小麦赤霉病菌VeA调控系统对DON毒素合成调控的分子机制研究

Fusarium graminearum is the major causal agent of Fusarium head blight (FHB) on wheat, which causes yield loss and affects the quality of grains. The mycotoxins, such as deoxynivalenol (DON) and its derivatives produced by the fungus in infected grains, pose a serious threat to human and animal health. In addition to the specific enzymes and regulators encoded by at least 15 TRI genes, it is now clear that the regulation of DON biosynthesis is controlled by various regulatory systems in response to external environment, such as moisture, nutrition, pH, et al. Our previous studies showed that the light regulated DON biosynthesis via VeA regulatory system. In this proposal, we will investigate the function of each element of the VeA regulatory system, and the interactions among these elements under light and dark conditions, analysis the role of the different interaction mode in regulating the DON biosynthesis. Result of this project will help us understand the molecular mechanism of DON biosynthesis regulated by light, accelerate the construction of regulatory network system of DON biosynthesis.

禾谷镰孢菌引起的小麦赤霉病严重威胁我国小麦生产安全，此外，病菌产生的脱氧雪腐镰刀菌烯醇（DON）毒素也严重威胁食品安全。DON毒素的合成除了受毒素基因（Tri）的调控外，还受水分、营养、pH等多个环境因子的影响。项目组前期研究发现，禾谷镰孢菌的VeA调控系统参与光照对DON毒素的合成调控过程，在此基础上，本项目拟进一步研究禾谷镰孢菌VeA调控系统中各个元件的生物学功能，分析各元件在光照和黑暗条件下不同的互作模式对DON毒素合成的影响，阐明光照对禾谷镰孢菌DON毒素合成调控的分子机制，为下一步构建毒素合成调控基因网络系统奠定基础。

禾谷镰孢菌是引起麦类赤霉病的重要致病真菌，病菌产生的脱氧雪腐镰刀菌烯醇（DON）毒素也严重威胁食品安全。DON毒素的合成除了受毒素基因（Tri）的调控外，还受水分、营养、pH等多个环境因子的影响。项目组前期研究发现，禾谷镰孢菌的VeA调控系统参与光照对DON毒素的合成调控过程，本项目对VeA调控系统中的34个基因进行了功能研究，利用靶向基因敲除和互补技术对获得了相关基因的缺失和互补突变体，发现FgLaeA1基因和甲基转移酶FgSet1基因在禾谷镰刀菌的生长发育、致病以及次生代谢物的合成过程中起着重要的调控作用。相关的研究成果为构建毒素合成调控基因网络系统奠定基础，也为开发靶向于VeA调控系统的新型安全抑制剂提供分子靶标，进而为提出赤霉病防控策略、减少毒素污染提供科学依据。