PXO_03177 encoding a hypothetical protein from Xanthomonas oryzae pv. oryzae is involved in polysaccharide production, stress tolerance, biofilm formation and virulence
F. LIU (1), G. Qian (2), G. Wu (1), Y. Zhao (1) (1) Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, China; (2) College of Plant Protection, Nanjing Agricultural University, China

Xanthomonas oryzae pv. oryzae (Xoo) is the pathogen of rice blight, a serious disease in rice production in Asia. Glycosyltransferases, which catalyzes the transfer of sugar moieties from activated donor molecules to specific acceptor molecules and form glycosidic bonds, is crucial for the pathogenicity of bacteria. Recently, with analyzing the genome of Xanthomonas oryzae pv. oryzae and systemic mutation in glycosyltransferases domain containing protein, we identified PXO_03177 ,which encoded a hypothetical protein containing glycosyl hydrolase family 99-like domain of WbsX-like glycosyltransferases. Further study showed that PXO_03177 was required for production of extracellular polysaccharides and biofilm formation. In addition, Mutation of PXO_03177 may be involved in LPS synthesis for which the loss of one LPS bands was observed on sodium dodecyl sulphate-polyacrylamide gels. However, the mutant showed no effect on cell motility and flagellar formation. Quantitative reverse transcription-PCR assays indicated that mutation of PXO_03177 did not impair the expression of other reported key virulence genes, such as flgD, flgE, rpfF, and wxacO of Xoo. The mutant was more sensitive to different environmental stresses than the wild-type strain, and showed reduced virulence and decreased growth on rice leaves. All these results suggested that the function of PXO_03177 contributed to the virulence and adaptation of Xoo in the process of infection on host rice.

Abstract Number: P7-186
Session Type: Poster