稻飞虱鞘脂类代谢关键酶的特征及对其r-对策形成的作用

The proposed project will clone, characterize the biochemical and phylogenetic relation and the physiological functions of the ceramidase, ceramide synthase, ceramide kinase and sphingomyelase, the key enzymes in regulation ceramide homestasis in the sphingolipid metabolism pathway, from the three key agricultural rice pest planthoppers. In the project: (1) The spatial-temporal expression patterns of the four enzymes in different developmental stage and tissue/organs, the responses of the enzymes and sphingolipid profile to biotic and abiotic -stresses such as the infection of rice virus, stress of insecticide and host plant resistance will be monitered, therefore their interrelationship will be understood, the adaptation mechanism of the r-strategic planthoppers would be illustrated in the sphingolipid pathway. (2) The roles of ceramide and other metabolites in development, growth, survival, reproduction and plant-virus transmission in planthoppers, the regulation role of the four enzymes in ceramide homeostasis and planthopper population biology will carefully analyzed, to explain the contribution of the characters in sphingolipid pathway to the evolution of r-strategy of the planthoppers. (3) The effective inhibitors of the key enzymes in the sphingolipid pathway which influence significantly the cell growth, development and reproduction of planthopper population will be screened. .The general aim is to find the novel regulators in planthopper population biology, to potential molecular targets to interfere the development, survival and reproduction and virus-transmission, so the “innate regulation factor” from the planthopper organism will be dig out for the purpose of sustainable pest management.

明确重大农业害虫稻飞虱的鞘脂质代谢途径的关键物质－神经酰胺的神经酰胺酶、神经酰胺合酶、神经酰胺激酶和鞘磷脂酶的基因、生化特征、系统发生和生理功能；检测四个代谢酶在各虫态和器官的表达格局、对植物病毒、农药、寄主植物种类和抗性等环境胁迫的应激反应、稻飞虱体内鞘脂质代谢组的变化,了解四种酶表达与传毒、抗药性、植物抗虫性之间的互作，解析稻飞虱作为r-对策者在鞘脂类代谢水平上对胁迫的适应性机制；分析神经酰胺在稻飞虱生长、发育、存活、繁殖和传毒中的作用，阐明代谢酶对飞虱神经酰胺稳态的调控、对飞虱种群生物学的影响，解析鞘脂类代谢途径特征对稻飞虱r-对策形成的作用；筛选相应的有效抑制剂，以调控稻飞虱种群生物学特征. 从而有望从一个全新的角度揭示稻飞虱种群生物学的调控机制，发现潜在的作用分子靶标和物质来干扰稻飞虱的存活、繁殖和传毒，发掘害虫本身的“内禀控制因子”，为最终实现对飞虱的可持续治理打下坚实的基础。

鞘脂类是真核细胞膜必不可少的、普遍存在的、具有生物活性的脂质成分，也是增殖、凋亡等生物过程的第二信使。筛选克隆出重大农业害虫稻飞虱的鞘脂质代谢途径中的关键酶（神经酰胺酶、神经酰胺合酶、鞘磷脂合酶和鞘磷脂酶）的同源基因序列并进行系统发生学分析；研究上述关键代谢酶在飞虱各龄期和器官的时空表达特性、生化特征及其生理功能；检测上述关键代谢酶对植物病毒、农药、抗性植株等环境胁迫的应激反应；结合稻飞虱体内鞘脂质代谢物质变化，解析鞘脂质代谢关键酶在飞虱传毒、产生抗药性、危害抗性植物过程中的功能作用，从而寻找稻飞虱作为r-对策者在鞘脂类代谢水平上对胁迫的适应性机制。分析鞘脂质代谢关键酶在稻飞虱生长发育、存活、繁殖和传毒中的作用，阐明代谢酶对飞虱体内鞘脂质稳态的调控，解析鞘脂类代谢途径特征对稻飞虱r-对策形成的作用；筛选相应的有效抑制剂，以调控稻飞虱种群生物学特征，从而有望从一个全新的角度揭示稻飞虱种群生物学的调控机制，发现潜在的作用分子靶标和物质来干扰稻飞虱的存活、繁殖和传毒，发掘害虫本身的“内禀控制因子”，为最终实现对飞虱的可持续治理打下坚实的基础。