Project description:Pathogens target phytohormone signalling pathways to promote disease. Plants deploy salicylic acid (SA) mediated defences against biotrophs. Pathogens antagonise SA immunity by activating jasmonate signalling, e.g. Pseudomonas syringae pv. tomato DC3000 produces coronatine (COR), a jasmonate (JA) mimic. This study found unexpected dynamics between SA, JA and COR and co-operation between JAZ jasmonate repressor proteins during DC3000 infection. JA did not accumulate until late in the infection process and was higher in leaves challenged with coronatine deficient P. syringae or in the more resistant JA receptor mutant coi1. JAZ regulation was complex and coronatine alone was insufficient to sustainably induce JAZs. RNA was extracted from leaves of wild type Col-0 or the jaz5/10 mutant plants from leaves 6, 8, 12 or 16 hours after challenged with Pseudomonas syringae pv. tomato DC3000.
Project description:We examined whether the budding yeast Saccharomyces cerevisiae can sense chemical signals from prokaryotes, specifically a variety of quorum sensing molecules from different bacteria species and from Candida albicans. We found that only N-acyl-3-oxo-dodecanoyl homoserine lactone (C12) from the opportunistic human pathogen Pseudomonas aeruginosa induces a stress response in yeast. Microarray experiments were performed in order to continue investigating the stress response. We treated S. cerevesiae (WT strain W303) with N-(3-oxo-dodecanoyl) homoserine lactone (C12), a quorum sensing molecule of Pseudomonas aeruginosa, which we found causes a stress response using a GFP reporter for HSP-12. Treatment conditions: 100 uM C12, 100 uM C12-lactam (control: synthetic analogue of C12 that is inactive in P. aeruginosa), DMSO (control: solvent), and 0.3 mM H2O2 (for comparison to oxidative stress).
Project description:Pathogens target phytohormone signalling pathways to promote disease. Plants deploy salicylic acid (SA) mediated defences against biotrophs. Pathogens antagonise SA immunity by activating jasmonate signalling, e.g. Pseudomonas syringae pv. tomato DC3000 produces coronatine (COR), a jasmonate (JA) mimic. This study found unexpected dynamics between SA, JA and COR and co-operation between JAZ jasmonate repressor proteins during DC3000 infection. JA did not accumulate until late in the infection process and was higher in leaves challenged with coronatine deficient P. syringae or in the more resistant JA receptor mutant coi1. JAZ regulation was complex and coronatine alone was insufficient to sustainably induce JAZs.
2015-08-28 | GSE72461 | GEO
Project description:Acyl Homoserine Lactone treatment to Ginseng soil
Project description:Expression profiling of wild-type plants and mutants with defects in key components of the defense signaling network was used to model the Arabidopsis network 24 hours after infection by Pseudomonas syringae pv. maculicola strain Psm ES4326. Results using the Affymetrix ATH1 array revealed that expression levels of most pathogen-responsive genes were affected by mutations in coi1, ein2, npr1, pad4, or sid2. These five mutations defined a small number of different expression patterns displayed by the majority of pathogen-responsive genes. P. syringae pv. tomato strain Pst DC3000 elicited a much weaker salicylic acid response than Psm ES4326. Additional mutants were profiled using a custom array. Profiles of pbs3 and ndr1 revealed major effects of these mutations and allowed PBS3 and NDR1 to be placed between the EDS1/PAD4 node and the SA synthesis node in the defense network. Comparison of coi1, dde2, and jar1 profiles showed that many genes were affected by coi1, but very few were affected by dde2 or jar1. Profiles of coi1 plants infected with Psm ES4326 were very similar to those of wild-type plants infected with bacteria unable to produce the phytotoxin coronatine, indicating that essentially all COI1-dependent gene expression changes in this system are caused by coronatine. This experiment consists of three biological replicates. For each genotype, two leaves per plant were pooled from three pots to prepare total RNA.
Project description:In order to gain coherent insights into plant responses we performed transcriptional analysis of Arabidopsis seedling after treatment with three different AHLs: N-hexanoyl-L-homoserine lactone (C6-HSL), N-3-oxo-decanoyl-L-homoserine lactone (oxo-C10-HSL), and N-3-oxo-tetradecanoyl-L-homoserine lactone (oxo-C14-HSL). Furthermore, we analyzed the transcriptome of oxo-C14-HSL pretreated plants after a secondary challenge with 100 nM flg22 for 2 and 24 hours after treatment. Gene expression in Arabidopsis thaliana seedlings were measured after a 3-days-pretreatment with 6 µM of three different N-acyl homoserine lactones in comparison to plants treated with the coresponding volume of acetone (solvent control). Plants pretreated with oxo-C14-HSL were in addition treated with 100nM of flg22 to induced defense response. Three independent experiments were performed (replicates).
Project description:Acyl-homoserine lactone (acyl-HSL) quorum sensing was first discovered in Vibrio fischeri where it serves as a key control element of the seven-gene luminescence (lux) operon. Since this initial discovery, other bacteria have been shown to control hundreds of genes by acyl-HSL quorum sensing. Until recently, it has been difficult to examine the global nature of quorum sensing in V. fischeri. However, the complete genome sequence of V. fischeri is now available and this has enabled us to use transcriptomics to identify quorum-sensing regulated genes and to study the quorum-controlled regulon of this bacterium. In this study, we used DNA microarray technology to identify over two-dozen V. fischeri genes regulated by the quorum sensing signal N-3-oxohexanoyl-L-homoserine lactone (3OC6-HSL). Keywords: Comparison of transcriptome profiles
Project description:Expression profiling of wild-type plants and mutants with defects in key components of the defense signaling network was used to model the Arabidopsis network 24 hours after infection by Pseudomonas syringae pv. maculicola strain Psm ES4326. Results using the Affymetrix ATH1 array revealed that expression levels of most pathogen-responsive genes were affected by mutations in coi1, ein2, npr1, pad4, or sid2. These five mutations defined a small number of different expression patterns displayed by the majority of pathogen-responsive genes. P. syringae pv. tomato strain Pst DC3000 elicited a much weaker salicylic acid response than Psm ES4326. Additional mutants were profiled using a custom array. Profiles of pbs3 and ndr1 revealed major effects of these mutations and allowed PBS3 and NDR1 to be placed between the EDS1/PAD4 node and the SA synthesis node in the defense network. Comparison of coi1, dde2, and jar1 profiles showed that many genes were affected by coi1, but very few were affected by dde2 or jar1. Profiles of coi1 plants infected with Psm ES4326 were very similar to those of wild-type plants infected with bacteria unable to produce the phytotoxin coronatine, indicating that essentially all COI1-dependent gene expression changes in this system are caused by coronatine.
Project description:The independent data acquisition (DIA) approach, which is a proteomic quantitative analysis method, was applied to quantitatively trace coronatine production and proteomic changes in Pseudomonas syringae pv. tomato DC3000 under different FeCl3 culture conditions.Coronatine (COR) is a new type of plant growth regulator that is produced by Pseudomonas syringae pathovars and plays an important role in modulating plant growth, development, and tolerance to multiple stresses.