title: Functional characterization and transcriptome analysis reveal multiple roles for prc in the pathogenicity of the black rot pathogen Xanthomonas campestris pv. campestris.
abstract: Gram-negative phytopathogenic Xanthomonas campestris pv. campestris (Xcc) is the causal agent of black rot in crucifers. The ability of Xcc to incite this disease in plants depends on a number of factors, including exopolysaccharides, extracellular enzymes and biofilm production. In this study, transposon mutagenesis led to identification of the prc gene, encoding a tail-specific protease, which plays a role in Xcc pathogenesis. Mutation of prc resulted in decreased virulence, extracellular protease production and bacterial attachment, with restoration to the levels of wild type by the intact prc gene. From subsequent quantitative RT-PCR analysis and reporter assay, the major extracellular protease gene prt1, biofilm-related gene galE encoding a UDP-galactose 4-epimerase and two putative adhesin genes (yapH and XC_4290 encoding autotransporter-like protein H and hemagglutinin, respectively) were found to be reduced in the prc mutant. Results of transcriptome profiling of Xcc wild type and prc mutant by RNA sequencing (RNA-Seq) showed that mutation of prc in Xcc leads to alteration in the transcriptional levels (more than twofold) of 91 genes. These differentially expressed genes were associated with a wide range of biological functions such as carbohydrate transport and metabolism, cell wall/membrane biogenesis, posttranslational modification, protein turnover and chaperones, inorganic ion transport and metabolism and signal transduction mechanisms. The results of this study facilitate the functional understanding of and provide new information about the regulatory role of prc.
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung 406, Taiwan. Electronic address: ctliao@ctust.edu.tw.
authors.forename: Chao-Tsai
authors.initials: CT
authors.lastname: Liao
authors.affiliation: Department of Biomedical Sciences, Chung Shan Medical University, Taichung 402, Taiwan. Electronic address: yfliu@csmu.edu.tw.
authors.forename: Yu-Fan
authors.initials: YF
authors.lastname: Liu
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung 406, Taiwan. Electronic address: m09401003@gmail.com.
authors.forename: Ying-Chuan
authors.initials: YC
authors.lastname: Chiang
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung 406, Taiwan. Electronic address: sslo@ctust.edu.tw.
authors.forename: Hsueh-Hsia
authors.initials: HH
authors.lastname: Lo
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung 406, Taiwan. Electronic address: spark1129@hotmail.com.
authors.forename: Shin-Chiao
authors.initials: SC
authors.lastname: Du
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung 406, Taiwan. Electronic address: patty3464@hotmail.com.
authors.forename: Pei-Chi
authors.initials: PC
authors.lastname: Hsu
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung 406, Taiwan. Electronic address: ymhsiao@ctust.edu.tw.
authors.forename: Yi-Min
authors.initials: YM
authors.lastname: Hsiao
mesh_terms: D001937:Brassica / Q000382:microbiology; D004251:DNA Transposable Elements; D010450:Endopeptidases / Q000235:genetics* / Q000378:metabolism*; D020869:Gene Expression Profiling; D005816:Genetic Complementation Test; D006801:Humans; D016254:Mutagenesis, Insertional; D009154:Mutation; D010935:Plant Diseases / Q000382:microbiology*; D060888:Real-Time Polymerase Chain Reaction; D018085:Regulon; D014774:Virulence; D016959:Xanthomonas campestris / Q000235:genetics* / Q000472:pathogenicity*
chemical_list: D004251:DNA Transposable Elements; D010450:Endopeptidases; C072135:C-terminal processing peptidase
keywords: Reporter assay; Transcriptional regulation; Virulence