The xrvA gene of Xanthomonas oryzae pv. oryzae, encoding an H-NS-like protein, regulates virulence in rice.
Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight disease in rice, one of the most serious rice diseases. The xrvA gene from Xoo strain 1,3751 encodes a protein containing a histone-like nucleoid-structuring protein (H-NS) domain. The expression of xrvA in strain 1,3751 was enhanced in XOM2 minimal medium. Mutation of the xrvA gene of strain 1,3751 led to a significant reduction in virulence in the host plant rice, a delayed hypersensitive response in the nonhost castor-oil plant, a decrease in extracellular polysaccharide and diffusible signal factor production, and an increase in intracellular glycogen accumulation. Northern hybridization analyses revealed that the virulence-associated genes hrpG, hrpX, rpfC, rpfF, rpfG and gumB were downregulated in the xrvA mutant compared to the wild-type and complemented strains. Interestingly, increase of copy number of xrvA in the wild-type strain 1,3751 resulted in a strain showing similar phenotypes as the xrvA mutant and a reduction of the expression of gumB, hrpX, rpfC, rpfF and rpfG. These findings indicate that the xrvA gene, which is highly conserved in the sequenced strains of Xanthomonas, encodes an important regulatory factor for the virulence of Xoo.
Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, PR China.
Jia-Xun
JX
Feng
Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, PR China.
Zhi-Zhong
ZZ
Song
Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, PR China.
Cheng-Jie
CJ
Duan
Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, PR China.
Shuai
S
Zhao
Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, PR China.
Ying-Qiao
YQ
Wu
Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, PR China.
Chao
C
Wang
BIOMERIT Research Centre, Department of Microbiology, BioSciences Institute, National University of Ireland, Cork, Ireland.
J Maxwell
JM
Dow
Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, PR China.
Ji-Liang
JL
Tang
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D006003:Glycogen / Q000378:metabolism; D008969:Molecular Sequence Data; D012275:Oryza / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology*; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis; D012278:Ricinus / Q000382:microbiology; D014158:Transcription, Genetic; D014774:Virulence; D037521:Virulence Factors / Q000096:biosynthesis / Q000235:genetics; D014974:Xanthomonas / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C031908:H-NS protein, bacteria; D011135:Polysaccharides, Bacterial; D037521:Virulence Factors; D006003:Glycogen