水稻条斑病菌是水稻上重要的细菌病原物，引起水稻细菌性条斑病。营养的获取对于病原物在寄主水稻体内生长繁殖、成功建立侵染关系异常重要。申请人前期研究，从水稻条斑病菌突变体库中扫描出新的毒性因子-编码异柠檬酸脱氢酶（isocitrate dehydrogenase, IcdH），icdH突变，病原菌的致病性、全毒性、在水稻组织中的生长能力均显著下降，同时它还调控着DSF信号通路关键基因rpfF、rpfG、clp的转录表达，但其分子机理尚不清楚。本项目拟通过碳代谢途径分析、毒性相关因子检测以及DSF定性/量检测等手段，分析icdH与毒性、群体感应DSF信号分子的关联性；借助代表性基因转录分析，明确碳代谢与hrp基因表达之间的调控关系；最终全面解析icdH参与条斑病菌全毒性的分子机理。这对于揭示病原细菌与植物互作的分子机理、筛选药物靶标、开展高效的生物防治策略等，均具有重要的科学意义和实践价值。

Xanthomonas oryzae pv. oryzicola is the important bacterial pathogen, causing serious bacterial leaf streak (BLS) in rice. The ability to acquire carbohydrate is essential for a pathogen to propagate and successfully establish an infection relationship in host plant. The applicant previously study that scan a novel virulence factor, isocitrate dehydrogenase (IcdH), from a mutant library of Xanthomonas oryzae pv. oryzicola. The mutation in icdH, not only remarkably impaired bacterial pathogenicity, virulence in planta, but also observably reduced bacterial growth capability in rice. In addition, the mutagenesis in this unique icdH gene of Xanthomonas oryzae pv. oryzicola also regulated the transcription expression level of the key genes, such as rpfF, rpfG and clp, in DSF signaling pathway. But the molecular mechanism is still not clear. This project draws up to utilize carbon metabolic pathway analysis, virulence-associated factors detection, and DSF detection and analysis to research the correlation between icdH and virulence, quorum sensing DSF signal molecules. By analyzing the representative genes transcription expression, ascertains the regulation relationship between the carbon metabolism and the hrp gene. Ultimately, via the above analysis roundly reveals the molecular mechanism of the icdH in the carbon metabolic pathways involved in full virulence of Xanthomonas oryzae pv. oryzicola. All these may prove important scientific significance and practical value in revealing the mechanism of plant and pathogenic bacteria molecular interaction, screening potential drug target, and carrying out efficient biological control strategy.