title: The rsmA-like gene rsmA(Xcc) of Xanthomonas campestris pv. campestris is involved in the control of various cellular processes, including pathogenesis.
abstract: 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.
authors.affiliation: 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.
authors.forename: Nai-Xia
authors.initials: NX
authors.lastname: Chao
authors.forename: Ke
authors.initials: K
authors.lastname: Wei
authors.forename: Qi
authors.initials: Q
authors.lastname: Chen
authors.forename: Qing-Lin
authors.initials: QL
authors.lastname: Meng
authors.forename: Dong-Jie
authors.initials: DJ
authors.lastname: Tang
authors.forename: Yong-Qiang
authors.initials: YQ
authors.lastname: He
authors.forename: Guang-Tao
authors.initials: GT
authors.lastname: Lu
authors.forename: Bo-Le
authors.initials: BL
authors.lastname: Jiang
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Liang
authors.forename: Jia-Xun
authors.initials: JX
authors.lastname: Feng
authors.forename: Baoshan
authors.initials: B
authors.lastname: Chen
authors.forename: Ji-Liang
authors.initials: JL
authors.lastname: Tang
mesh_terms: 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
chemical_list: D001426:Bacterial Proteins; D011134:Polysaccharides; D006003:Glycogen; D000681:Amylases; D002480:Cellulase