Abstract：
Spodoptera frugiperda is a kind of polyphagous pest, and can damage a large number different host plants around the worldwide. The molecular mechanisms of two general odorant binding proteins (GOBPs) binding with general volatiles and insecticides are still blank. In this study, we investigated the function of two GOBPs in S. frugiperda, by expressing two SfruGOBPs and tested the binding affinities by the fluorescence competition binding assays. The results exhibited that SfruGOBP1 has binding affinities to 4 of 38 general volatiles and 3 of 7 insecticides. In contrast, SfruGOBP2 showed a broader ligand-binding spectrum to 21 volatiles and 4 insecticides, suggesting SfruGOBP2 may plays a more important role in perceiving host volatiles than SfruGOBP1. Furthermore, we used molecular docking and site-directed mutagenesis assay to explored the key amino acid residues of two SfruGOBP to insecticides ligand. This study provides some valuable information to exploring the olfactory mechanism of two GOBPs bound the host plant volatiles and insecticides in S. frugiperda.
摘要：
节食夜蛾是一种多食性害虫,并可能损害世界各地大量不同的寄主植物。两种通用气味剂结合蛋白（GOBPs）与通用挥发物和杀虫剂结合的分子机制仍是空白。在这项研究中,我们研究了两种GOBP在S.frugiperda中的功能，通过表达两个SfruGOBP并通过荧光竞争结合测定法测试结合亲和力。结果表明，SfruGOBP1对38种一般挥发物中的4种和7种杀虫剂中的3种具有结合亲和力。相比之下,SfruGOBP2对21种挥发物和4种杀虫剂显示出更广泛的配体结合谱，这表明SfruGOBP2在感知宿主挥发物方面可能比SfruGOBP1起更重要的作用。此外，我们采用分子对接和定点突变实验来探索两个SfruGOBP的关键氨基酸残基对杀虫剂配体的影响。本研究为探索两种GOBPs结合植物挥发物和杀虫剂的嗅觉机制提供了有价值的信息。
