Project description:Transcriptome analysis of Arabidopsis colonized by a plant-growth promoting rhizobacterium reveals a general effect on disease resistance RNA transcript levels of Arabidopsis plants, infected by the rhizobacterium Pseudomonas thivervalensis (strain MLG45), and axenic control plants were compared using cDNA microarrays representing approximately 14 300 genes. The analysis revealed an increase of defence-related transcripts in the shoots of bacterized plants relative to control (axenic) plants. These modifications of transcript levels were confirmed by physiological experiments. Plants infected with P. thivervalensis were more resistant to subsequent infections by the virulent pathogen P. syringae pv. tomato (strain DC3000) than control plants. In addition, photosynthesis rates were repressed consistently with the reduced growth of plants colonized by P. thivervalensis. These results highlight the value of molecular phenotyping to predict physiological changes.
Project description:Transcriptome analysis of Arabidopsis colonized by a plant-growth promoting rhizobacterium reveals a general effect on disease resistance RNA transcript levels of Arabidopsis plants, infected by the rhizobacterium Pseudomonas thivervalensis (strain MLG45), and axenic control plants were compared using cDNA microarrays representing approximately 14 300 genes. The analysis revealed an increase of defence-related transcripts in the shoots of bacterized plants relative to control (axenic) plants. These modifications of transcript levels were confirmed by physiological experiments. Plants infected with P. thivervalensis were more resistant to subsequent infections by the virulent pathogen P. syringae pv. tomato (strain DC3000) than control plants. In addition, photosynthesis rates were repressed consistently with the reduced growth of plants colonized by P. thivervalensis. These results highlight the value of molecular phenotyping to predict physiological changes. Set of arrays that are part of repeated experiments Keywords: Biological Replicate
Project description:Transcriptome analysis of Arabidopsis colonized by a plant-growth promoting rhizobacterium reveals a general effect on disease resistance RNA transcript levels of Arabidopsis plants, infected by the rhizobacterium Pseudomonas thivervalensis (strain MLG45), and axenic control plants were compared using cDNA microarrays representing approximately 14 300 genes. The analysis revealed an increase of defence-related transcripts in the shoots of bacterized plants relative to control (axenic) plants. These modifications of transcript levels were confirmed by physiological experiments. Plants infected with P. thivervalensis were more resistant to subsequent infections by the virulent pathogen P. syringae pv. tomato (strain DC3000) than control plants. In addition, photosynthesis rates were repressed consistently with the reduced growth of plants colonized by P. thivervalensis. These results highlight the value of molecular phenotyping to predict physiological changes. Set of arrays that are part of repeated experiments Biological Replicate Computed
Project description:Arabidopsis thaliana 4-day-old seedlings were treated with the plant growth promoting rhizobacteria Caulobacter RHG1 or the neutral bacteria Bacillus sp. At 12 and 48 hours after treatment, roots were harvested, RNA was extracted and RNA-Seq data were generated. The goal of this experiment was to detect changes at the transcript level that were specific for the plant growth promoting rhizobacteria RHG1.
Project description:Brevicompanines are natural products isolated from the culture filtrate of the fungus Penicillium brevicompactum. They showed plant growth regulating properties in several species including lettuce, rice or Arabidopsis thaliana. We used microarrays to gather information about the reprogramming of gene transcription when Arabidopsis leaves were treated with Brevicompanine C (BrvC) that showed significant activity in plant growth assays.
Project description:Plants are colonized by a variety of microorganisms, the plant microbiota. In the phyllosphere, the above-ground parts of plants, bacteria are the most abundant inhabitants. Most of these microorganisms are not pathogenic and the plant responses to commensals or to pathogen infection in the presence of commensals are not well understood. We report the Arabidopsis leaf transcriptome after 3 to 4 weeks of colonization by Methylobacterium extorquens PA1 and Sphingomonas melonis Fr1, representatives of two abundant genera in the phyllosphere, compared to axenic plants. In addition, we also sequenced the transcriptome of Arabidopsis 2 and 7 days after spray-infection with a low dose of P. syringae DC3000 and in combination with the commensals.
Project description:Some soil bacteria promote plant growth, including Pseudomonas species. With this approach we detected significant changes in Arabidopsis genes related to primary metabolism that were induced by the bacteria.
Project description:Unlike pathogens that trigger plant defense responses, beneficial microbes are compatible with plants. One possible reason for the compatibility is that the microbial factors from beneficial microbes are inert in that they do not trigger plant defense responses. Little is known about the mechanisms underlying this seemingly inert relation. Here we report that Arabidopsis lacking the gene Growth-Promotion 1 (GP1) becomes defensive to microbial volatiles from Bacillus amyloliqueficiens strain GB03, a beneficial rhizobacterium. The gp1 mutant was isolated in a forward genetic screen for mutants that show defectiveness in GB03-triggered plant inducible vigor. GP1 encodes a stearoyl-ACP desaturase that catalyzes the desaturation of stearic acid (18:0) to oleic acid (18:1). Consistently, plant inducible vigor was also impaired by chemical enhancement of 18:1 catabolism, while genetic disruption of 18:1 catabolism largely restored the inducible vigor in gp1. When exposed to GB03-emitted microbial volatiles (GMVs), wild type plants showed transcriptional up-regulation of growth-promoting processes and down-regulation of defense responses; in contrast, the gp1 transcriptome displayed elevated defense responses when treated with GMVs. Meanwhile disruption of salicylic acid-mediated defense partially restored plant inducible vigor in gp1. Microbiota profiling revealed that GP1 dysfunction alters the assemblage of plant-associated rhizobacteria communities, including a reduction in the Bacillaceae family that is known to contain many beneficial rhizobacteria species. Consistently, gp1 mutants showed severely impaired root colonization of GB03. Our findings suggest that GP1 prevents the plant defense system from being mistakenly activated by non-pathogenic microbial factors, thereby allowing mutualistic association between the plant and beneficial microbes.