气味受体识别茶尺蠖产卵信息素的分子机制

茶尺蠖是重要的茶树害虫。研究发现茶尺蠖雌蛾趋向于其幼虫为害的茶苗上产卵，但调控其产卵选择行为的嗅觉机制尚不明确。本项目从气味受体(odorant receptors, ORs)的角度出发，重点研究雌蛾嗅觉感器特异的ORs与吸引雌蛾产卵的茶树挥发物的对应识别关系。前期通过GC-EAD结合GC-MS鉴定了吸引雌蛾产卵的害虫诱导茶树释放的挥发物组分。拟通过单感器记录技术测定嗅觉感器对茶树挥发物的电生理反应，对嗅觉感器进行功能分类；发掘雌蛾触角高表达的ORs基因，通过原位杂交技术研究ORs的感器定位；爪蟾卵母细胞异源表达ORs结合电压钳记录测定ORs与茶树挥发物的结合特性，选取活性配体测试引诱效果；干扰雌蛾特异ORs的表达，通过触角电位和行为检测雌蛾对关键挥发物的趋性是否改变，最终阐明ORs识别产卵信息素的分子机制。本研究将为利用ORs为靶向设计新型高效的行为调控剂，干扰茶尺蠖的寄主定位提供依据。

The tea geometrid Ectropis obliqua is one destructive defoliator of tea bushes in China. Previous study has revealed that female E. obliqua moths were more attracted by infested tea plants and preferentially oviposited on these plants. In current study, we focus on the odorant receptors (ORs) to investigate the specific recognition of oviposition pheromones by ORs expressed in olfactory sensilla. To investigate the putative bioactive components in herbivore-induced plant volatiles (HIPVs), gas chromatography-electroantennographic detection (GC-EAD) coupled with gas chromatography-mass spectrometry (GC-MS) analysis have been performed to the antennal responses to these chemicals. In present study, the single sensillum recording (SSR) is firstly performed, in order to record the electrophysiological responses of single olfactory sensillum toward different volatiles. Secondly, the high-throughput RNA-Seq method and qRT-PCR analysis are applied to explore the female antennae-biased ORs with underlying involvement in HIPVs perception, then the cellular location of OR proteins in different types of sensilla is investigated by in situ hybridization. Moreover, the binding affinities of HIPVs to ORs are measured by functional analysis using Xenopus oocytes expression and a two-electrode voltage clamp recording. Subsequently, the putative ligands of target ORs are selected to test the behavioral responses, then the trapping efficacies of different attractant formulas are evaluated by the field trapping experiment. Finally, the RNAi targeted to the female specific ORs is performed to suppress the gene expression, and then the response to host volatiles is analyzed by EAG and behavioral test in RNAi-treated individuals. Taken together, our results will elucidate the comprehensive roles of ORs in the recognization of oviposition pheromones. Our study could provide the theoretical basis for using ORs as targets to design the insect-behavior-modifying stimuli, and this project would contribute to the development of synthetic attractant to manipulate the host location of pests in novel pest management.