炭疽病是热带水果的主要采后病害，其安全有效地防治有赖于我们对该病原菌致病过程分子机制的充分了解。申请者业已发现芒果炭疽病菌Colletotrichum gloeosporioides (C.g）基因组中3个在侵染致病阶段高水平表达的几丁质脱乙酰酶（Chitin deacetylase，CDA）基因可能与C.g侵染过程中氨的分泌、寄主pH调控、细胞壁修饰、寄主的防御反应等致病性相关事件有密切关系。为阐明这3个CDA基因在该菌生长和致病过程中的具体作用，本项目拟通过外源基因重组技术从该菌基因组中分别敲除这3个CDA基因，研究CDA基因缺失突变对病原菌形态学特征、生长发育特性以及致病力的影响，并从分子水平上研究影响产生的机制。本研究结果可望加深人类对C.g致病机制的认识，有可能为今后利用分子手段控制热带水果炭疽病提供靶标基因，奠定安全有效防治该病的技术基础。

Anthracnose caused by Colletotrichum spp. is a very important postharvest disease of tropical fruits. A thorough understanding of the molecular mechanism involved in the pathogenesis of the fungi should help us to develop safer and more effective controlling strategies. Our preliminary results showed that three chitin deacetylase (CDA) genes were highly upregulated under the necrotrophic stage, suggesting these genes might be related to such pathogenesis events as ammonia production and secretion, host environmental pH regulation, pathogen cell wall modification and host defense reactions. In order to analyze the functions of the three CDA genes in the growth and pathogenesis of C.g, we are going to knock out them individually from the fungus genome to generate corresponding gene knockout mutants. The influences of CDA deletion on morphological and growth characteristics of the fungus will be characterized in relation to pathogenicity, and underlying mechanisms will also be studied at molecular level. The results obtained from this study should deepen our understanding of the pathogenesis of the fungi, and will most probably help us to identify target genes for future control of the disease, which will provide technical basis for developing safer and more effective control methods.