溃疡病是严重危害柑橘产业的检疫性细菌病害，防治困难，选育和应用抗病品种是最终解决该病防治问题的根本途径。由于缺乏抗病资源，抗病机理研究和抗溃疡病柑橘育种步履艰难。项目组通过多年筛选，找到一个独特的抗病柑橘资源，枸橼C-05。前期工作表明，枸橼C-05存在针对溃疡病菌入侵的固有免疫（PTI）反应。本项目拟在此基础上，挖掘抗病关键模式识别受体基因（PRRs），解析PRR基因参与抗病反应的分子基础和调控方式，进一步确定柑橘抗溃疡病PTI防疫的分子机理。本研究结果不仅有助于获得柑橘抗溃疡病基因，将特有的抗病资源转换为基因资源，还将对深入理解柑橘抗溃疡病机理，以及指导柑橘抗溃疡病育种具有重要意义。

Citrus canker caused by Xanthomonas citri subsp. Citri (Xcc) is an important quarantine disease, which seriously damages citrus industry and is very difficult to control. The fact indicates that resistant cultivars would provide a fundamental way to solve the disease control problem. Because of resistant germplasm lacking, the resistance mechanism and the breeding for citrus resistant to canker disease have difficulty to make any progress. By screening of resistant citrus genotypes for many years, we found a unique resistant citrus named as Citron C-05. The previous work indicated that PAMP triggered immunity (PTI) played some role in the resistance of Citron C-05 to Xcc infection. In this project, based on the results obtained, the key pattern recognition receptors (PRRs) related to the resistance of Citron C-05 to citrus canker will be identified. The molecular basis of these key PRR genes and the factors affecting its expression are going to be anlyzed. Furthermore, the regulation of PTI reaction in the resistance to Xcc would be revealed. The results of this project would obtain resistant PRR genes, and provide resistant gene resource for genetic improvement for resistance. Meanwhile, this project would be helpful to understand the mechanism of citrus resistant to Xcc, and guide the breeding for resistance to the disease.