[Cloning, sequencing and fuctional study of gacA gene from Xanthomonas oryzae pv. oryzicola].
A gacA homologue, designated gacA(Xooc), was cloned from Xanthomonas oryzae pv. oryzicola (Xooc), a bacterium that causes leaf streak of rice, with degenerated primers by polymerase amplification reaction (PCR). NCBI blast search indicated that GacA(Xooc) had a similar structure to that of other GacA proteins, and had a CheB (Chemotaxis response regulator containing a CheY-like receiver domain)domain. Sequence comparison showed that the gacA(Xooc) was conserved in the Xanthomonas genus. Homology search revealed that the gacA(Xooc) was 99.7% similarities to gacA (AY870457, this lab) of Xanthomonas oryzae pv. oryzae (Xoo). A gacA(Xooc), disruption mutant was successfully generated by a single cross-over event, and confirmed by PCR and Southern blot. But the mutant still had strong pathogenicity,and its virulence was not obviously different from that of wild type strain. The gacA did not globally regulate metabolism in Xooc, which was different from DC3000 of P. syringae pv. tomato, CHAO of P. fluorescens and IC1270 of Serratia plymuthica. Chemotaxis to 0.1% tryptone of the mutants was reduced compared to wild type strain. The results suggest that gacA(X00c) is involved chemotaxis of Xooc. Nevertheless, how gacA to regulate chemotaxis of Xooc, transcription and expression of genes involved in regulation still need to be further studied.
Yang
Wan-feng
WF
Key Laboratory of Monitoring and Management of Plant Diseases and Insects of Chinese Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China. ywf307@163.com
Chen
Lei
L
Liu
Hong-xia
HX
Hu
Bai-shi
BS
Liu
Feng-quan
FQ
D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D002633:Chemotaxis; D003001:Cloning, Molecular; D009154:Mutation; D012275:Oryza / Q000382:microbiology*; D014974:Xanthomonas / Q000235:genetics*
D001426:Bacterial Proteins; C091100:GacA protein, Bacteria