title: A putative colR(XC1049)-colS(XC1050) two-component signal transduction system in Xanthomonas campestris positively regulates hrpC and hrpE operons and is involved in virulence, the hypersensitive response and tolerance to various stresses.
abstract: The ColR-ColS two-component signal transduction system was originally characterized as a regulatory system involved in the capacity of root-colonizing biocontrol bacterium Pseudomonas fluorescens to colonize plant roots. There are three pairs of putative colR-colS two-component regulatory systems annotated in the phytopathogen Xanthomonas campestris pathovar campestris. Mutational studies revealed that one of them, named colR(XC1049) and colS(XC1050), is a global regulatory system involved in various cellular processes, including virulence, hypersensitive response and stress tolerance. Growth rate determination showed that, although the colR(XC1049) and colS(XC1050) mutants are not auxotrophic, colR(XC1049) and colS(XC1050) are required for the pathogen to proliferate well in standard media and host plants. Assays of beta-glucuronidase activities of plasmid-driven promoter-gusA reporters and/or semi-quantitative RT-PCR demonstrated that colR(XC1049) and colS(XC1050) positively regulate expression of hrpC and hrpE operons, and that expression of colR(XC1049) and colS(XC1050) is not controlled by key hrp regulators HrpG and HrpX.
authors.affiliation: Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China.
authors.forename: Sui-Sheng
authors.initials: SS
authors.lastname: Zhang
authors.forename: Yong-Qiang
authors.initials: YQ
authors.lastname: He
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Xu
authors.forename: Bo-Wen
authors.initials: BW
authors.lastname: Chen
authors.forename: Bo-Le
authors.initials: BL
authors.lastname: Jiang
authors.forename: Jie
authors.initials: J
authors.lastname: Liao
authors.forename: Jin-Rui
authors.initials: JR
authors.lastname: Cao
authors.forename: Dan
authors.initials: D
authors.lastname: Liu
authors.forename: Yan-Qiang
authors.initials: YQ
authors.lastname: Huang
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Liang
authors.forename: Dong-Jie
authors.initials: DJ
authors.lastname: Tang
authors.forename: Guang-Tao
authors.initials: GT
authors.lastname: Lu
authors.forename: Ji-Liang
authors.initials: JL
authors.lastname: Tang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D009154:Mutation; D009876:Operon; D010935:Plant Diseases / Q000382:microbiology*; D031224:Raphanus / Q000382:microbiology*; D015398:Signal Transduction; D015854:Up-Regulation; D014774:Virulence; D016959:Xanthomonas campestris / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology
chemical_list: D001426:Bacterial Proteins