Project description:This study evaluates the transcriptome of four genotypes of Arabidopsis thaliana infected at the seedling stage with the Pseudomonas syringae strain DC3000 cor-. Overall design: Arabidopsis thaliana seedlings were grown under short day conditions (9h of light at 21°C - 15h of dark at 18°C) for two weeks. Plants were sprayed with a suspension of the Pseudomonas syringae strain DC3000 cor- and harvested after 24h. A mock treatment was also included. Lines Col-0 (3 replicates), UBQ10::YFP-TCP14-4 (3 replicates), tcp14-6 (3 replicates) and coi1-16 (3 replicates) were used in the experiment. Each replicate corresponds to approximately 30 seedlings grown in the same pot.
Project description:We implemented transcriptional analysis methods using cDNA and high-throughput sequencing data to identify HrpL-regulated genes for six strains of Pseudomonas syringae Each Pseudomonas syringae strains was transformed with either pBAD::EV or pBAD containing native hrpL sequence. Strains were grown in MM media supplemented with arabinose and collected 1, 3, and 5 hours post arabinose treatment. RNA was extracted for each time point and mixed at a 1/3 ratio. After removal of rRNA, double stranded cDNA was generated and library prepared accordeing to Illumina protocols.
Project description:This study evaluates the transcriptome of Arabidopsis thaliana infected with the Pseudomonas syringae strain DC3000 cor- carrying the type three secretion system effector HopBB1 Overall design: Two-week-old Arabidopsis thaliana seedlings (Col-0 ecotype) were sprayed with a mock solution (10 mM MgCl2) or bacteria [Pto DC3000 (EV), Pto DC3000 cor- (EV); Pto DC3000 cor- (HopBB1); Pto DC3000 cor- (HopBB1G126D)] at OD600=0.2 with 10mM MgCl2 and 0.04% Silwet L-77. Samples were harvested 24 hours after infection. This experiment included three biological replicates, each one corresponding to approximately 30 seedlings grown in the same pot.
Project description:Pseudomonas syringae pv. phaseolicola (Pph) is a significant bacterial pathogen of agricultural crops, and phage Φ6 and other members of the dsRNA virus family Cystoviridae undergo lytic (virulent) infection of Pph, using the type IV pilus as the initial site of cellular attachment. Despite the popularity of Pph/phage Φ6 as a model system in evolutionary biology, Pph resistance to phage Φ6 remains poorly characterized. To investigate differences between phage Φ6 resistant Pseudomonas syringae pathovar phaseolicola strains, we performed expression analysis of super and non piliated strains of Pseudomonas syringae to determine the genetic cause of resistance to viral infection.
Project description:Pseudomonas syringae uses two-component system RhpRS to regulate the expression of type III secretion system (T3SS) genes and bacterial virulence. However, the molecular mechanism and the regulons of RhpRS have yet to be fully elucidated. Here we show that RhpS functions as an autokinase, an RhpR kinase, and a P-RhpR phosphatase. RhpR can also be phosphorylated by small phosphodonor acetyl phosphate. A specific RhpR-binding site containing an inverted repeat (IR) motif GTATC-N6-GATAC, was mapped to its own promoter by DNase I footprint analysis. Electrophoretic mobility shift assay (EMSA) indicated that P-RhpR has higher binding activity than RhpR to the IR motif. To identify additional targets of RhpR in P. syringae, we performed chromatin immunoprecipitation followed by high-throughput DNA sequencing (ChIP-seq), which detected 167 enriched loci including the hrpR promoter, indicating the direct regulation of T3SS cascade genes by RhpR. Genome-wide microarray analysis showed that, besides the T3SS cascade genes, RhpR differentially regulates a large set of genes of various functions in response to different growth conditions. Together, these results suggested that RhpRS is a global regulator that allows P. syringae to sense and respond to environmental changes to coordinate the T3SS and many other biological processes. ChIP-seq analysis of RhpR
Project description:We used three different strains of Pseudomonas syringae pv tomato DC3000 to investigate systemic responses to infection in Arabidopsis and the development of SAR. Wildtype DC3000, the hrpA mutant and DC3000 carrying the avirulence gene avrRpm1 were syringe infiltrated into 4-week-old plants at a concentration of 10e8 cfu/ml. At least 5 leaves per plant were infiltrated and at least 10 plants were pooled for each sample. Systemic, uninfected tissue was then harvested at 8, 12 and 21h after inoculation. Three independent experiments were carried out to give three biological replicates for each timepoint. Overall design: 27 samples were used in this experiment.
Project description:This study investigates extent and functional significance of alternative splicing in Arabidopsis thaliana defense against the bacterial pathogen Pseudomonas syringae pv tomato (Pst). We have provided a detailed characterization of the Arabidopsis thaliana transcriptional response to Pseudomonas syringae infection in both susceptible and resistant hosts. We carried out two independent inoculation experiments (biological replicates) for each treatment. Col-0 is susceptible to virulent Pst DC3000 but has a functional RPS4 resistance gene effective against DC3000 expressing AvrRps4