Expression profiles of hrpRS- and hrpL- mutants
Ontology highlight
ABSTRACT:
ORGANISM(S): Pseudomonas syringae pv. tomato str. DC3000
PROVIDER: GSE4848 | GEO | 2006/08/01
SECONDARY ACCESSION(S): PRJNA95847
REPOSITORIES: GEO
Similar Datasets
Project description:The type III secretion system (T3SS) is the main machinery for Pseudomonas syringae and other Gram-negative bacteria to invade plant cells. HrpR/HrpS heterodimer are key factors to activate HrpL which induces all T3SS genes by binding to a ‘hrp box’ in promoters. However, the molecular mechanisms of HrpRS on T3SS or non-T3SS genes have not been fully understood. Following by chromatin immunoprecipitation coupled to high-throughput DNA sequencing (ChIP-seq), we found that HrpRSL had 8, 38, and 36 targets on the genome, respectively. HrpS directly bound to the promoter regions of T3SS genes (hrpK1, hrpA2 and hopAJ1) as well as a group of non-T3SS genes (PSPPH_1496, PSPPH_1525, PSPPH_3494 and PSPPH_3495). Subsequent biochemical and genetic assays showed that HrpS independently regulated these genes in a hrpL deletion strain. In addition, a HrpS-binding motif (GTGCCAAA) in the hrpL promoter was identified by truncation, which was verified by EMSA in vitro and lux-reporter assay in vivo. On the contrary, HrpR alone couldn’t activate hrpL. Overall, our results demonstrated that HrpS directly regulated a group of T3SS and non-T3SS genes, which is independent on HrpL. HrpS functions as the center of the regulatory cascade in T3SS. This work deciphered the key HrpRSL-T3SS regulatory network, which provides insights to develop new strategies to control P. syringae infection in the future.
2018-06-30 | GSE103921 | GEO
Project description:The bacterial Lon protease participates in a variety of biological processes. In Pseudomonas syringae, mutation of lon is known to activate hrpL and a few hrpL-regulated genes in the rich medium. The elevated expression of hrpL and hrpL-regulated genes results from of increased stability of HrpR, the transcriptional activator of hrpL, in the lon mutant. Here we conducted a microarray analysis to determine genes that are differently expressed in the lon- mutant of P. s. pv. tomato DC3000 grown in the rich medium KB. Most genes induced in the lon- mutant belong to the HrpL-regulon or are related to the transcription, protein synthesis, and energy metabolism. The major group of genes reduced in the lon- mutant is related to cell wall biogenesis. The HrpL-regulated genes exhibit different induction patterns in the lon- mutant, suggesting the involvement of regulators additional to HrpL in regulating these genes. Compared with the wild type bacteria, the lon- mutants exhibit elevated hrpL expression in KB medium but reduced hrpL expression in the minimal medium (MM). The reduced hrpL RNA is correlated with the reduced hrpR and hrpS RNAs, suggesting that the Lon-mediated regulation of hrpL involves different mechanisms in KB and MM. Consistent with the reduced expression of the hrpL in MM, the lon- mutants are less pathogenic on host plants. Keywords: Expression profiles of lonB mutant in KB
2007-10-15 | GSE6121 | GEO
Project description:The bacterial Lon protease participates in a variety of biological processes. In Pseudomonas syringae, mutation of lon is known to activate hrpL and a few hrpL-regulated genes in the rich medium. The elevated expression of hrpL and hrpL-regulated genes results from of increased stability of HrpR, the transcriptional activator of hrpL, in the lon mutant. Here we conducted a microarray analysis to determine genes that are differently expressed in the lon- mutant of P. s. pv. tomato DC3000 grown in the rich medium KB. Most genes induced in the lon- mutant belong to the HrpL-regulon or are related to the transcription, protein synthesis, and energy metabolism. The major group of genes reduced in the lon- mutant is related to cell wall biogenesis. The HrpL-regulated genes exhibit different induction patterns in the lon- mutant, suggesting the involvement of regulators additional to HrpL in regulating these genes. Compared with the wild type bacteria, the lon- mutants exhibit elevated hrpL expression in KB medium but reduced hrpL expression in the minimal medium (MM). The reduced hrpL RNA is correlated with the reduced hrpR and hrpS RNAs, suggesting that the Lon-mediated regulation of hrpL involves different mechanisms in KB and MM. Consistent with the reduced expression of the hrpL in MM, the lon- mutants are less pathogenic on host plants. Keywords: Expression profiles of lonB mutant in KB three samples ( biological replicates) of mutation were analyzed
2007-10-14 | E-GEOD-6121 | biostudies-arrayexpress
Project description:ChIP-seq for HrpR, HrpS, and HrpL
| PRJNA408144 | ENA
Project description:Pseudomonas syringae pv. tomato DC3000 (Pst) is a virulent pathogen, which causes disease on tomato and Arabidopsis. The type III secretion system (TTSS) plays a key role in pathogenesis by translocating virulence effectors from the bacteria into the plant host cell, while the phytotoxin coronatine (COR) contributes to virulence and disease symptom development. Recent studies suggest that both the TTSS and and COR are involved in the suppression of host basal defenses. However, little is known about the interplay between the host gene expression associated with basal defenses and the virulence activities of the TTSS and COR during infection. The global effects of the TTSS and COR on host gene expression associated with other host cellular processes during bacterial infection are also not well characterized. In this study, we used the Affymetrix full genome chip to determine the Arabidopsis transcriptome associated with basal defense to Pst DC3000 hrp mutants and the human pathogenic bacterium Escherichia coli O157:H7. We then used Pst DC3000 virulence mutants to characterize Arabidopsis transcriptional responses to the action of hrp-regulated virulence factors (e.g., TTSS and COR) during bacterial infection. Additionally, we used bacterial fliC mutants to assess the role of the PAMP flagellin in induction of basal defense-associated transcriptional responses. In total, our global gene expression analysis identified more than 5000 Arabidopsis genes that are reproducibly regulated more than 2-fold in three independent biological replicates of at least one type of comparison. Regulation of these genes provides a molecular signature for Arabidopsis basal defense to plant and human pathogenic bacteria, and illustrates both common and distinct global virulence effects of the TTSS, COR, and possibly other hrp-regulated virulence factors during Pst DC3000 infection. Experimenter name = William Underwood; Experimenter phone = 517-353-9182; Experimenter fax = 517-353-9168; Experimenter address = Michigan State University; Experimenter address = 222 Plant Biology Building; Experimenter address = 178 Wilson R.d. Experimenter address = East Lansing, MI; Experimenter zip/postal_code = 48824; Experimenter country = USA Experiment Overall Design: 40 samples were used in this experiment
2008-06-13 | E-GEOD-5520 | biostudies-arrayexpress
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.
2014-01-01 | E-GEOD-46930 | biostudies-arrayexpress
Project description:Pseudomonas syringae pv. tomato DC3000 (Pst) is a virulent pathogen, which causes disease on tomato and Arabidopsis. The type III secretion system (TTSS) plays a key role in pathogenesis by translocating virulence effectors from the bacteria into the plant host cell, while the phytotoxin coronatine (COR) contributes to virulence and disease symptom development. Recent studies suggest that both the TTSS and and COR are involved in the suppression of host basal defenses. However, little is known about the interplay between the host gene expression associated with basal defenses and the virulence activities of the TTSS and COR during infection. The global effects of the TTSS and COR on host gene expression associated with other host cellular processes during bacterial infection are also not well characterized. In this study, we used the Affymetrix full genome chip to determine the Arabidopsis transcriptome associated with basal defense to Pst DC3000 hrp mutants and the human pathogenic bacterium Escherichia coli O157:H7. We then used Pst DC3000 virulence mutants to characterize Arabidopsis transcriptional responses to the action of hrp-regulated virulence factors (e.g., TTSS and COR) during bacterial infection. Additionally, we used bacterial fliC mutants to assess the role of the PAMP flagellin in induction of basal defense-associated transcriptional responses. In total, our global gene expression analysis identified more than 5000 Arabidopsis genes that are reproducibly regulated more than 2-fold in three independent biological replicates of at least one type of comparison. Regulation of these genes provides a molecular signature for Arabidopsis basal defense to plant and human pathogenic bacteria, and illustrates both common and distinct global virulence effects of the TTSS, COR, and possibly other hrp-regulated virulence factors during Pst DC3000 infection. Experimenter name = William Underwood Experimenter phone = 517-353-9182 Experimenter fax = 517-353-9168 Experimenter address = Michigan State University Experimenter address = 222 Plant Biology Building Experimenter address = 178 Wilson R.d. Experimenter address = East Lansing, MI Experimenter zip/postal_code = 48824 Experimenter country = USA Keywords: pathogenicity_design
2006-08-15 | GSE5520 | GEO
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
2014-01-01 | GSE46930 | GEO
Project description:The bacterial pathogen Erwinia amylovora is the causal agent of fire blight, an economically significant disease of apple and pear. Disease initiation by E. amylovora requires the translocation of effector proteins into host cells by the hypersensitive response and pathogenicity (hrp) type III secretion system (T3SS). The alternate sigma factor HrpL positively regulates the transcription of structural and translocated components of the T3SS via hrp promoter elements. To characterize genome-wide hrpL-dependent gene expression in E. amylovora Ea1189, wild-type and Ea1189hrpL strains were cultured in hrp-inducing minimal medium, and total RNA was compared using a custom microarray designed to represent the annotated genes of E. amylovora ATCC 49946. Results revealed 24 genes differentially-regulated in Ea1189hrpL compared to Ea1189 with fold-change expression ratios greater than 1.5; of these, the expression of 19 genes was up-regulated while five genes exhibited negative regulation. To expand our understanding of the HrpL regulon and to elucidate direct versus indirect hrpL-mediated effects on gene expression, the genome of E. amylovora ATCC 49946 was examined in silico using a hidden Markov model assembled from known Erwinia spp. hrp promoters. This technique identified 21 putative type III novel hrp promoters; of these, 8+ were validated with quantitative polymerase chain reaction based on expression analyses. In total, hrpL-regulated genes encode all known components of the hrp T3SS and 5 putative type III effectors. Eight genes displayed apparent indirect hrpL regulation suggesting that the hrpL regulon is connected to downstream signaling networks. Construction of deletion mutants of three novel hrpL-regulated genes has resulted in the identification of additional virulence factors in E. amylovora as well as mutants displaying abnormal motility and biofilm phenotypes.
2012-03-28 | E-TABM-1137 | biostudies-arrayexpress
Project description:Pseudomonas syringae, a Gram-negative plant pathogen, infects more than 50 crops with its type III secretion system (T3SS) and causes severe economic losses around the world. Although the mechanisms of virulence-associated regulators of P. syringae T3SS have been studied for decades, the crosstalk and network underlying these regulators are still elusive. Previously, we have individually studied a group of T3SS regulators, including AefR, HrpS, and RhpRS. In the present study, we found 4 new T3SS regulator genes (envZ, ompR, tsiS and phoQ) via transposon-mediated mutagenesis. Two-component systems EnvZ and TsiS natively regulate T3SS. In order to uncover the crosstalk between 16 virulence-associated regulators, (including AefR, AlgU, CvsR, GacA, HrpL, HrpR, HrpS, MgrA, OmpR, PhoP, PilR, PsrA, RhpR, RpoN, TsiR and Vfr) in P. syringae, we mapped an intricate network named PSVnet (Pseudomonas syringae Virulence Regulatory Network) by combining differentially expression genes in RNA-seq and binding loci in ChIP-seq of all regulators.
2021-03-29 | GSE138204 | GEO