The rsmA-like gene rsmA(Xcc) of Xanthomonas campestris pv. campestris is involved in the control of various cellular processes, including pathogenesis.
RsmA is an RNA-binding protein functioning as a global post-transcriptional regulator of various cellular processes in bacteria and has been demonstrated to be an important virulence regulator in many animal bacterial pathogens. However, its function in other phytopathogenic bacteria is unclear, except for the Erwinia carotovora RsmA, which acts as a negative virulence regulator. In this work, we investigated the function of the rsmA-like gene, named rsmA(Xcc), of the phytopathogen Xanthomonas campestris pv. campestris. Deletion of rsmA(Xcc) resulted in complete loss of virulence on the host plant Chinese radish, hypersensitive response on the nonhost plant pepper ECW-10R, and motility on the surface of an agar plate. The rsmA(Xcc) mutant displayed a significant reduction in the production of extracellular amylase, endoglucanase, and polysaccharide, but a significant increase in intracellular glycogen accumulation and an enhanced bacterial aggregation and cell adhesion. Microarray hybridization and semiquantitative reverse-transcription polymerase chain reaction analysis showed that deletion of rsmA(Xcc) led to significantly reduced expression of genes encoding the type III secretion system (T3SS), T3SS-effectors, and the bacterial aggregate dispersing enzyme endo-beta-1,4-mannanase. These results suggest that rsmA(Xcc) is involved in the control of various cellular processes, including pathogenesis of X. campestris pv. campestris.
Chao
Nai-Xia
NX
Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, Guangxi University, 100 Daxue Road, Nanning Guangxi 530004, China.
Wei
Ke
K
Chen
Qi
Q
Meng
Qing-Lin
QL
Tang
Dong-Jie
DJ
He
Yong-Qiang
YQ
Lu
Guang-Tao
GT
Jiang
Bo-Le
BL
Liang
Xiao-Xia
XX
Feng
Jia-Xun
JX
Chen
Baoshan
B
Tang
Ji-Liang
JL
D000595:Amino Acid Sequence; D000681:Amylases / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology; D002480:Cellulase / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006003:Glycogen / Q000378:metabolism; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D011134:Polysaccharides / Q000378:metabolism; D031224:Raphanus / Q000254:growth & development / Q000382:microbiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014774:Virulence / Q000235:genetics; D016959:Xanthomonas campestris / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity
D001426:Bacterial Proteins; D011134:Polysaccharides; D006003:Glycogen; D000681:Amylases; D002480:Cellulase