A novel two-component system PdeK/PdeR regulates c-di-GMP turnover and virulence of Xanthomonas oryzae pv. oryzae.
Two-component systems (TCS) consisting of histidine kinases (HK) and response regulators (RR) play essential roles in bacteria to sense environmental signals and regulate cell functions. One type of RR is involved in metabolism of cyclic diguanylate (c-di-GMP), a ubiquitous bacterial second messenger. Although genomic studies predicted a large number of them existing in different bacteria, only a few have been studied. In this work, we characterized a novel TCS consisting of PdeK(PXO_01018)/PdeR(PXO_ 01019) from Xanthomonas oryzae pv. oryzae, which causes the bacterial leaf blight of rice. PdeR (containing GGDEF, EAL, and REC domains) was shown to have phosphodiesterase (PDE) activity in vitro by colorimetric assays and high-performance liquid chromatography analysis. The PDE activity of full-length PdeR needs to be triggered by HK PdeK. Deletion of pdeK or pdeR in X. oryzae pv. oryzae PXO99(A) had attenuated its virulence on rice. ΔpdeK and ΔpdeR secreted less exopolysaccharide than the wild type but there were no changes in terms of motility or extracellular cellulase activity, suggesting the activity of PdeK/PdeR might be specific.
Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Fenghuan
F
Yang
Fang
F
Tian
Lei
L
Sun
Huamin
H
Chen
Maosen
M
Wu
Ching-Hong
CH
Yang
Chenyang
C
He
D001426:Bacterial Proteins / Q000378:metabolism*; D003001:Cloning, Molecular; D019295:Computational Biology; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D000071677:Histidine Kinase; D012275:Oryza / Q000382:microbiology; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D014774:Virulence; D014974:Xanthomonas / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*
D001426:Bacterial Proteins; C062025:bis(3',5')-cyclic diguanylic acid; D011494:Protein Kinases; D000071677:Histidine Kinase; D010727:Phosphoric Diester Hydrolases; D006152:Cyclic GMP