Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North China, Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China.
Bioassay Research Department, Central Agricultural Pesticide Laboratory, Sabahia Plant Protection Research Station, Agricultural Research Center, Alexandria, Egypt.
Pest Manag Sci. 2021 Jan;77(1):378-388. doi: 10.1002/ps.6027. Epub 2020 Sep 2.
Chemosensory proteins (CSPs) are thought to play essential roles in insect chemical communication, but their exact physiological functions remain unclear.
In this study, we investigated the functions of the CSP2 gene in the whitefly Bemisia tabaci using protein expression and the binding affinity spectrum of CSP2 to different types of odor molecules. Moreover, the evolutionary characteristics of the CSP2 gene were studied. The data obtained using binding assay showed that the CSP2 protein can bind to a broad range of plant volatiles including the homoterpene (E)-3,8-dimethyl-1,4,7-nonatriene (DMNT) and its analogs. In addition, using a behavioral experimental approach we identified that DMNT can repel the selection and oviposition of B. tabaci. Furthermore, protein structure modeling, molecular docking analyses and a functional mutation experiment were carried out resulting in the final identification of key amino acid residue Y11, which displayed important roles in the binding of CSP2 to DMNT. The results also showed that Y11 is located in the pocket region where CSP2 has a pi-alkyl interaction with DMNT. Meanwhile, comparative and evolutionary analyses indicated that CSP2 shared a high sequence similarity with CSPs of other insect family members such as Sternorrhyncha and Auchenorrhyncha including aphids, whiteflies and planthoppers.
These results suggested that CSP2 likely contributes to mediating responses of B. tabaci to plant volatiles, which may play a pivotal role in its feeding and oviposition preferences. Moreover, these findings could provide key information for exploring efficiency monitoring and integrated pest management strategies of B. tabaci.
化学感受蛋白（CSPs）被认为在昆虫的化学通讯中发挥着重要作用，但它们的确切生理功能仍不清楚。
在这项研究中，我们使用蛋白质表达和 CSP2 对不同类型气味分子的结合亲和力谱来研究烟粉虱 Bemisia tabaci 中 CSP2 基因的功能。此外，还研究了 CSP2 基因的进化特征。结合测定获得的数据表明，CSP2 蛋白可以与广泛的植物挥发物结合，包括顺式-3,8-二甲基-1,4,7-壬三烯（DMNT）及其类似物。此外，通过行为实验方法，我们确定 DMNT 可以排斥烟粉虱的选择和产卵。此外，还进行了蛋白质结构建模、分子对接分析和功能突变实验，最终确定了关键的氨基酸残基 Y11，它在 CSP2 与 DMNT 的结合中起着重要作用。结果还表明，Y11 位于口袋区域，CSP2 与 DMNT 发生π-烷基相互作用。同时，比较和进化分析表明，CSP2 与其他昆虫科成员（如半翅目和同翅目）的 CSPs 具有高度的序列相似性，包括蚜虫、粉虱和叶蝉。
这些结果表明，CSP2 可能有助于调节烟粉虱对植物挥发物的反应，这可能在其取食和产卵偏好中发挥关键作用。此外，这些发现可以为探索烟粉虱的效率监测和综合虫害管理策略提供关键信息。
