Project description:Chemical signaling in the plant microbiome can have drastic effects on microbial community structure, and on host growth and development. Previously, we demonstrated that the auxin metabolic signal interference performed by the bacterial genus Variovorax via a novel auxin degradation locus was essential for maintaining stereotypic root development in an ecologically-relevant bacterial synthetic community. Here, we dissect the Variovorax auxin degradation locus to define the genes necessary and sufficient for indole-3-acetic acid (IAA) degradation and signal interference. We determine the crystal structures and binding properties of the operon’s MarR-family repressor with IAA and other auxins. We identify auxin-degradation operons across the bacterial tree of life and define two distinct types based on gene content and metabolic products: iac-like and iad-like. We solve the structures of MarRs from representatives of each auxin degradation operon type, establishing that each have distinct IAA binding pockets. Comparison of representative IAA degrading strains from diverse bacterial genera show that while all degrade IAA, only strains containing iad-like auxin degrading operons interfere with auxin signaling in a complex synthetic community context. This suggests that iad-like operon containing strains, including Variovorax species, play a key ecological role in modulating auxins in the plant microbiome.
2022-08-11 | GSE210968 | GEO
Project description:Fungal community of plant litter
| PRJNA985932 | ENA
Project description:Plant litter fungal community structure.
Project description:We performed RNA-Seq based gene expression analysis of Arabidopsis Col-0 plants grown in presence of SynComCol-0 (eubiotic bacterial community), SynCommfec (dysbiotic bacterial community) and Axenic conditions in GnotoPot plant gnotobiotic growth system. SynCom preparation was done by mixing equal ratio of the each strain measured based on optical density of (OD600) in 10 mM MgCl2 and adjusting to the final combined OD600 of 0.04. Plants were grow in GnotoPots as described in (Chen et al, Nature 2020). We identified genes differentially enriched in response to presence of eubiotic and dysbiotic bacterial communities. Our results suggested that in presence of dysbiotic community there is over abundance of gene expression for immunity/defense-related genes in SynCommfec compared SynComCol-0 colonized plants.
2023-07-19 | GSE218962 | GEO
Project description:Keystone species affect bacterial community assembly and plant productivity