A systematic analysis of the role of GGDEF-EAL domain proteins in virulence and motility in Xanthomonas oryzae pv. oryzicola

作者：Wei, Chao; Jiang, Wendi; Zhao, Mengran; Ling, Junjie; Zeng, Xin; Deng, Jun; Jin, Dongli; Dow, John Maxwell; Sun, Wenxian^*

来源：Scientific Reports, 2016, 6(1): 23769.

DOI：10.1038/srep23769

• CYCLIC-DI-GMP
• PSEUDOMONAS-FLUORESCENS PF0-1
• BIOFILM FORMATION
• EXOPOLYSACCHARIDE PRODUCTION
• ACETOBACTER-XYLINUM
• CELLULOSE SYNTHESIS
• BACTERIAL-BLIGHT
• BINDING PROTEIN
• GENE-EXPRESSION
• CAMPESTRIS

The second messenger c-di-GMP is implicated in regulation of various aspects of the lifestyles and virulence of Gram-negative bacteria. Cyclic di-GMP is formed by diguanylate cyclases with a GGDEF domain and degraded by phosphodiesterases with either an EAL or HD-GYP domain. Proteins with tandem GGDEF-EAL domains occur in many bacteria, where they may be involved in c-di-GMP turnover or act as enzymatically-inactive c-di-GMP effectors. Here, we report a systematic study of the regulatory action of the eleven GGDEF-EAL proteins in Xanthomonas oryzae pv. oryzicola, an important rice pathogen causing bacterial leaf streak. Mutational analysis revealed that XOC_2335 and XOC_2393 positively regulate bacterial swimming motility, while XOC_2102, XOC_2393 and XOC_ 4190 negatively control sliding motility. The Delta OC_2335/XOC_2393 mutant that had a higher intracellular c-di-GMP level than the wild type and the Delta OC_4190 mutant exhibited reduced virulence to rice after pressure inoculation. In vitro purified XOC_ 4190 and XOC_ 2102 have little or no diguanylate cyclase or phosphodiesterase activity, which is consistent with unaltered c-di-GMP concentration in Delta OC_4190. Nevertheless, both proteins can bind to c-di-GMP with high affinity, indicating a potential role as c-di-GMP effectors. Overall our findings advance understanding of c-di-GMP signaling and its links to virulence in an important rice pathogen.

• 出版日期2016-4-7
• 单位中国农业大学