禾谷镰刀菌SR蛋白调控有性生殖和致病性的分子机制

人体SR蛋白特异激酶SRPK1通过磷酸化SR蛋白调控了RNA剪接，进而在细胞分化、器官发育等过程中扮演了重要的角色。在丝状真菌的不同发育时期也存在RNA剪接现象，但是对其调控机制还不太清楚。前期研究工作显示：禾谷镰刀菌中唯一的SR蛋白特异激酶FgSrpk1能通过调控RNA剪接和基因转录影响有性生殖、产毒和致病力。近期又发现SR蛋白FgHrb1和FgSrp1也都参与了有性生殖、产毒和致病性且与FgSrpk1互作。本项目拟以FgHrb1和FgSrp1为研究对象进一步寻找RNA剪接和转录水平受SR蛋白调控的靶基因，鉴定出SR蛋白特异结合的RNA序列、剪接因子以及剪接体组分等蛋白，检测SR蛋白是否被FgSrpk1或其它蛋白激酶激活，从而最终揭示SR蛋白调控禾谷镰刀菌有性生殖、产毒和致病力的分子机制。本研究将加深我们对禾谷镰刀菌致病机制的认识，并为小麦赤霉病的防治提供新的药物靶标。

In human, SR protein-specific kinase SRPK1 regulates RNA splicing by phosphorylating SR proteins and plays an essential role in cellular differentiation and organs development. In filamentous fungi, RNA splicing was found in diverse development stages, but little is known about its regulatory mechanism. Previous studies indicated that the only SR protein-specific kinase (FgSrpk1) from Fusarium graminearum may regulate sexual reproduction, DON production and pathogenicity by modulating RNA splicing and gene transcription. Recently, we found that two SR protein FgHrb1 and FgSrp1 are also involved in sexual reproduction, DON production and pathogenicity, and can interact with FgSrpk1. In this study, we will identify the genes whose RNA splicing or transcriptional level is regulated by SR protein. Subsequently, we will try to identify SR protein-associated RNA sequence and proteins including splicing factors and components of spliceosome, and detect whether SR proteins are phosphorylated by FgSrpk1 or other kinases. Our goal is to determine the molecular mechanism of SR proteins in regulating sexual reproduction, DON production and pathogenicity in F. graminearum. Over all, results for proposed project will be helpful not only to better understand the pathogenesis of Fusarium head blight but also to provide a novel drug target for control of the Fusarium head blight.