title: UDP-glucose dehydrogenase gene of Xanthomonas campestris is required for virulence.
abstract: Xanthomonas campestris pv. campestris (Xc) is the casual agent of black rot in crucifers. The Xc gene (udgH) coding for UDP-glucose dehydrogenase, an enzyme catalyzing the conversion of UDP-glucose to UDP-glucuronic acid, was previously shown to be required for the biosynthesis of xanthan gum, a substance necessary for the bacterium to cause disease. In this study, the transcription start site of the udgH was determined and the promoter activity monitored by the xylE reporter system indicated that expression of the udgH increases following cell growth and that the udgH gene may possess a second promoter that is responsive to stationary-phase change retaining high levels of expression. Results of Southern hybridization suggest that the udgH gene may be ubiquitous in Xanthomonas, coincident with the notion that members of this genus are capable of xanthan gum biosynthesis. Mutation of the udgH gene in Xc and X. campestris pv. vesicatoria, the casual agent of leaf spot in pepper and tomato, was found to cause a loss of virulence.
authors.affiliation: Institute of Molecular Biology, National Chung Hsing University, Taichung 402, Taiwan, Republic of China.
authors.forename: K W
authors.initials: KW
authors.lastname: Chang
authors.forename: S F
authors.initials: SF
authors.lastname: Weng
authors.forename: Y H
authors.initials: YH
authors.lastname: Tseng
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010935:Plant Diseases / Q000382:microbiology*; D014158:Transcription, Genetic; D014533:Uridine Diphosphate Glucose Dehydrogenase / Q000235:genetics* / Q000502:physiology; D014774:Virulence; D016959:Xanthomonas campestris / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity
chemical_list: D014533:Uridine Diphosphate Glucose Dehydrogenase