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.
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.
Zhang
Sui-Sheng
SS
Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China.
He
Yong-Qiang
YQ
Xu
Li-Ming
LM
Chen
Bo-Wen
BW
Jiang
Bo-Le
BL
Liao
Jie
J
Cao
Jin-Rui
JR
Liu
Dan
D
Huang
Yan-Qiang
YQ
Liang
Xiao-Xia
XX
Tang
Dong-Jie
DJ
Lu
Guang-Tao
GT
Tang
Ji-Liang
JL
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
D001426:Bacterial Proteins