昆虫免疫真菌的侵染，是一个复杂的分子动态过程，体现在免疫基因表达策略，但表达调控机制不清楚。本项目拟以小菜蛾为研究对象，在已测定小菜蛾转录组和小RNA文库的基础上，利用RNA-seq和基因芯片筛选小菜蛾免疫虫生真菌侵染不同时间的mRNAs(F-mRs)和microRNAs(F-miRs)，RNAi分别沉默F-mRs和F-miRs在小菜蛾体内的表达，运用定量RT-PCR、Northern blot检测小菜蛾免疫基因的表达差异，阐明F-mRs和 F-miRs在小菜蛾免疫真菌中的功能；利用荧光素酶载体系统和RNAi技术明确F-miRs调控的靶标基因，并明确F-mRs和F-miRs在免疫真菌中的动态关系。通过上述研究，阐明F-mRs和F-miRs调控小菜蛾免疫真菌侵染的分子机制。研究结果不仅以害虫免疫系统为靶标的新型绿色真菌杀虫剂的研制有重大指导意义，也为通过调控害虫的免疫系统来控制害虫奠定基础。

Immunity defense of insect against fungal infection is a complex process, which involved in the dynamic strategy of immune gene expression. however, its regulation mechanism is not clear. In this project, we intend to use Plutella xylostella as the research object. On the basis of transcriptome and small RNA libraries has been sequenced, RNA-seq and Microarray will be used to screen the mRNAs(named F-mRs) and miRNAs(named F-miRs) which expressed in the different time of fungal infection. Quantitative RT-PCR and Northern blot will be used to verify the spatial and temporal expression profiles of other immune-related genes, after F-mRs and F-miRs are silenced by RNA interference (RNAi) to elucidate the functions of F-mRs and F-miRs in the immune process of p. xylostella against the infection of entomopathogenic fungi. The software will be used to predict gene target of F-miRs, and then confirmed by luciferase system and RNAi, the result will clarify the dynamic correlation of F-mRs and F-miRs in the immune process of P. xylostella. From the above research will elucidate the dynamic molecular mechanisms of the immunity system of P. xylostella against the infection of entomopathogenic fungi. The results of this project will not only guide to explore the new green fungal pesticides, but also lay a basis for biological control of insect pests based on the regulation of insect immune system.