十字花科黑腐病菌(Xanthomonas campestris pv. campestris, Xcc)是引起十字花科植物黑腐病的病原菌，Xcc对十字花科植物的病理系统也是研究微生物与植物相互作用机理的重要模型系统之一。基因组注释表明Xcc 8004拥有110个双组份系统基因，其编码的感受子和调控子分别感受和响应外界环境的变化。由于双组份系统之间存在信号的交叉转导，因而目前对Xcc双组份系统信号转导及下游调控机制还不清晰。本项目将以Xcc 8004为实验材料，通过分子生物学及基因组学等手段，系统研究双组份系统基因XC3067/XC3068的基因功能、信号转导及调控网络。本项目研究的结果将阐明XC3067/XC3068调控Xcc致病的分子机制并明确XC3067/XC3068在Xcc致病及感受外界信号中的具体作用。该研究将为我们更进一步的研究Xcc的信号转导及调控网络提供基础。

The Gram-negative bacterium Xanthomonas campestris pv. campestris (hereafter Xcc) is the causal agent of black rot disease of cruciferous plants. The pathosystem of Xcc infecting cruciferous plants is one of the model system in studying microbe-plant interaction. The genome of Xcc 8004 harbors 110 two-component signal transduction systems (TCSs) genes, which encode histidine kinases(HKs) and response regulators (RRs) to monitor and respond to environmental stimuli. The significant similarity at both the primary sequence level and the sructure level raises the possibility of cross-talk between different TCSs, so the mechanism of signal transduction and downstream regulation is still unclear. This project will focus on in-depth study on TCSs genes XC3067/XC3068 in Xcc 8004 by using molecular and genomics approaches to elucidate the gene functions, signal transduction and regulatory networks of XC3067/XC3068. The results will not only reveal the stimuli sensing by XC3067/XC3068 but also unveil the mechanism of XC3067/XC3068 in influencing the pathogenicity of Xcc 8004. The research on XC3067/XC3068 in this study will facilitate greatly the future studies on signaling and regulatory networks of this important phytopathogenic bacterium.