核受体在甲硫氨酸调控褐飞虱卵壳发生中的功能研究

害虫种群爆发的主要原因之一是其高繁殖力。营养是影响昆虫繁殖力的重要因素，其中甲硫氨酸是决定繁殖力的关键营养因子，但其对昆虫繁殖力的调控机制还很不清楚。项目组前期生测、电镜和组学分析发现甲硫氨酸缺失导致褐飞虱无法产卵，卵壳发生过程受阻，多个与卵壳发生相关核受体基因的表达受影响。据此，本项目拟利用RNAi技术鉴定出影响褐飞虱卵壳发生的关键核受体，通过转录组测序筛选受核受体调控的下游卵壳蛋白基因，利用凝胶迁移技术和双荧光素酶报告基因系统验证两者的相互作用关系，最后在昆虫活体中研究重要核受体对褐飞虱繁殖力的影响，揭示核受体对甲硫氨酸的响应及其调控卵壳发生的分子机制。研究结果不仅有助于阐明营养影响昆虫繁殖力的分子基础，丰富昆虫卵壳发生调控理论，也为更好地选育水稻抗虫品种提供科学依据。

High fecundity is one of the major reasons of pest outbreak. Nutrition is critical for insect fecundity, and methionine is thought to be one of the essential nutritional factors for insect reproduction. However, the molecular mechanism of insect fecundity regulated by methionine is not clearly known. By using bioassay, transmission electron microscopy and transcriptomic analysis, we found that choriogenesis and oviposition could be inhibited by methionine deprivation, and the expression levels of several nuclear receptors (NRs) were reduced. Here, we will identify choriogenesis related NRs through RNAi, and screen out the chorion genes regulated by NRs. After selected one NR and one chorion gene responsed to methionine, we will study their interaction using electrophoretic mobility shift assay (EMSA) combined with dual luciferase reporter gene assay system. Finally, we will study the effects of NRs on insect fecundity. The expected results will improve the understanding of molecular basis of insect fecundity regulated by nutrition and insect choriogenesis. Our results would also be helpful for selecting pest resistant rice varieties.