Project description:The spaceflight environment imparts unique selective pressures on the plants and microbes of plant growth chambers on the International Space Station (ISS), which generally manifests through genetic signatures associated with a heightened response to stress. Terrestrially, a baseline understanding of the gene fitness response for any plant growth promoting microbe when in a tripartite relationship with host and pathogen is currently unknown and is important to characterize before closed-environment spaceflight implementation. To that end, this study evaluated the behavior of an ISS plant habitat isolate of Burkholderia contaminans as tomato seeds transition to seedlings and assessed gene fitness during challenge with Fusarium oxysporum f. sp. lycopersici (FOL), the causal agent of Fusarium wilt. To probe mechanisms underlying the bacterial-fungal interaction between B. contaminans and FOL in the tomato root zone, a genome-wide transposon mutant library was developed of the B. contaminans isolate. Using a seed film delivery method vetted for spaceflight, a Tn-Seq library of B. contaminans was applied to Solanum lycopersicum cv. Red Robin seeds. Transposon sequencing (Tn-Seq) analysis revealed that the type II secretion system (T2SS) was critical for root zone establishment, whereas a Nudix hydrolase was specifically important for responding to FOL infection, and provided further confirmation that antifungal and siderophore-producing gene clusters were not.
Project description:We isolated an efficient doxycycline degrading strain Chryseobacterium sp. WX1. To investigate gene expression patterns during doxycyclinedegradation by strain WX1, we conducted a comparative transcriptomic analysis using cultures of strain WX1 with and without doxycycline addition. The RNA-Seq data revealed that 90.44-96.56% of the reads mapped to the genome of Chryseobacterium sp. WX1 across all samples. Differentially expressed genes (DEGs) analysis (|log2FC| >2; p < 0.01) showed that 693 genes were significantly up-regulated and 592 genes were significantly down-regulated.
Project description:In this study, we isolated a potent doxycycline-degrading bacterium, Chryseobacterium sp. WX1, from environmental samples. To elucidate the molecular mechanisms underlying doxycycline degradation by strain WX1, we assessed and interpreted the proteomic profiles of Chryseobacterium sp. WX1 under conditions both with and without doxycycline exposure.
