抗嘧霉胺的番茄灰霉病菌中CGS和MS基因的功能研究

嘧霉胺等苯胺基嘧啶类杀菌剂的生化作用机制是抑制甲硫氨酸的生物合成，但其分子靶标和抗性机制尚不明确。根据已有的背景信息，番茄灰霉病菌中甲硫氨酸合成途径中存在三个必需的酶CGS（胱硫醚-γ-合成酶）、CBL（胱硫醚-β-裂解酶）和MS（甲硫氨酸合成酶），已经有报道认为CBL不是嘧霉胺的作用靶标，因此推测嘧霉胺可能作用于CGS或MS上，但是目前仍没有直接证据表明CGS或MS为嘧霉胺的作用靶标。因此该项目拟以对嘧霉胺不同敏感性的番茄灰霉病菌为材料，以甲硫氨酸合成途径中CGS和MS为对象，通过基因克隆，序列分析、Real-Time PCR、点突变、基因敲除与回复和生物学功能分析等方法，研究CGS和MS在嘧霉胺抗性中的作用，以及嘧霉胺是否作用于CGS或MS，同时明确CGS和MS在番茄灰霉病菌生长发育中的功能，为灰霉病的治理和新型杀菌剂的创制提供理论依据和借鉴。

The biochemical mechanism of pyrimethanil and other anilinoprimidine fungicides is the inhibition of the biosynthesis of methionine, but the molecular targets and the resistance mechanism to anilinoprimidine fungicides is not yet clear. So far, three major enzymes, CGS (cystathionine γ-synthase), CBL (cystathionine β-lyase), and MS(Methionine Synthase)are necessary in methionine biosynthetic pathway of Botrytis cinerea. It has been reported that the CBL is not the primary target site of pyrimethanil. These results indicate that the CGS and MS may be the primary target of pyrimethanil, but it have not been to confirmed yet. Therefore, the project study on the different sensitivity levels to pyrmethanil of Botrytis cinerea strains, the CGS and MS in methionine biosynthetic pathway, which use gene cloning, sequence analysis, real-time PCR, point mutation, gene knockout and complement and function analysis, is to prove the role of CGS and MS in pyrimethanil resistance, and make clear whichone is the primary target of pyrimethanil, and their functions in the growth. The results will provide the theoretical basis and reference for Botrytis cinerea resistance management and new fungicide creation.