Project description:To characterize the PTI response of tomato and the effect of the delivery of a subset of effectors, we performed an RNA-seq analysis of tomato Rio Grande prf3 leaves challenged with either the flgII-28 peptide or the following bacterial strains: Agrobacterium tumefaciens GV2260, Pseudomonas fluorescens 55, Pseudomonas putida KT2440, Pseudomonas syringae pv. tomato (Pst) DC3000, Pst DC3000 deltahrcQ-U deltafliC and Pst DC3000 deltaavrPto deltaavrPtoB. NOTE: Samples in SRA were assigned the same sample accession. This is incorrect as there are different samples, hence âSource Nameâ was replaced with new values. Comment[ENA_SAMPLE] contains the original SRA sample accessions.
Project description:To explore the effect of light perception on Pseudomonas syringae pv. tomato DC3000 at a global level, we carried out microarray hybridization experiments. We hybridize custom-designed microarrays (Agilent Technologies) with probes isolated from PsPto after a 10 min treatment with either 20 μE/m2s blue light, 20 μE/m2s red light, 70 μE/m2s white light, or cells kept in the darkness.
Project description:Background: Plants attenuate their responses to a variety of bacterial and fungal pathogens, leading to higher incidences of pathogen infection at night. However, little is known about the molecular mechanism responsible for the light-induced defence response; transcriptome data would likely facilitate the elucidation of this mechanism. Results: In this study, we observed diurnal changes in tomato resistance to Pseudomonas syringae pv. tomato DC3000 (Pto DC3000), with the greatest susceptibility before midnight. Nightly light treatment, particularly red light treatment, significantly enhanced the resistance; this effect was correlated with increased salicylic acid (SA) accumulation and defence-related gene transcription. RNA-seq analysis revealed that red light induced a set of circadian rhythm-related genes involved in the phytochrome and SA-regulated resistance response. The biosynthesis and signalling pathways of multiple plant hormones (auxin, SA, jasmonate, and ethylene) were co-ordinately regulated following Pto DC3000 infection and red light, and the SA pathway was most significantly affected by red light and Pto DC3000 infection. This result indicates that SA-mediated signalling pathways are involved in red light-induced resistance to pathogens. Importantly, silencing of nonexpressor of pathogensis-related genes 1 (NPR1) partially compromised red light-induced resistance against Pto DC3000. Furthermore, sets of genes involved in redox homeostasis (respiratory burst oxidase homologue, RBOH; glutathione S-transferases, GSTs; glycosyltransferase, GTs), calcium (calmodulin, CAM; calmodulin-binding protein, CBP), and defence (polyphenol oxidase, PPO; nudix hydrolase1, NUDX1) as well as transcription factors (WRKY18, WRKY53, WRKY60, WRKY70) and cellulose synthase were differentially induced at the transcriptional level by red light in response to pathogen challenge. Conclusions: Taken together, our results suggest that there is a diurnal change in susceptibility to Pto DC3000 with greatest susceptibility in the evening. The red light induced-resistance to Pto DC3000 at night is associated with enhancement of the SA pathway, cellulose synthase, and reduced redox homeostasis.
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:Background: Plants attenuate their responses to a variety of bacterial and fungal pathogens, leading to higher incidences of pathogen infection at night. However, little is known about the molecular mechanism responsible for the light-induced defence response; transcriptome data would likely facilitate the elucidation of this mechanism. Results: In this study, we observed diurnal changes in tomato resistance to Pseudomonas syringae pv. tomato DC3000 (Pto DC3000), with the greatest susceptibility before midnight. Nightly light treatment, particularly red light treatment, significantly enhanced the resistance; this effect was correlated with increased salicylic acid (SA) accumulation and defence-related gene transcription. RNA-seq analysis revealed that red light induced a set of circadian rhythm-related genes involved in the phytochrome and SA-regulated resistance response. The biosynthesis and signalling pathways of multiple plant hormones (auxin, SA, jasmonate, and ethylene) were co-ordinately regulated following Pto DC3000 infection and red light, and the SA pathway was most significantly affected by red light and Pto DC3000 infection. This result indicates that SA-mediated signalling pathways are involved in red light-induced resistance to pathogens. Importantly, silencing of nonexpressor of pathogensis-related genes 1 (NPR1) partially compromised red light-induced resistance against Pto DC3000. Furthermore, sets of genes involved in redox homeostasis (respiratory burst oxidase homologue, RBOH; glutathione S-transferases, GSTs; glycosyltransferase, GTs), calcium (calmodulin, CAM; calmodulin-binding protein, CBP), and defence (polyphenol oxidase, PPO; nudix hydrolase1, NUDX1) as well as transcription factors (WRKY18, WRKY53, WRKY60, WRKY70) and cellulose synthase were differentially induced at the transcriptional level by red light in response to pathogen challenge. Conclusions: Taken together, our results suggest that there is a diurnal change in susceptibility to Pto DC3000 with greatest susceptibility in the evening. The red light induced-resistance to Pto DC3000 at night is associated with enhancement of the SA pathway, cellulose synthase, and reduced redox homeostasis. Four treatments including control, three biological replicates each treatment
Project description:Arabidopsis thaliana (Col-0) plants were treated with BABA and gene expression differences to control plants were monitored after dip-inoculation with Pseudomonas syringae pv tomato DC3000. Keywords: transcript profiling, response to BABA-induced priming and infection
Project description:The goals of the study are to compare the influence of CO2 concentration and Pseudomonas syringae pv. tomato DC3000 (Pst) in wild type and βca3 mutant plants to cover the mechanism of βCA3-mediated basal immunity.
Project description:To understand role of SALT- AND DROUGHT-INDUCED REALLY INTERESTING NEW GENE FINGER1 Gene (SDIR1). The expression profiling studies of SDIR1 overexpression plants and sdir1 mutants infected with P. syringae pv. tomato (DC3000) in comparison with wild-type control plants was conducted for plants three weeks after germination. Transcriptome data show that SDIR1 plays key role in suppression of salicylic acid (SA) mediated defense to cause susceptibility against biotrophic or hemi-biotrphic pathogens and resistance against necrotrophic pathogens.
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.
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