Project description:Asymptomatic plants grown in natural soil are colonized by phylogenetically structured communities of microbes known as the microbiota. Individual microbes can activate microbe-associated molecular pattern (MAMP)-triggered immunity (MTI), which limits pathogen proliferation but curtails plant growth, a phenomenon known as the growth-defense trade-off. We report that in mono-associations, 41% (62/151) of taxonomically diverse root bacteria commensals suppress Arabidopsis thaliana root growth inhibition (RGI) triggered by immune-stimulating MAMPs or damage-associated molecular patterns. Amplicon sequencing of bacteria 16S rRNA genes reveal that immune activation alters the profile of synthetic communities (SynComs) comprised of RGI-non-suppressive strains, while the presence of RGI-suppressive strains attenuates this effect. Root colonization by SynComs with different complexities and RGI-suppressive activities alters the expression of 174 core host genes with functions related to root development and nutrient transport. Further, RGI-suppressive SynComs specifically downregulate a subset of immune-related genes. Mutation of one commensal-downregulated transcription factor, MYB15, or pre-colonization with RGI-suppressive SynComs render plants more susceptible to opportunistic Pseudomonas pathogens. Our results suggest that RGI-non-suppressive and suppressive root commensals modulate host susceptibility to pathogens by either eliciting or dampening MTI responses, respectively. This interplay buffers the plant immune system against pathogen perturbation and defense-associated growth inhibition, ultimately leading to commensal-host homeostasis.
Project description:In order to investigate the diurnal oscillations of ruminal bacteria, and their responses to the changes in different feeding patterns, we conducted an animal experiment by feeding the sheep ad libitum with a hay-based diet (50% of alfalfa hay and 46% of oats hay) and a grain-based diet (45% of corn meal and 11% of soybean meal) for 30 days, and ruminal fluid samples were collected at six different timepoints from T2 to T22 in one day, and the composition and diversity of the bacterial communities in rumen microbiomes of the sheep in the Grain-diet and Hay-diet groups at different timepoints were analyzed through 16S rRNA sequencing.
Project description:We aim to determine if mice in our mouse colony had similar of different microbiomes. To do this, we perfromed 16S sequencing of stool from unifected mice of the gentotypes listed below. We also looked at how infection causes dysbiosis of the mircobiome, measuring 16S sequencing over a C.rodentium infection timecourse.