植物挥发物对棉铃虫嗅觉行为调控的神经和分子机理

Plant volatiles play a predominant role in mediating phytophagous insect's behaviors inluding host-seeking, selection of oviposition sites as well as nectar feeding. According to this phenomenon, we could develop environment-friendly behavioral regulator of pest insects.Major advance has been made about studies on chemical ecology of host-insect interaction in the past two decades.However, Neural and molecular mechanisms of insect seeking host-plant volatiles is largely unknown. In previous work, we identified 42 odor receptor genes from Helicoverpa armigera antennae through transcriptome sequence and further functional characterized more than 10 odor receptors. In this proposal, we firstly identify and characterize the odor receptor genes encoding ten important plant volatiles in Helicoverpa armigera antenna using heterologous expression and electrophysiological recording and followed by clarifying the projection position in brain antennal lobe of these olfactory receptor neurons in which express the accordingly odor receptors identified above through single-sensillum recording and neruonal staining.And then we would like to address how glomeruli in the antennal lobe process electrophysiological signals input from the dendrites of olfactory receptor neurons using intracellular recording and staining techniques. In addition, we would like to screen and characterize agonists, antagonists and potentiators of odor receptors identified above. These studies may elucidate nerual and molecular mechanisms of encoding important plant volatiles in Helicoverpa armigera, which provides the logic proofs and technical platforms for screening and designing high efficient attractants or repellents in the molecular level.

植物挥发物在植食性昆虫的寄主定向、产卵、聚集等行为中发挥着重要的作用，根据这一特性可以发展环境友好的害虫行为调节剂。国内外在昆虫与寄主互作的化学生态学领域进行了深入的研究，但是，对于昆虫识别寄主挥发物的神经和分子机理却知之甚少。本申请拟在棉铃虫触角转录组测定的基础上，通过体外表达和电生理记录鉴定编码正庚醛等主要寄主挥发物的气味受体，通过单细胞记录和染色标记技术明确与之对应的嗅觉受体神经在脑触角叶中的投射位置；利用细胞内记录技术揭示棉铃虫脑触角叶中的嗅小球如何对嗅觉受体神经树突输入的电信号进行整合编码；在此基础上筛选获得重要气味受体的激活剂、抑制剂和拮抗剂。通过以上的研究，揭示棉铃虫识别主要寄主挥发物的嗅觉神经回路和分子机理，为从分子水平筛选和设计高效的害虫引诱剂、驱避剂和嗅觉封闭剂提供理论依据和技术支撑。

植物挥发物在植食性昆虫的寄主定向、产卵、聚集等行为中发挥着重要的作用，根据这一特性可以发展环境友好的害虫行为调控剂。国内外在昆虫与寄主互作的化学生态学领域进行了深入的研究，但是，对于昆虫识别寄主挥发物的神经和分子机理却知之甚少。本项目通过对转录组和基因组序列的生物信息学分析，鉴定了棉铃虫嗅觉相关基因家族，包括气味受体、离子型嗅觉受体等；比较系统研究了棉铃虫气味受体基因家族的功能，鉴定了棉铃虫用于感受正庚醛，苯甲醛等重要寄主植物挥发物以及性信息素的受体；通过单细胞记录明确了棉铃虫用于感受这些重要气味分子的感受器及嗅觉受体神经，结合染色标记技术明确了相应的嗅觉受体神经在脑触角叶中的投射；利用细胞内记录技术揭示棉铃虫脑触角叶中的嗅小球如何对嗅觉受体神经树突输入的电信号进行整合编码。在以上研究的基础上，提出了以气味受体为靶标筛选害虫行为调控剂的新策略，并以鉴定的重要的气味受体为靶标，筛选获得了高效棉铃虫引诱剂。以上的研究，不但揭示了棉铃虫识别主要寄主挥发物以及性信息素的神经和分子机理，而且证明了以气味受体为靶标筛选和设计高效的害虫引诱剂和驱避剂是可行的。受该项目资助共发表SCI论文33篇，文章发表在Current Biology （2篇）、Insect Biochemistry and Molecular Biology、BMC Genomics等高水平期刊上，应邀为Biological Reviews以及Progress in molecular biology and translational science撰写综述各1篇。圆满完成了计划研究内容，发表论文的质量和数量都明显高于计划书中的考核指标。