title: A novel locus involved in extracellular polysaccharide production and virulence of Xanthomonas campestris pathovar campestris.
abstract: Xanthomonas campestris pathovar campestris (Xcc) is the causal agent of black rot disease in cruciferous plants. The extracellular polysaccharide (EPS) produced by Xcc is an important pathogenicity factor and also has a range of industrial uses. In preliminary work a number of transposon-mediated insertion mutants in Xcc with defects in EPS production were identified. Here, one of these mutated loci was investigated in detail. Six ORFs within the locus (ORFs XC3811-3816) were disrupted by plasmid integration. Mutation of XC3813, XC3814 or XC3815 resulted in significantly reduced EPS production and significantly reduced virulence on the host plant Chinese radish (Raphanus sativus). The EPS production and virulence of XC3813, XC3814 and XC3815 mutants could be restored by intact XC3813, XC3814 and XC3815 genes, respectively, when provided in trans. Although bioinformatic analysis suggested a role for XC3814 and XC3815 in lipopolysaccharide biosynthesis, the lipopolysaccharides produced by the mutants were indistinguishable from those of the wild-type, as judged by electrophoretic mobility in SDS-polyacrylamide gels. These results reveal that XC3813, XC3814 and XC3815 comprise a novel gene cluster involved in EPS production and virulence of Xcc.
authors.affiliation: 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, China.
authors.forename: Guang-Tao
authors.initials: GT
authors.lastname: Lu
authors.affiliation: 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, China.
authors.forename: Zeng-Feng
authors.initials: ZF
authors.lastname: Ma
authors.affiliation: 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, China.
authors.forename: Jiang-Ru
authors.initials: JR
authors.lastname: Hu
authors.affiliation: 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, China.
authors.forename: Dong-Jie
authors.initials: DJ
authors.lastname: Tang
authors.affiliation: 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, China.
authors.forename: Yong-Qiang
authors.initials: YQ
authors.lastname: He
authors.affiliation: 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, China.
authors.forename: Jia-Xun
authors.initials: JX
authors.lastname: Feng
authors.affiliation: 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, China.
authors.forename: Ji-Liang
authors.initials: JL
authors.lastname: Tang
mesh_terms: D004591:Electrophoresis, Polyacrylamide Gel; D005816:Genetic Complementation Test; D008070:Lipopolysaccharides / Q000032:analysis; D016254:Mutagenesis, Insertional; D016366:Open Reading Frames / Q000235:genetics; D010935:Plant Diseases / Q000382:microbiology; D010957:Plasmids / Q000235:genetics; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis* / Q000235:genetics; D031224:Raphanus / Q000382:microbiology*; D014774:Virulence / Q000235:genetics; D016959:Xanthomonas campestris / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity
chemical_list: D008070:Lipopolysaccharides; D011135:Polysaccharides, Bacterial