由柑橘溃疡病菌(Xcc)引起的细菌性溃疡病是柑橘上最重要的病害之一，在我国柑橘主产区发生严重。病原菌利用由tale基因编码的转录激活类似效应因子（TALE）来激活柑橘的感病性。我们前期研究发现中国Xcc菌株含有的tale基因呈现遗传多样性以及主效毒性TALE蛋白PthA在柑橘中的靶标基因为感病基因CsLOB1。但是，这些tale基因调控柑橘感病性的机理未知。为了明确这些tale基因在致病性中的作用，本项目拟分离中国Xcc菌株特异的tale基因，通过tale-free菌株介导的接种方法来评价单个tale基因在致病性中的贡献；利用RNA-seq、计算生物学、dTALE和ChIP等途径鉴定TALE蛋白对应的S基因和其在溃疡病斑形成中的功能来揭示tale基因调控柑橘感病性的机理，为培育广谱的抗溃疡病的柑橘材料奠定基础。

Citrus bacterial canker (CBC) caused by Xanthomonas citri subsp. citri (Xcc) is one of the most important bacterial disease in citrus, which occurs severely in citrus main producing region in China. The pathogenic bacteria rely on transcription activator-like effector (TALE) encode by tale genes to activate disease susceptibility of host citrus. We previously found that Chinese Xcc strains exhibit genetic diversity based on tale genes and a potential disease susceptibility gene CsLOB1 is targeted by a major virulence TALE effector PthA. However, the molecular mechanisms of diverse tale genes manipulating citrus susceptibility is unknown. In this proposal, we are going: to isolate the tale genes which are specific in Chinese Xcc strains, then evaluate the role of individual tale gene in pathogenicity by inoculation using a tale-free strain; to identify TALE-targeted S gene in citrus and to reveal the functions of these S genes for citrus canker development by several approaches including RNA-seq technology, TALE-target computational prediction, designing dTALE and ChIP technology. Through the suggested project, we expect to understand the molecular mechanisms how the tale genes manipulate citrus susceptibility and obtain broad spectrum plant resistance to most kinds of citrus canker.