# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 8697 | 0 | 1.0000 | Deciphering the Root Endosphere Microbiome of the Desert Plant Alhagi sparsifolia for Drought Resistance-Promoting Bacteria. Drought is among the most destructive abiotic stresses limiting crop growth and yield worldwide. Although most research has focused on the contribution of plant-associated microbial communities to plant growth and disease suppression, far less is known about the microbes involved in drought resistance among desert plants. In the present study, we applied 16S rRNA gene amplicon sequencing to determine the structure of rhizosphere and root endosphere microbiomes of Alhagi sparsifolia Compared to those of the rhizosphere, endosphere microbiomes had lower diversity but contained several taxa with higher relative abundance; many of these taxa were also present in the roots of other desert plants. We isolated a Pseudomonas strain (LTGT-11-2Z) that was prevalent in root endosphere microbiomes of A. sparsifolia and promoted drought resistance during incubation with wheat. Complete genome sequencing of LTGT-11-2Z revealed 1-aminocyclopropane-1-carboxylate deaminases, siderophore, spermidine, and colanic acid biosynthetic genes, as well as type VI secretion system (T6SS) genes, which are likely involved in biofilm formation and plant-microbe interactions. Together, these results indicate that drought-enduring plants harbor bacterial endophytes favorable to plant drought resistance, and they suggest that novel endophytic bacterial taxa and gene resources may be discovered among these desert plants.IMPORTANCE Understanding microbe-mediated plant resistance to drought is important for sustainable agriculture. We performed 16S rRNA gene amplicon sequencing and culture-dependent functional analyses of Alhagi sparsifolia rhizosphere and root endosphere microbiomes and identified key endophytic bacterial taxa and their genes facilitating drought resistance in wheat. This study improves our understanding of plant drought resistance and provides new avenues for drought resistance improvement in crop plants under field conditions. | 2020 | 32220847 |
| 8662 | 1 | 0.9994 | Relationships between Phyllosphere Bacterial Communities and Leaf Functional Traits in a Temperate Forest. As a vital component of biodiversity, phyllosphere bacteria in forest canopy play a critical role in maintaining plant health and influencing the global biogeochemical cycle. There is limited research on the community structure of phyllosphere bacteria in natural forests, which creates a gap in our understanding of whether and/or how phyllosphere bacteria are connected to leaf traits of their host. In this study, we investigated the bacterial diversity and composition of the canopy leaves of six dominant tree species in deciduous broad-leaved forests in northeastern China, using high-throughput sequencing. We then compare the differences in phyllosphere bacterial community structure and functional genes of dominant tree species. Fourteen key leaf functional traits of their host trees were also measured according to standard protocols to investigate the relationships between bacterial community composition and leaf functional traits. Our result suggested that tree species with closer evolutionary distances had similar phyllosphere microbial alpha diversity. The dominant phyla of phyllosphere bacteria were Proteobacteria, Actinobacteria, and Firmicutes. For these six tree species, the functional genes of phyllosphere bacteria were mainly involved in amino acid metabolism and carbohydrate metabolism processes. The redundancy and envfit analysis results showed that the functional traits relating to plant nutrient acquisition and resistance to diseases and pests (such as leaf area, isotope carbon content, and copper content) were the main factors influencing the community structure of phyllosphere bacteria. This study highlights the key role of plant interspecific genetic relationships and plant attributes in shaping phyllosphere bacterial diversity. | 2023 | 38005751 |
| 7522 | 2 | 0.9993 | Plants select antibiotic resistome in rhizosphere in early stage. Knowledge of the dissemination and emergence of antibiotic resistance genes (ARGs) in the plant rhizosphere is essential for evaluating the risk of the modern ARGs in soil planetary health. However, little is known about the selection mechanism in the plant rhizosphere. Here, we firstly analyzed the dynamic changes in the rhizosphere antibiotic resistome during the process of three passage enrichment of the rhizosphere microbiome in Arabidopsis thaliana (Col-0) and found evidence that plants directionally enriched levels of beneficial functional bacteria with many ARGs. Using the metagenome, we next evaluated the enrichment potential of the resistome in four common crops (barley, indica rice, japonica rice, and wheat) and found that the wheat rhizosphere harbored more abundant ARGs. Therefore, we finally cultivated the rhizosphere microbiome of wheat for three generations and found that approximately 60 % of ARGs were associated with beneficial bacteria enriched in the wheat rhizosphere, which might enter the soil food web and threaten human health, despite also performing beneficial functions in the plant rhizosphere. Our study provides new insights into the dissemination of ARGs in the plant rhizosphere, and the obtained data may be useful for sustainable and ecologically safe agricultural development. | 2023 | 36461576 |
| 8699 | 3 | 0.9993 | Hordeum vulgare differentiates its response to beneficial bacteria. BACKGROUND: In nature, beneficial bacteria triggering induced systemic resistance (ISR) may protect plants from potential diseases, reducing yield losses caused by diverse pathogens. However, little is known about how the host plant initially responds to different beneficial bacteria. To reveal the impact of different bacteria on barley (Hordeum vulgare), bacterial colonization patterns, gene expression, and composition of seed endophytes were explored. RESULTS: This study used the soil-borne Ensifer meliloti, as well as Pantoea sp. and Pseudomonas sp. isolated from barley seeds, individually. The results demonstrated that those bacteria persisted in the rhizosphere but with different colonization patterns. Although root-leaf translocation was not observed, all three bacteria induced systemic resistance (ISR) against foliar fungal pathogens. Transcriptome analysis revealed that ion- and stress-related genes were regulated in plants that first encountered bacteria. Iron homeostasis and heat stress responses were involved in the response to E. meliloti and Pantoea sp., even if the iron content was not altered. Heat shock protein-encoding genes responded to inoculation with Pantoea sp. and Pseudomonas sp. Furthermore, bacterial inoculation affected the composition of seed endophytes. Investigation of the following generation indicated that the enhanced resistance was not heritable. CONCLUSIONS: Here, using barley as a model, we highlighted different responses to three different beneficial bacteria as well as the influence of soil-borne Ensifer meliloti on the seed microbiome. In total, these results can help to understand the interaction between ISR-triggering bacteria and a crop plant, which is essential for the application of biological agents in sustainable agriculture. | 2023 | 37789272 |
| 8700 | 4 | 0.9993 | Beneficial Endophytic Bacteria-Serendipita indica Interaction for Crop Enhancement and Resistance to Phytopathogens. Serendipita (=Piriformospora) indica is a fungal endophytic symbiont with the capabilities to enhance plant growth and confer resistance to different stresses. However, the application of this fungus in the field has led to inconsistent results, perhaps due to antagonism with other microbes. Here, we studied the impact of individual bacterial isolates from the endophytic bacterial community on the in vitro growth of S. indica. We further analyzed how combinations of bacteria and S. indica influence plant growth and protection against the phytopathogens Fusarium oxysporum and Rhizoctonia solani. Bacterial strains of the genera Bacillus, Enterobacter and Burkholderia negatively affected S. indica growth on plates, whereas Mycolicibacterium, Rhizobium, Paenibacillus strains and several other bacteria from different taxa stimulated fungal growth. To further explore the potential of bacteria positively interacting with S. indica, four of the most promising strains belonging to the genus Mycolicibacterium were selected for further experiments. Some dual inoculations of S. indica and Mycolicibacterium strains boosted the beneficial effects triggered by S. indica, further enhancing the growth of tomato plants, and alleviating the symptoms caused by the phytopathogens F. oxysporum and R. solani. However, some combinations of S. indica and bacteria were less effective than individual inoculations. By analyzing the genomes of the Mycolicibacterium strains, we revealed that these bacteria encode several genes predicted to be involved in the stimulation of S. indica growth, plant development and tolerance to abiotic and biotic stresses. Particularly, a high number of genes related to vitamin and nitrogen metabolism were detected. Taking into consideration multiple interactions on and inside plants, we showed in this study that some bacterial strains may induce beneficial effects on S. indica and could have an outstanding influence on the plant-fungus symbiosis. | 2019 | 31921065 |
| 8698 | 5 | 0.9993 | Metagenomics of Virus Diversities in Solid-State Brewing Process of Traditional Chinese Vinegar. Traditional Chinese vinegar offers an exceptional flavor and rich nutrients due to its unique solid-state fermentation process, which is a multiple microbial fermentation system including various bacteria, fungi and viruses. However, few studies on the virus diversities in traditional Chinese vinegar have been reported. In this paper, using Zhenjiang aromatic vinegar as a model system, we systemically explored the viral communities in the solid-state brewing process of traditional Chinese vinegar using bacterial and viral metagenomes. Results showed that the viral diversity in vinegar Pei was extensive and the virus communities varied along with the fermentation process. In addition, there existed some interactions between viral and bacterial communities. Moreover, abundant antibiotic resistance genes were found in viromes, indicating that viruses might protect fermentation bacteria strains from the stress of antibiotics in the fermentation environment. Remarkably, we identified abundant auxiliary carbohydrate metabolic genes (including alcohol oxidases, the key enzymes for acetic acid synthesis) from viromes, implying that viruses might participate in the acetic acid synthesis progress of the host through auxiliary metabolic genes. Taken together, our results indicated the potential roles of viruses in the vinegar brewing process and provided a new perspective for studying the fermentation mechanisms of traditional Chinese vinegar. | 2022 | 37431044 |
| 8770 | 6 | 0.9993 | Phyllosphere symbiont promotes plant growth through ACC deaminase production. Plant growth promoting bacteria can confer resistance to various types of stress and increase agricultural yields. The mechanisms they employ are diverse. One of the most important genes associated with the increase in plant biomass and stress resistance is acdS, which encodes a 1-aminocyclopropane-1-carboxylate- or ACC-deaminase. The non-proteinogenic amino acid ACC is the precursor and means of long-distance transport of ethylene, a plant hormone associated with growth arrest. Expression of acdS reduces stress induced ethylene levels and the enzyme is abundant in rhizosphere colonizers. Whether ACC hydrolysis plays a role in the phyllosphere, both as assembly cue and in growth promotion, remains unclear. Here we show that Paraburkholderia dioscoreae Msb3, a yam phyllosphere symbiont, colonizes the tomato phyllosphere and promotes plant growth by action of its ACC deaminase. We found that acdS is required for improved plant growth but not for efficient leaf colonization. Strain Msb3 readily proliferates on the leaf surface of tomato, only occasionally spreading to the leaf endosphere through stomata. The strain can also colonize the soil or medium around the roots but only spreads into the root if the plant is wounded. Our results indicate that the degradation of ACC is not just an important trait of plant growth promoting rhizobacteria but also one of leaf dwelling phyllosphere bacteria. Manipulation of the leaf microbiota by means of spray inoculation may be more easily achieved than that of the soil. Therefore, the application of ACC deaminase containing bacteria to the phyllosphere may be a promising strategy to increasing plant stress resistance, pathogen control, and harvest yields. | 2023 | 37264153 |
| 6730 | 7 | 0.9992 | The ecological role of bacterial seed endophytes associated with wild cabbage in the United Kingdom. Endophytic bacteria are known for their ability in promoting plant growth and defense against biotic and abiotic stress. However, very little is known about the microbial endophytes living in the spermosphere. Here, we isolated bacteria from the seeds of five different populations of wild cabbage (Brassica oleracea L) that grow within 15 km of each other along the Dorset coast in the UK. The seeds of each plant population contained a unique microbiome. Sequencing of the 16S rRNA genes revealed that these bacteria belong to three different phyla (Actinobacteria, Firmicutes, and Proteobacteria). Isolated endophytic bacteria were grown in monocultures or mixtures and the effects of bacterial volatile organic compounds (VOCs) on the growth and development on B. oleracea and on resistance against a insect herbivore was evaluated. Our results reveal that the VOCs emitted by the endophytic bacteria had a profound effect on plant development but only a minor effect on resistance against an herbivore of B. oleracea. Plants exposed to bacterial VOCs showed faster seed germination and seedling development. Furthermore, seed endophytic bacteria exhibited activity via volatiles against the plant pathogen F. culmorum. Hence, our results illustrate the ecological importance of the bacterial seed microbiome for host plant health and development. | 2020 | 31721471 |
| 8646 | 8 | 0.9992 | A Degeneration Gradient of Poplar Trees Contributes to the Taxonomic, Functional, and Resistome Diversity of Bacterial Communities in Rhizosphere Soils. Bacterial communities associated with roots influence the health and nutrition of the host plant. However, the microbiome discrepancy are not well understood under different healthy conditions. Here, we tested the hypothesis that rhizosphere soil microbial diversity and function varies along a degeneration gradient of poplar, with a focus on plant growth promoting bacteria (PGPB) and antibiotic resistance genes. Comprehensive metagenomic analysis including taxonomic investigation, functional detection, and ARG (antibiotics resistance genes) annotation revealed that available potassium (AK) was correlated with microbial diversity and function. We proposed several microbes, Bradyrhizobium, Sphingomonas, Mesorhizobium, Nocardioides, Variovorax, Gemmatimonadetes, Rhizobacter, Pedosphaera, Candidatus Solibacter, Acidobacterium, and Phenylobacterium, as candidates to reflect the soil fertility and the plant health. The highest abundance of multidrug resistance genes and the four mainly microbial resistance mechanisms (antibiotic efflux, antibiotic target protection, antibiotic target alteration, and antibiotic target replacement) in healthy poplar rhizosphere, corroborated the relationship between soil fertility and microbial activity. This result suggested that healthy rhizosphere soil harbored microbes with a higher capacity and had more complex microbial interaction network to promote plant growing and reduce intracellular levels of antibiotics. Our findings suggested a correlation between the plant degeneration gradient and bacterial communities, and provided insight into the role of high-turnover microbial communities as well as potential PGPB as real-time indicators of forestry soil quality, and demonstrated the inner interaction contributed by the bacterial communities. | 2021 | 33810508 |
| 7521 | 9 | 0.9991 | Rhizosphere suppression hinders antibiotic resistance gene (ARG) spread under bacterial invasion. The rhizosphere is an extremely important component of the "one health" scenario by linking the soil microbiome and plants, in which the potential enrichment of antibiotic resistance genes (ARGs) might ultimately flow into the human food chain. Despite the increased occurrence of soil-borne diseases, which can lead to increased use of pesticides and antibiotic-producing biocontrol agents, the understanding of the dynamics of ARG spread in the rhizosphere is largely overlooked. Here, tomato seedlings grown in soils conducive and suppressive to the pathogen Ralstonia solanacearum were selected as a model to investigate ARG spread in the rhizosphere with and without pathogen invasion. Metagenomics data revealed that R. solanacearum invasion increased the density of ARGs and mobile genetic elements (MGEs). Although we found ARGs originating from human pathogenic bacteria in both soils, the enrichment was alleviated in the suppressive soil. In summary, the suppressive soil hindered ARG spread through pathogen suppression and had a lower number of taxa carrying antibiotic resistance. | 2023 | 36683960 |
| 9001 | 10 | 0.9991 | Bacterial Methionine Metabolism Genes Influence Drosophila melanogaster Starvation Resistance. Animal-associated microorganisms (microbiota) dramatically influence the nutritional and physiological traits of their hosts. To expand our understanding of such influences, we predicted bacterial genes that influence a quantitative animal trait by a comparative genomic approach, and we extended these predictions via mutant analysis. We focused on Drosophila melanogaster starvation resistance (SR). We first confirmed that D. melanogaster SR responds to the microbiota by demonstrating that bacterium-free flies have greater SR than flies bearing a standard 5-species microbial community, and we extended this analysis by revealing the species-specific influences of 38 genome-sequenced bacterial species on D. melanogaster SR. A subsequent metagenome-wide association analysis predicted bacterial genes with potential influence on D. melanogaster SR, among which were significant enrichments in bacterial genes for the metabolism of sulfur-containing amino acids and B vitamins. Dietary supplementation experiments established that the addition of methionine, but not B vitamins, to the diets significantly lowered D. melanogaster SR in a way that was additive, but not interactive, with the microbiota. A direct role for bacterial methionine metabolism genes in D. melanogaster SR was subsequently confirmed by analysis of flies that were reared individually with distinct methionine cycle Escherichia coli mutants. The correlated responses of D. melanogaster SR to bacterial methionine metabolism mutants and dietary modification are consistent with the established finding that bacteria can influence fly phenotypes through dietary modification, although we do not provide explicit evidence of this conclusion. Taken together, this work reveals that D. melanogaster SR is a microbiota-responsive trait, and specific bacterial genes underlie these influences.IMPORTANCE Extending descriptive studies of animal-associated microorganisms (microbiota) to define causal mechanistic bases for their influence on animal traits is an emerging imperative. In this study, we reveal that D. melanogaster starvation resistance (SR), a model quantitative trait in animal genetics, responds to the presence and identity of the microbiota. Using a predictive analysis, we reveal that the amino acid methionine has a key influence on D. melanogaster SR and show that bacterial methionine metabolism mutants alter normal patterns of SR in flies bearing the bacteria. Our data further suggest that these effects are additive, and we propose the untested hypothesis that, similar to bacterial effects on fruit fly triacylglyceride deposition, the bacterial influence may be through dietary modification. Together, these findings expand our understanding of the bacterial genetic basis for influence on a nutritionally relevant trait of a model animal host. | 2018 | 29934334 |
| 8705 | 11 | 0.9991 | Culturable Bacterial Endophytes of Wild White Poplar (Populus alba L.) Roots: A First Insight into Their Plant Growth-Stimulating and Bioaugmentation Potential. The white poplar (Populus alba L.) has good potential for a green economy and phytoremediation. Bioaugmentation using endophytic bacteria can be considered as a safe strategy to increase poplar productivity and its resistance to toxic urban conditions. The aim of our work was to find the most promising strains of bacterial endophytes to enhance the growth of white poplar in unfavorable environmental conditions. To this end, for the first time, we performed whole-genome sequencing of 14 bacterial strains isolated from the tissues of the roots of white poplar in different geographical locations. We then performed a bioinformatics search to identify genes that may be useful for poplar growth and resistance to environmental pollutants and pathogens. Almost all endophytic bacteria obtained from white poplar roots are new strains of known species belonging to the genera Bacillus, Corynebacterium, Kocuria, Micrococcus, Peribacillus, Pseudomonas, and Staphylococcus. The genomes of the strains contain genes involved in the enhanced metabolism of nitrogen, phosphorus, and metals, the synthesis of valuable secondary metabolites, and the detoxification of heavy metals and organic pollutants. All the strains are able to grow on media without nitrogen sources, which indicates their ability to fix atmospheric nitrogen. It is concluded that the strains belonging to the genus Pseudomonas and bacteria of the species Kocuria rosea have the best poplar growth-stimulating and bioaugmentation potential, and the roots of white poplar are a valuable source for isolation of endophytic bacteria for possible application in ecobiotechnology. | 2023 | 38132345 |
| 8247 | 12 | 0.9991 | The Role of Secretion Systems, Effectors, and Secondary Metabolites of Beneficial Rhizobacteria in Interactions With Plants and Microbes. Beneficial rhizobacteria dwell in plant roots and promote plant growth, development, and resistance to various stress types. In recent years there have been large-scale efforts to culture root-associated bacteria and sequence their genomes to uncover novel beneficial microbes. However, only a few strains of rhizobacteria from the large pool of soil microbes have been studied at the molecular level. This review focuses on the molecular basis underlying the phenotypes of three beneficial microbe groups; (1) plant-growth promoting rhizobacteria (PGPR), (2) root nodulating bacteria (RNB), and (3) biocontrol agents (BCAs). We focus on bacterial proteins and secondary metabolites that mediate known phenotypes within and around plants, and the mechanisms used to secrete these. We highlight the necessity for a better understanding of bacterial genes responsible for beneficial plant traits, which can be used for targeted gene-centered and molecule-centered discovery and deployment of novel beneficial rhizobacteria. | 2020 | 33240304 |
| 7713 | 13 | 0.9991 | Metagenome analyses of corroded concrete wastewater pipe biofilms reveal a complex microbial system. BACKGROUND: Concrete corrosion of wastewater collection systems is a significant cause of deterioration and premature collapse. Failure to adequately address the deteriorating infrastructure networks threatens our environment, public health, and safety. Analysis of whole-metagenome pyrosequencing data and 16S rRNA gene clone libraries was used to determine microbial composition and functional genes associated with biomass harvested from crown (top) and invert (bottom) sections of a corroded wastewater pipe. RESULTS: Taxonomic and functional analysis demonstrated that approximately 90% of the total diversity was associated with the phyla Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. The top (TP) and bottom pipe (BP) communities were different in composition, with some of the differences attributed to the abundance of sulfide-oxidizing and sulfate-reducing bacteria. Additionally, human fecal bacteria were more abundant in the BP communities. Among the functional categories, proteins involved in sulfur and nitrogen metabolism showed the most significant differences between biofilms. There was also an enrichment of genes associated with heavy metal resistance, virulence (protein secretion systems) and stress response in the TP biofilm, while a higher number of genes related to motility and chemotaxis were identified in the BP biofilm. Both biofilms contain a high number of genes associated with resistance to antibiotics and toxic compounds subsystems. CONCLUSIONS: The function potential of wastewater biofilms was highly diverse with level of COG diversity similar to that described for soil. On the basis of the metagenomic data, some factors that may contribute to niche differentiation were pH, aerobic conditions and availability of substrate, such as nitrogen and sulfur. The results from this study will help us better understand the genetic network and functional capability of microbial members of wastewater concrete biofilms. | 2012 | 22727216 |
| 7676 | 14 | 0.9991 | The intestinal microbial community and function of Riptortus pedestris at different developmental stages and its effects on development. INTRODUCTION: Riptortus pedestris is a destructive pest that threatens multiple leguminous crops in China. The intestinal microbiota plays a crucial role in the growth and reproduction of host insects. However, the composition and function of the gut microbiota at different developmental stages remain unclear. METHODS: Here, metagenomic sequencing was performed to clarify the gut microbial diversity and function in 2nd-, 3rd-, 4th-, and 5th- instar nymphs (2 N-5 N) and female adults (FAs) of R. pedestris and the effects of vital gut bacteria on development was detected. The gut bacteria have the stage specificity, indicating their function in the development of R. pedestris. RESULTS: Enterococcus and Caballerronia were the predominant bacteria present during the development of the 2 N-FAs. In addition, the microbial abundances in the 3 N and 4 N guts were significantly greater than those in the others guts. Furthermore, 5 N harbored the abundant microbiota Burkholderia-Paraburkholderia-Caballeronia. The metabolic pathways were significantly enriched from 2 N to FAs. Carbohydrate metabolism, including glycoside hydrolases (GHs) and glycosyl transferases (GTs), occurs throughout the entire developmental stage. Many antibiotic resistance genes (ARGs) were detected from 2 N to FAs. The bacteria from Pseudomonadota and Bacillota presented a broad spectrum of antibiotic resistance. Excitingly, Burkholderia bacteria eliminated by antibiotic treatment were unable to molt normally, and their lifespan was shortened in nymphs, indicating that the gut microbiota had a significant effect on nymph development. CONCLUSION: In summary, our results, for the first time, systematically illustrate the abundance and function across the gut microbiota from the different developmental stages of R. pedestris and demonstrate that the genera Burkholderia are crucial during the development of R. pedestris. This study provides the basis for stinkbug management strategies that focus on the pivotal gut microbiota. | 2025 | 39935633 |
| 8696 | 15 | 0.9991 | Specific Enriched Acinetobacter in Camellia Weevil Gut Facilitate the Degradation of Tea Saponin: Inferred from Bacterial Genomic and Transcriptomic Analyses. Beneficial gut bacteria can enhance herbivorous arthropod adaptation to plant secondary compounds (PSMs), and specialist herbivores provide excellent examples of this. Tea saponin (TS) of Camellia oleifera is triterpenoids toxic to seed-feeding weevil pest, Curculio chinensis (CW). Previous studies disclosed that Acinetobacter, which was specific enriched in the CW's gut, was involved in helping CW evade TS toxicity of C. oleifera. However, it is still not clear whether Acinetobacter is associated with other anti-insect compounds, and the molecular mechanism of Acinetobacter degradation of TS has not been clarified. To address these questions, we explored the relationship between host plant toxin content and Acinetobacter of CW gut bacteria. Results demonstrated that TS content significantly affected the CW gut microbiome structure and enriched bacteria functional for TS degradation. We further isolated Acinetobacter strain and conducted its genome and transcriptome analyses for bacterial characterization and investigation on its role in TS degradation. Biological tests were carried out to verify the ability of the functional bacterium within CW larvae to detoxify TS. Our results showed that TS-degrading bacteria strain (Acinetobacter sp. AS23) genome contains 47 genes relating to triterpenoids degradation. The AS23 strain improved the survival rate of CW larvae, and the steroid degradation pathway could be the key one for AS23 to degrade TS. This study provides the direct evidence that gut bacteria mediate adaptation of herbivorous insects to phytochemical resistance. IMPORTANCE Microorganism is directly exposed to the plant toxin environment and play a crucial third party in herbivores gut. Although previous studies have proved the existence of gut bacteria that help CWs degrade TS, the specific core flora and its function have not been explored. In this study, we investigated the correlation between the larva gut microbiome and plant secondary metabolites. Acinetobacter genus was the target flora related to TS degradation. There were many terpenoids genes in Acinetobacter sp. AS23 genome. Results of transcriptome analysis and biological tests suggested that steroid degradation pathway be the key pathway of AS23 to degrade TS. This study not only provides direct evidence that gut microbes mediate the rapid adaptation of herbivorous insects to phytochemical resistance, but also provides a theoretical basis for further research on the molecular mechanism of intestinal bacteria cooperating with pests to adapt to plant toxins. | 2022 | 36413019 |
| 155 | 16 | 0.9991 | RNA-Seq transcriptomic analysis reveals gene expression profiles of acetic acid bacteria under high-acidity submerged industrial fermentation process. Acetic acid bacteria (AAB) are Gram-negative obligate aerobics in Acetobacteraceae family. Producing acetic acid and brewing vinegars are one of the most important industrial applications of AAB, attributed to their outstanding ability to tolerate the corresponding stresses. Several unique acid resistance (AR) mechanisms in AAB have been revealed previously. However, their overall AR strategies are still less-comprehensively clarified. Consequently, omics analysis was widely performed for a better understanding of this field. Among them, transcriptome has recently obtained more and more attention. However, most currently reported transcriptomic studies were conducted under lab conditions and even in low-acidity environment, which may be unable to completely reflect the conditions that AAB confront under industrialized vinegar-brewing processes. In this study, we performed an RNA-Seq transcriptomic analysis concerning AAB's AR mechanisms during a continuous and periodical industrial submerged vinegar fermentation process, where a single AAB strain performed the fermentation and the acetic acid concentration fluctuated between ~8% and ~12%, the highest acidity as far we know for transcriptomic studies. Samples were directly taken from the initial (CK), mid, and final stages of the same period of the on-going fermentation. 16S rRNA sequence analysis indicated the participation of Komagataeibacter europaeus in the fermentation. Transcriptomic results demonstrated that more genes were downregulated than upregulated at both mid and final stages. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrich analysis reflected that the upregulated genes mainly carried out tricarboxylic acid cycle and oxidative phosphorylation processes, probably implying a considerable role of acetic acid overoxidation in AR during fermentation. Besides, upregulation of riboflavin biosynthesis pathway and two NAD(+)-dependent succinate-semialdehyde dehydrogenase-coding genes suggested a critical role of succinate oxidation in AR. Meanwhile, downregulated genes were mainly ribosomal protein-coding ones, reflecting that the adverse impact on ribosomes initiates at the transcription level. However, it is ambiguous whether the downregulation is good for stress responding or it actually reflects the stress. Furthermore, we also assumed that the fermentation stages may have a greater effect on gene expression than acidity. Additionally, it is possible that some physiological alterations would affect the AR to a larger extent than changes in gene expression, which suggests the combination of molecular biology and physiology research will provide deeper insight into the AR mechanisms in AAB. | 2022 | 36246236 |
| 7523 | 17 | 0.9991 | Transfer of antibiotic resistance genes from soil to wheat: Role of host bacteria, impact on seed-derived bacteria, and affecting factors. The transfer of antibiotic resistance genes (ARGs) from soils to plants is poorly understood, especially the role of host bacteria in soils and its impact on seed-derived bacteria. Wheat (Triticum aestivum L.) was thus used to fill the gap by conducting pot experiments, with target ARGs and bacterial community analyzed. Results showed that the relative abundances of target ARGs gradually decreased during transfer of ARGs from the rhizosphere soil to root and shoot. Host bacteria in the rhizosphere soil were the primary source of ARGs in wheat. The 38, 21, and 19 potential host bacterial genera of target ARGs and intI1 in the rhizosphere soil, root, and shoot were identified, respectively, and they mainly belonged to phylum Proteobacteria. The abundance of ARGs carried by pathogenic Corynebacterium was reduced in sequence. During transfer of ARGs from the rhizosphere soil to root and shoot, some seed-derived bacteria and pathogenic Acinetobacter obtained ARGs through horizontal gene transfer and became potential host bacteria. Furthermore, total organic carbon, available nitrogen of the rhizosphere soil, water use efficiency, vapor pressure deficit, and superoxide dismutase of plants were identified as the key factors affecting potential host bacteria transfer in soils to wheat. This work provides important insights into transfer of ARGs and deepens our understanding of potential health risks of ARGs from soils to plants. | 2023 | 37741386 |
| 6731 | 18 | 0.9990 | Bacterial, archaeal and micro-eukaryotic communities characterize a disease-suppressive or conducive soil and a cultivar resistant or susceptible to common scab. Control of common scab disease can be reached by resistant cultivars or suppressive soils. Both mechanisms are likely to translate into particular potato microbiome profiles, but the relative importance of each is not known. Here, microbiomes of bulk and tuberosphere soil and of potato periderm were studied in one resistant and one susceptible cultivar grown in a conducive and a suppressive field. Disease severity was suppressed similarly by both means yet, the copy numbers of txtB gene (coding for a pathogenicity determinant) were similar in both soils but higher in periderms of the susceptible cultivar from conducive soil. Illumina sequencing of 16S rRNA genes for bacteria (completed by 16S rRNA microarray approach) and archaea, and of 18S rRNA genes for micro-eukarytes showed that in bacteria, the more important was the effect of cultivar and diversity decreased from resistant cultivar to bulk soil to susceptible cultivar. The major changes occurred in proportions of Actinobacteria, Chloroflexi, and Proteobacteria. In archaea and micro-eukaryotes, differences were primarily due to the suppressive and conducive soil. The effect of soil suppressiveness × cultivar resistance depended on the microbial community considered, but differed also with respect to soil and plant nutrient contents particularly in N, S and Fe. | 2019 | 31619759 |
| 8767 | 19 | 0.9990 | Poly-γ-glutamic acid enhanced the drought resistance of maize by improving photosynthesis and affecting the rhizosphere microbial community. BACKGROUND: Compared with other abiotic stresses, drought stress causes serious crop yield reductions. Poly-γ-glutamic acid (γ-PGA), as an environmentally friendly biomacromolecule, plays an important role in plant growth and regulation. RESULTS: In this project, the effect of exogenous application of γ-PGA on drought tolerance of maize (Zea mays. L) and its mechanism were studied. Drought dramatically inhibited the growth and development of maize, but the exogenous application of γ-PGA significantly increased the dry weight of maize, the contents of ABA, soluble sugar, proline, and chlorophyll, and the photosynthetic rate under severe drought stress. RNA-seq data showed that γ-PGA may enhance drought resistance in maize by affecting the expression of ABA biosynthesis, signal transduction, and photosynthesis-related genes and other stress-responsive genes, which was also confirmed by RT-PCR and promoter motif analysis. In addition, diversity and structure analysis of the rhizosphere soil bacterial community demonstrated that γ-PGA enriched plant growth promoting bacteria such as Actinobacteria, Chloroflexi, Firmicutes, Alphaproteobacteria and Deltaproteobacteria. Moreover, γ-PGA significantly improved root development, urease activity and the ABA contents of maize rhizospheric soil under drought stress. This study emphasized the possibility of using γ-PGA to improve crop drought resistance and the soil environment under drought conditions and revealed its preliminary mechanism. CONCLUSIONS: Exogenous application of poly-γ-glutamic acid could significantly enhance the drought resistance of maize by improving photosynthesis, and root development and affecting the rhizosphere microbial community. | 2022 | 34979944 |