title: The Zur of Xanthomonas campestris is involved in hypersensitive response and positively regulates the expression of the hrp cluster via hrpX but not hrpG.
abstract: In bacteria, Zur is a key regulator for zinc homeostasis. Our previous work has shown that, in the phytopathogen Xanthomonas campestris pv. campestris, in addition to regulating zinc homeostasis, Zur is essential for full virulence. Here, we demonstrate that the X. campestris pv. campestris Zur is involved in hypersensitive response (HR) and positively regulates the transcription of hrpA to hrpF operons and hrpX but not hrpG. Constitutively expressing hrpX but not hrpG in the zur mutant could bypass the requirement of Zur for the expression of hrpA to hrpF operons and the induction of wild-type HR, indicating that Zur controls the expression of hrp cluster via hrpX. Promoter-gusA reporter and semiquantitative reverse-transcription polymerase chain reaction analyses revealed that HrpG controls the expression of hrpX and HrpX regulates the expression of all the six hrp operons (hrpA to hrpF) in X. campestris pv. campestris.
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: Dong-Liang
authors.initials: DL
authors.lastname: Huang
authors.forename: Dong-Jie
authors.initials: DJ
authors.lastname: Tang
authors.forename: Qing
authors.initials: Q
authors.lastname: Liao
authors.forename: Xiao-Qian
authors.initials: XQ
authors.lastname: Li
authors.forename: Yong-Qiang
authors.initials: YQ
authors.lastname: He
authors.forename: Jia-Xun
authors.initials: JX
authors.lastname: Feng
authors.forename: Bo-Le
authors.initials: BL
authors.lastname: Jiang
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*; D002212:Capsicum / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D016959:Xanthomonas campestris / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; C102404:HrpG protein, Xanthomonas campestris; C080371:HrpX protein, Bacteria; D014157:Transcription Factors