O-甘露糖基化修饰影响绿僵菌细胞壁组成、结构及侵染致病的作用机制

项目名称： O-甘露糖基化修饰影响绿僵菌细胞壁组成、结构及侵染致病的作用机制

项目编号： No.31270040

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 农业科学

项目作者： 金凯

作者单位： 重庆大学

项目金额： 80万元

中文摘要： 昆虫病原真菌是重要生防微生物，其细胞壁主要由多糖和蛋白组成，糖基化修饰对细胞壁合成至关重要。在模式真菌中，O-甘露糖基转移酶（PMTs和MNTs）是蛋白O-糖基化修饰的重要酶类，与真菌的生长发育、细胞壁合成及侵染致病密切相关。在昆虫病原真菌中，PMTs的功能研究未见报道，O-甘露糖基化修饰影响其细胞壁组成、结构及侵染致病的机制还缺乏研究。经分析发现，绿僵菌中存在3个PMTs基因。本项目将采用real-time RT-PCR、基因敲除或干扰及超表达的方法，分析PMTs基因的表达特征及其对绿僵菌抗逆和毒力的影响；以绿僵菌MNTs和PMTs系列转化子为研究材料，利用透射电镜观察、原子力显微观察、荧光染色、双向电泳和液质联用等技术，测定不同菌株细胞壁的组成结构。阐明O-甘露糖基化修饰对绿僵菌细胞壁组成、结构及侵染致病的作用机制。本研究将有助于理解昆虫病原真菌的侵染致病机制，为菌株改良提供理论依据。

中文关键词： 生物防治；昆虫病原真菌；O-甘露糖基化修饰；毒力；细胞壁

英文摘要： Entomopathogenic fungi have been considered as a promising alternative or supplement to chemical pesticides. However, the disadvantages have retarded widespread application, including poor efficacy and sensitivity to adversities. Thus, an understanding of the pathogenesis in M. acridum is necessary for improvement of the biocontrol fungus. The fungal cell wall, which comprises a polysaccharide-protein complex, can protect the cell from harsh environments and plays a prominent role in resisting host response. The cell wall is now seen as a dynamic structure that is continuously changing to respond to the various extracellular stimuli. Glycosylation is an extremely common and highly conserved type of protein modi?cation involving the addition of carbohydrate residues to target proteins. It plays a critical role in determining the structure and function of numerous secreted and membrane-bound proteins. O-mannosylation is an important type of glycosylation. Many roles have been described for fungal O-mannosylation, including in cell wall integrity, cell morphology, and localization of proteins. The initial O-mannosylation reaction is performed by protein O-mannosyltransferases (PMTs), which are integral endoplasmic reticulum membrane proteins that add the ?rst mannose to Ser or Thr residues of target proteins. Studi

英文关键词： biocontrol；entomopathogenic fungus；O-mannosylation；virulence；cell wall