Project description:The microbiota hosted in the pig gastrointestinal tract are important to health of this biomedical model. However, the individual species and functional repertoires that make up the pig gut microbiome remain largely undefined. Here we comprehensively investigated the genomes and functions of the piglet gut microbiome using culture-based and metagenomics approaches. A collection included 266 cultured genomes and 482 metagenome-assembled genomes (MAGs) that were clustered to 428 species across 10 phyla was established. Among these clustered species, 333 genomes represent potential new species. Less matches between cultured genomes and MAGs revealed a substantial bias for the acquisition of reference genomes by the two strategies. Glycoside hydrolases was the dominant category of carbohydrate-active enzymes. Four-hundred forty-five secondary metabolite biosynthetic genes were predicted from 292 genomes with bacteriocin being the most. Pan genome analysis of Limosilactobacillus reuteri uncover the biosynthesis of reuterin was strain-specific and the production was experimentally determined. This study provides a comprehensive view of the microbiome composition and the function landscape of the gut of weanling piglets and a valuable bacterial resource for further experimentations. IMPORTANCE The microorganism communities resided in mammalian gastrointestinal tract impacted the health and disease of the host. Our study complements metagenomic analysis with culture-based approach to establish a bacteria and genome collection and comprehensively investigate the microbiome composition and function of the gut of weanling piglets. We provide a valuable resource for further study of gut microbiota of weanling piglet and development of probiotics for prevention of disease.
Project description:Understanding gut microbiome functions requires cultivated bacteria for experimental validation and reference bacterial genome sequences to interpret metagenome datasets and guide functional analyses. We present the Human Gastrointestinal Bacteria Culture Collection (HBC), a comprehensive set of 737 whole-genome-sequenced bacterial isolates, representing 273 species (105 novel species) from 31 families found in the human gastrointestinal microbiota. The HBC increases the number of bacterial genomes derived from human gastrointestinal microbiota by 37%. The resulting global Human Gastrointestinal Bacteria Genome Collection (HGG) classifies 83% of genera by abundance across 13,490 shotgun-sequenced metagenomic samples, improves taxonomic classification by 61% compared to the Human Microbiome Project (HMP) genome collection and achieves subspecies-level classification for almost 50% of sequences. The improved resource of gastrointestinal bacterial reference sequences circumvents dependence on de novo assembly of metagenomes and enables accurate and cost-effective shotgun metagenomic analyses of human gastrointestinal microbiota.
Project description:Plant pathogens can cause serious diseases that impact global agriculture1. Understanding how the plant immune system naturally restricts pathogen infection holds a key to sustainable disease control in modern agricultural practices. However, despite extensive studies into the molecular and genetic basis of plant defense against pathogens since the 1950s2,3, one of the most fundamental questions in plant pathology remains unanswered: how resistant plants halt pathogen growth during immune activation. In the case of bacterial infections, a major bottleneck is an inability to determine the global bacterial transcriptome and metabolic responses in planta. Here, we developed an innovative pipeline that allows for in planta high-resolution bacterial transcriptome analysis with RNA-Seq, using the model plant Arabidopsis thaliana and the foliar bacterial pathogen Pseudomonas syringae. We examined a total of 27 combinations of plant immunity and bacterial virulence mutants to gain an unprecedented insight into the bacterial transcriptomic responses during plant immunity. We were able to identify specific bacterial transcriptomic signatures that are linked to bacterial inhibition during two major forms of plant immunity: pattern-triggered immunity and effector-triggered immunity. Among them, regulation of a P. syringae sigma factor gene, involved in iron regulation and an unknown process(es), was found to play a causative role in bacterial restriction during plant immunity. This study unlocked the enigmatic mechanisms of bacterial growth inhibition during plant immunity; results have broad basic and practical implications for future study of plant diseases.
Project description:Plant pathogens can cause serious diseases that impact global agriculture1. Understanding how the plant immune system naturally restricts pathogen infection holds a key to sustainable disease control in modern agricultural practices. However, despite extensive studies into the molecular and genetic basis of plant defense against pathogens since the 1950s2,3, one of the most fundamental questions in plant pathology remains unanswered: how resistant plants halt pathogen growth during immune activation. In the case of bacterial infections, a major bottleneck is an inability to determine the global bacterial transcriptome and metabolic responses in planta. Here, we developed an innovative pipeline that allows for in planta high-resolution bacterial transcriptome analysis with RNA-Seq, using the model plant Arabidopsis thaliana and the foliar bacterial pathogen Pseudomonas syringae. We examined a total of 27 combinations of plant immunity and bacterial virulence mutants to gain an unprecedented insight into the bacterial transcriptomic responses during plant immunity. We were able to identify specific bacterial transcriptomic signatures that are linked to bacterial inhibition during two major forms of plant immunity: pattern-triggered immunity and effector-triggered immunity. Among them, regulation of a P. syringae sigma factor gene, involved in iron regulation and an unknown process(es), was found to play a causative role in bacterial restriction during plant immunity. This study unlocked the enigmatic mechanisms of bacterial growth inhibition during plant immunity; results have broad basic and practical implications for future study of plant diseases.
Project description:We previously demonstrated that flavonoid metabolites inhibit cancer cell proliferation through both CDK-dependent and -independent mechanisms. The existing evidence suggests that gut microbiota is capable of flavonoid biotransformation to generate bioactive metabolites including 2,4,6-trihydroxybenzoic acid (2,4,6-THBA), 3,4-dihydroxybenzoic acid (3,4-DHBA), 3,4,5-trihyroxybenzoic acid (3,4,5-THBA) and 3,4-dihydroxyphenylacetic acid (DOPAC). In this study, we screened 94 human gut bacterial species for their ability to biotransform flavonoid quercetin into different metabolites. We demonstrated that five of these species were able to degrade quercetin including Bacillus glycinifermentans, Flavonifractor plautii, Bacteroides eggerthii, Olsenella scatoligenes and Eubacterium eligens. Additional studies showed that B. glycinifermentans could generate 2,4,6-THBA and 3,4-DHBA from quercetin while F. plautii generates DOPAC. In addition to the differences in the metabolites produced, we also observed that the kinetics of quercetin degradation was different between B. glycinifermentans and F. plautii, suggesting that the pathways of degradation are likely different between these strains. Similar to the antiproliferative effects of 2,4,6-THBA and 3,4-DHBA demonstrated previously, DOPAC also inhibited colony formation ex vivo in the HCT-116 colon cancer cell line. Consistent with this, the bacterial culture supernatant of F. plautii also inhibited colony formation in this cell line. Thus, as F. plautii and B. glycinifermentans generate metabolites possessing antiproliferative activity, we suggest that these strains have the potential to be developed into probiotics to improve human gut health.
Project description:The intercellular space or apoplast constitutes the main interface in plant-pathogen interactions. Apoplastic subtilisin-like proteases -subtilases- may play an important role in defence and they have been identified as targets of pathogen-secreted effector proteins. However, most evidence is limited to the interaction of plants with non-vascular foliar pathogens. Here, we characterise the role of the Solanaceae-specific P69 subtilase family in the interaction between tomato and the vascular bacterial wilt pathogen Ralstonia solanacearum.
Project description:Effector-Triggered Immunity (ETI) and Pattern-Triggered Immunity (PTI) are well-defined modes of plant immunity triggered by recognition of pathogen effector proteins and microbe-associated molecular patterns, respectively. While ETI and PTI network extensively share signaling components, the shared components are used in different ways, resulting in distinct network properties in the model plant Arabidopsis: immunity is highly robust against network perturbations in ETI but relatively sensitive in PTI. However, the molecular mechanism how the shared network leads to the different properties is not known. Here we show that salicylic acid (SA) reponsive genes can respond in the absense of SA during ETI. A 24 DNA microarray study using total RNA from Arabidopsis wildtype Col-0 and sid2-2 mutant infected with Pto hrcC-, Pto EV, Pto AvrRpt2 or water.
Project description:Purpose: Investigate genes associated to resistance of Xanthomonas perforans race T4 in tomato line with different resistance level Methods: Resistant and susceptible tomato breeding lines were subjected to the inoculation with Xanthomonas perforans race T4 followed by sample collection at 48 hpi and RNA-seq analysis for screening differential expressed genes associated with inoculation of pathogen. Results: Revealed gene expression profiles associated disease resistance and susceptiblilty.