. Similarly, in response to Bacteriodes doreii, IL-Iβ and IL-6 gene upregulation were detected (P < 0.05), but AvBD10 gene expression remained unaffected. These data suggested that AvBD8-10 gene expression was not induced by commensal gut bacteria. Bacterial time-kill assays employing recombinant (r)AvBD6, 9 and 10 peptides (0.5μM - 12μM), indicated an antimicrobial hierarchy, linked to charge, of AvBD6 > AvBD9 > AvBD10 against Escherichia coli, but AvBD10 > AvBD9 > AvBD6 using Enterococcus faecalis. rAvBD10, selected due to its reduced cationic charge was, using CHCC-OU2 cells, investigated for cell proliferation and wound healing properties, but none were observed. These data suggest that in healthy broiler chicken tissues AvBD6/7 and AvBD8-10 gene expression profiles are independent of the in vitro antimicrobial hierarchies of the encoded AvBD6, 9 and 10 peptides.},
}
@article {pmid30060189,
year = {2018},
author = {Río Bártulos, C and Rogers, MB and Williams, TA and Gentekaki, E and Brinkmann, H and Cerff, R and Liaud, MF and Hehl, AB and Yarlett, NR and Gruber, A and Kroth, PG and van der Giezen, M},
title = {Mitochondrial Glycolysis in a Major Lineage of Eukaryotes.},
journal = {Genome biology and evolution},
volume = {10},
number = {9},
pages = {2310-2325},
pmid = {30060189},
issn = {1759-6653},
support = {//Wellcome Trust/United Kingdom ; 078566/A/05/Z//Wellcome Trust/United Kingdom ; },
mesh = {Biological Evolution ; Blastocystis/cytology/enzymology/genetics/*metabolism ; Diatoms/cytology/enzymology/genetics/*metabolism ; Energy Metabolism ; Genome, Mitochondrial ; *Glycolysis ; Mitochondria/genetics/*metabolism ; Symbiosis ; Transformation, Genetic ; },
abstract = {The establishment of the mitochondrion is seen as a transformational step in the origin of eukaryotes. With the mitochondrion came bioenergetic freedom to explore novel evolutionary space leading to the eukaryotic radiation known today. The tight integration of the bacterial endosymbiont with its archaeal host was accompanied by a massive endosymbiotic gene transfer resulting in a small mitochondrial genome which is just a ghost of the original incoming bacterial genome. This endosymbiotic gene transfer resulted in the loss of many genes, both from the bacterial symbiont as well the archaeal host. Loss of genes encoding redundant functions resulted in a replacement of the bulk of the host's metabolism for those originating from the endosymbiont. Glycolysis is one such metabolic pathway in which the original archaeal enzymes have been replaced by bacterial enzymes from the endosymbiont. Glycolysis is a major catabolic pathway that provides cellular energy from the breakdown of glucose. The glycolytic pathway of eukaryotes appears to be bacterial in origin, and in well-studied model eukaryotes it takes place in the cytosol. In contrast, here we demonstrate that the latter stages of glycolysis take place in the mitochondria of stramenopiles, a diverse and ecologically important lineage of eukaryotes. Although our work is based on a limited sample of stramenopiles, it leaves open the possibility that the mitochondrial targeting of glycolytic enzymes in stramenopiles might represent the ancestral state for eukaryotes.},
}
@article {pmid29929338,
year = {2018},
author = {Che, R and Deng, Y and Wang, F and Wang, W and Xu, Z and Hao, Y and Xue, K and Zhang, B and Tang, L and Zhou, H and Cui, X},
title = {Autotrophic and symbiotic diazotrophs dominate nitrogen-fixing communities in Tibetan grassland soils.},
journal = {The Science of the total environment},
volume = {639},
number = {},
pages = {997-1006},
doi = {10.1016/j.scitotenv.2018.05.238},
pmid = {29929338},
issn = {1879-1026},
mesh = {*Grassland ; Nitrogen ; *Nitrogen Fixation ; Soil ; *Soil Microbiology ; Symbiosis/*physiology ; Tibet ; },
abstract = {Biological nitrogen fixation, conducted by soil diazotrophs, is the primary nitrogen source for natural grasslands. However, the diazotrophs in grassland soils are still far from fully investigated. Particularly, their regional-scale distribution patterns have never been systematically examined. Here, soils (0-5 cm) were sampled from 54 grasslands on the Tibetan Plateau to examine the diazotroph abundance, diversity, and community composition, as well as their distribution patterns and driving factors. The diazotroph abundance was expressed as nifH gene copies, measured using real-time PCR. The diversity and community composition of diazotrophs were analyzed through MiSeq sequencing of nifH genes. The results showed that Cyanobacteria (47.94%) and Proteobacteria (45.20%) dominated the soil diazotroph communities. Most Cyanobacteria were classified as Nostocales which are main components of biological crusts. Rhizobiales, most of which were identified as potential symbiotic diazotrophs, were also abundant in approximately half of the soil samples. The soil diazotroph abundance, diversity, and community composition followed the distribution patterns in line with mean annual precipitation. Moreover, they also showed significant correlations with prokaryotic abundance, plant biomass, vegetation cover, soil pH values, and soil nutrient contents. Among these environmental factors, the soil moisture, organic carbon, available phosphorus, and inorganic nitrogen contents could be the main drivers of diazotroph distribution due to their strong correlations with diazotroph indices. These findings suggest that autotrophic and symbiotic diazotrophs are the predominant nitrogen fixers in Tibetan grassland soils, and highlight the key roles of water and nutrient availability in determining the soil diazotroph distribution on the Tibetan Plateau.},
}
@article {pmid29119317,
year = {2018},
author = {Woodhams, DC and LaBumbard, BC and Barnhart, KL and Becker, MH and Bletz, MC and Escobar, LA and Flechas, SV and Forman, ME and Iannetta, AA and Joyce, MD and Rabemananjara, F and Gratwicke, B and Vences, M and Minbiole, KPC},
title = {Prodigiosin, Violacein, and Volatile Organic Compounds Produced by Widespread Cutaneous Bacteria of Amphibians Can Inhibit Two Batrachochytrium Fungal Pathogens.},
journal = {Microbial ecology},
volume = {75},
number = {4},
pages = {1049-1062},
pmid = {29119317},
issn = {1432-184X},
support = {DEB-1136662//Division of Environmental Biology/ ; },
mesh = {Animals ; Antifungal Agents/pharmacology ; Anura/microbiology ; Bacteria/classification/isolation & purification/*metabolism ; Biological Control Agents/antagonists & inhibitors ; Chytridiomycota/*drug effects/growth & development/pathogenicity ; Indoles/*antagonists & inhibitors/chemistry/*metabolism ; Microbial Sensitivity Tests ; Panama ; Phylogeny ; Prodigiosin/*antagonists & inhibitors/chemistry/*metabolism ; Serratia/classification/isolation & purification/metabolism ; Skin/microbiology ; Switzerland ; Symbiosis ; United States ; Volatile Organic Compounds/*antagonists & inhibitors/chemistry/*metabolism ; },
abstract = {Symbiotic bacteria can produce secondary metabolites and volatile compounds that contribute to amphibian skin defense. Some of these symbionts have been used as probiotics to treat or prevent the emerging disease chytridiomycosis. We examined 20 amphibian cutaneous bacteria for the production of prodigiosin or violacein, brightly colored defense compounds that pigment the bacteria and have characteristic spectroscopic properties making them readily detectable, and evaluated the antifungal activity of these compounds. We detected violacein from all six isolates of Janthinobacterium lividum on frogs from the USA, Switzerland, and on captive frogs originally from Panama. We detected prodigiosin from five isolates of Serratia plymuthica or S. marcescens, but not from four isolates of S. fonticola or S. liquefaciens. All J. lividum isolates produced violacein when visibly purple, while prodigiosin was only detected on visibly red Serratia isolates. When applied to cultures of chytrid fungi Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal), prodigiosin caused significant growth inhibition, with minimal inhibitory concentrations (MIC) of 10 and 50 μM, respectively. Violacein showed a MIC of 15 μM against both fungi and was slightly more active against Bsal than Bd at lower concentrations. Although neither violacein nor prodigiosin showed aerosol activity and is not considered a volatile organic compound (VOC), J. lividum and several Serratia isolates did produce antifungal VOCs. White Serratia isolates with undetectable prodigiosin levels could still inhibit Bd growth indicating additional antifungal compounds in their chemical arsenals. Similarly, J. lividum can produce antifungal compounds such as indole-3-carboxaldehyde in addition to violacein, and isolates are not always purple, or turn purple under certain growth conditions. When Serratia isolates were grown in the presence of cell-free supernatant (CFS) from the fungi, CFS from Bd inhibited growth of the prodigiosin-producing isolates, perhaps indicative of an evolutionary arms race; Bsal CFS did not inhibit bacterial growth. In contrast, growth of one J. lividum isolate was facilitated by CFS from both fungi. Isolates that grow and continue to produce antifungal compounds in the presence of pathogens may represent promising probiotics for amphibians infected or at risk of chytridiomycosis. In a global analysis, 89% of tested Serratia isolates and 82% of J. lividum isolates were capable of inhibiting Bd and these have been reported from anurans and caudates from five continents, indicating their widespread distribution and potential for host benefit.},
}
@article {pmid29119316,
year = {2018},
author = {Grigorescu, AS and Renoz, F and Sabri, A and Foray, V and Hance, T and Thonart, P},
title = {Accessing the Hidden Microbial Diversity of Aphids: an Illustration of How Culture-Dependent Methods Can Be Used to Decipher the Insect Microbiota.},
journal = {Microbial ecology},
volume = {75},
number = {4},
pages = {1035-1048},
doi = {10.1007/s00248-017-1092-x},
pmid = {29119316},
issn = {1432-184X},
support = {Grant FRFC 6886819//Fonds De La Recherche Scientifique - FNRS/ ; },
mesh = {Animals ; Aphids/*microbiology ; Bacteria/classification/genetics/growth & development/*isolation & purification ; *Biodiversity ; Culture Techniques/*methods ; DNA/isolation & purification ; Fungi/classification/genetics/growth & development/*isolation & purification ; Genes, Bacterial/genetics ; Genes, Fungal/genetics ; High-Throughput Nucleotide Sequencing ; Microbiota/genetics/*physiology ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Serratia/classification/isolation & purification/physiology ; Symbiosis ; },
abstract = {Microorganism communities that live inside insects can play critical roles in host development, nutrition, immunity, physiology, and behavior. Over the past decade, high-throughput sequencing reveals the extraordinary microbial diversity associated with various insect species and provides information independent of our ability to culture these microbes. However, their cultivation in the laboratory remains crucial for a deep understanding of their physiology and the roles they play in host insects. Aphids are insects that received specific attention because of their ability to form symbiotic associations with a wide range of endosymbionts that are considered as the core microbiome of these sap-feeding insects. But, if the functional diversity of obligate and facultative endosymbionts has been extensively studied in aphids, the diversity of gut symbionts and other associated microorganisms received limited consideration. Herein, we present a culture-dependent method that allowed us to successfully isolate microorganisms from several aphid species. The isolated microorganisms were assigned to 24 bacterial genera from the Actinobacteria, Firmicutes, and Proteobacteria phyla and three fungal genera from the Ascomycota and Basidiomycota phyla. In our study, we succeeded in isolating already described bacteria found associated to aphids (e.g., the facultative symbiont Serratia symbiotica), as well as microorganisms that have never been described in aphids before. By unraveling a microbial community that so far has been ignored, our study expands our current knowledge on the microbial diversity associated with aphids and illustrates how fast and simple culture-dependent approaches can be applied to insects in order to capture their diverse microbiota members.},
}
@article {pmid29119315,
year = {2018},
author = {DeLong, JP and Al-Ameeli, Z and Lyon, S and Van Etten, JL and Dunigan, DD},
title = {Size-dependent Catalysis of Chlorovirus Population Growth by A Messy Feeding Predator.},
journal = {Microbial ecology},
volume = {75},
number = {4},
pages = {847-853},
pmid = {29119315},
issn = {1432-184X},
mesh = {Animals ; Catalysis ; Chlorella/virology ; Ciliophora/*physiology ; DNA Viruses ; Food Chain ; Host-Pathogen Interactions/*physiology ; Paramecium/*virology ; Phycodnaviridae/growth & development/*physiology ; Population Dynamics ; *Predatory Behavior ; *Symbiosis ; },
abstract = {Many chloroviruses replicate in endosymbiotic zoochlorellae that are protected from infection by their symbiotic host. To reach the high virus concentrations that often occur in natural systems, a mechanism is needed to release zoochlorellae from their hosts. We demonstrate that the ciliate predator Didinium nasutum foraging on zoochlorellae-bearing Paramecium bursaria can release live zoochlorellae from the ruptured prey cell that can then be infected by chloroviruses. The catalysis process is very effective, yielding roughly 95% of the theoretical infectious virus yield as determined by sonication of P. bursaria. Chlorovirus activation is more effective with smaller Didinia, as larger Didinia typically consume entire P. bursaria cells without rupturing them, precluding the release of zoochlorellae. We also show that the timing of Chlorovirus growth is tightly linked to the predator-prey cycle between Didinium and Paramecium, with the most rapid increase in chloroviruses temporally linked to the peak foraging rate of Didinium, supporting the idea that predator-prey cycles can drive cycles of Chlorovirus abundance.},
}
@article {pmid29110065,
year = {2018},
author = {Li, J and Chen, D and Yu, B and He, J and Zheng, P and Mao, X and Yu, J and Luo, J and Tian, G and Huang, Z and Luo, Y},
title = {Fungi in Gastrointestinal Tracts of Human and Mice: from Community to Functions.},
journal = {Microbial ecology},
volume = {75},
number = {4},
pages = {821-829},
pmid = {29110065},
issn = {1432-184X},
support = {31301987//National Natural Science Foundation of China/ ; 3167131062//National Natural Science Foundation of China/ ; },
mesh = {Animals ; Ascomycota/physiology ; Basidiomycota/physiology ; Biodiversity ; Candida/pathogenicity/physiology ; Chytridiomycota/physiology ; Diet ; Dysbiosis/microbiology ; Food ; Fungi/classification/*pathogenicity/*physiology ; Gastrointestinal Microbiome/immunology/*physiology ; Gastrointestinal Tract/immunology/*microbiology ; *Host-Pathogen Interactions/immunology/physiology ; Humans ; Inflammatory Bowel Diseases/immunology/microbiology ; Intestinal Mucosa/microbiology ; Lectins, C-Type/metabolism ; Mice ; Mycobiome/*physiology ; Mycoses ; Symbiosis ; Toll-Like Receptor 2/metabolism ; Toll-Like Receptor 4/metabolism ; },
abstract = {Fungi are often ignored in studies on gut microbes because of their low level of presence (making up only 0.1% of the total microorganisms) in the gastrointestinal tract (GIT) of monogastric animals. Recent studies using novel technologies such as next generation sequencing have expanded our understanding on the importance of intestinal fungi in humans and animals. Here, we provide a comprehensive review on the fungal community, the so-called mycobiome, and their functions from recent studies in humans and mice. In the GIT of humans, fungi belonging to the phyla Ascomycota, Basidiomycota and Chytridiomycota are predominant. The murine intestines harbor a more diverse assemblage of fungi. Diet is one of the major factors influencing colonization of fungi in the GIT. Presence of the genus Candida is positively associated with dietary carbohydrates, but are negatively correlated with dietary amino acids, proteins, and fatty acids. However, the relationship between diet and the fungal community (and functions), as well as the underlying mechanisms remains unclear. Dysbiosis of intestinal fungi can cause invasive infections and inflammatory bowel diseases (IBD). However, it is not clear whether dysbiosis of the mycobiome is a cause, or a result of IBD. Compared to non-inflamed intestinal mucosa, the abundance and diversity of fungi is significantly increased in the inflamed mucosa. The commonly observed commensal fungal species Candida albicans might contribute to occurrence and development of IBD. Limited studies show that Candida albicans might interact with immune cells of the host intestines through the pathways associated with Dectin-1, Toll-like receptor 2 (TLR2), and TLR4. This review is expected to provide new thoughts for future studies on intestinal fungi and for new therapies to fungal infections in the GIT of human and animals.},
}
@article {pmid29071368,
year = {2018},
author = {Theron-De Bruin, N and Dreyer, LL and Ueckermann, EA and Wingfield, MJ and Roets, F},
title = {Birds Mediate a Fungus-Mite Mutualism.},
journal = {Microbial ecology},
volume = {75},
number = {4},
pages = {863-874},
pmid = {29071368},
issn = {1432-184X},
support = {na//Department of Science and Technology/National Research Foundation Centre of Excellence in Tree Health Biotechnology/ ; },
mesh = {Animals ; Arthropod Vectors/*microbiology ; Birds/*microbiology ; DNA, Fungal/analysis ; Fungi/isolation & purification/*physiology ; Mites/*microbiology ; Proteaceae/microbiology ; South Africa ; Spores, Fungal ; Symbiosis/*physiology ; Trees/microbiology ; },
abstract = {Mutualisms between ophiostomatoid fungi and arthropods have been well documented. These fungi commonly aid arthropod nutrition and, in turn, are transported to new niches by these arthropods. The inflorescences of Protea trees provide a niche for a unique assemblage of ophiostomatoid fungi. Here, mites feed on Sporothrix fungi and vector the spores to new niches. Protea-pollinating beetles transport the spore-carrying mites between Protea trees. However, many Protea species are primarily pollinated by birds that potentially play a central role in the Protea-Sporothrix-mite system. To investigate the role of birds in the movement of mites and/or fungal spores, mites were collected from Protea inflorescences and cape sugarbirds, screened for Sporothrix fungal spores and tested for their ability to feed and reproduce on the fungal associates. Two mite species where abundant in both Protea inflorescences and on cape sugarbirds and regularly carried Sporothrix fungal spores. One of these mite species readily fed and reproduced on its transported fungal partner. For dispersal, this mite (a Glycyphagus sp.) attached to a larger mite species (Proctolaelaps vandenbergi) which, in turn, were carried by the birds to new inflorescences. The results of this study provide compelling evidence for a new mite-fungus mutualism, new mite-mite commensalisms and the first evidence of birds transporting mites with Sporothrix fungal spores to colonise new Protea trees.},
}
@article {pmid28864228,
year = {2017},
author = {de León-Martínez, JA and Yañez-Ocampo, G and Wong-Villarreal, A},
title = {Burkholderia species associated with legumes of Chiapas, Mexico, exhibit stress tolerance and growth in aromatic compounds.},
journal = {Revista Argentina de microbiologia},
volume = {49},
number = {4},
pages = {394-401},
doi = {10.1016/j.ram.2017.04.009},
pmid = {28864228},
issn = {0325-7541},
mesh = {*Burkholderia/genetics/isolation & purification ; DNA, Bacterial ; *Fabaceae/microbiology ; Mexico ; Phylogeny ; RNA, Ribosomal, 16S ; Sequence Analysis, DNA ; Stress, Physiological ; Symbiosis ; },
abstract = {Leguminous plants have received special interest for the diversity of β-proteobacteria in their nodules and are promising candidates for biotechnological applications. In this study, 15 bacterial strains were isolated from the nodules of the following legumes: Indigofera thibaudiana, Mimosa diplotricha, Mimosa albida, Mimosa pigra, and Mimosa pudica, collected in 9 areas of Chiapas, Mexico. The strains were grouped into four profiles of genomic fingerprints through BOX-PCR and identified based on their morphology, API 20NE biochemical tests, sequencing of the 16S rRNA, nifH and nodC genes as bacteria of the Burkholderia genus, genetically related to Burkholderia phenoliruptrix, Burkholderia phymatum, Burkholderia sabiae, and Burkholderia tuberum. The Burkholderia strains were grown under stress conditions with 4% NaCl, 45°C, and benzene presence at 0.1% as the sole carbon source. This is the first report on the isolation of these nodulating species of the Burkholderia genus in legumes in Mexico.},
}
@article {pmid28747779,
year = {2017},
author = {Kotilínek, M and Hiiesalu, I and Košnar, J and Šmilauerová, M and Šmilauer, P and Altman, J and Dvorský, M and Kopecký, M and Doležal, J},
title = {Fungal root symbionts of high-altitude vascular plants in the Himalayas.},
journal = {Scientific reports},
volume = {7},
number = {1},
pages = {6562},
pmid = {28747779},
issn = {2045-2322},
mesh = {Altitude ; *Biodiversity ; Endophytes/*classification/cytology/genetics/*physiology ; India ; Microscopy ; Mycorrhizae/*classification/*physiology ; Phylogeny ; Plant Roots/*microbiology ; *Symbiosis ; },
abstract = {Arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) form symbiotic relationships with plants influencing their productivity, diversity and ecosystem functions. Only a few studies on these fungi, however, have been conducted in extreme elevations and none over 5500 m a.s.l., although vascular plants occur up to 6150 m a.s.l. in the Himalayas. We quantified AMF and DSE in roots of 62 plant species from contrasting habitats along an elevational gradient (3400-6150 m) in the Himalayas using a combination of optical microscopy and next generation sequencing. We linked AMF and DSE communities with host plant evolutionary history, ecological preferences (elevation and habitat type) and functional traits. We detected AMF in elevations up to 5800 m, indicating it is more constrained by extreme conditions than the host plants, which ascend up to 6150 m. In contrast, DSE were found across the entire gradient up to 6150 m. AMF diversity was unimodally related to elevation and positively related to the intensity of AMF colonization. Mid-elevation steppe and alpine plants hosted more diverse AMF communities than plants from deserts and the subnival zone. Our results bring novel insights to the abiotic and biotic filters structuring AMF and DSE communities in the Himalayas.},
}
@article {pmid30709144,
year = {2019},
author = {Owolabi, KM and Hammouch, Z},
title = {Mathematical modeling and analysis of two-variable system with noninteger-order derivative.},
journal = {Chaos (Woodbury, N.Y.)},
volume = {29},
number = {1},
pages = {013145},
doi = {10.1063/1.5086909},
pmid = {30709144},
issn = {1089-7682},
abstract = {The aim of this paper is to apply the newly trending Atangana-Baluanu derivative operator to model some symbiosis systems describing commmensalism and predator-prey processes. The choice of using this derivative is due to the fact that it combines nonlocal and nonsingular properties in its formulation, which are the essential ingredients when dealing with models of real-life applications. In addition, it is only the Atangana-Baleanu derivative that has both Markovian and non-Markovian properties. Also, its waiting time takes into account the power, exponential, and Mittag-Leffler laws in its formulation. Mathematical analysis of these dynamical models is considered to guide in the correct use of parameters therein, with chaotic and spatiotemporal results reported for some instances of fractional power α.},
}
@article {pmid30708940,
year = {2019},
author = {Mei, L and Yang, X and Cao, H and Zhang, T and Guo, J},
title = {Arbuscular Mycorrhizal Fungi Alter Plant and Soil C:N:P Stoichiometries Under Warming and Nitrogen Input in a Semiarid Meadow of China.},
journal = {International journal of environmental research and public health},
volume = {16},
number = {3},
pages = {},
doi = {10.3390/ijerph16030397},
pmid = {30708940},
issn = {1660-4601},
support = {(No. 31470405) and (No. 31770359)//National Natural Science Foundation of China/ ; },
abstract = {Ecological stoichiometry has been widely used to determine how plant-soil systems respond to global change and to reveal which factors limit plant growth. Arbuscular mycorrhizal fungi (AMF) can increase plants' uptake of nutrients such as nitrogen (N) and phosphorus (P), thereby altering plant and soil stoichiometries. To understand the regulatory effect of AMF feedback on plants and soil stoichiometry under global change, a microcosm experiment was conducted with warming and N input. The C₄ grass Setaria viridis, C₃ grass Leymus chinensis, and Chenopodiaceae species Suaeda corniculata were studied. The results showed that the mycorrhizal benefits for the C₄ grass S. viridis were greater than those for the C₃ grass L. chinensis, whereas for the Chenopodiaceae species S. corniculata, AMF symbiosis was antagonistic. Under N input and a combination of warming and N input, AMF significantly decreased the N:P ratios of all three species. Under N input, the soil N content and the N:P ratio were decreased significantly in the presence of AMF, whereas the soil C:N ratio was increased. These results showed that AMF can reduce the P limitation caused by N input and improve the efficiency of nutrient utilization, slow the negative influence of global change on plant growth, and promote grassland sustainability.},
}
@article {pmid30708045,
year = {2019},
author = {Chen, J and Bai, X and Hua, Y and Zhang, H and Wang, H},
title = {Fusariumins C and D, two novel antimicrobial agents from Fusarium oxysporum ZZP-R1 symbiotic on Rumex madaio Makino.},
journal = {Fitoterapia},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.fitote.2019.01.016},
pmid = {30708045},
issn = {1873-6971},
abstract = {Bioassay-guided fractionation of the crude extract of fermentation broth of one symbiotic strain Fusarium oxysporum ZZP-R1 derived from coastal plant Rumex madaio Makino, one traditional Chinese medicine used as a treatment of inflammation and toxication, yielded two novel compounds, fusariumins C (1) and D (2). Chemical structures of 1 and 2 were respectively determined as one meroterpene with cyclohexanone moiety and a sesquiterpene ester with a conjugated triene and an unusual oxetene ring by a combination of spectroscopic methods, including 1D and 2D NMR, mass spectrometry, and optical rotation analysis, as well as by comparison with literature data. Bioassay results indicated that compound 1 displayed potent activity against Staphyloccocus aureus with an MIC value of 6.25 μM, and compound 2 had a moderate inhibitory effect on S. aureus with an MIC value of 25.0 μM. It was the first report that phytochemical investigation of Fusarium strain from R. madaio Makino led to isolation of new antimicrobial agents.},
}
@article {pmid30707488,
year = {2019},
author = {Popović-Djordjević, J and Marjanović, ŽS and Gršić, N and Adžić, T and Popović, B and Bogosavljević, J and Brčeski, I},
title = {Essential elements as a distinguishing factor between mycorrhizal potentials of two cohabiting truffle species in riparian forest habitat in Serbia.},
journal = {Chemistry & biodiversity},
volume = {},
number = {},
pages = {},
doi = {10.1002/cbdv.201800693},
pmid = {30707488},
issn = {1612-1880},
abstract = {True truffles (Tuber sp.) that establish ectomycorrhizal symbiosis (ECM) with trees in the Mediterranean and temporal regions have species specific abilities to assimilate soil born elements. Suitable habitats are usually inhabited by few truffle species, while distinguishing their symbiotic potentials appeared very difficult. Two species that commonly inhabit riparian forests in Serbia are the most prized one, Tuber magnatum Pico (Piedmont white truffle) and not so highly valued Tuber brumale Vitt. In order to assess potential differences between their assimilation and accumulation abilities, the differences between contents of elements that may be the subjects of the symbiotic trade between the host plant and fungi were evaluated in accumulation target (ascocarps) and their source (the soil). Essential macro (K, Na, Ca, Mg, Fe, P, S and Zn) and essential trace (Co, Cr, Cu, Mn and Se) elements in truffles and soil samples were determined by means of inductively coupled plasma with optical emission spectrometry (ICP-OES). Their concentrations (mg/kg) in ascocarps were in the range from 1.364±0.591 (Cr) to 10760.862±16.058 (K), while in soil ranged from 23.035±0.010 (Cr) to 20809.300±122.934 (Fe). Element accumulation potential (bioaccumulation factor) was calculated in the system truffle/soil. The statistical approaches were used for establishing the differences, while the possible differentiation between symbiotic potentials of two mycelia in the defined soil conditions was discussed.},
}
@article {pmid30706343,
year = {2019},
author = {Martínez-García, S and Ortiz-García, CI and Cruz-Aguilar, M and Zenteno, JC and Murrieta-Coxca, JM and Pérez-Tapia, SM and Rodríguez-Martínez, S and Cancino-Diaz, ME and Cancino-Diaz, JC},
title = {Competition/antagonism associations of biofilm formation among Staphylococcus epidermidis Agr groups I, II, and III.},
journal = {Journal of microbiology (Seoul, Korea)},
volume = {57},
number = {2},
pages = {143-153},
doi = {10.1007/s12275-019-8322-5},
pmid = {30706343},
issn = {1976-3794},
abstract = {Staphylococci have quorum-sensing (QS) systems that enable cell-to-cell communication, as well as the regulation of numerous colonization and virulence factors. The accessory gene regulator (Agr) operon is one of the Staphylococcus genus QS systems. Three groups (I, II, and III) are present in Staphylococcus epidermidis Agr operon. To date, it is unknown whether Agr groups can interact symbiotically during biofilm development. This study analyzed a symbiotic association among Agr groups during biofilm formation in clinical and commensal isolates. Different combinations among Agr group isolates was used to study biofilm formation in vitro and in vivo (using a mouse catheter-infection model). The analysis of Agr groups were also performed from samples of human skin (head, armpits, and nostrils). Different predominant coexistence was found within biofilms, suggesting symbiosis type. In vitro, Agr I had a competition with Agr II and Agr III. Agr II had a competition with Agr III, and Agr II was an antagonist to Agr I and III when the three strains were combined. In vivo, Agr II had a competition to Agr I, but Agr I and II were antagonists to Agr III. The associations found in vitro and in vivo were also found in different sites of the skin. Besides, other associations were observed: Agr III antagonized Agr I and II, and Agr III competed with Agr I and Agr II. These results suggest that, in S. epidermidis, a symbiotic association of competition and antagonism occurs among different Agr groups during biofilm formation.},
}
@article {pmid30705119,
year = {2019},
author = {Sivakumar, R and Ranjani, J and Vishnu, US and Jayashree, S and Lozano, GL and Miles, J and Broderick, NA and Guan, C and Gunasekaran, P and Handelsman, J and Rajendhran, J},
title = {Evaluation of InSeq To Identify Genes Essential for Pseudomonas aeruginosa PGPR2 Corn Root Colonization.},
journal = {G3 (Bethesda, Md.)},
volume = {},
number = {},
pages = {},
doi = {10.1534/g3.118.200928},
pmid = {30705119},
issn = {2160-1836},
abstract = {The reciprocal interaction between rhizosphere bacteria and their plant hosts results in a complex battery of genetic and physiological responses. In this study, we used insertion sequencing (INSeq) to reveal the genetic determinants responsible for the fitness of Pseudomonas aeruginosa PGPR2 during root colonization. We generated a random transposon mutant library of Pseudomonas aeruginosa PGPR2 comprising 39,500 unique insertions and identified genes required for growth in culture and on corn roots. A total of 108 genes were identified as contributing to the fitness of strain PGPR2 on roots. The importance in root colonization of four genes identified in the TnSeq screen was verified by constructing deletion mutants in the genes and testing them for the ability to colonize corn roots singly or in competition with the wild type. All four mutants were affected in corn root colonization, displaying 5- to 100-fold reductions in populations in single inoculations, and all were outcompeted by the wild type by almost 100-fold after seven days on corn roots in mixed inoculations of the wild type and mutant. The genes identified in the screen had homology to genes involved in amino acid catabolism, stress adaptation, detoxification, signal transduction, and transport. INSeq technology proved a successful tool to identify fitness factors in Paeruginosa PGPR2 for root colonization.},
}
@article {pmid30602371,
year = {2019},
author = {Buret, AG and Motta, JP and Allain, T and Ferraz, J and Wallace, JL},
title = {Pathobiont release from dysbiotic gut microbiota biofilms in intestinal inflammatory diseases: a role for iron?.},
journal = {Journal of biomedical science},
volume = {26},
number = {1},
pages = {1},
doi = {10.1186/s12929-018-0495-4},
pmid = {30602371},
issn = {1423-0127},
support = {183-681-2011, 413888-2012//Natural Sciences and Engineering Research Council of Canada/ ; 12033//Canadian Institutes of Health Research/Canada ; 20142017//Crohn's and Colitis Canada/ ; PCOFUND-GA-2013-609398//AgreenSkillsPlus/ ; },
mesh = {*Bacterial Physiological Phenomena ; *Biofilms ; Dysbiosis/immunology/microbiology/*physiopathology ; Gastrointestinal Microbiome/*physiology ; Homeostasis ; Humans ; Inflammatory Bowel Diseases/complications/*immunology/microbiology ; Iron/*metabolism ; Symbiosis ; },
abstract = {Gut microbiota interacting with an intact mucosal surface are key to the maintenance of homeostasis and health. This review discusses the current state of knowledge of the biofilm mode of growth of these microbiota communities, and how in turn their disruptions may cause disease. Beyond alterations of relative microbial abundance and diversity, the aim of the review is to focus on the disruptions of the microbiota biofilm structure and function, the dispersion of commensal bacteria, and the mechanisms whereby these dispersed commensals may become pathobionts. Recent findings have linked iron acquisition to the expression of virulence factors in gut commensals that have become pathobionts. Causal studies are emerging, and mechanisms common to enteropathogen-induced disruptions, as well as those reported for Inflammatory Bowel Disease and colo-rectal cancer are used as examples to illustrate the great translational potential of such research. These new observations shed new light on our attempts to develop new therapies that are able to protect and restore gut microbiota homeostasis in the many disease conditions that have been linked to microbiota dysbiosis.},
}
@article {pmid30509793,
year = {2018},
author = {Baquiran, JIP and Conaco, C},
title = {Sponge-microbe partnerships are stable under eutrophication pressure from mariculture.},
journal = {Marine pollution bulletin},
volume = {136},
number = {},
pages = {125-134},
doi = {10.1016/j.marpolbul.2018.09.011},
pmid = {30509793},
issn = {1879-3363},
mesh = {Animals ; Coral Reefs ; *Ecosystem ; Environmental Monitoring/*methods ; *Eutrophication ; Fisheries ; *Microbiota/genetics ; Philippines ; *Porifera/genetics/microbiology ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; },
abstract = {Sponges harbor a great diversity of symbiotic microorganisms. However, environmental stresses can affect this partnership and influence the health and abundance of the host sponges. In Bolinao, Pangasinan, Philippines, chronic input of organic materials from mariculture activities contributes to a eutrophic coastal environment. To understand how these conditions might affect sponge-microbial partnerships, transplantation experiments were conducted with the marine sponge Gelliodes obtusa. High-throughput sequencing of 16S rRNA revealed that the associated microbial community of the sponges did not exhibit significant shifts after six weeks of transplantation at a eutrophic fish farm site compared to sponges grown at a coral reef or a seagrass area. However, sponges at the fish farm revealed higher abundance of the amoA gene, suggesting that microbiome members are responsive to increased ammonium levels at the site. The stable association between G. obtusa and its microbiome indicates that the sponge holobiont can withstand eutrophication pressure from mariculture.},
}
@article {pmid30089146,
year = {2018},
author = {Anjos, D and Dáttilo, W and Del-Claro, K},
title = {Unmasking the architecture of ant-diaspore networks in the Brazilian Savanna.},
journal = {PloS one},
volume = {13},
number = {8},
pages = {e0201117},
pmid = {30089146},
issn = {1932-6203},
mesh = {Animals ; Ants/*physiology ; Brazil ; Ecology ; *Ecosystem ; Fruit/chemistry ; Grassland ; Plants/chemistry ; Seed Dispersal/*physiology ; Seeds/chemistry ; Symbiosis ; },
abstract = {Ant-diaspore interactions are directly related to fruit consumption, seed predation and dispersal, being determinant for the plant fitness. However, although abundant and diversified, these ecological interactions have been neglected in network studies. Understanding the structure of these networks is the first step in preserving these ecological functions. However, describing the network structure is not enough; we need to understand what mechanisms are behind the network patterns. In this study, for the first time, we describe the structure of the ant-diaspore network, considering only the interactions that can benefit plants, separating it into fruit consumption and diaspore removal networks in the Brazilian Savanna. We postulated that ant-diaspore interactions tend to be more specialized in the diaspore removal network compared to the fruit consumption network. Furthermore, we tested whether morphological features, such as size of mandibles of ants and diaspores, could modulate these ecological networks. Overall, we recorded 24 ant and 29 plant species interacting. We found that fruit consumption and diaspore removal networks exhibited similar patterns of interactions (i.e., non-modular), although only the diaspore removal network was nested. The diaspore removal network did not show a more specialized pattern than the fruit consumption network, since both networks consisted of opportunistic interactions. We found that ant mandible and diaspore size does not explain the structure of ecological networks, but in diaspore removal networks the relationship between these morphological traits may explain the pattern of interactions. Thus, we showed that mandible size of ants may have implications on seedling recruitment, suggesting that mandible size can predict possible effects on plant fitness within in diaspore removal networks. Overall, ant-diaspore networks maintain important ecological functions, such as fruit consumption and seed dispersal, which often implies an increase in reproductive success of the plants.},
}
@article {pmid29306352,
year = {2017},
author = {Reid, CJ and Wyrsch, ER and Roy Chowdhury, P and Zingali, T and Liu, M and Darling, AE and Chapman, TA and Djordjevic, SP},
title = {Porcine commensal Escherichia coli: a reservoir for class 1 integrons associated with IS26.},
journal = {Microbial genomics},
volume = {3},
number = {12},
pages = {},
pmid = {29306352},
issn = {2057-5858},
mesh = {Animals ; Australia ; Drug Resistance, Multiple, Bacterial/*genetics ; Environmental Pollutants ; Escherichia coli/*classification/*genetics/isolation & purification/pathogenicity ; Feces/*microbiology ; *Food Microbiology ; Gene Transfer, Horizontal ; Genetic Variation ; Humans ; Integrons/*genetics ; Mutagenesis, Insertional ; Swine/*microbiology ; Symbiosis ; Virulence/genetics ; Whole Genome Sequencing ; Zoonoses/microbiology ; },
abstract = {Porcine faecal waste is a serious environmental pollutant. Carriage of antimicrobial-resistance genes (ARGs) and virulence-associated genes (VAGs), and the zoonotic potential of commensal Escherichia coli from swine are largely unknown. Furthermore, little is known about the role of commensal E. coli as contributors to the mobilization of ARGs between food animals and the environment. Here, we report whole-genome sequence analysis of 103 class 1 integron-positive E. coli from the faeces of healthy pigs from two commercial production facilities in New South Wales, Australia. Most strains belonged to phylogroups A and B1, and carried VAGs linked with extraintestinal infection in humans. The 103 strains belonged to 37 multilocus sequence types and clonal complex 10 featured prominently. Seventeen ARGs were detected and 97 % (100/103) of strains carried three or more ARGs. Heavy-metal-resistance genes merA, cusA and terA were also common. IS26 was observed in 98 % (101/103) of strains and was often physically associated with structurally diverse class 1 integrons that carried unique genetic features, which may be tracked. This study provides, to our knowledge, the first detailed genomic analysis and point of reference for commensal E. coli of porcine origin in Australia, facilitating tracking of specific lineages and the mobile resistance genes they carry.},
}
@article {pmid30703093,
year = {2019},
author = {Suzaki, T and Takeda, N and Nishida, H and Hoshino, M and Ito, M and Misawa, F and Handa, Y and Miura, K and Kawaguchi, M},
title = {Correction: LACK OF SYMBIONT ACCOMMODATION controls intracellular symbiont accommodation in root nodule and arbuscular mycorrhizal symbiosis in Lotus japonicus.},
journal = {PLoS genetics},
volume = {15},
number = {1},
pages = {e1007966},
doi = {10.1371/journal.pgen.1007966},
pmid = {30703093},
issn = {1553-7404},
abstract = {[This corrects the article DOI: 10.1371/journal.pgen.1007865.].},
}
@article {pmid30700990,
year = {2018},
author = {Sogawa, A and Yamazaki, A and Yamasaki, H and Komi, M and Manabe, T and Tajima, S and Hayashi, M and Nomura, M},
title = {SNARE Proteins LjVAMP72a and LjVAMP72b Are Required for Root Symbiosis and Root Hair Formation in Lotus japonicus.},
journal = {Frontiers in plant science},
volume = {9},
number = {},
pages = {1992},
doi = {10.3389/fpls.2018.01992},
pmid = {30700990},
issn = {1664-462X},
abstract = {SNARE (soluble N-ethyl maleimide sensitive factor attachment protein receptor) proteins mediate membrane trafficking in eukaryotic cells. Both LjVAMP72a and LjVAMP72b are members of R-SNARE and belong to a symbiotic subgroup of VAMP72 in Lotus japonicus. Their sequences are closely related and both were induced in the root upon rhizobial inoculation. The expression level of LjVAMP72a in the nodules was higher than in the leaves or roots; however, LjVMAP72b was expressed constitutively in the leaves, roots, and nodules. Immunoblot analysis showed that not only LjVAMP72a but also LjVAMP72b were accumulated in a symbiosome-enriched fraction, suggesting its localization in the symbiosome membrane during nodulation. Since there was 89% similarity between LjVAMP72a and LjVAMP72b, knockdown mutant by RNAi suppressed both genes. The suppression of both genes impaired root nodule symbiosis (RNS). The number of bacteroids and the nitrogen fixation activity were severely curtailed in the nodules formed on knockdown roots (RNAi-LjVAMP72a/72b). Arbuscular mycorrhization (AM) was also attenuated in knockdown roots, indicating that LjVAMP72a and LjVAMP72b were required to establish not only RNS but also AM. In addition, transgenic hairy roots of RNAi-LjVAMP72a/72b suppressed the elongation of root hairs without infections by rhizobia or arbuscular mycorrhizal fungi. Amino acid alignment showed the symbiotic subclade of VAMP72s containing LjVAMP72a and LjVAMP72b were a conserved six amino acid region (HHQAQD) within the SNARE motif. Taken together, our data suggested that LjVAMP72a and LjVAMP72b positively controlled both symbioses and root hair formation by affecting the secretory pathway.},
}
@article {pmid30468749,
year = {2019},
author = {Moran, RA and Hall, RM},
title = {pBuzz: A cryptic rolling-circle plasmid from a commensal Escherichia coli has two inversely oriented oriTs and is mobilised by a B/O plasmid.},
journal = {Plasmid},
volume = {101},
number = {},
pages = {10-19},
doi = {10.1016/j.plasmid.2018.11.001},
pmid = {30468749},
issn = {1095-9890},
mesh = {ATP-Binding Cassette Transporters/*genetics/metabolism ; Ampicillin/pharmacology ; Anti-Bacterial Agents/pharmacology ; Base Pairing ; Base Sequence ; *Conjugation, Genetic ; DNA Replication ; DNA, Bacterial/*genetics ; Drug Resistance, Bacterial/*genetics ; Escherichia coli/drug effects/*genetics/growth & development ; Escherichia coli Proteins/*genetics/metabolism ; Humans ; Plasmids/*chemistry/metabolism ; Sequence Alignment ; Streptomycin/pharmacology ; Sulfamethoxazole/pharmacology ; Symbiosis/physiology ; },
abstract = {Ampicillin, streptomycin and sulphamethoxazole resistant commensal E. coli 838-3B contains five plasmids that range in size from >90 kb to <2 kb. The resistance genes blaTEM (ampicillin), strA (streptomycin) and sul2 (sulphamethoxazole) transferred along with a B/O plasmid named p838B-R. However, three plasmids smaller than 7 kb were also found in transconjugants, suggesting that they could be mobilised by the B/O plasmid. The complete sequences of p838B-R and pBuzz, a small plasmid mobilised by p838B-R with 70% efficiency, were determined. p838B-R is 94,803 bp and contains an 8400 bp resistance island that includes the three antibiotic resistance genes. The p838B-R backbone contains a complete conjugative transfer region, including an oriT site upstream of nikAB that resembles the experimentally-defined oriT of R64. The 1982 bp pBuzz contains a rep gene and sites associated with replication that resemble those of pC194/pUB110 family rolling-circle plasmids. It also contains two, inversely oriented copies of an 84 bp sequence that differs from the oriT region in p838B-R at just 6 positions. These oriT-like sites likely explain the ability of pBuzz to co-transfer with the B/O plasmid using the NikB relaxase and NikA accessory protein encoded by p838B-R, i.e. pBuzz utilises relaxase-in trans mobilisation. Several rolling-circle plasmids related to pBuzz were found in the GenBank non-redundant nucleotide database. They contain diverse potential oriTs, including sequences similar to known oriTs found in conjugative plasmids of I-complex (I1, B/O, K, Z and I2), L or M types.},
}
@article {pmid30317530,
year = {2019},
author = {Adak, A and Khan, MR},
title = {An insight into gut microbiota and its functionalities.},
journal = {Cellular and molecular life sciences : CMLS},
volume = {76},
number = {3},
pages = {473-493},
doi = {10.1007/s00018-018-2943-4},
pmid = {30317530},
issn = {1420-9071},
support = {under Unit of Excellence Project (BT/550/NE/U-Excel/2014)//Department of Science and Technology, India/ ; },
mesh = {Computational Biology ; Gastrointestinal Microbiome/genetics/immunology/*physiology ; Gastrointestinal Tract/microbiology ; Humans ; Symbiosis ; },
abstract = {Gut microbiota has evolved along with their hosts and is an integral part of the human body. Microbiota acquired at birth develops in parallel as the host develops and maintains its temporal stability and diversity through adulthood until death. Recent developments in genome sequencing technologies, bioinformatics and culturomics have enabled researchers to explore the microbiota and in particular their functions at more detailed level than before. The accumulated evidences suggest that though a part of the microbiota is conserved, the dynamic members vary along the gastrointestinal tract, from infants to elderly, primitive tribes to modern societies and in different health conditions. Though the gut microbiota is dynamic, it performs some basic functions in the immunological, metabolic, structural and neurological landscapes of the human body. Gut microbiota also exerts significant influence on both physical and mental health of an individual. An in-depth understanding of the functioning of gut microbiota has led to some very exciting developments in therapeutics, such as prebiotics, probiotics, drugs and faecal transplantation leading to improved health.},
}
@article {pmid29452714,
year = {2018},
author = {Stefan, A and Van Cauwenberghe, J and Rosu, CM and Stedel, C and Labrou, NE and Flemetakis, E and Efrose, RC},
title = {Genetic diversity and structure of Rhizobium leguminosarum populations associated with clover plants are influenced by local environmental variables.},
journal = {Systematic and applied microbiology},
volume = {41},
number = {3},
pages = {251-259},
doi = {10.1016/j.syapm.2018.01.007},
pmid = {29452714},
issn = {1618-0984},
mesh = {Altitude ; DNA, Bacterial/genetics ; Genes, Bacterial ; *Genetic Variation ; Genetics, Population ; Medicago/*microbiology ; Multilocus Sequence Typing ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rhizobium leguminosarum/*genetics ; Romania ; Root Nodules, Plant/*microbiology ; Sequence Analysis, DNA ; Soil/chemistry ; Symbiosis ; Trifolium/*microbiology ; },
abstract = {The identification and conservation of indigenous rhizobia associated with legume plants and their application as biofertilizers is becoming an agricultural worldwide priority. However, little is known about the genetic diversity and phylogeny of rhizobia in Romania. In the present study, the genetic diversity and population composition of Rhizobium leguminosarum symbiovar trifolii isolates from 12 clover plants populations located across two regions in Romania were analyzed. Red clover isolates were phenotypically evaluated and genotyped by sequencing 16S rRNA gene, 16S-23S intergenic spacer, three chromosomal genes (atpD, glnII and recA) and two plasmid genes (nifH and nodA). Multilocus sequence typing (MLST) analysis revealed that red clover plants are nodulated by a wide genetic diversity of R. leguminosarum symbiovar trifolii sequence types (STs), highly similar to the ones previously found in white clover. Rhizobial genetic variation was found mainly within the two clover populations for both chromosomal and plasmid types. Many STs appear to be unique for this region and the genetic composition of rhizobia differs significantly among the clover populations. Furthermore, our results showed that both soil pH and altitude contributed to plasmid sequence type composition while differences in chromosomal composition were affected by the altitude and were strongly correlated with distance.},
}
@article {pmid29426636,
year = {2018},
author = {Schrallhammer, M and Castelli, M and Petroni, G},
title = {Phylogenetic relationships among endosymbiotic R-body producer: Bacteria providing their host the killer trait.},
journal = {Systematic and applied microbiology},
volume = {41},
number = {3},
pages = {213-220},
doi = {10.1016/j.syapm.2018.01.005},
pmid = {29426636},
issn = {1618-0984},
mesh = {Alphaproteobacteria/*classification/genetics ; Bacterial Proteins/*genetics ; DNA, Bacterial/genetics ; Paramecium/*microbiology/physiology ; Phenotype ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; },
abstract = {R-body producing bacterial endosymbionts of Paramecium spp. transform their hosts into "killer" paramecia and provide them a selective advantage. This killer trait is connected to the presence of R-bodies, which are peculiar, tightly coiled protein ribbons capable of rapid unrolling. Based mainly on those two characteristics the respective obligate intracellular bacteria have been comprised in the genus Caedibacter and additional traits such as host species, subcellular localization, and R-body dimensions and mode of unrolling were used for species discrimination. Previous studies applying the full-cycle rRNA approach demonstrated the polyphyly of this assemblage. Following this approach, we obtained new sequences and in situ hybridizations for five strains of Caedibacter taeniospiralis and four strains associated to Caedibacter varicaedens and Caedibacter caryophilus. Detailed phylogenetic reconstructions confirm the association of C. taeniospiralis to Fastidiosibacteraceae and to Holosporales in case of the others. Therefore, we critically revise the taxonomy of the latter group. The high 16S rRNA gene sequence similarity among the type strains of Caedibacter varicaedens and C. caryophilus indicate that they should be classified within a single species for which we propose Caedimonas varicaedens comb. nov. owing to the priority of Caedibacter varicaedens. Moreover, we propose to establish the new family Caedimonadaceae fam. nov. to encompass Caedimonas varicaedens, "Ca. Paracaedimonas acanthamoebae" comb. nov. and "Ca. Nucleicultrix amoebiphila" within the order Holosporales.},
}
@article {pmid29310897,
year = {2018},
author = {Belhadi, D and de Lajudie, P and Ramdani, N and Le Roux, C and Boulila, F and Tisseyre, P and Boulila, A and Benguedouar, A and Kaci, Y and Laguerre, G},
title = {Vicia faba L. in the Bejaia region of Algeria is nodulated by Rhizobium leguminosarum sv. viciae, Rhizobium laguerreae and two new genospecies.},
journal = {Systematic and applied microbiology},
volume = {41},
number = {2},
pages = {122-130},
doi = {10.1016/j.syapm.2017.10.004},
pmid = {29310897},
issn = {1618-0984},
mesh = {Algeria ; DNA, Bacterial/genetics ; DNA, Ribosomal Spacer/genetics ; Genes, Bacterial ; Multilocus Sequence Typing ; *Phylogeny ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; Rhizobium/*classification/genetics/isolation & purification ; Rhizobium leguminosarum/*classification/genetics/isolation & purification ; Root Nodules, Plant/microbiology ; Sequence Analysis, DNA ; Symbiosis ; Vicia faba/*microbiology ; },
abstract = {Fifty-eight rhizobial strains were isolated from root nodules of Vicia faba cv. Equina and Vicia faba cv. Minor by the host-trapping method in soils collected from eleven sites in Bejaia, Eastern Algeria. Eleven genotypic groups were distinguished based on the combined PCR/RFLP of 16S rRNA, 16S-23S rRNA intergenic spacer and symbiotic (nodC and nodD-F) genes and further confirmed by multilocus sequence analysis (MLSA) of three housekeeping genes (recA, atpD and rpoB), the 16S rRNA gene and the nodulation genes nodC and nodD. Of the 11 genotypes, 5 were dominant and 2 were the most represented. Most of the strains shared high nodD gene sequence similarity with Rhizobium leguminosarum sv. viciae; their nodC sequences were similar to both Rhizobium leguminosarum and Rhizobium laguerreae. Sequence analyses of the 16S-23S rRNA intergenic spacer showed that all the new strains were phylogenetically related to those described from Vicia sativa and V. faba in several African, European, American and Asian countries, with which they form a group related to Rhizobium leguminosarum. Phylogenetic analysis based on MLSA of 16S rRNA, recA, atpD and rpoB genes allowed the affiliations of strain AM11R to Rhizobium leguminosarum sv. viciae and of strains EB1 and ES8 to Rhizobium laguerreae. In addition, two separate clades with <97% similarity may represent two novel genospecies within the genus Rhizobium.},
}
@article {pmid29307475,
year = {2018},
author = {Taha, K and Berraho, EB and El Attar, I and Dekkiche, S and Aurag, J and Béna, G},
title = {Rhizobium laguerreae is the main nitrogen-fixing symbiont of cultivated lentil (Lens culinaris) in Morocco.},
journal = {Systematic and applied microbiology},
volume = {41},
number = {2},
pages = {113-121},
doi = {10.1016/j.syapm.2017.09.008},
pmid = {29307475},
issn = {1618-0984},
mesh = {Bacterial Typing Techniques ; DNA, Bacterial ; Genes, Bacterial ; Genetic Variation ; Genetics, Population ; Lens Plant/*microbiology ; Morocco ; *Nitrogen Fixation ; *Phylogeny ; RNA, Ribosomal, 16S ; Rhizobium/*classification/genetics ; Root Nodules, Plant/microbiology ; Sequence Analysis, DNA ; Symbiosis ; },
abstract = {Genetic diversity and population structure of 268 Lens culinaris symbiotic rhizobia collected from 40 cultivated fields in the main lentil production regions in Morocco were estimated. Three chromosomal housekeeping genes (recA, glnII and atpD) and one common symbiotic gene (nodC) were sequenced and analyzed in order to identify the local symbionts of lentil. The molecular phylogeny of the concatenated housekeeping genes clustered more than 95% of the isolates in one main clade together with Rhizobium laguerreae species. R. laguerreae represents the main symbiont of cultivated lentil in Morocco and, for the first time, a large sample of individuals is obtained for this species. There is a significant and high genetic differentiation of bacterial populations among the four regions for their symbiotic gene, and much lower for their housekeeping genes. The reasons why R. laguerreae is so frequently recovered in our study is discussed.},
}
@article {pmid30697746,
year = {2019},
author = {Gibert, A and Tozer, W and Westoby, M},
title = {Plant performance response to eight different types of symbiosis.},
journal = {The New phytologist},
volume = {},
number = {},
pages = {},
doi = {10.1111/nph.15392},
pmid = {30697746},
issn = {1469-8137},
support = {//Australian Research Council/ ; },
abstract = {Almost all plant species interact with one or more symbioses somewhere within their distribution range. Bringing together plant trait data and growth responses to symbioses spanning 552 plant species, we provide for the first time on a large scale (597 studies) a quantitative synthesis on plant performance differences between eight major types of symbiosis, including mycorrhizas, N-fixing bacteria, fungal endophytes and ant-plant interactions. Frequency distributions of plant growth responses varied considerably between different types of symbiosis, in terms of both mean effect and 'risk', defined here as percentage of experiments reporting a negative effect of symbiosis on plants. Contrary to expectation, plant traits were poor predictors of growth response across and within all eight symbiotic associations. Our analysis showed no systematic additive effect when a host plant engaged in two functionally different symbioses. This synthesis suggests that plant species' ecological strategies have little effect in determining the influence of a symbiosis on host plant growth. Reliable quantification of differences in plant performance across symbioses will prove valuable for developing general hypotheses on how species become engaged in mutualisms without a guarantee of net returns.},
}
@article {pmid30696553,
year = {2019},
author = {Lynge Pedersen, AM and Belstrøm, D},
title = {The role of natural salivary defences in maintaining a healthy oral microbiota.},
journal = {Journal of dentistry},
volume = {80 Suppl 1},
number = {},
pages = {S3-S12},
doi = {10.1016/j.jdent.2018.08.010},
pmid = {30696553},
issn = {1879-176X},
abstract = {OBJECTIVES: To provide an update on our current understanding of how saliva and its various constituents directly and indirectly affect oral bacteria and thereby play a role in the modulation and maintenance of a healthy oral microbiota and also the associations with symbiosis and dysbiosis.
METHODS: The search for biomedical literature on saliva and its antimicrobial activities (years 1966 to 2017) was conducted in PubMed, Embase and Web of Science databases.
RESULTS: This review underlines that saliva plays an essential role in shaping and maintaining the ecological equilibrium of the resident oral microbiota. Saliva contributes to the formation of the salivary pellicle, which covers the oral hard and soft tissues, and thereby determines the initial adhesion and colonisation of microorganisms. Saliva facilitates clearance of dietary carbohydrates and microorganisms from the oral cavity, but also supplies bacteria with nutrients through enzymatic breakdown of dietary starch and proteins and salivary glycoproteins. In addition, saliva comprises proteins such as mucins, which block the adherence of certain microorganisms to oral surfaces through binding and aggregating mechanisms. Saliva also provides antimicrobial activity through numerous proteins and peptides including mucins, lactoferrin, lysozyme, lactoperoxidase, statherin, histatins and secretory immunoglobulin A.
CONCLUSIONS: A balanced oral microbiome is important for the maintenance of oral health and symbiosis. Conditions associated with salivary gland hypofunction, impaired oral clearance, low salivary pH and altered salivary composition, often lead to perturbation of the function and composition of the oral microbiome causing dysbiosis, and an associated risk of oral disease.
CLINICAL SIGNIFICANCE: Saliva plays a significant role in keeping the relationship between the host and oral microbiota in a symbiotic state. In conditions with salivary gland dysfunction, the natural balance of the oral microbiome is often disturbed, leading to dysbiosis and associated risks of gingivitis, caries and fungal infection.},
}
@article {pmid30695562,
year = {2016},
author = {Sidelnikov, GD and Valikhov, AR},
title = {[On the role of endogenous retroviruses in tumor growth biology].},
journal = {Voprosy onkologii},
volume = {62},
number = {6},
pages = {758-766},
pmid = {30695562},
issn = {0507-3758},
abstract = {Retrotransposons are the mobile part of the genetic material in mammals. Such a close proximity is a unique in its kind example of the genetic symbiosis. As a result of long-term co-evolution retroviruses purchased the actual immortality and protection from adverse factors, providing instead the recombinant opportunities of its genetic apparatus for the implementation of the evolutionary, adaptive and biological processes that are vital to the host organism. The consequence of the violation of the established biological balance is the pathological activity of retrotransposons that can affect the expression of any gene. This review examines the point of view on the key role of retrotrasposons in the biology of tumor development as a result of aggressive parasitism and speculates about the causes of the violations of adequate immune response in the process of tumor growth.},
}
@article {pmid30341476,
year = {2018},
author = {Li, J and Liu, S and Guo, K and Zhang, F and Qiao, H and Chen, J and Yang, M and Zhu, X and Xu, R and Xu, C and Chen, J},
title = {Plant-mediated competition facilitates a phoretic association between a gall mite and a psyllid vector.},
journal = {Experimental & applied acarology},
volume = {76},
number = {3},
pages = {325-337},
pmid = {30341476},
issn = {1572-9702},
support = {81673699//National Natural Science Foundation of China/ ; 81470168//National Natural Science Foundation of China/ ; 2016-I2 M-3-017//Chinese Academy of Medical Science Innovation Fund for Medical Science/ ; },
mesh = {Animals ; Female ; Hemiptera/growth & development/*physiology ; Larva/growth & development/physiology ; *Lycium/growth & development ; Male ; Mites/growth & development/*physiology ; Nymph/growth & development/physiology ; Plant Tumors/parasitology ; *Symbiosis ; },
abstract = {Phoretic associations between mites and insects commonly occur in patchy and ephemeral habitats. As plants provide stable habitats for herbivores, herbivorous mites are rarely dependent on other animals for phoretic dispersal. However, a phoretic gall mite, Aceria pallida, which is found on plants, seasonally attaches to a herbivorous insect, Bactericera gobica, for overwintering survival. After detachment, the gall mite shares a habitat with its vector and is likely to compete with this vector for plant resources. However, excessive competition works against the sustainability of the seasonal phoretic association. How the gall mite, as an obligate phoretic mite, balances this relationship with its vector during the growing season to achieve phoresy is unknown. Here, the plant-mediated interspecific interaction between the gall mite and the psyllid after detachment was studied in the laboratory and field. The laboratory results showed that infestation by the gall mite had detrimental effects on the survival and development of psyllid nymphs. Meanwhile, the mite population and the gall size were also adversely affected. The results from the field showed that the mean densities of the mite galls and psyllids were lower in the mixed-species infestation treatment than in the single-species infestation treatment across the investigation period. However, the interspecific interaction between the gall mite and the psyllid decreased rather than accelerated leaf abscission caused by the psyllid, which promoted the persistence of the psyllid population and then indirectly contributed to phoretic association. Our results suggest that the plant-mediated competition between the phoretic gall mite and its vector after detachment facilitates the maintenance of the phoretic association.},
}
@article {pmid30169517,
year = {2018},
author = {Borst, ACW and Verberk, WCEP and Angelini, C and Schotanus, J and Wolters, JW and Christianen, MJA and van der Zee, EM and Derksen-Hooijberg, M and van der Heide, T},
title = {Foundation species enhance food web complexity through non-trophic facilitation.},
journal = {PloS one},
volume = {13},
number = {8},
pages = {e0199152},
pmid = {30169517},
issn = {1932-6203},
mesh = {Animals ; Behavior, Animal/*physiology ; *Biodiversity ; Dominance-Subordination ; *Ecosystem ; *Food Chain ; Founder Effect ; Predatory Behavior/*physiology ; Principal Component Analysis ; Species Specificity ; Symbiosis/*physiology ; },
abstract = {Food webs are an integral part of every ecosystem on the planet, yet understanding the mechanisms shaping these complex networks remains a major challenge. Recently, several studies suggested that non-trophic species interactions such as habitat modification and mutualisms can be important determinants of food web structure. However, it remains unclear whether these findings generalize across ecosystems, and whether non-trophic interactions affect food webs randomly, or affect specific trophic levels or functional groups. Here, we combine analyses of 58 food webs from seven terrestrial, freshwater and coastal systems to test (1) the general hypothesis that non-trophic facilitation by habitat-forming foundation species enhances food web complexity, and (2) whether these enhancements have either random or targeted effects on particular trophic levels, functional groups, and linkages throughout the food web. Our empirical results demonstrate that foundation species consistently enhance food web complexity in all seven ecosystems. Further analyses reveal that 15 out of 19 food web properties can be well-approximated by assuming that foundation species randomly facilitate species throughout the trophic network. However, basal species are less strongly, and carnivores are more strongly facilitated in foundation species' food webs than predicted based on random facilitation, resulting in a higher mean trophic level and a longer average chain length. Overall, we conclude that foundation species strongly enhance food web complexity through non-trophic facilitation of species across the entire trophic network. We therefore suggest that the structure and stability of food webs often depends critically on non-trophic facilitation by foundation species.},
}
@article {pmid30130476,
year = {2018},
author = {Czyzewska, U and Bartoszewicz, M and Siemieniuk, M and Tylicki, A},
title = {Genetic relationships and population structure of Malassezia pachydermatis strains isolated from dogs with otitis externa and healthy dogs.},
journal = {Mycologia},
volume = {110},
number = {4},
pages = {666-676},
doi = {10.1080/00275514.2018.1495981},
pmid = {30130476},
issn = {1557-2536},
mesh = {Animals ; DNA, Intergenic ; DNA, Ribosomal ; Dog Diseases/epidemiology/*microbiology ; Dogs/microbiology ; *Genetic Variation ; Genotype ; Malassezia/*genetics/isolation & purification/*pathogenicity/physiology ; Otitis Externa/epidemiology/microbiology/*veterinary ; Phylogeny ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Random Amplified Polymorphic DNA Technique ; Symbiosis ; Virulence ; },
abstract = {Malassezia pachydermatis causes infections of the skin and mucous membranes, especially in animals. It is commonly accepted that symptom manifestation depends on the physiological status of the host (different metabolic, hormonal, and immunological disorders). However, it should be considered whether distinct strains of M. pachydermatis could have different pathogenic potential and maintain opposite relations with the host, such as commensalism or parasitism. The scope of this study was to explore the population structure, genetic diversity, and phylogenetic relationships of M. pachydermatis strains isolated from dogs with clinical symptoms of otitis externa and from healthy dogs in order to investigate their relationships and evolutionary history. For all tests, a group of 30 strains derived from dogs with otitis externa and 34 strains from healthy dogs were used. The level of genetic diversity was initially assessed by polymerase chain reaction (PCR)-based random amplification of polymorphic DNA (RAPD-PCR), whereas evolutionary history was assessed by comparison of the nucleotide sequences of the internal transcribed spacer ITS1 region of nuclear rDNA. RAPD-PCR fingerprinting revealed a high level of genetic polymorphism in both tested groups (85% of unique profiles), but clinical isolates usually grouped together with other strains from otitis externa cases. Sequencing analysis identified 17 distinct genotypes with 59 polymorphic sites within both populations; however, putatively virulent strains were more closely related, indicating a probable correlation between the genotype and the virulence potential. Therefore, the hypothesis that M. pachydermatis virulence depends solely on the host's properties should be reconsidered including evolutionary and epidemiological data.},
}
@article {pmid30016354,
year = {2018},
author = {Adachi, S and Honma, T and Yasaka, R and Ohshima, K and Tokuda, M},
title = {Effects of infection by Turnip mosaic virus on the population growth of generalist and specialist aphid vectors on turnip plants.},
journal = {PloS one},
volume = {13},
number = {7},
pages = {e0200784},
pmid = {30016354},
issn = {1932-6203},
mesh = {Animals ; Aphids/*virology ; Brassica napus/*virology ; Hydrogen-Ion Concentration ; Insect Vectors/virology ; Japan ; Phylogeny ; Plant Diseases/*virology ; Population Growth ; *Potyvirus ; Raphanus ; Species Specificity ; *Symbiosis ; Viral Proteins/genetics ; },
abstract = {Recent studies have revealed that relationships between plant pathogens and their vectors differ depending on species, strains and associated host plants. Turnip mosaic virus (TuMV) is one of the most important plant viruses worldwide and is transmitted by at least 89 aphid species in a non-persistent manner. TuMV is fundamentally divided into six phylogenetic groups; among which Asian-BR, basal-BR and world-B groups are known to occur in Japan. In Kyushu Japan, basal-BR has invaded approximately 2000 and immediately replaced the predominant world-B virus group. To clarify the relationships between TuMV and vector aphids, we examined the effects of the TuMV phylogenetic group on the population growth of aphid vectors in turnip plants. The population growth of a generalist aphid, Myzus persicae, was not significantly different between non-infected and TuMV-infected treatments. The population growth of a specialist aphid, Lipaphis erysimi, was higher in TuMV-infected plants than non-infected ones. Similar results were obtained in experiments using world-B and basal-BR groups of TuMV. Therefore, we conclude that L. erysimi is more mutualistic with TuMV than M. persicae, and differences in TuMV phylogenetic groups do not affect the growth of aphid vectors on turnip plants.},
}
@article {pmid30016257,
year = {2018},
author = {Brouat, C and Diagne, CA and Ismaïl, K and Aroussi, A and Dalecky, A and Bâ, K and Kane, M and Niang, Y and Diallo, M and Sow, A and Galal, L and Piry, S and Dardé, ML and Mercier, A},
title = {Seroprevalence of Toxoplasma gondii in commensal rodents sampled across Senegal, West Africa.},
journal = {Parasite (Paris, France)},
volume = {25},
number = {},
pages = {32},
pmid = {30016257},
issn = {1776-1042},
mesh = {Africa, Western/epidemiology ; Agglutination Tests ; Animals ; Antibodies, Protozoan/*blood ; Female ; Humans ; Male ; Murinae/*parasitology ; Rodent Diseases ; Senegal/epidemiology ; *Seroepidemiologic Studies ; Symbiosis ; Toxoplasma/*immunology ; Toxoplasmosis, Animal/blood/*epidemiology/*immunology/parasitology ; },
abstract = {Risks related to Toxoplasma gondii infection in humans remain poorly known in Senegal. Although rodent surveys could help to assess the circulation of T. gondii, they have seldom been set up in sub-Saharan Africa. The aim of this study was to examine Toxoplasma seroprevalence in rodents from villages and towns across Senegal. Rodents were sampled in 40 localities using a standardised trapping protocol. Detection of T. gondii antibodies was performed on 1205 rodents, using a modified agglutination test (MAT) technique. Seroprevalence data were analysed depending on geography, the local rodent community, and individual characteristics of the rodent hosts. We found 44 seropositive rodents from four different species (Mastomys erythroleucus, Mastomys natalensis, Mus musculus domesticus, Rattus rattus). Toxoplasma seroprevalence was low, averaging 4% in the localities. Higher Toxoplasma seroprevalence (up to 24%) was found in northern Senegal, a region known to be the heart of pastoral herding in the country.},
}
@article {pmid29990378,
year = {2018},
author = {Vicente, CSL and Mondal, SI and Akter, A and Ozawa, S and Kikuchi, T and Hasegawa, K},
title = {Genome analysis of new Blattabacterium spp., obligatory endosymbionts of Periplaneta fuliginosa and P. japonica.},
journal = {PloS one},
volume = {13},
number = {7},
pages = {e0200512},
pmid = {29990378},
issn = {1932-6203},
mesh = {Ammonia/chemistry ; Animals ; Bacteroidetes/*genetics ; Blattellidae/*microbiology ; DNA, Bacterial/genetics ; *Genome, Bacterial ; Male ; Nitrogen/chemistry ; Periplaneta/*microbiology ; Phylogeny ; Symbiosis ; Urea/chemistry ; Uric Acid/chemistry ; },
abstract = {The successful adaptation of cockroaches is, in part, dependent of the activity of their obligatory endosymbionts, Blattabacterium spp., which are involved in uric acid degradation, nitrogen assimilation and nutrient provisioning. Their strategic localization, within bacteriocytes in the proximities of uric acid storage cells (urocytes), highlights their importance in the recycling of nitrogen from urea and ammonia, end-products not secreted by their host insects. In this study, we present the complete genome sequence of two new Blattabacterium spp. from Periplaneta fuliginosa (BPfu) and P. japonica (BPja), and detailed comparison with other Blattabacterium strains from different cockroach species. The genomes of BPfu and BPja show a high degree of stability as showed with for other Blattabacterium representatives, only presenting a 19-kb fragment inversion between BPja and BPfu. In fact, the phylogenomics showed BPja as an ancestor species of BPfu, BPLAN (P. americana) and BBor (Blatta orientalis), in congruence with their host cockroach phylogeny. Their functional profile is similar and closest to the omnivorous strain BBge (Blattella germanica). Interesting, BPja possesses the complete set of enzymes involved sulfate assimilatory pathway only found in BBge and BMda (Mastotermes darwiniensis). The newly sequenced genomes of BPja and BPfu emphasise the remarkable stability of Blattabacterium genomes supported by their long-term coevolution and obligatory lifestyle in their host insect.},
}
@article {pmid29950179,
year = {2018},
author = {Rami, A and Raz, A and Zakeri, S and Dinparast Djadid, N},
title = {Isolation and identification of Asaia sp. in Anopheles spp. mosquitoes collected from Iranian malaria settings: steps toward applying paratransgenic tools against malaria.},
journal = {Parasites & vectors},
volume = {11},
number = {1},
pages = {367},
pmid = {29950179},
issn = {1756-3305},
mesh = {Acetobacteraceae/cytology/genetics/*isolation & purification/*physiology ; Animals ; Anopheles/anatomy & histology/*microbiology ; Biological Control Agents ; Digestive System/microbiology ; Female ; Humans ; Iran/epidemiology ; Larva/physiology ; Malaria/*epidemiology/parasitology/prevention & control ; Male ; Microbiota ; Middle East/epidemiology ; Mosquito Control/methods ; Mosquito Vectors/*microbiology ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; },
abstract = {BACKGROUND: In recent years, the genus Asaia (Rhodospirillales: Acetobacteraceae) has been isolated from different Anopheles species and presented as a promising tool to combat malaria. This bacterium has unique features such as presence in different organs of mosquitoes (midgut, salivary glands and reproductive organs) of female and male mosquitoes and vertical and horizontal transmission. These specifications lead to the possibility of introducing Asaia as a robust candidate for malaria vector control via paratransgenesis technology. Several studies have been performed on the microbiota of Anopheles mosquitoes (Diptera: Culicidae) in Iran and the Middle East to find a suitable candidate for controlling the malaria based on paratransgenesis approaches. The present study is the first report of isolation, biochemical and molecular characterization of the genus Asaia within five different Anopheles species which originated from different zoogeographical zones in the south, east, and north of Iran.
METHODS: Mosquitoes originated from field-collected and laboratory-reared colonies of five Anopheles spp. Adult mosquitoes were anesthetized; their midguts were isolated by dissection, followed by grinding the midgut contents which were then cultured in enrichment broth media and later in CaCO3 agar plates separately. Morphological, biochemical and physiological characterization were carried out after the appearance of colonies. For molecular confirmation, selected colonies were cultured, their DNAs were extracted and PCR was performed on the 16S ribosomal RNA gene using specific newly designed primers.
RESULTS: Morphological, biochemical, physiological and molecular results indicated that all isolates are members of the genus Asaia.
CONCLUSIONS: Contrary to previous opinions, our findings show that Asaia bacteria are present in both insectary-reared colonies and field-collected mosquitoes and can be isolated by simple and specific methods. Furthermore, with respect to the fact that we isolated Asaia within the different Anopheles specimens from distinct climatic and zoogeographical regions, it is promising and may be concluded that species of this genus can tolerate the complicated environmental conditions of the vector-borne diseases endemic regions. Therefore, it can be considered as a promising target in paratransgenesis and vector control programs. However, we suggest that introducing the new technologies such as next generation sequencing and robust in silico approaches may pave the way to find a unique biomarker for rapid and reliable differentiation of the Asaia species.},
}
@article {pmid29776375,
year = {2018},
author = {Kaufman, EL and Stone, NE and Scoles, GA and Hepp, CM and Busch, JD and Wagner, DM},
title = {Range-wide genetic analysis of Dermacentor variabilis and its Francisella-like endosymbionts demonstrates phylogeographic concordance between both taxa.},
journal = {Parasites & vectors},
volume = {11},
number = {1},
pages = {306},
pmid = {29776375},
issn = {1756-3305},
support = {2010-65104-20386//National Institute of Food and Agriculture/International ; },
mesh = {Animals ; Arachnid Vectors/microbiology ; Canada ; Coxiella burnetii/genetics/pathogenicity ; DNA, Bacterial/genetics ; Dermacentor/classification/*genetics/*microbiology ; Disease Vectors ; Francisella/classification/*genetics/pathogenicity ; Genes, Mitochondrial/genetics ; Humans ; *Phylogeny ; Phylogeography ; RNA, Ribosomal, 16S/genetics ; Rickettsia/genetics/pathogenicity ; Sequence Analysis, DNA/methods ; Symbiosis/genetics ; United States ; },
abstract = {BACKGROUND: The American dog tick, Dermacentor variabilis, is an important vector of pathogens to humans, wildlife and domestic animals in North America. Although this tick species is widely distributed in the USA and Canada, knowledge of its range-wide phylogeographic patterns remains incomplete.
METHODS: We carried out a phylogenetic analysis of D. variabilis using samples collected from 26 USA states and five Canadian provinces. Tick samples (n = 1053 in total) originated from two main sources: existing archives (2000-2011), and new collections made from 2012 to 2013. We sequenced a 691 bp fragment of the cox1 gene from a subset (n = 332) of geographically diverse D. variabilis. DNA extracted from individual ticks (n = 1053) was also screened for a Francisella-like endosymbiont, using a targeted 16S rRNA sequencing approach, and important pathogens (Rickettsia spp. and Coxiella burnetii), using species-specific quantitative PCR assays.
RESULTS: Maximum parsimony analysis of cox1 sequences revealed two major groups within D. variabilis with distinct geographical distributions: one from the eastern USA/Canada (Group 1) and one from the west coast states of the USA (California and Washington; Group 2). However, genetic subdivisions within both of these two major groups were weak to moderate and not tightly correlated with geography. We found molecular signatures consistent with Francisella-like endosymbionts in 257 of the DNA extracts from the 1053 individual ticks, as well as Rickettsia spp. and Coxiella burnetii in a small number of ticks (n = 29 and 2, respectively). Phylogenetic patterns for Francisella-like endosymbionts, constructed using sequence data from the bacterial 16S rRNA locus, were similar to those for D. variabilis, with two major groups that had a nearly perfect one-to-one correlation with the two major groups within D. variabilis.
CONCLUSIONS: Our findings reveal a distinct phylogenetic split between the two major D. variabilis populations. However, high levels of genetic mixture among widely separated geographical localities occur within each of these two major groups. Furthermore, our phylogenetic analyses provide evidence of long-term tick-symbiont co-evolution. This work has implications for understanding the dispersal and evolutionary ecology of D. variabilis and associated vector-borne diseases.},
}
@article {pmid29748120,
year = {2018},
author = {Špitalská, E and Sparagano, O and Stanko, M and Schwarzová, K and Špitalský, Z and Škultéty, Ľ and Havlíková, SF},
title = {Diversity of Coxiella-like and Francisella-like endosymbionts, and Rickettsia spp., Coxiella burnetii as pathogens in the tick populations of Slovakia, Central Europe.},
journal = {Ticks and tick-borne diseases},
volume = {9},
number = {5},
pages = {1207-1211},
doi = {10.1016/j.ttbdis.2018.05.002},
pmid = {29748120},
issn = {1877-9603},
mesh = {Animals ; Arachnid Vectors/*microbiology ; Bacterial Infections/epidemiology/transmission ; Coxiella/cytology/genetics/isolation & purification/pathogenicity ; Coxiella burnetii/genetics/*isolation & purification/pathogenicity ; DNA, Bacterial/genetics ; Dermacentor/microbiology ; Female ; Francisella/classification/genetics/*isolation & purification/pathogenicity ; Ixodes/microbiology ; Ixodidae/*microbiology ; Male ; Phylogeny ; Public Health ; Rickettsia/genetics/*isolation & purification/pathogenicity ; Slovakia/epidemiology ; Symbiosis ; },
abstract = {Ticks are important vectors of pathogens affecting humans and animals worldwide. They do not only carry pathogens but diverse commensal and symbiotic microorganisms are also present in ticks. A molecular screening for tick-borne pathogens and endosymbionts was carried out in Ixodes ricinus, Dermacentor reticulatus and Haemaphysalis inermis questing ticks collected in Slovakia. The presence of Rickettsia spp., Coxiella burnetii, Coxiella-like and Francisella-like microorganisms was evaluated by PCR in 605 individuals and by randomly sequencing 66 samples. Four species of rickettsiae (R. raoultii, R. slovaca, R. helvetica and R. monacensis) were identified and reported with an overall prevalence range between 0.4 and 50.3% (±8.0) depending on tick species, sex and locality. Partial sequencing of the gltA gene of 5 chosen samples in H. inermis showed 99% identity with Candidatus Rickettsia hungarica. The total prevalence of C. burnetii in ticks was 2.2 ± 1.7%; bacteria were confirmed in I. ricinus and D. reticulatus ticks. The sequences from 2 D. reticulatus males and 1 I. ricinus female ticks were compared to GenBank submissions and a 99.8% match was obtained with the pathogenic C. burnetii. Coxiella-like endosymbionts were registered in all three species of ticks from all studied sites with an average prevalence of 32.7 ± 3.7%. A phylogenetic analysis of this Coxiella sp. showed that it does not group with the pathogenic C. burnetii. The prevalence of Francisella-like microorganisms in questing ticks was 47.9 ± 3.9%, however H. inermis (n = 108) were not infested. Obtained sequences were 98% identical with previously identified Francisella-like endosymbionts in D. reticulatus and I. ricinus. Coxiella-like and Francisella-like microorganisms were identified for the first time in Slovakia, they might be considered as a non-pathogenic endosymbiont of I. ricinus, D. reticulatus and H. inermis, and future investigations could aim to assess their role in these ticks. However, this work provided further data and broadened our knowledge on bacterial pathogens and endosymbionts present in ticks in Slovakia to help understanding co-infestations, combined treatments and public health issues linked to tick bites.},
}
@article {pmid29653599,
year = {2018},
author = {Li, LH and Zhang, Y and Zhu, D},
title = {Effects of antibiotic treatment on the fecundity of Rhipicephalus haemaphysaloides ticks.},
journal = {Parasites & vectors},
volume = {11},
number = {1},
pages = {242},
pmid = {29653599},
issn = {1756-3305},
support = {2016YFC1202001 and No.2016YFC1200500//National Key Research and Development Program of China/International ; No. GWIV-29//the fourth round of Three-Year Public Health Action Plan 2015-2017/International ; No.201202019//the Special Fund for Health Research in the Public Interest China/International ; 2017BSQD52//the Scientific Research Foundation for Doctors of Weifang Medical College/International ; },
mesh = {Animals ; Anti-Bacterial Agents/*administration & dosage/adverse effects/therapeutic use ; Coxiella/genetics ; DNA, Ribosomal/genetics ; Female ; Fertility/drug effects ; Male ; Microbial Consortia/drug effects/*genetics ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rhipicephalus/*drug effects/genetics/microbiology/*physiology ; Rickettsia/genetics ; Sequence Analysis, DNA ; Symbiosis/drug effects ; },
abstract = {BACKGROUND: Endosymbiotic bacteria inhabit a variety of arthropods including ticks and may have multiple effects on the host's survival, reproduction or pathogen acquisition and transmission. Rhipicephalus haemaphysaloides is one of the most widely distributed tick species in China. The symbiotic bacteria composition and their impacts to R. haemaphysaloides ticks have not been studied. The present study investigated the composition of microbial community in R. haemaphysaloides ticks and then assessed the effects of endosymbionts on the host's fecundity by antibiotic treatment experiments.
METHODS: The microbial population of female and male R. haemaphysaloides ticks was analyzed using Illumina Miseq sequencing of 16S rRNA gene. Thirty engorged female ticks were then randomly divided into five groups and injected with ampicillin, ciprofloxacin, kanamycin, tetracycline, or phosphate-buffered solution (PBS), respectively. Effects of antibiotic treatments on maternal oviposition, egg hatching and density of endosymbionts were evaluated.
RESULTS: Illumina Miseq sequencing showed that Coxiella and Rickettsia were the predominant bacterial genera inhabiting R. haemaphysaloides ticks. Antibiotic treatment experiments found that kanamycin reduced the density of Coxiella-like endosymbiont (Coxiella-LE hereafter) in eggs, ciprofloxacin reduced the density of Rickettsia-like endosymbiont (Rickettsia-LE), and tetracycline had effect on both endosymbionts, while ampicillin affected neither. Meanwhile hatching rates of eggs were observed to decrease greatly in the kanamycin or tetracycline-treated group but maintained in the ampicillin or ciprofloxacin-treated group. Furthermore, the reduced hatching rates were found to be associated with density of Coxiella-LE in eggs.
CONCLUSIONS: The findings indicate that Coxiella-LE is essential for the reproduction of R. haemaphysaloides ticks, and that kanamycin can be used to study the role of Coxiella-LE on ticks.},
}
@article {pmid29558974,
year = {2018},
author = {Altinli, M and Gunay, F and Alten, B and Weill, M and Sicard, M},
title = {Wolbachia diversity and cytoplasmic incompatibility patterns in Culex pipiens populations in Turkey.},
journal = {Parasites & vectors},
volume = {11},
number = {1},
pages = {198},
pmid = {29558974},
issn = {1756-3305},
support = {ANR-16-CE02-0006-01//Agence Nationale de la Recherche/International ; },
mesh = {Animals ; Culex/*microbiology ; Cytoplasm/*microbiology/pathology ; DNA, Mitochondrial/genetics ; *Disease Vectors ; *Genetic Variation ; Gram-Negative Bacterial Infections/epidemiology ; Mosquito Vectors/*microbiology ; Polymerase Chain Reaction ; Reproduction ; Symbiosis ; Turkey/epidemiology ; Wolbachia/*genetics/isolation & purification/physiology ; },
abstract = {BACKGROUND: Wolbachia are maternally transmitted bacteria that can manipulate their hosts' reproduction causing cytoplasmic incompatibility (CI). CI is a sperm-egg incompatibility resulting in embryonic death. Due to this sterilising effect on mosquitoes, Wolbachia are considered for vector control strategies. Important vectors for arboviruses, filarial nematodes and avian malaria, mosquitoes of Culex pipiens complex are suitable for Wolbachia-based vector control. They are infected with Wolbachia wPip strains belonging to five genetically distinct groups (wPip-I to V) within the Wolbachia B supergroup. CI properties of wPip strongly correlate with this genetic diversity: mosquitoes infected with wPip strains from a different wPip group are more likely to be incompatible with each other. Turkey is a critical spot for vector-borne diseases due to its unique geographical position as a natural bridge between Asia, Europe and Africa. However, general wPip diversity, distribution and CI patterns in natural Cx. pipiens (s.l.) populations in the region are unknown. In this study, we first identified wPip diversity in Turkish Cx. pipiens (s.l.) populations, by assigning them to one of the five groups within wPip (wPip-Ito V). We further investigated CI properties between different wPip strains from this region.
RESULTS: We showed a wPip fixation in Cx. pipiens (s.l.) populations in Turkey by analysing 753 samples from 59 sampling sites. Three wPip groups were detected in the region: wPip-I, wPip-II and wPip-IV. The most dominant group was wPip-II. While wPip-IV was restricted to only two locations, wPip-I and wPip-II had wider distributions. Individuals infected with wPip-II were found co-existing with individuals infected with wPip-I or wPip-IV in some sampling sites. Two mosquito isofemale lines harbouring either a wPip-I or a wPip-II strain were established from a population in northwestern Turkey. Reciprocal crosses between these lines showed that they were fully compatible with each other but bidirectionally incompatible with wPip-IV Istanbul infected line.
CONCLUSION: Our findings reveal a high diversity of wPip and CI properties in Cx. pipiens (s.l.) populations in Turkey. Knowledge on naturally occurring CI patterns caused by wPip diversity in Turkey might be useful for Cx. pipiens (s.l.) control in the region.},
}
@article {pmid29277086,
year = {2018},
author = {Hagström, E and Andersson, SG},
title = {The challenges of integrating two genomes in one cell.},
journal = {Current opinion in microbiology},
volume = {41},
number = {},
pages = {89-94},
doi = {10.1016/j.mib.2017.12.003},
pmid = {29277086},
issn = {1879-0364},
mesh = {Bacteria/*genetics/metabolism/pathogenicity ; Cell Nucleus/genetics ; *Evolution, Molecular ; *Genome ; Genome, Mitochondrial ; Humans ; Mitochondria/*genetics ; Oxygen/metabolism ; Phylogeny ; Respiration ; Symbiosis/genetics ; },
abstract = {Mutualistic bacteria and mitochondria have small genomes that harbor host-essential genes. A major question is why a distinct bacterial or mitochondrial genome is needed to encode these functions. The dual location of genes demand two sets of information processing systems, coordination of gene expression and elaborate transport systems. A simpler solution would be to harbor all genes in a single genome. Functional gene transfers to the host nuclear genome is uncommon in mutualistic bacteria and lost gene functions are rather rescued by co-symbiotic bacteria. Recent findings suggest that the mitochondrial genome is retained to avoid conflicting signals between protein targeting pathways in the cell. However, if the selective pressure for oxygenic respiration is lost, the mitochondrial genome will start to deteriorate and soon be lost.},
}
@article {pmid29183410,
year = {2018},
author = {Goedknegt, MA and Shoesmith, D and Jung, AS and Luttikhuizen, PC and van der Meer, J and Philippart, CJM and van der Veer, HW and Thieltges, DW},
title = {Trophic relationship between the invasive parasitic copepod Mytilicola orientalis and its native blue mussel (Mytilus edulis) host.},
journal = {Parasitology},
volume = {145},
number = {6},
pages = {814-821},
doi = {10.1017/S0031182017001779},
pmid = {29183410},
issn = {1469-8161},
mesh = {Animals ; Copepoda/*physiology ; Ecosystem ; Feeding Behavior ; Food Chain ; *Host-Parasite Interactions ; Isotope Labeling/methods ; Mytilus edulis/parasitology/*physiology ; *Symbiosis ; },
abstract = {Invasive parasites can spill over to new hosts in invaded ecosystems with often unpredictable trophic relationships in the newly arising parasite-host interactions. In European seas, the intestinal copepod Mytilicola orientalis was co-introduced with Pacific oysters (Magallana gigas) and spilled over to native blue mussels (Mytilus edulis), with negative impacts on the condition of infected mussels. However, whether the parasite feeds on host tissue and/or stomach contents is yet unknown. To answer this question, we performed a stable isotope analysis in which we included mussel host tissue and the primary food sources of the mussels, microphytobenthos (MPB) and particulate organic matter (POM). The copepods were slightly enriched in δ15N (mean Δ15N ± s.d.; 1·22 ± 0·58‰) and δ13C (Δ13C 0·25 ± 0·32‰) with respect to their host. Stable isotope mixing models using a range of trophic fractionation factors indicated that host tissue was the main food resource with consistent additional contributions of MPB and POM. These results suggest that the trophic relationship of the invasive copepod with its mussel host is parasitic as well as commensalistic. Stable isotope studies such as this one may be a useful tool to unravel trophic relationships in new parasite-host associations in the course of invasions.},
}
@article {pmid29112885,
year = {2018},
author = {Neville, BA and Forster, SC and Lawley, TD},
title = {Commensal Koch's postulates: establishing causation in human microbiota research.},
journal = {Current opinion in microbiology},
volume = {42},
number = {},
pages = {47-52},
doi = {10.1016/j.mib.2017.10.001},
pmid = {29112885},
issn = {1879-0364},
support = {//Wellcome Trust/United Kingdom ; },
mesh = {Gastrointestinal Microbiome/genetics/physiology ; Humans ; Metagenomics/methods ; *Microbiota ; Research ; *Symbiosis ; },
abstract = {Advances in high-throughput sequencing technologies and the development of sophisticated bioinformatics analysis methods, algorithms, and pipelines to handle the large amounts of data generated have driven the field of human microbiome research forward. This specialist knowledge has been crucial to thoroughly mine the human gut microbiota, particularly in the absence of methods for the routine cultivation of most enteric microorganisms. In recent years, however, significant efforts have been made to address the 'great plate count anomaly' and to overcome the barriers to cultivation of the fastidious and mostly strictly anaerobic bacteria that reside in the human gut. As a result, many new species have been discovered, characterised, genome sequenced, and deposited in culture collections. These continually expanding resources enable experimental investigation of the human gut microbiota, validation of hypotheses made with sequence-based analyses, and phenotypic characterisation of its constituent microbes. Herein we propose a variant of Koch's postulates, aimed at providing a framework to establish causation in microbiome studies, with a particular focus on demonstrating the health-promoting role of the commensal gut microbiota.},
}
@article {pmid29101189,
year = {2018},
author = {Chidebe, IN and Jaiswal, SK and Dakora, FD},
title = {Distribution and Phylogeny of Microsymbionts Associated with Cowpea (Vigna unguiculata) Nodulation in Three Agroecological Regions of Mozambique.},
journal = {Applied and environmental microbiology},
volume = {84},
number = {2},
pages = {},
pmid = {29101189},
issn = {1098-5336},
mesh = {Bradyrhizobium/*genetics/isolation & purification/metabolism ; DNA, Bacterial/genetics ; DNA, Ribosomal Spacer/genetics ; Gene Transfer, Horizontal ; Genetic Variation ; Geography ; Mozambique ; Nitrogen Fixation ; *Phylogeny ; Plant Root Nodulation ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; Rhizobium/*genetics/isolation & purification/metabolism ; Root Nodules, Plant/microbiology ; Symbiosis/genetics ; Vigna/*microbiology ; },
abstract = {Cowpea derives most of its N nutrition from biological nitrogen fixation (BNF) via symbiotic bacteroids in root nodules. In Sub-Saharan Africa, the diversity and biogeographic distribution of bacterial microsymbionts nodulating cowpea and other indigenous legumes are not well understood, though needed for increased legume production. The aim of this study was to describe the distribution and phylogenies of rhizobia at different agroecological regions of Mozambique using PCR of the BOX element (BOX-PCR), restriction fragment length polymorphism of the internal transcribed spacer (ITS-RFLP), and sequence analysis of ribosomal, symbiotic, and housekeeping genes. A total of 122 microsymbionts isolated from two cowpea varieties (IT-1263 and IT-18) grouped into 17 clades within the BOX-PCR dendrogram. The PCR-ITS analysis yielded 17 ITS types for the bacterial isolates, while ITS-RFLP analysis placed all test isolates in six distinct clusters (I to VI). BLASTn sequence analysis of 16S rRNA and four housekeeping genes (glnII, gyrB, recA, and rpoB) showed their alignment with Rhizobium and Bradyrhizobium species. The results revealed a group of highly diverse and adapted cowpea-nodulating microsymbionts which included Bradyrhizobium pachyrhizi, Bradyrhizobium arachidis, Bradyrhizobium yuanmingense, and a novel Bradyrhizobium sp., as well as Rhizobium tropici, Rhizobium pusense, and Neorhizobium galegae in Mozambican soils. Discordances observed in single-gene phylogenies could be attributed to horizontal gene transfer and/or subsequent recombinations of the genes. Natural deletion of 60 bp of the gyrB region was observed in isolate TUTVU7; however, this deletion effect on DNA gyrase function still needs to be confirmed. The inconsistency of nifH with core gene phylogenies suggested differences in the evolutionary history of both chromosomal and symbiotic genes.IMPORTANCE A diverse group of both Bradyrhizobium and Rhizobium species responsible for cowpea nodulation in Mozambique was found in this study. Future studies could prove useful in evaluating these bacterial isolates for symbiotic efficiency and strain competitiveness in Mozambican soils.},
}
@article {pmid28786370,
year = {2018},
author = {Zélé, F and Denoyelle, J and Duron, O and Rivero, A},
title = {Can Wolbachia modulate the fecundity costs of Plasmodium in mosquitoes?.},
journal = {Parasitology},
volume = {145},
number = {6},
pages = {775-782},
doi = {10.1017/S0031182017001330},
pmid = {28786370},
issn = {1469-8161},
mesh = {Animals ; Coinfection/microbiology/parasitology ; Culex/parasitology ; Culicidae/*microbiology/physiology ; Fertility ; *Host-Parasite Interactions ; Malaria/transmission ; Mosquito Vectors/*microbiology/physiology ; Plasmodium/pathogenicity ; Symbiosis ; Wolbachia/*pathogenicity ; },
abstract = {Vertically transmitted parasites (VTPs) such as Wolbachia are expected not only to minimize the damage they inflict on their hosts, but also to protect their hosts against the damaging effects of coinfecting parasites. By modifying the fitness costs of the infection, VTPs can therefore play an important role in the evolution and epidemiology of infectious diseases.Using a natural system, we explore the effects of a Wolbachia-Plasmodium co-infection on mosquito fecundity. While Plasmodium is known to frequently express its virulence by partially castrating its mosquito vectors, the effects of Wolbachia infections on mosquito fecundity are, in contrast, highly variable. Here, we show that Plasmodium drastically decreases the fecundity of mosquitoes by ca. 20%, and we provide the first evidence that this decrease is independent of the parasite's burden. Wolbachia, on the other hand, increases fecundity by roughly 10%, but does not alter the tolerance (fecundity-burden relationship) of mosquitoes to Plasmodium infection.Although Wolbachia-infected mosquitoes fare overall better than uninfected ones, Wolbachia does not confer a sufficiently high reproductive boost to mosquitoes to compensate for the reproductive losses inflicted by Plasmodium. We discuss the potential mechanisms and implications underlying the conflicting effects of these two parasites on mosquito reproduction.},
}
@article {pmid28534452,
year = {2018},
author = {Gauthier, J and Drezen, JM and Herniou, EA},
title = {The recurrent domestication of viruses: major evolutionary transitions in parasitic wasps.},
journal = {Parasitology},
volume = {145},
number = {6},
pages = {713-723},
doi = {10.1017/S0031182017000725},
pmid = {28534452},
issn = {1469-8161},
mesh = {Animals ; DNA, Viral/genetics ; *Domestication ; *Evolution, Molecular ; Genome, Insect ; Genomics ; *Host-Parasite Interactions ; Polydnaviridae/genetics ; Symbiosis ; Virulence ; Viruses/*genetics ; Wasps/genetics/*virology ; },
abstract = {Several lineages of endoparasitoid wasps, which develop inside the body of other insects, have domesticated viruses, used as delivery tools of essential virulence factors for the successful development of their progeny. Virus domestications are major evolutionary transitions in highly diverse parasitoid wasps. Much progress has recently been made to characterize the nature of these ancestrally captured endogenous viruses that have evolved within the wasp genomes. Virus domestication from different viral families occurred at least three times in parasitoid wasps. This evolutionary convergence led to different strategies. Polydnaviruses (PDVs) are viral gene transfer agents and virus-like particles of the wasp Venturia canescens deliver proteins. Here, we take the standpoint of parasitoid wasps to review current knowledge on virus domestications by different parasitoid lineages. Then, based on genomic data from parasitoid wasps, PDVs and exogenous viruses, we discuss the different evolutionary steps required to transform viruses into vehicles for the delivery of the virulence molecules that we observe today. Finally, we discuss how endoparasitoid wasps manipulate host physiology and ensure parasitism success, to highlight the possible advantages of viral domestication as compared with other virulence strategies.},
}
@article {pmid28496167,
year = {2017},
author = {Saravanakumar, K and Li, Y and Yu, C and Wang, QQ and Wang, M and Sun, J and Gao, JX and Chen, J},
title = {Effect of Trichoderma harzianum on maize rhizosphere microbiome and biocontrol of Fusarium Stalk rot.},
journal = {Scientific reports},
volume = {7},
number = {1},
pages = {1771},
pmid = {28496167},
issn = {2045-2322},
mesh = {Antibiosis ; Fusarium/*physiology ; Gene Expression Profiling ; Gene Expression Regulation, Enzymologic ; Gene Expression Regulation, Fungal ; Metabolome ; Metabolomics/methods ; *Microbiota ; Plant Diseases/*microbiology/*prevention & control ; Plant Roots/microbiology ; *Rhizosphere ; Symbiosis ; Trichoderma/*physiology ; Zea mays/*microbiology ; },
abstract = {Fusarium stalk rot (FSR) caused by Fusarium graminearum (FG) significantly affects the productivity of maize grain crops. Application of agrochemicals to control the disease is harmful to environment. In this regard, use of biocontrol agent (BCA) is an alternative to agrochemicals. Although Trichoderma species are known as BCA, the selection of host-pathogen specific Trichoderma is essential for the successful field application. Hence, we screened a total of 100 Trichoderma isolates against FG, selected Trichoderma harzianum (CCTCC-RW0024) for greenhouse experiments and studied its effect on changes of maize rhizosphere microbiome and biocontrol of FSR. The strain CCTCC-RW0024 displayed high antagonistic activity (96.30%), disease reduction (86.66%), biocontrol-related enzyme and gene expression. The root colonization of the strain was confirmed by eGFP tagging and qRT-PCR analysis. Pyrosequencing revealed that exogenous inoculation of the strain in maize rhizosphere increased the plant growth promoting acidobacteria (18.4%), decreased 66% of FG, and also increased the plant growth. In addition, metabolites of this strain could interact with pathogenicity related transcriptional cofactor FgSWi6, thereby contributing to its inhibition. It is concluded that T. harzianum strain CCTCC-RW0024 is a potential BCA against FSR.},
}
@article {pmid30694431,
year = {2019},
author = {Yin, J and Guan, X and Zhang, H and Wang, L and Li, H and Zhang, Q and Chen, T and Xu, Z and Hong, Z and Cao, Y and Zhang, Z},
title = {An MAP kinase interacts with LHK1 and regulates nodule organogenesis in Lotus japonicus.},
journal = {Science China. Life sciences},
volume = {},
number = {},
pages = {},
doi = {10.1007/s11427-018-9444-9},
pmid = {30694431},
issn = {1869-1889},
abstract = {Symbiosis receptor-like kinase (SymRK) is a key protein mediating the legume-Rhizobium symbiosis. Our previous work has identified an MAP kinase kinase, SIP2, as a SymRK-interacting protein to positively regulate nodule organogenesis in Lotus japonicus, suggesting that an MAPK cascade might be involved in Rhizobium-legume symbiosis. In this study, LjMPK6 was identified as a phosphorylation target of SIP2. Stable transgenic L. japonicus with RNAi silencing of LjMPK6 decreased the numbers of nodule primordia (NP) and nodule, while plants overexpressing LjMPK6 increased the numbers of nodule, infection threads (ITs), and NP, indicating that LjMPK6 plays a positive role in nodulation. LjMPK6 could interact with a cytokinin receptor, LHK1 both in vivo and in vitro. LjMPK6 was shown to compete with LHP1 to bind to the receiver domain (RD) of LHK1and to downregulate the expression of two LjACS (1-aminocyclopropane-1-carboxylic acid synthase) genes and ethylene levels during nodulation. This study demonstrated an important role of LjMPK6 in regulation of nodule organogenesis and ethylene production in L. japonicus.},
}
@article {pmid30541943,
year = {2018},
author = {Kasbekar, DP},
title = {A cross-eyed geneticist's view II. Riddles, wrapped in mysteries, inside … mealybugs.},
journal = {Journal of biosciences},
volume = {43},
number = {5},
pages = {819-822},
pmid = {30541943},
issn = {0973-7138},
mesh = {Adaptation, Physiological/genetics ; Animals ; Betaproteobacteria/*physiology ; Chromosomes, Insect/chemistry/metabolism ; Citrus/parasitology ; Eukaryotic Cells/metabolism/microbiology ; Female ; Gammaproteobacteria/*physiology ; Genotype ; *Inheritance Patterns ; Male ; *Meiosis ; Phloem/parasitology ; Planococcus Insect/*genetics/microbiology ; Ploidies ; Reproduction ; Symbiosis/*genetics ; },
}
@article {pmid30197044,
year = {2018},
author = {Lin, Z and Wang, L and Chen, M and Chen, J},
title = {The acute transcriptomic response of coral-algae interactions to pH fluctuation.},
journal = {Marine genomics},
volume = {42},
number = {},
pages = {32-40},
doi = {10.1016/j.margen.2018.08.006},
pmid = {30197044},
issn = {1876-7478},
mesh = {Animals ; Anthozoa/genetics/*physiology ; China ; Dinoflagellida/genetics/*physiology ; Hydrogen-Ion Concentration ; *Symbiosis ; *Transcriptome ; },
abstract = {Little is known about how the coral host and its endosymbiont interactions change when they are exposed to a sudden nonlinear environmental transformation, yet this is crucial to coral survival in extreme events. Here, we present a study that investigates the transcriptomic response of corals and their endosymbionts to an abrupt change in pH (pH 7.60 and 8.35). The transcriptome indicates that the endosymbiont demonstrates a synchronized downregulation in carbon acquisition and fixation processes and may result in photosynthetic dysfunction in endosymbiotic Symbiodinium, suggesting that the mutualistic continuum of coral-algae interactions is compromised in response to high-CO2 exposure. Transcriptomic data also shows that corals are still capable of calcifying in response to the low pH but could experience a series of negative effects on their energy dynamics, which including protein damage, DNA repair, ion transport, cellular apoptosis, calcification acclimation and maintenance of intracellular pH homeostasis and stress tolerance to pH swing. This suggests enhanced energy costs for coral metabolic adaptation. This study provides a deeper understanding of the biological basis related to the symbiotic corals in response to extreme future climate change and environmental variability.},
}
@article {pmid29218845,
year = {2018},
author = {Antwis, RE and Harrison, XA},
title = {Probiotic consortia are not uniformly effective against different amphibian chytrid pathogen isolates.},
journal = {Molecular ecology},
volume = {27},
number = {2},
pages = {577-589},
doi = {10.1111/mec.14456},
pmid = {29218845},
issn = {1365-294X},
mesh = {Amphibians/genetics/*microbiology ; Animals ; Chytridiomycota/*pathogenicity ; Communicable Diseases/genetics/microbiology ; Host-Pathogen Interactions/*genetics ; Humans ; Microbiota/*genetics ; Probiotics/metabolism ; Symbiosis/genetics ; },
abstract = {Symbiotic bacterial communities can protect their hosts from infection by pathogens. Treatment of wild individuals with protective bacteria (probiotics) isolated from hosts can combat the spread of emerging infectious diseases. However, it is unclear whether candidate probiotic bacteria can offer consistent protection across multiple isolates of globally distributed pathogens. Here, we use the lethal amphibian fungal pathogen Batrachochytrium dendrobatidis to investigate whether probiotic richness (number of bacteria) or genetic distance among consortia members influences broad-scale in vitro inhibitory capabilities of probiotics across multiple isolates of the pathogen. We show that inhibition of multiple pathogen isolates by individual bacteria is rare, with no systematic pattern among bacterial genera in ability to inhibit multiple B. dendrobatidis isolates. Bacterial consortia can offer stronger protection against B. dendrobatidis compared to single strains, and this tended to be more pronounced for consortia containing multiple genera compared with those consisting of bacteria from a single genus (i.e., with lower genetic distance), but critically, this effect was not uniform across all B. dendrobatidis isolates. These novel insights have important implications for the effective design of bacterial probiotics to mitigate emerging infectious diseases.},
}
@article {pmid28729739,
year = {2017},
author = {Sun, ZJ and Li, ZX},
title = {Host plants and obligate endosymbionts are not the sources for biosynthesis of the aphid alarm pheromone.},
journal = {Scientific reports},
volume = {7},
number = {1},
pages = {6041},
pmid = {28729739},
issn = {2045-2322},
mesh = {Animals ; Aphids/*metabolism ; Buchnera ; Gas Chromatography-Mass Spectrometry ; *Host-Parasite Interactions ; Pheromones/analysis/*biosynthesis ; Plant Diseases/parasitology ; Plants/*microbiology/*parasitology ; *Symbiosis ; Volatile Organic Compounds/analysis ; },
abstract = {(E)-β-farnesene (EβF) is the major component of the alarm pheromone of many aphid species, but where EβF is synthesized in aphids is only partly understood. There are at least three most possible sources for the alarm pheromone: host plants, aphid obligate endosymbiont and aphids themselves. Here we eliminated the possibility of host plants and the obligate endosymbiont Buchnera aphidicola as the sources for EβF released by aphids. We excluded the possible effects of host plants on EβF biosynthesis by rearing aphids on non-plant diets. Both the diet-reared aphids, including the cotton aphid Aphis gossypii and the green peach aphid Myzus persicae, could still release EβF based on solid-phase micro-extraction combined with gas chromatography-mass spectrometer analysis. Meanwhile, we treated host aphids with antibiotics to fully eliminate Buchnera bacteria. Though the treatment seriously affected the development and fecundity of host aphids, the treated aphids could still release EβF, and there was no significant difference in the EβF concentration as per the aphid weight under different rearing conditions. Taken together, our experimental results suggest that host plants and obligate endosymbionts are not the sources for EβF released by aphids, indicating that it is most probably the aphid itself synthesizes the alarm pheromone.},
}
@article {pmid30687830,
year = {2019},
author = {Le Quéré, A and Gully, D and Teulet, A and Navarro, E and Gargani, D and Fardoux, J and Cruveiller, S and Neyra, M and Giraud, E and Krasova Wade, T},
title = {Complete Genome Sequence of Bradyrhizobium sp. Strain ORS3257, an Efficient Nitrogen-Fixing Bacterium Isolated from Cowpea in Senegal.},
journal = {Microbiology resource announcements},
volume = {8},
number = {3},
pages = {},
doi = {10.1128/MRA.01449-18},
pmid = {30687830},
issn = {2576-098X},
abstract = {Here, we report the complete genome sequence of Bradyrhizobium sp. strain ORS3257, which forms efficient symbioses with cowpea, peanut, or groundnut. These genomic data will be useful to identify genes associated with symbiotic performance and host compatibility on several legumes, including Aeschynomene species, with which a Nod-independent type III secretion system (T3SS)-dependent symbiosis can be established.},
}
@article {pmid30687394,
year = {2018},
author = {Schwab, DB and Casasa, S and Moczek, AP},
title = {On the Reciprocally Causal and Constructive Nature of Developmental Plasticity and Robustness.},
journal = {Frontiers in genetics},
volume = {9},
number = {},
pages = {735},
doi = {10.3389/fgene.2018.00735},
pmid = {30687394},
issn = {1664-8021},
abstract = {Exposure to environmental variation is a characteristic feature of normal development, one that organisms can respond to during their lifetimes by actively adjusting or maintaining their phenotype in order to maximize fitness. Plasticity and robustness have historically been studied by evolutionary biologists through quantitative genetic and reaction norm approaches, while more recent efforts emerging from evolutionary developmental biology have begun to characterize the molecular and developmental genetic underpinnings of both plastic and robust trait formation. In this review, we explore how our growing mechanistic understanding of plasticity and robustness is beginning to force a revision of our perception of both phenomena, away from our conventional view of plasticity and robustness as opposites along a continuum and toward a framework that emphasizes their reciprocal, constructive, and integrative nature. We do so in three sections. Following an introduction, the first section looks inward and reviews the genetic, epigenetic, and developmental mechanisms that enable organisms to sense and respond to environmental conditions, maintaining and adjusting trait formation in the process. In the second section, we change perspective and look outward, exploring the ways in which organisms reciprocally shape their environments in ways that influence trait formation, and do so through the lens of behavioral plasticity, niche construction, and host-microbiota interactions. In the final section, we revisit established plasticity and robustness concepts in light of these findings, and highlight research opportunities to further advance our understanding of the causes, mechanisms, and consequences of these ubiquitous, and interrelated, phenomena.},
}
@article {pmid30644356,
year = {2019},
author = {Shaikevich, E and Bogacheva, A and Ganushkina, L},
title = {Dirofilaria and Wolbachia in mosquitoes (Diptera: Culicidae) in central European Russia and on the Black Sea coast.},
journal = {Parasite (Paris, France)},
volume = {26},
number = {},
pages = {2},
doi = {10.1051/parasite/2019002},
pmid = {30644356},
issn = {1776-1042},
mesh = {Animals ; Black Sea ; Culex/microbiology/parasitology ; Culicidae/*microbiology/*parasitology ; DNA, Helminth/isolation & purification ; Dirofilaria immitis/genetics/isolation & purification/physiology ; Dirofilaria repens/isolation & purification/physiology ; Dirofilariasis/*epidemiology/*transmission ; Dog Diseases/epidemiology ; Dogs ; Female ; Larva/microbiology/parasitology ; Mosquito Vectors/microbiology/parasitology ; Russia/epidemiology ; Symbiosis ; Wolbachia/genetics/*isolation & purification/physiology ; },
abstract = {Dirofilariasis is endemic in Russia, as well as in many other European countries. The aim of this study was to assess the ability of mosquitoes to transfer Dirofilaria immitis and Dirofilaria repens in regions with temperate and subtropical climates. The possible impact of the symbiotic bacterium Wolbachia on Dirofilaria transmission was also investigated. 5333 female mosquitoes were collected at 11 points in central European Russia and on the Black Sea coast during the period 2013-2017. Out of 20 mosquito species examined, 14 were infected with D. repens and 13 with D. immitis. Both species of Dirofilaria were found in different climatic regions. The total Dirofilaria spp. estimated infection rate (EIR) in the central part of Russia varied from 3.1% to 3.7% and, in the southern region, from 1.1% to 3.0%. The highest estimated infection rate was found in Anopheles messeae, the lowest in Culex pipiens. The greatest epidemiological danger was represented by Aedes aegypti, Ae. geniculatus, An. messeae and Ae. communis. Six out of 20 mosquito species were infected with Wolbachia. Pools of Aedes albopictus, Cx. pipiens and Coquillettidia richiardii were simultaneously infected with Dirofilaria and Wolbachia. After checking mosquitoes individually, it was found that there was no development of Dirofilaria to the infective larval stage in specimens infected with Wolbachia. Twenty-two Dirofilaria-infective pools were Wolbachia-free and only two mosquito pools were Wolbachia-infected. The potential for transmission of Dirofilaria in mosquito species naturally uninfected with the symbiotic bacterium Wolbachia is higher than in species infected with the bacterium.},
}
@article {pmid30237040,
year = {2018},
author = {Oborník, M},
title = {The Birth of Red Complex Plastids: One, Three, or Four Times?.},
journal = {Trends in parasitology},
volume = {34},
number = {11},
pages = {923-925},
doi = {10.1016/j.pt.2018.09.001},
pmid = {30237040},
issn = {1471-5007},
mesh = {Apicomplexa ; Cell Cycle ; *Plastids ; *Symbiosis ; },
}
@article {pmid29970182,
year = {2018},
author = {Starr, EP and Shi, S and Blazewicz, SJ and Probst, AJ and Herman, DJ and Firestone, MK and Banfield, JF},
title = {Stable isotope informed genome-resolved metagenomics reveals that Saccharibacteria utilize microbially-processed plant-derived carbon.},
journal = {Microbiome},
volume = {6},
number = {1},
pages = {122},
pmid = {29970182},
issn = {2049-2618},
mesh = {Avena/metabolism/*microbiology ; Bacteria/*genetics/*metabolism ; Carbon/metabolism ; Carbon Dioxide/analysis/*chemistry ; DNA, Bacterial/*biosynthesis/genetics ; Energy Metabolism/*genetics ; Genome, Bacterial/*genetics ; Isotope Labeling ; Metagenomics ; Plant Roots/microbiology ; RNA, Bacterial/*biosynthesis/genetics ; Rhizosphere ; Soil Microbiology ; Symbiosis ; },
abstract = {BACKGROUND: The transformation of plant photosynthate into soil organic carbon and its recycling to CO2 by soil microorganisms is one of the central components of the terrestrial carbon cycle. There are currently large knowledge gaps related to which soil-associated microorganisms take up plant carbon in the rhizosphere and the fate of that carbon.
RESULTS: We conducted an experiment in which common wild oats (Avena fatua) were grown in a 13CO2 atmosphere and the rhizosphere and non-rhizosphere soil was sampled for genomic analyses. Density gradient centrifugation of DNA extracted from soil samples enabled distinction of microbes that did and did not incorporate the 13C into their DNA. A 1.45-Mbp genome of a Saccharibacteria (TM7) was identified and, despite the microbial complexity of rhizosphere soil, curated to completion. The genome lacks many biosynthetic pathways, including genes required to synthesize DNA de novo. Rather, it requires externally derived nucleotides for DNA and RNA synthesis. Given this, we conclude that rhizosphere-associated Saccharibacteria recycle DNA from bacteria that live off plant exudates and/or phage that acquired 13C because they preyed upon these bacteria and/or directly from the labeled plant DNA. Isotopic labeling indicates that the population was replicating during the 6-week period of plant growth. Interestingly, the genome is ~ 30% larger than other complete Saccharibacteria genomes from non-soil environments, largely due to more genes for complex carbon utilization and amino acid metabolism. Given the ability to degrade cellulose, hemicellulose, pectin, starch, and 1,3-β-glucan, we predict that this Saccharibacteria generates energy by fermentation of soil necromass and plant root exudates to acetate and lactate. The genome also encodes a linear electron transport chain featuring a terminal oxidase, suggesting that this Saccharibacteria may respire aerobically. The genome encodes a hydrolase that could breakdown salicylic acid, a plant defense signaling molecule, and genes to interconvert a variety of isoprenoids, including the plant hormone zeatin.
CONCLUSIONS: Rhizosphere Saccharibacteria likely depend on other bacteria for basic cellular building blocks. We propose that isotopically labeled CO2 is incorporated into plant-derived carbon and then into the DNA of rhizosphere organisms capable of nucleotide synthesis, and the nucleotides are recycled into Saccharibacterial genomes.},
}
@article {pmid29484603,
year = {2018},
author = {Robledo, M and Matia-González, AM and García-Tomsig, NI and Jiménez-Zurdo, JI},
title = {Identification of Small RNA-Protein Partners in Plant Symbiotic Bacteria.},
journal = {Methods in molecular biology (Clifton, N.J.)},
volume = {1737},
number = {},
pages = {351-370},
doi = {10.1007/978-1-4939-7634-8_20},
pmid = {29484603},
issn = {1940-6029},
mesh = {Aptamers, Nucleotide/genetics/*metabolism ; Chromatography, Affinity/*methods ; Host Factor 1 Protein/genetics/*metabolism ; Mass Spectrometry ; Plants/microbiology ; RNA, Bacterial/genetics/*metabolism ; RNA, Small Untranslated/genetics/*metabolism ; Sinorhizobium meliloti/genetics/growth & development/*metabolism ; Symbiosis ; },
abstract = {The identification of the protein partners of bacterial small noncoding RNAs (sRNAs) is essential to understand the mechanistic principles and functions of riboregulation in prokaryotic cells. Here, we describe an optimized affinity chromatography protocol that enables purification of in vivo formed sRNA-protein complexes in Sinorhizobium meliloti, a genetically tractable nitrogen-fixing plant symbiotic bacterium. The procedure requires the tagging of the desired sRNA with the MS2 aptamer, which is affinity-captured by the MS2-MBP protein conjugated to an amylose resin. As proof of principle, we show recovery of the RNA chaperone Hfq associated to the strictly Hfq-dependent AbcR2 trans-sRNA. This method can be applied for the investigation of sRNA-protein interactions on a broad range of genetically tractable α-proteobacteria.},
}
@article {pmid29330647,
year = {2018},
author = {Brambilla, S and Frare, R and Soto, G and Jozefkowicz, C and Ayub, N},
title = {Absence of the Nitrous Oxide Reductase Gene Cluster in Commercial Alfalfa Inoculants Is Probably Due to the Extensive Loss of Genes During Rhizobial Domestication.},
journal = {Microbial ecology},
volume = {76},
number = {2},
pages = {299-302},
pmid = {29330647},
issn = {1432-184X},
support = {PICT-2014-3659//Fondo para la Investigación Científica y Tecnológica/ ; },
mesh = {Bacteria/*genetics/metabolism ; Denitrification/genetics ; Evolution, Molecular ; Genome Size ; Medicago sativa/*microbiology ; *Multigene Family ; Nitrates/metabolism ; Nitrites/metabolism ; Nitrogen Fixation ; Nitrous Oxide/metabolism ; Oxidoreductases/*genetics ; Rhizobium/*genetics ; Symbiosis ; },
abstract = {As other legume crops, alfalfa cultivation increases the emission of the greenhouse gas nitrous oxide (N2O). Since legume-symbiotic nitrogen-fixing bacteria play a crucial role in this emission, it is important to understand the possible impacts of rhizobial domestication on the evolution of denitrification genes. In comparison with the genomes of non-commercial strains, those of commercial alfalfa inoculants exhibit low total genome size, low number of ORFs and high numbers of both frameshifted genes and pseudogenes, suggesting a dramatic loss of genes during bacterial domestication. Genomic analysis focused on denitrification genes revealed that commercial strains have perfectly conserved the nitrate (NAP), nitrite (NIR) and nitric (NOR) reductase clusters related to the production of N2O from nitrate but completely lost the nitrous oxide (NOS) reductase cluster (nosRZDFYLX genes) associated with the reduction of N2O to gas nitrogen. Based on these results, we propose future screenings for alfalfa-nodulating isolates containing both nitrogen fixation and N2O reductase genes for environmental sustainability of alfalfa production.},
}
@article {pmid29327073,
year = {2018},
author = {Choix, FJ and López-Cisneros, CG and Méndez-Acosta, HO},
title = {Azospirillum brasilense Increases CO2 Fixation on Microalgae Scenedesmus obliquus, Chlorella vulgaris, and Chlamydomonas reinhardtii Cultured on High CO2 Concentrations.},
journal = {Microbial ecology},
volume = {76},
number = {2},
pages = {430-442},
pmid = {29327073},
issn = {1432-184X},
support = {247006//Project SENER-CONACyT/ ; 2517//Programa Catedrás CONACyT/ ; },
mesh = {Azospirillum brasilense/growth & development/*metabolism ; Biomass ; *Carbon Cycle ; Carbon Dioxide/*metabolism ; Cell Count ; Cells, Immobilized ; Chlamydomonas reinhardtii/growth & development/*metabolism ; Chlorella vulgaris/growth & development/*metabolism ; Culture Media ; Indoleacetic Acids/metabolism ; Microalgae/growth & development/*metabolism ; Microbial Interactions/physiology ; Plant Growth Regulators/metabolism ; Scenedesmus/*metabolism ; Symbiosis ; Tryptophan/metabolism ; },
abstract = {Mutualism interactions of microalgae with other microorganisms are widely used in several biotechnological processes since symbiotic interaction improves biotechnological capabilities of the microorganisms involved. The interaction of the bacterium Azospirillum brasilense was assessed with three microalgae genus, Scenedesmus, Chlorella, and Chlamydomonas, during CO2 fixation under high CO2 concentrations. The results in this study have demonstrated that A. brasilense maintained a mutualistic interaction with the three microalgae assessed, supported by the metabolic exchange of indole-3-acetic acid (IAA) and tryptophan (Trp), respectively. Besides, CO2 fixation increased, as well as growth and cell compound accumulation, mainly carbohydrates, in each microalgae evaluated, interacting with the bacterium. Overall, these results propose the mutualism interaction of A. brasilense with microalgae for improving biotechnological processes based on microalgae as CO2 capture and their bio-refinery capacity.},
}
@article {pmid29299617,
year = {2018},
author = {Deignan, LK and Pawlik, JR and Erwin, PM},
title = {Agelas Wasting Syndrome Alters Prokaryotic Symbiont Communities of the Caribbean Brown Tube Sponge, Agelas tubulata.},
journal = {Microbial ecology},
volume = {76},
number = {2},
pages = {459-466},
pmid = {29299617},
issn = {1432-184X},
support = {OCE-0095724//National Science Foundation/ ; OCE-0550468//National Science Foundation/ ; OCE-1029515//National Science Foundation/ ; OCE-1558580//National Science Foundation/ ; OCE-1558580//National Science Foundation/ ; },
mesh = {Agelas/*microbiology ; Animal Diseases/*microbiology ; Animals ; Archaea/classification/physiology ; Bacteria/classification ; Bacterial Physiological Phenomena ; Cachexia ; Caribbean Region ; Chloroflexi/physiology ; *Dysbiosis ; Florida ; Gammaproteobacteria/physiology ; Microbiota ; Phylogeny ; Porifera/microbiology ; Prokaryotic Cells/*physiology ; Proteobacteria/physiology ; Seawater/microbiology ; *Symbiosis ; Wasting Syndrome/epidemiology/*microbiology ; },
abstract = {The brown tube sponge Agelas tubulata (cf. Agelas conifera) is an abundant and long-lived sponge on Caribbean reefs. Recently, a disease-like condition, Agelas wasting syndrome (AWS), was described from A. tubulata in the Florida Keys, where prevalence of the syndrome increased from 7 to 35% of the sponge population between 2010 and 2015. In this study, we characterized the prokaryotic symbiont community of A. tubulata for the first time from individuals collected within the same monitoring plots where AWS was described. We also sampled tissue from A. tubulata exhibiting symptoms of AWS to determine its effect on the diversity and structure of prokaryotic symbiont communities. Bacteria from the phyla Chloroflexi and Proteobacteria, particularly the class Gammaproteobacteria, dominated the sponge microbiome in tissue samples of both healthy sponges and those exhibiting AWS. Prokaryotic community structure differed significantly between the diseased and healthy sponge samples, with greater variability among communities in diseased samples compared to healthy samples. These differences in prokaryotic community structure included a shift in relative abundance of the dominant, ammonia-oxidizing (Thaumarchaeota) symbionts present in diseased and healthy sponge samples. Further research is required to determine the functional consequences of this shift in microbial community structure and the causal relationship of dysbiosis and sponge disease in A. tubulata.},
}
@article {pmid29290035,
year = {2018},
author = {Angelella, G and Nalam, V and Nachappa, P and White, J and Kaplan, I},
title = {Endosymbionts Differentially Alter Exploratory Probing Behavior of a Nonpersistent Plant Virus Vector.},
journal = {Microbial ecology},
volume = {76},
number = {2},
pages = {453-458},
pmid = {29290035},
issn = {1432-184X},
support = {107483//U.S. Department of Agriculture - National Institute of Food and Agriculture (US) Predoctoral Fellowship/ ; 2014-67013-21576//U.S. Department of Agriculture - National Institute of Food and Agriculture (US)/ ; },
mesh = {Animals ; Aphids/*microbiology/physiology ; Bacteriophages ; Enterobacteriaceae/physiology/*virology ; Host-Pathogen Interactions ; Insect Vectors/physiology/*virology ; Medicago sativa/virology ; Plant Diseases/virology ; Plant Viruses/pathogenicity/*physiology ; Potyvirus/pathogenicity/physiology ; Robinia/virology ; *Symbiosis ; },
abstract = {Insect endosymbionts (hereafter, symbionts) can modify plant virus epidemiology by changing the physiology or behavior of vectors, but their role in nonpersistent virus pathosystems remains uninvestigated. Unlike propagative and circulative viruses, nonpersistent plant virus transmission occurs via transient contamination of mouthparts, making direct interaction between symbiont and virus unlikely. Nonpersistent virus transmission occurs during exploratory intracellular punctures with styletiform mouthparts when vectors assess potential host-plant quality prior to phloem feeding. Therefore, we used an electrical penetration graph (EPG) to evaluate plant probing of the cowpea aphid, Aphis craccivora Koch, an important vector of cucurbit viruses, in the presence and absence of two facultative, intracellular symbionts. We tested four isolines of A. craccivora: two isolines were from a clone from black locust (Robinia pseudoacacia L.), one infected with Arsenophonus sp. and one cured, and two derived from a clone from alfalfa (Medicago sativa L.), one infected with Hamiltonella defensa and one cured. We quantified exploratory intracellular punctures, indicated by a waveform potential drop recorded by the EPG, initiation speed and frequency within the initial 15 min on healthy and watermelon mosaic virus-infected pumpkins. Symbiont associations differentially modified exploratory intracellular puncture frequency by aphids, with H. defensa-infected aphids exhibiting depressed probing, and Arsenophonus-infected aphids an increased frequency of probing. Further, there was greater overall aphid probing on virus-infected plants, suggesting that viruses manipulate their vectors to enhance acquisition-transmission rates, independent of symbiont infection. These results suggest facultative symbionts differentially affect plant-host exploration behaviors and potentially nonpersistent virus transmission by vectors.},
}
@article {pmid29285550,
year = {2018},
author = {Kellner, K and Kardish, MR and Seal, JN and Linksvayer, TA and Mueller, UG},
title = {Symbiont-Mediated Host-Parasite Dynamics in a Fungus-Gardening Ant.},
journal = {Microbial ecology},
volume = {76},
number = {2},
pages = {530-543},
pmid = {29285550},
issn = {1432-184X},
support = {DEB-0919519//Division of Environmental Biology/ ; DEB-1354629//Division of Environmental Biology/ ; IOS-1552822//Division of Integrative Organismal Systems/ ; },
mesh = {Animal Diseases/microbiology ; Animals ; Ants/*microbiology ; *Biological Coevolution ; Disease Resistance/physiology ; Ecology ; Fungi/classification/genetics/isolation & purification/*pathogenicity ; *Gardening ; Genotype ; Host-Pathogen Interactions/*physiology ; Hypocreales/classification/genetics/isolation & purification/pathogenicity ; *Symbiosis ; },
abstract = {Group-living can promote the evolution of adaptive strategies to prevent and control disease. Fungus-gardening ants must cope with two sets of pathogens, those that afflict the ants themselves and those of their symbiotic fungal gardens. While much research has demonstrated the impact of specialized fungal pathogens that infect ant fungus gardens, most of these studies focused on the so-called higher attine ants, which are thought to coevolve diffusely with two clades of leucocoprinaceous fungi. Relatively few studies have addressed disease ecology of lower Attini, which are thought to occasionally recruit (domesticate) novel leucocoprinaceous fungi from free-living populations; coevolution between lower-attine ants and their fungi is therefore likely weaker (or even absent) than in the higher Attini, which generally have many derived modifications. Toward understanding the disease ecology of lower-attine ants, this study (a) describes the diversity in the microfungal genus Escovopsis that naturally infect fungus gardens of the lower-attine ant Mycocepurus smithii and (b) experimentally determines the relative contributions of Escovopsis strain (a possible garden disease), M. smithii ant genotype, and fungal cultivar lineage to disease susceptibility and colony fitness. In controlled in-vivo infection laboratory experiments, we demonstrate that the susceptibility to Escovopsis infection was an outcome of ant-cultivar-Escovopsis interaction, rather than solely due to ant genotype or fungal cultivar lineage. The role of complex ant-cultivar-Escovopsis interactions suggests that switching M. smithii farmers onto novel fungus types might be a strategy to generate novel ant-fungus combinations resistant to most, but perhaps not all, Escovopsis strains circulating in a local population of this and other lower-attine ants.},
}
@article {pmid29113014,
year = {2017},
author = {Glassman, SI and Wang, IJ and Bruns, TD},
title = {Environmental filtering by pH and soil nutrients drives community assembly in fungi at fine spatial scales.},
journal = {Molecular ecology},
volume = {26},
number = {24},
pages = {6960-6973},
doi = {10.1111/mec.14414},
pmid = {29113014},
issn = {1365-294X},
mesh = {California ; DNA, Fungal/genetics ; DNA, Ribosomal Spacer/genetics ; Forests ; Hydrogen-Ion Concentration ; Models, Biological ; Mycorrhizae/*classification ; Pinus/*microbiology ; Soil/*chemistry ; *Soil Microbiology ; Symbiosis ; },
abstract = {Whether niche processes, like environmental filtering, or neutral processes, like dispersal limitation, are the primary forces driving community assembly is a central question in ecology. Here, we use a natural experimental system of isolated tree "islands" to test whether environment or geography primarily structures fungal community composition at fine spatial scales. This system consists of isolated pairs of two distantly related, congeneric pine trees established at varying distances from each other and the forest edge, allowing us to disentangle the effects of geographic distance vs. host and edaphic environment on associated fungal communities. We identified fungal community composition with Illumina sequencing of ITS amplicons, measured all relevant environmental parameters for each tree-including tree age, size and soil chemistry-and calculated geographic distances from each tree to all others and to the nearest forest edge. We applied generalized dissimilarity modelling to test whether total and ectomycorrhizal fungal (EMF) communities were primarily structured by geographic or environmental filtering. Our results provide strong evidence that as in many other organisms, niche and neutral processes both contribute significantly to turnover in community composition in fungi, but environmental filtering plays the dominant role in structuring both free-living and symbiotic fungal communities at fine spatial scales. In our study system, we found pH and organic matter primarily drive environmental filtering in total soil fungal communities and that pH and cation exchange capacity-and, surprisingly, not host species-were the largest factors affecting EMF community composition. These findings support an emerging paradigm that pH may play a central role in the assembly of all soil-mediated systems.},
}
@article {pmid30605507,
year = {2017},
author = {Vera-Ponce de León, A and Ormeño-Orrillo, E and Ramírez-Puebla, ST and Rosenblueth, M and Degli Esposti, M and Martínez-Romero, J and Martínez-Romero, E},
title = {Candidatus Dactylopiibacterium carminicum, a Nitrogen-Fixing Symbiont of Dactylopius Cochineal Insects (Hemiptera: Coccoidea: Dactylopiidae).},
journal = {Genome biology and evolution},
volume = {9},
number = {9},
pages = {2237-2250},
doi = {10.1093/gbe/evx156},
pmid = {30605507},
issn = {1759-6653},
mesh = {Animals ; Female ; Genome, Bacterial ; Hemiptera/*microbiology ; *Nitrogen Fixation ; Ovary/microbiology ; Phylogeny ; Rhodocyclaceae/*classification/isolation & purification ; *Symbiosis ; },
abstract = {The domesticated carmine cochineal Dactylopius coccus (scale insect) has commercial value and has been used for more than 500 years for natural red pigment production. Besides the domesticated cochineal, other wild Dactylopius species such as Dactylopius opuntiae are found in the Americas, all feeding on nutrient poor sap from native cacti. To compensate nutritional deficiencies, many insects harbor symbiotic bacteria which provide essential amino acids or vitamins to their hosts. Here, we characterized a symbiont from the carmine cochineal insects, Candidatus Dactylopiibacterium carminicum (betaproteobacterium, Rhodocyclaceae family) and found it in D. coccus and in D. opuntiae ovaries by fluorescent in situ hybridization, suggesting maternal inheritance. Bacterial genomes recovered from metagenomic data derived from whole insects or tissues both from D. coccus and from D. opuntiae were around 3.6 Mb in size. Phylogenomics showed that dactylopiibacteria constituted a closely related clade neighbor to nitrogen fixing bacteria from soil or from various plants including rice and other grass endophytes. Metabolic capabilities were inferred from genomic analyses, showing a complete operon for nitrogen fixation, biosynthesis of amino acids and vitamins and putative traits of anaerobic or microoxic metabolism as well as genes for plant interaction. Dactylopiibacterium nif gene expression and acetylene reduction activity detecting nitrogen fixation were evidenced in D. coccus hemolymph and ovaries, in congruence with the endosymbiont fluorescent in situ hybridization location. Dactylopiibacterium symbionts may compensate for the nitrogen deficiency in the cochineal diet. In addition, this symbiont may provide essential amino acids, recycle uric acid, and increase the cochineal life span.},
}
@article {pmid30683833,
year = {2019},
author = {Wang, H and Wu, MA and Woo, YJ},
title = {Photosynthetic symbiotic therapy.},
journal = {Aging},
volume = {},
number = {},
pages = {},
doi = {10.18632/aging.101796},
pmid = {30683833},
issn = {1945-4589},
}
@article {pmid30681912,
year = {2019},
author = {Vostinar, AE and Ofria, C},
title = {Spatial Structure Can Decrease Symbiotic Cooperation.},
journal = {Artificial life},
volume = {},
number = {},
pages = {1-21},
doi = {10.1162/artl_a_00273},
pmid = {30681912},
issn = {1064-5462},
abstract = {Mutualisms occur when at least two species provide a net fitness benefit to each other. These types of interactions are ubiquitous in nature, with more being discovered regularly. Mutualisms are vital to humankind: Pollinators and soil microbes are critical in agriculture, bacterial microbiomes regulate our health, and domesticated animals provide us with food and companionship. Many hypotheses exist on how mutualisms evolve; however, they are difficult to evaluate without bias, due to the fragile and idiosyncratic systems most often investigated. Instead, we have created an artificial life simulation, Symbulation, which we use to examine mutualism evolution based on (1) the probability of vertical transmission (symbiont being passed to offspring) and (2) the spatial structure of the environment. We found that spatial structure can lead to less mutualism at intermediate vertical transmission rates. We provide evidence that this effect is due to the ability of quasi species to purge parasites, reducing the diversity of available symbionts. Our simulation is easily extended to test many additional hypotheses about the evolution of mutualism and serves as a general model to quantitatively compare how different environments affect the evolution of mutualism.},
}
@article {pmid30680683,
year = {2019},
author = {Garg, N and Kashyap, L},
title = {Joint effects of Si and mycorrhiza on the antioxidant metabolism of two pigeonpea genotypes under As (III) and (V) stress.},
journal = {Environmental science and pollution research international},
volume = {},
number = {},
pages = {},
doi = {10.1007/s11356-019-04256-5},
pmid = {30680683},
issn = {1614-7499},
support = {UGC-No.f.25-1/2013-14(BSR)/7-151/2007(BSR)//University Grants Commission (IN)/ ; DBT- BT/PR9466/AGR/21/231/2007//Department of Biotechnology , Ministry of Science and Technology (IN)/ ; },
abstract = {Arsenic (As) is the most hazardous soil contaminant, which inactivates metabolic enzymes and restrains plant growth. To withstand As stress conditions, use of some alleviative tools, such as arbuscular mycorrhizal (AM) fungi and silicon (Si), has gained importance. Therefore, the present study evaluated comparative and interactive effects of Si and arbuscular mycorrhiza-Rhizophagus irregularis on phytotoxicity of arsenate (As V) and arsenite (As III) on plant growth, ROS generation, and antioxidant defense responses in pigeonpea genotypes (Tolerant-Pusa 2002; Sensitive-Pusa 991). Roots of As III treated plants accumulated significantly higher total As than As V supplemented plants, more in Pusa 991 than Pusa 2002, which corresponded to proportionately decreased plant growth, root to biomass ratio, and oxidative burst. Although Si nutrition and AM inoculations improved plant growth by significantly reducing As uptake and the resultant oxidative burst, AM was relatively more efficient in upregulating enzymatic and non-enzymatic antioxidant defense responses as well as ascorbate-glutathione pathway when compared with Si. Pusa 2002 was more receptive to Si nourishment due to its ability to establish more efficient mycorrhizal symbiosis, which led to higher Si uptake and lower As concentrations. Moreover, +Si+AM bestowed better metalloid resistance by further reducing ROS and strengthening antioxidants. Results demonstrated that the genotype with more efficient AM symbiosis in As-contaminated soils could accrue higher benefits of Si fertilization in terms of metalloid tolerance in pigeonpea.},
}
@article {pmid30680121,
year = {2019},
author = {Helmkampf, M and Bellinger, MR and Frazier, M and Takabayashi, M},
title = {Symbiont type and environmental factors affect transcriptome-wide gene expression in the coral Montipora capitata.},
journal = {Ecology and evolution},
volume = {9},
number = {1},
pages = {378-392},
doi = {10.1002/ece3.4756},
pmid = {30680121},
issn = {2045-7758},
abstract = {Reef-building corals may harbor genetically distinct lineages of endosymbiotic dinoflagellates in the genus Symbiodinium, which have been shown to affect important colony properties, including growth rates and resilience against environmental stress. However, the molecular processes underlying these differences are not well understood. In this study, we used whole transcriptome sequencing (RNA-seq) to assess gene expression differences between 27 samples of the coral Montipora capitata predominantly hosting two different Symbiodinium types in clades C and D. The samples were further characterized by their origin from two field sites on Hawai'i Island with contrasting environmental conditions. We found that transcriptome-wide gene expression profiles clearly separated by field site first, and symbiont clade second. With 273 differentially expressed genes (DEGs, 1.3% of all host transcripts), symbiont clade had a measurable effect on host gene expression, but the effect of field site proved almost an order of magnitude higher (1,957 DEGs, 9.6%). According to SNP analysis, we found moderate evidence for host genetic differentiation between field sites (FST = 0.046) and among corals harboring alternative symbiont clades (FST = 0.036), suggesting that site-related gene expression differences are likely due to a combination of local adaptation and acclimatization to environmental factors. The correlation between host gene expression and symbiont clade may be due to several factors, including host genotype or microhabitat selecting for alternative clades, host physiology responding to different symbionts, or direct modulation of host gene expression by Symbiodinium. However, the magnitude of these effects at the level of transcription was unexpectedly small considering the contribution of symbiont type to holobiont phenotype.},
}
@article {pmid30679075,
year = {2019},
author = {Moraïs, S and Mizrahi, I},
title = {The Road Not Taken: The Rumen Microbiome, Functional Groups, and Community States.},
journal = {Trends in microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.tim.2018.12.011},
pmid = {30679075},
issn = {1878-4380},
abstract = {The rumen ecosystem represents a classic example of host-microbiome symbiosis. In this obligatory relationship, the host feeds on plant fibers that can only be degraded through a set of complex metabolic cascades, exclusively encoded in rumen-associated microbes. These various metabolic pathways are distributed across a multitude of microbial populations. Application of basic ecological principles to this ecosystem can contribute to profound understanding of the rules that shape it. Here, we discuss recent studies by examining the mapping between host attributes, rumen ecosystem composition, and functionality to propose simple, yet powerful concepts to guide the interpretation of microbiome data and enable a better understanding of how the system responds to perturbations.},
}
@article {pmid30678653,
year = {2019},
author = {Lin, HF and Xiong, J and Zhou, HM and Chen, CM and Lin, FZ and Xu, XM and Oelmüller, R and Xu, WF and Yeh, KW},
title = {Growth promotion and disease resistance induced in Anthurium colonized by the beneficial root endophyte Piriformospora indica.},
journal = {BMC plant biology},
volume = {19},
number = {1},
pages = {40},
doi = {10.1186/s12870-019-1649-6},
pmid = {30678653},
issn = {1471-2229},
support = {31761130073 and 31422047//National Natural Science Foundation of China/ ; KXGH17005//Ministry of Science and Technology, Taiwan/ ; },
abstract = {BACKGROUND: Anthurium andraeanum, an important ornamental flower, has to go through a growth-delaying period after transfer from tissue culture to soil, which requires time and extra costs. Furthermore, during this period, the plantlets are highly susceptible to bacterial infections, which results in impaired development and severe losses. Here, we aimed to address whether application of the endophytic fungus, Piriformospora indica protects the A. andraeanum root system during the critical propagation period, and whether P. indica reduce the mortality rate by stimulating the host's resistance against diseases.
RESULTS: We demonstrate that P. indica shortens the recovery period of Anthurium, promotes growth and confers disease resistance. The beneficial effect of P. indica results in faster elongation of Anthurium roots early in the interaction. P. indica-colonized plants absorb more phosphorus and exhibit higher photosynthesis rates than uncolonized control plants. Moreover, higher activities of stress-related enzymes, of jasmonic acid levels and mRNA levels of jasmonic acid-responsive genes suggest that the fungus prepares the plant to respond more efficiently to potentially upcoming threats, including bacterial wilt.
CONCLUSION: These results suggest that P. indica is a helpful symbiont for promoting Anthurium rooting and development. All our evidences are sufficient to support the disease resistance conferred by P. indica through the plant-fungal symbiosis. Furthermore, it implicates that P. indica has strong potential as bio-fertilizer for utilization in ornamental plant cultivation.},
}
@article {pmid30356280,
year = {2018},
author = {Winter, DJ and Ganley, ARD and Young, CA and Liachko, I and Schardl, CL and Dupont, PY and Berry, D and Ram, A and Scott, B and Cox, MP},
title = {Repeat elements organise 3D genome structure and mediate transcription in the filamentous fungus Epichloë festucae.},
journal = {PLoS genetics},
volume = {14},
number = {10},
pages = {e1007467},
pmid = {30356280},
issn = {1553-7404},
mesh = {AT Rich Sequence/genetics ; DNA, Fungal/chemistry/*genetics ; Epichloe/*genetics ; Fungal Proteins/genetics ; GC Rich Sequence/genetics ; Gene Expression Profiling/methods ; *Gene Expression Regulation, Fungal ; Genome, Fungal/*genetics ; Hyphae/genetics ; Repetitive Sequences, Nucleic Acid/*genetics ; Sequence Analysis, DNA/methods ; Symbiosis/genetics ; },
abstract = {Structural features of genomes, including the three-dimensional arrangement of DNA in the nucleus, are increasingly seen as key contributors to the regulation of gene expression. However, studies on how genome structure and nuclear organisation influence transcription have so far been limited to a handful of model species. This narrow focus limits our ability to draw general conclusions about the ways in which three-dimensional structures are encoded, and to integrate information from three-dimensional data to address a broader gamut of biological questions. Here, we generate a complete and gapless genome sequence for the filamentous fungus, Epichloë festucae. We use Hi-C data to examine the three-dimensional organisation of the genome, and RNA-seq data to investigate how Epichloë genome structure contributes to the suite of transcriptional changes needed to maintain symbiotic relationships with the grass host. Our results reveal a genome in which very repeat-rich blocks of DNA with discrete boundaries are interspersed by gene-rich sequences that are almost repeat-free. In contrast to other species reported to date, the three-dimensional structure of the genome is anchored by these repeat blocks, which act to isolate transcription in neighbouring gene-rich regions. Genes that are differentially expressed in planta are enriched near the boundaries of these repeat-rich blocks, suggesting that their three-dimensional orientation partly encodes and regulates the symbiotic relationship formed by this organism.},
}
@article {pmid30676313,
year = {2019},
author = {Cambronero-Heinrichs, JC and Matarrita-Carranza, B and Murillo-Cruz, C and Araya-Valverde, E and Chavarría, M and Pinto-Tomás, AA},
title = {Phylogenetic analyses of antibiotic-producing Streptomyces sp. isolates obtained from the stingless-bee Tetragonisca angustula (Apidae: Meliponini).},
journal = {Microbiology (Reading, England)},
volume = {},
number = {},
pages = {},
doi = {10.1099/mic.0.000754},
pmid = {30676313},
issn = {1465-2080},
abstract = {Many insects have been associated with actinobacteria in protective symbiosis where antimicrobial metabolites inhibit host pathogens. However, the microbiota of neotropical insects such as the stingless-bee Tetragonica angustula is poorly explored. T. angustula is a meliponid bee widely distributed in Latin America, its honey is traditionally exploited because of its ethno-pharmacological properties and its antimicrobial activity has been demonstrated. Also, the well-structured nest of this species allows exploration of the microbiota of its different components. Even though Streptomyces spp. have been cultured from stingless-bees, little is known about their role in this insect-microbe relationship. In this study, we examined the association between culturable actinobacteria and T. angustula, and evaluated the isolates' potential as antimicrobial producers. We isolated 51 actinobacteria from adult bees and different substrates of the hive of T. angustula (pollen and honey storage, garbage pellets and cerumen). We then performed a 16S rRNA phylogenetic analysis that clusters the bacteria to previously described lineages of host-associated Streptomyces. In addition, all the isolates were classified according to their antibacterial activity against human pathogens, measured by a growth inhibition test based on diffusion in agar. More than 50 % of our isolates exhibit antimicrobial activity, mainly to Gram-positive bacteria and fungi and only two against Gram-negative bacteria. Additionally, we obtained electron micrographs of adult bees with what appears to be patches of hyphae with Streptomyces-like cell morphology on their body surface. Our results suggest that T. angustula possibly uptakes and transfers actinobacteria from the environment, acting as vectors for these potentially beneficial organisms. This research provides new insights regarding the microbiota associated with T. angustula and justify future studies exploring the full diversity of the microbial community associated with the hive and the possible exchange of microbes with the crops they pollinate.},
}
@article {pmid30106668,
year = {2018},
author = {Wang, Y and Mao, L and Sun, Y and Wang, Z and Zhang, J and Zhang, J and Peng, Y and Xia, L},
title = {A Novel Francisella-Like Endosymbiont in Haemaphysalis longicornis and Hyalomma asiaticum, China.},
journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)},
volume = {18},
number = {12},
pages = {669-676},
doi = {10.1089/vbz.2017.2252},
pmid = {30106668},
issn = {1557-7759},
mesh = {Animal Distribution ; Animals ; China ; Francisella/*genetics/*isolation & purification ; Ixodidae/*microbiology ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; },
abstract = {Francisella tularensis causes a highly infectious zoonotic disease tularemia. Both Haemaphysalis longicornis and Hyalomma asiaticum are widely distributed in China, but the presence of Francisella and Francisella-like endosymbionts (FLEs) in the two tick species is poorly understood. Therefore, a total of 627 H. longicornis (471 adults and 156 nymphs) and 88 Hy. asiaticum ticks (adults) were collected, of which 88 were from Bole of Xinjiang, 236 from Liaoyang, and 176 from Shenyang of Liaoning, and 215 from Wuhan of Hubei. Notably, five H. longicornis pools from Liaoyang of Liaoning province might have harbored F. tularensis, showing a minimum prevalence of 2.12% (5/236). This study should alert the health department and veterinarians working within the region to prevent and control the emergence of tularemia. After the screening of 16S rRNA and tul4 genes, the results revealed that FLEs were detected in Hy. asiaticum ticks in Bole and in H. longicornis ticks in Liaoyang and Shenyang. Their infection rate was 100% (88/88), 3.39% (8/236 is a minimum), and 8.52% (15/176), respectively. Phylogenetic analyses indicated that the sequence named bole in Hy. Asiaticum from Bole, the sequence named liaoyang1 in H. longicornis from Liaoyang, and the sequence named shanyang1 in H. longicornis from Shenyang shared consistent 16S rRNA sequence, and the difference between Chinese FLEs and the known FLEs was obvious. These findings suggest that this FLE species might be a potentially novel FLE circulating in H. longicornis and Hy. asiaticum from China.},
}
@article {pmid28620748,
year = {2018},
author = {Guidolin, AS and Cônsoli, FL},
title = {Diversity of the Most Commonly Reported Facultative Symbionts in Two Closely-Related Aphids with Different Host Ranges.},
journal = {Neotropical entomology},
volume = {47},
number = {4},
pages = {440-446},
pmid = {28620748},
issn = {1678-8052},
support = {2011/50877-0//Fundação de Amparo à Pesquisa do Estado de São Paulo/ ; 2012/04287-0//Fundação de Amparo à Pesquisa do Estado de São Paulo/ ; 490474/2011-0//Conselho Nacional de Desenvolvimento Científico e Tecnológico/ ; },
mesh = {Animals ; Aphids/*microbiology ; Buchnera/isolation & purification ; DNA, Bacterial/genetics ; Plants ; Rickettsia/isolation & purification ; Species Specificity ; Spiroplasma/isolation & purification ; *Symbiosis ; },
abstract = {Richness and abundance of facultative symbionts vary strongly with aphid species and genotype, symbiont strain, host plant, biogeography, and a number of abiotic factors. Despite indications that aphids in the same ecological niche show similar levels of facultative symbiont richness, existing reports do not consider the potential role of host plants on aphid microbial community. Little is known about how oligophagy and polyphagy may be influenced by secondary symbiont distribution, mainly because studies on secondary symbiont diversity are biased towards polyphagous aphids from the Northern Hemisphere. Here, we demonstrate the richness and abundance of the most common aphid-associated facultative symbionts in two tropical aphid species, the oligophagous Aphis (Toxoptera) citricidus (Kirkaldy) (Hemiptera: Aphididae) and the polyphagous Aphis aurantii (Boyer de Fonscolombe) (Hemiptera: Aphididae). Aphis citricidus is restricted to Citrus sp. host plants and closely related genera, whereas A. aurantii successfully exploits a wide variety of host plants from different families. Both were collected in the same ecological niche and our data basically indicated the same richness of secondary symbionts, but the abundance at which secondary symbionts occurred was very distinct between the two species. Spiroplasma was the most abundant facultative symbiont associated with A. citricidus and A. aurantii in the ecological niche studied. Single and multiple secondary symbiont infections were observed, but diversity of multiple infections was particularly high in A. citricidus. We discuss our findings and suggest hypotheses to explain causes and consequences of the differences in secondary symbiont diversity observed between these two aphid species.},
}
@article {pmid30671951,
year = {2019},
author = {Clark, TJ and Friel, CA and Grman, E and Friesen, ML and Shachar-Hill, Y},
title = {Unfair trade underground revealed by integrating data with Nash bargaining models.},
journal = {The New phytologist},
volume = {},
number = {},
pages = {},
doi = {10.1111/nph.15703},
pmid = {30671951},
issn = {1469-8137},
abstract = {Mutually beneficial resource exchange is foundational to global biogeochemical cycles and plant and animal nutrition. However, there is inherent potential conflict in mutualisms, as each organism benefits more when the exchange ratio ('price') minimizes its own costs and maximizes its benefits. Understanding the bargaining power that each partner has in these interactions is key to our ability to predict the exchange ratio and thus the functionality of the cell, organism, community, and ecosystem. We tested whether partners have symmetric ('fair') or asymmetric ('unfair') bargaining power in a legume-rhizobia nitrogen fixing symbiosis using measurements of carbon and nitrogen dynamics in a mathematical modeling framework derived from economic theory. A model of symmetric bargaining power was not consistent with our data. Instead, our data indicate that the growth benefit to the plant (Medicago truncatula) has greater weight in determining trade dynamics than the benefit to the bacteria. Quantitative estimates of the relative power of the plant reveal that the plant's influence rises as soil nitrogen availability decreases and trade benefits to both partners increase. Our finding that M. truncatula legumes have more bargaining power than the rhizobial partner at lower nitrogen availabilities highlights the importance of context-dependence for the evolution of mutualism with increasing nutrient deposition. This article is protected by copyright. All rights reserved.},
}
@article {pmid30671290,
year = {2019},
author = {Vesala, R and Harjuntausta, A and Hakkarainen, A and Rönnholm, P and Pellikka, P and Rikkinen, J},
title = {Termite mound architecture regulates nest temperature and correlates with species identities of symbiotic fungi.},
journal = {PeerJ},
volume = {6},
number = {},
pages = {e6237},
doi = {10.7717/peerj.6237},
pmid = {30671290},
issn = {2167-8359},
abstract = {Background: Large and complex mounds built by termites of the genus Macrotermes characterize many dry African landscapes, including the savannas, bushlands, and dry forests of the Tsavo Ecosystem in southern Kenya. The termites live in obligate symbiosis with filamentous fungi of the genus Termitomyces. The insects collect dead plant material from their environment and deposit it into their nests where indigestible cell wall compounds are effectively decomposed by the fungus. Above-ground mounds are built to enhance nest ventilation and to maintain nest interior microclimates favorable for fungal growth.
Objectives: In Tsavo Ecosystem two Macrotermes species associate with three different Termitomyces symbionts, always with a monoculture of one fungal species within each termite nest. As mound architecture differs considerably both between and within termite species we explored potential relationships between nest thermoregulatory strategies and species identity of fungal symbionts.
Methods: External dimensions were measured from 164 Macrotermes mounds and the cultivated Termitomyces species were identified by sequencing internal transcribed spacer (ITS) region of ribosomal DNA. We also recorded the annual temperature regimes of several termite mounds to determine relations between mound architecture and nest temperatures during different seasons.
Results: Mound architecture had a major effect on nest temperatures. Relatively cool temperatures were always recorded from large mounds with open ventilation systems, while the internal temperatures of mounds with closed ventilation systems and small mounds with open ventilation systems were consistently higher. The distribution of the three fungal symbionts in different mounds was not random, with one fungal species confined to "hot nests."
Conclusions: Our results indicate that different Termitomyces species have different temperature requirements, and that one of the cultivated species is relatively intolerant of low temperatures. The dominant Macrotermes species in our study area can clearly modify its mound architecture to meet the thermal requirements of several different symbionts. However, a treacherous balance seems to exist between symbiont identity and mound architecture, as the maintenance of the thermophilic fungal species obviously requires reduced mound architecture that, in turn, leads to inadequate gas exchange. Hence, our study concludes that while the limited ventilation capacity of small mounds sets strict limits to insect colony growth, in this case, improving nest ventilation would invariable lead to excessively low nest temperatures, with negative consequences to the symbiotic fungus.},
}
@article {pmid30671068,
year = {2018},
author = {Gauthier-Coles, C and White, RG and Mathesius, U},
title = {Nodulating Legumes Are Distinguished by a Sensitivity to Cytokinin in the Root Cortex Leading to Pseudonodule Development.},
journal = {Frontiers in plant science},
volume = {9},
number = {},
pages = {1901},
doi = {10.3389/fpls.2018.01901},
pmid = {30671068},
issn = {1664-462X},
abstract = {Root nodule symbiosis (RNS) is a feature confined to a single clade of plants, the Fabids. Among Fabids capable of RNS, legumes form root cortex-based nodules in symbioses with rhizobia, while actinorhizal species form lateral root-based nodules with actinomycetes. Cytokinin has previously been shown to be sufficient for "pseudonodule" initiation in model legumes. Here, we tested whether this response correlates with the ability to nodulate across a range of plant species. We analyzed the formation of pseudonodules in 17 nodulating and non-nodulating legume species, and 11 non-legumes, including nodulating actinorhizal species, using light and fluorescence microscopy. Cytokinin-induced pseudonodules arising from cortical cell divisions occurred in all nodulating legume species, but not in any of the other species, including non-nodulating legumes. Pseudonodule formation was dependent on the CRE1 cytokinin receptor in Medicago truncatula. Inhibition of root growth by cytokinin occurred across plant groups, indicating that pseudonodule development is the result of a specific cortical cytokinin response unique to nodulating legumes. Lack of a cortical cytokinin response from the Arabidopsis thaliana cytokinin reporter TCSn::GFP supported this hypothesis. Our results suggest that the ability to form cortical cell-derived nodules was gained in nodulating legumes, and likely lost in non-nodulating legumes, due to a specific root cortical response to cytokinin.},
}
@article {pmid30670646,
year = {2019},
author = {Aihara, Y and Maruyama, S and Baird, AH and Iguchi, A and Takahashi, S and Minagawa, J},
title = {Green fluorescence from cnidarian hosts attracts symbiotic algae.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {},
number = {},
pages = {},
doi = {10.1073/pnas.1812257116},
pmid = {30670646},
issn = {1091-6490},
abstract = {Reef-building corals thrive in nutrient-poor marine environments because of an obligate symbiosis with photosynthetic dinoflagellates of the genus Symbiodinium Symbiosis is established in most corals through the uptake of Symbiodinium from the environment. Corals are sessile for most of their life history, whereas free-living Symbiodinium are motile; hence, a mechanism to attract Symbiodinium would greatly increase the probability of encounter between host and symbiont. Here, we examined whether corals can attract free-living motile Symbiodinium by their green fluorescence, emitted by the excitation of endogenous GFP by purple-blue light. We found that Symbiodinium have positive and negative phototaxis toward weak green and strong purple-blue light, respectively. Under light conditions that cause corals to emit green fluorescence, (e.g., strong blue light), Symbiodinium were attracted toward live coral fragments. Symbiodinium were also attracted toward an artificial green fluorescence dye with similar excitation and emission spectra to coral-GFP. In the field, more Symbiodinium were found in traps painted with a green fluorescence dye than in controls. Our results revealed a biological signaling mechanism between the coral host and its potential symbionts.},
}
@article {pmid30670545,
year = {2019},
author = {Ogden, AJ and McAleer, JM and Kahn, ML},
title = {Characterization of the Sinorhizobium meliloti HslUV and ClpXP protease systems in free-living and symbiotic states.},
journal = {Journal of bacteriology},
volume = {},
number = {},
pages = {},
doi = {10.1128/JB.00498-18},
pmid = {30670545},
issn = {1098-5530},
abstract = {Symbiotic nitrogen fixation (SNF) in the interaction between the soil bacteria Sinorhizobium meliloti and legume plant Medicago sativa is carried out in specialized root organs called nodules. During nodule development, each symbiont must drastically alter their proteins, transcripts and metabolites in order to support nitrogen fixation. Moreover, bacteria within the nodules are under stress, including challenges by plant antimicrobial peptides, low pH, limited oxygen availability, and strongly reducing conditions, all of which challenge proteome integrity. S. meliloti stress adaptation, proteome remodeling and quality control are controlled in part by the large oligomeric protease complexes HslUV and ClpXP1. To improve understanding of the roles of S. meliloti HslUV and ClpXP1 in free-living conditions and in symbiosis with M. sativa, we generated ΔhslU, ΔhslV, ΔhslUV, and ΔclpP1 knockout mutants. Shoot dry weight of M. sativa plants inoculated with each deletion mutant was significantly reduced, suggesting a role in symbiosis. Further, slower free-living growth of ΔhslUV and ΔclpP1 suggest HslUV and ClpP1 were involved in adapting to heat stress, while ΔhslU and ΔclpP1 mutants were sensitive to kanamycin. All deletion mutants produced less exopolysaccharide and succinoglycan, as shown by replicate spot plating and Calcofluor binding. We also generated endogenous C-terminal eGFP fusions to HslU, HslV, ClpX and ClpP1 in S. meliloti Using anti-eGFP antibodies, native coimmunoprecipitation experiments of proteins from free-living and nodule tissues were performed and analyzed by mass spectrometry. The results suggest HslUV and ClpXP were closely associated with ribosomal and proteome quality control proteins, and identified several novel putative protein-protein interactions.Importance Symbiotic nitrogen fixation (SNF) is the primary means by which biologically available nitrogen enters the biosphere, and is therefore a critical component of the global nitrogen cycle and modern agriculture. SNF is the result of highly coordinated interactions between legume plants and soil bacteria collectively referred to as rhizobia, e.g. Medicago sativa and S. meliloti, respectively. Accomplishing SNF requires significant proteome changes in both organisms to create a microaerobic environment suitable for high-level bacterial nitrogenase activity. Bacterial protease systems, HslUV and ClpXP are important in proteome quality control, metabolic remodeling, and in adapting to stress. This work shows that S. meliloti HslUV and ClpXP are involved in SNF, in exopolysaccharide production, and in free-living stress adaptation.},
}
@article {pmid30669397,
year = {2019},
author = {Chialva, M and Fangel, JU and Novero, M and Zouari, I and di Fossalunga, AS and Willats, WGT and Bonfante, P and Balestrini, R},
title = {Understanding Changes in Tomato Cell Walls in Roots and Fruits: The Contribution of Arbuscular Mycorrhizal Colonization.},
journal = {International journal of molecular sciences},
volume = {20},
number = {2},
pages = {},
doi = {10.3390/ijms20020415},
pmid = {30669397},
issn = {1422-0067},
abstract = {Modifications in cell wall composition, which can be accompanied by changes in its structure, were already reported during plant interactions with other organisms, such as the mycorrhizal fungi. Arbuscular mycorrhizal (AM) fungi are among the most widespread soil organisms that colonize the roots of land plants, where they facilitate mineral nutrient uptake from the soil in exchange for plant-assimilated carbon. In AM symbiosis, the host plasma membrane invaginates and proliferates around all the developing intracellular fungal structures, and cell wall material is laid down between this membrane and the fungal cell surface. In addition, to improve host nutrition and tolerance/resistance to environmental stresses, AM symbiosis was shown to modulate fruit features. In this study, Comprehensive Microarray Polymer Profiling (CoMMP) technique was used to verify the impact of the AM symbiosis on the tomato cell wall composition both at local (root) and systemic level (fruit). Multivariate data analyses were performed on the obtained datasets looking for the effects of fertilization, inoculation with AM fungi, and the fruit ripening stage. Results allowed for the discernment of cell wall component modifications that were correlated with mycorrhizal colonization, showing a different tomato response to AM colonization and high fertilization, both at the root and the systemic level.},
}
@article {pmid30404910,
year = {2018},
author = {Medeiros, LP and Garcia, G and Thompson, JN and Guimarães, PR},
title = {The geographic mosaic of coevolution in mutualistic networks.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {115},
number = {47},
pages = {12017-12022},
pmid = {30404910},
issn = {1091-6490},
mesh = {Adaptation, Physiological ; Biological Coevolution/*genetics ; Biological Evolution ; Ecosystem ; Gene Flow/genetics ; Geography ; Models, Genetic ; Pollination ; Symbiosis ; },
abstract = {Ecological interactions shape adaptations through coevolution not only between pairs of species but also through entire multispecies assemblages. Local coevolution can then be further altered through spatial processes that have been formally partitioned in the geographic mosaic theory of coevolution. A major current challenge is to understand the spatial patterns of coadaptation that emerge across ecosystems through the interplay between gene flow and selection in networks of interacting species. Here, we combine a coevolutionary model, network theory, and empirical information on species interactions to investigate how gene flow and geographical variation in selection affect trait patterns in mutualistic networks. We show that gene flow has the surprising effect of favoring trait matching, especially among generalist species in species-rich networks typical of pollination and seed dispersal interactions. Using an analytical approximation of our model, we demonstrate that gene flow promotes trait matching by making the adaptive landscapes of different species more similar to each other. We use this result to show that the progressive loss of gene flow associated with habitat fragmentation may undermine coadaptation in mutualisms. Our results therefore provide predictions of how spatial processes shape the evolution of species-rich interactions and how the widespread fragmentation of natural landscapes may modify the coevolutionary process.},
}
@article {pmid30373839,
year = {2018},
author = {Mehta, AP and Supekova, L and Chen, JH and Pestonjamasp, K and Webster, P and Ko, Y and Henderson, SC and McDermott, G and Supek, F and Schultz, PG},
title = {Engineering yeast endosymbionts as a step toward the evolution of mitochondria.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {115},
number = {46},
pages = {11796-11801},
pmid = {30373839},
issn = {1091-6490},
support = {P41 GM103445/GM/NIGMS NIH HHS/United States ; },
mesh = {Adenosine Triphosphate/metabolism ; Amino Acid Sequence ; Bioengineering/*methods ; Biological Evolution ; Escherichia coli/genetics/metabolism ; Mitochondria/*genetics/metabolism ; Models, Biological ; Saccharomyces cerevisiae/genetics/metabolism ; Symbiosis/*genetics ; Thiamine/metabolism ; },
abstract = {It has been hypothesized that mitochondria evolved from a bacterial ancestor that initially became established in an archaeal host cell as an endosymbiont. Here we model this first stage of mitochondrial evolution by engineering endosymbiosis between Escherichia coli and Saccharomyces cerevisiae An ADP/ATP translocase-expressing E. coli provided ATP to a respiration-deficient cox2 yeast mutant and enabled growth of a yeast-E. coli chimera on a nonfermentable carbon source. In a reciprocal fashion, yeast provided thiamin to an endosymbiotic E. coli thiamin auxotroph. Expression of several SNARE-like proteins in E. coli was also required, likely to block lysosomal degradation of intracellular bacteria. This chimeric system was stable for more than 40 doublings, and GFP-expressing E. coli endosymbionts could be observed in the yeast by fluorescence microscopy and X-ray tomography. This readily manipulated system should allow experimental delineation of host-endosymbiont adaptations that occurred during evolution of the current, highly reduced mitochondrial genome.},
}
@article {pmid30348787,
year = {2018},
author = {Harcombe, WR and Chacón, JM and Adamowicz, EM and Chubiz, LM and Marx, CJ},
title = {Evolution of bidirectional costly mutualism from byproduct consumption.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {115},
number = {47},
pages = {12000-12004},
pmid = {30348787},
issn = {1091-6490},
mesh = {Biological Evolution ; Carbon ; Escherichia coli/genetics/metabolism ; Evolution, Molecular ; Galactose/biosynthesis/metabolism ; Methionine/biosynthesis/genetics ; Microbial Interactions/*physiology ; Salmonella enterica/genetics/metabolism ; Symbiosis/*physiology ; },
abstract = {Mutualisms are essential for life, yet it is unclear how they arise. A two-stage process has been proposed for the evolution of mutualisms that involve exchanges of two costly resources. First, costly provisioning by one species may be selected for if that species gains a benefit from costless byproducts generated by a second species, and cooperators get disproportionate access to byproducts. Selection could then drive the second species to provide costly resources in return. Previously, a synthetic consortium evolved the first stage of this scenario: Salmonella enterica evolved costly production of methionine in exchange for costless carbon byproducts generated by an auxotrophic Escherichia coli Growth on agar plates localized the benefits of cooperation around methionine-secreting S. enterica Here, we report that further evolution of these partners on plates led to hypercooperative E. coli that secrete the sugar galactose. Sugar secretion arose repeatedly across replicate communities and is costly to E. coli producers, but enhances the growth of S. enterica The tradeoff between individual costs and group benefits led to maintenance of both cooperative and efficient E. coli genotypes in this spatially structured environment. This study provides an experimental example of de novo, bidirectional costly mutualism evolving from byproduct consumption. The results validate the plausibility of costly cooperation emerging from initially costless exchange, a scenario widely used to explain the origin of the mutualistic species interactions that are central to life on Earth.},
}
@article {pmid29935729,
year = {2018},
author = {Kiran, GS and Sekar, S and Ramasamy, P and Thinesh, T and Hassan, S and Lipton, AN and Ninawe, AS and Selvin, J},
title = {Marine sponge microbial association: Towards disclosing unique symbiotic interactions.},
journal = {Marine environmental research},
volume = {140},
number = {},
pages = {169-179},
doi = {10.1016/j.marenvres.2018.04.017},
pmid = {29935729},
issn = {1879-0291},
mesh = {Animals ; Bacteria/genetics ; Biodiversity ; *Microbiota ; Phylogeny ; Porifera/microbiology/*physiology ; RNA, Ribosomal, 16S ; Seawater/microbiology ; *Symbiosis ; },
abstract = {Sponges are sessile benthic filter-feeding animals, which harbor numerous microorganisms. The enormous diversity and abundance of sponge associated bacteria envisages sponges as hot spots of microbial diversity and dynamics. Many theories were proposed on the ecological implications and mechanism of sponge-microbial association, among these, the biosynthesis of sponge derived bioactive molecules by the symbiotic bacteria is now well-indicated. This phenomenon however, is not exhibited by all marine sponges. Based on the available reports, it has been well established that the sponge associated microbial assemblages keep on changing continuously in response to environmental pressure and/or acquisition of microbes from surrounding seawater or associated macroorganisms. In this review, we have discussed nutritional association of sponges with its symbionts, interaction of sponges with other eukaryotic organisms, dynamics of sponge microbiome and sponge-specific microbial symbionts, sponge-coral association etc.},
}
@article {pmid28717232,
year = {2017},
author = {Tian, Z and Wang, R and Ambrose, KV and Clarke, BB and Belanger, FC},
title = {The Epichloë festucae antifungal protein has activity against the plant pathogen Sclerotinia homoeocarpa, the causal agent of dollar spot disease.},
journal = {Scientific reports},
volume = {7},
number = {1},
pages = {5643},
pmid = {28717232},
issn = {2045-2322},
mesh = {Ascomycota/*drug effects/pathogenicity ; Disease Resistance ; Epichloe/metabolism/*physiology ; Fungal Proteins/genetics/metabolism/*pharmacology ; Plant Diseases/microbiology ; Poaceae/microbiology ; Symbiosis ; },
abstract = {Epichloë spp. are naturally occurring fungal endophytic symbionts of many cool-season grasses. Infection by the fungal endophytes often confers biotic and abiotic stress tolerance to their hosts. Endophyte-mediated disease resistance is well-established in the fine fescue grass Festuca rubra subsp. rubra (strong creeping red fescue) infected with E. festucae. Resistance to fungal pathogens is not an established effect of endophyte infection of other grass species, and may therefore be unique to the fine fescues. The underlying mechanism of the disease resistance is unknown. E. festucae produces a secreted antifungal protein that is highly expressed in the infected plant tissues and may therefore be involved in the disease resistance. Most Epichloë spp. do not have a gene for a similar antifungal protein. Here we report the characterization of the E. festucae antifungal protein, designated Efe-AfpA. The antifungal protein partially purified from the apoplastic proteins of endophyte-infected plant tissue and the recombinant protein expressed in the yeast Pichia pastoris was found to have activity against the important plant pathogen Sclerotinia homoeocarpa. Efe-AfpA may therefore be a component of the disease resistance seen in endophyte-infected strong creeping red fescue.},
}
@article {pmid28717170,
year = {2017},
author = {Ruibal, MP and Triponez, Y and Smith, LM and Peakall, R and Linde, CC},
title = {Population structure of an orchid mycorrhizal fungus with genus-wide specificity.},
journal = {Scientific reports},
volume = {7},
number = {1},
pages = {5613},
pmid = {28717170},
issn = {2045-2322},
mesh = {Agaricales/*classification/genetics/growth & development ; DNA, Fungal/genetics ; Evolution, Molecular ; Genotyping Techniques ; Inbreeding ; *Microsatellite Repeats ; Mycorrhizae/*classification/genetics/growth & development ; Orchidaceae/*microbiology ; Phylogeny ; Plant Roots/microbiology ; Sequence Analysis, DNA ; Species Specificity ; Symbiosis ; },
abstract = {Fundamental life history processes of mycorrhizal fungi with inconspicuous fruiting bodies can be difficult to elucidate. In this study we investigated the species identities and life history of the orchid mycorrhizal Tulasnella fungi, which associate with the south eastern Australia orchid genus Chiloglottis. Tulasnella prima was the primary partner and was found to be associated with all 17 Chiloglottis species across a range of >1000 km, and to occur in the two edaphic conditions investigated (soil and sphagnum hammocks). Another Tulasnella species (T. sphagneti) appears to be restricted to moist conditions of alpine sphagnum hammocks. The population genetic structure of the widespread species T. prima, was investigated at 10 simple sequence repeat (SSR) markers and at four cross-amplified SSR loci for T. sphagneti. For both taxa, no sharing of multilocus genotypes was found between sites, but clones were found within sites. Evidence for inbreeding within T. prima was found at 3 of 5 sites. Significant genetic differentiation was found within and between taxa. Significant local positive spatial genetic autocorrelation was detected among non-clonal isolates at the scale of two metres. Overall, the population genetic patterns indicated that in Tulasnella mating occurs by inbreeding and dispersal is typically restricted to short-distances.},
}
@article {pmid28717159,
year = {2017},
author = {Ruiz, L and Bottacini, F and Boinett, CJ and Cain, AK and O'Connell-Motherway, M and Lawley, TD and van Sinderen, D},
title = {The essential genomic landscape of the commensal Bifidobacterium breve UCC2003.},
journal = {Scientific reports},
volume = {7},
number = {1},
pages = {5648},
pmid = {28717159},
issn = {2045-2322},
support = {WT098051//Wellcome Trust/United Kingdom ; G1100100/1//Medical Research Council/United Kingdom ; },
mesh = {Bacterial Proteins/*genetics ; Bifidobacterium breve/genetics/*growth & development ; DNA Transposable Elements ; Evolution, Molecular ; Genes, Essential ; Genome, Plant ; Molecular Sequence Annotation ; *Mutagenesis, Insertional ; Phylogeny ; Sequence Homology, Nucleic Acid ; Symbiosis ; },
abstract = {Bifidobacteria are common gut commensals with purported health-promoting effects. This has encouraged scientific research into bifidobacteria, though recalcitrance to genetic manipulation and scarcity of molecular tools has hampered our knowledge on the precise molecular determinants of their health-promoting attributes and gut adaptation. To overcome this problem and facilitate functional genomic analyses in bifidobacteria, we created a large Tn5 transposon mutant library of the commensal Bifidobacterium breve UCC2003 that was further characterized by means of a Transposon Directed Insertion Sequencing (TraDIS) approach. Statistical analysis of transposon insertion distribution revealed a set of 453 genes that are essential for or markedly contribute to growth of this strain under laboratory conditions. These essential genes encode functions involved in the so-called bifid-shunt, most enzymes related to nucleotide biosynthesis and a range of housekeeping functions. Comparison to the Bifidobacterium and B. breve core genomes highlights a high degree of conservation of essential genes at the species and genus level, while comparison to essential gene datasets from other gut bacteria identified essential genes that appear specific to bifidobacteria. This work establishes a useful molecular tool for scientific discovery of bifidobacteria and identifies targets for further studies aimed at characterizing essential functions not previously examined in bifidobacteria.},
}
@article {pmid30668787,
year = {2019},
author = {Chebbi, MA and Becking, T and Moumen, B and Giraud, I and Gilbert, C and Peccoud, J and Cordaux, R},
title = {The genome of Armadillidium vulgare (Crustacea, Isopoda) provides insights into sex chromosome evolution in the context of cytoplasmic sex determination.},
journal = {Molecular biology and evolution},
volume = {},
number = {},
pages = {},
doi = {10.1093/molbev/msz010},
pmid = {30668787},
issn = {1537-1719},
abstract = {The terrestrial isopod Armadillidium vulgare is an original model to study the evolution of sex determination and symbiosis in animals. Its sex can be determined by ZW sex chromosomes, or by feminizing Wolbachia bacterial endosymbionts. Here we report the sequence and analysis of the ZW female genome of A. vulgare. A distinguishing feature of the 1.72 gigabase assembly is the abundance of repeats (68% of genome). We show that the Z and W sex chromosomes are essentially undifferentiated at the molecular level and the W-specific region is extremely small (at most several hundreds of kilobases). Our results suggest that recombination suppression has not spread very far from the sex-determining locus, if at all. This is consistent with A. vulgare possessing evolutionarily young sex chromosomes. We characterized multiple Wolbachia nuclear inserts in the A. vulgare genome, none of which is associated with the W-specific region. We also identified several candidate genes that may be involved in the sex determination or sexual differentiation pathways. The A. vulgare genome serves as a resource for studying the biology and evolution of crustaceans, one of the most speciose and emblematic metazoan groups.},
}
@article {pmid30668688,
year = {2019},
author = {Fernández-Brime, S and Muggia, L and Maier, S and Grube, M and Wedin, M},
title = {Bacterial communities in an optional lichen symbiosis are determined by substrate, not algal photobionts.},
journal = {FEMS microbiology ecology},
volume = {},
number = {},
pages = {},
doi = {10.1093/femsec/fiz012},
pmid = {30668688},
issn = {1574-6941},
abstract = {Borderline lichens are simple mutualistic symbioses between fungi and algae, where the fungi form loose mycelia interweaving algal cells, instead of forming a lichen thallus. Schizoxylon albescens shows two nutritional modes: it can either live as a borderline lichen on Populus tremula bark or as a saprotroph on Populus wood. This enables us to investigate the microbiota diversity in simple fungal-algal associations and to study the impact of lichenization on the structure of bacterial communities. We sampled three areas in Sweden covering the distribution of Schizoxylon, and using high-throughput sequencing of the 16S rRNA gene and fluorescence in situ hybridization we characterized the associated microbiota. Bacterial communities in lichenized and saprotrophic Schizoxylon were clearly distinct, but when comparing the microbiota with the respective substrates, only the fruiting bodies show clear differences in composition and abundance from the communities in the substrates. The colonisation by either lichenized or saprotrophic mycelia of Schizoxylon did not significantly influence the microbiota in the substrate. This suggests that in a morphologically simple form of lichenization, as represented by the Schizoxylon-Coccomyxa system, algal-fungal interactions do not significantly influence bacterial communities, but a more complex structure of the lichen thallus is likely required for hosting specific microbiota.},
}
@article {pmid30666424,
year = {2019},
author = {Xie, S and Lan, Y and Sun, C and Shao, Y},
title = {Insect microbial symbionts as a novel source for biotechnology.},
journal = {World journal of microbiology & biotechnology},
volume = {35},
number = {2},
pages = {25},
doi = {10.1007/s11274-019-2599-8},
pmid = {30666424},
issn = {1573-0972},
support = {31601906//National Natural Science Foundation of China/ ; 2017QNA6024//The Fundamental Research Funds for the Central Universities/ ; CARS-18-ZJ0302//The Modern Agricultural Industry Technology System/ ; 2018C37060//Zhejiang province analysis and testing science and technology project/ ; },
abstract = {Insecta is the most diverse and largest class of animals on Earth, appearing together with the emergence of the first terrestrial ecosystem. Owing to this great diversity and long-term coexistence, an amazing variety of symbiotic microorganisms have adapted specifically to insects as hosts. Insect symbionts not only participate in many relationships with the hosts but also represent a novel resource for biotechnological applications. The exploitation of mutualistic symbiosis represents a promising area to search for bioactive compounds and new enzymes for potential clinical, industrial or environmental applications. Moreover, the manipulation of parasitic symbiosis has particular potential to solve practical problems for the control of agricultural pests and disease vectors. Although the study of microbial symbionts has been impaired by the unculturability of most symbionts, the rapidly growing catalogue of microbial genomes and the application of modern genetic techniques provide an alternative approach to using these microbes. This minireview presents examples of microbial symbionts isolated from insects for emerging biotechnological use and illuminates new ways for discovering microorganisms of applied value from a particularly promising source.},
}
@article {pmid30476897,
year = {2019},
author = {Qin, D and Shen, W and Wang, J and Han, M and Chai, F and Duan, X and Yan, X and Guo, J and Gao, T and Zuo, S and Dong, J},
title = {Enhanced production of unusual triterpenoids from Kadsura angustifolia fermented by a symbiont endophytic fungus, Penicillium sp. SWUKD4.1850.},
journal = {Phytochemistry},
volume = {158},
number = {},
pages = {56-66},
doi = {10.1016/j.phytochem.2018.11.005},
pmid = {30476897},
issn = {1873-3700},
mesh = {Antineoplastic Agents, Phytogenic/chemistry/pharmacology ; Drug Screening Assays, Antitumor ; Endophytes/physiology ; Fermentation ; Hep G2 Cells ; Humans ; Kadsura/chemistry/*metabolism/*microbiology ; Magnetic Resonance Spectroscopy ; Molecular Structure ; Penicillium/*physiology ; Spectrometry, Mass, Electrospray Ionization ; Symbiosis ; Triterpenes/*chemistry/*metabolism/pharmacology ; },
abstract = {Highly oxygenated schitriterpenoids are interesting for study of their structures, bioactivities and synthesis. From Kadsura angustifolia fermented by an associated symbiotic endophytic fungus, Penicillium sp. SWUKD4.1850, nine undescribed triterpenoids, kadhenrischinins A-H, and 7β-schinalactone C together with four known triterpenoids, henrischinins A and B, schinalactone C and nigranoic acid were isolated and established by the extensive 1D-, 2D-NMR, HR-ESI-MS and ECD data analysis. Except nigranoic acid, all these metabolites have been first detected in non-fermented K. angustifolia. Structurally, kadhenrischinins A-D belong to the relatively rare class of highly oxyg