Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400716, China; International Joint Laboratory of China-Belgium on Sustainable Crop Pest Control, Academy of Agricultural Sciences, Southwest University, Chongqing, 400716, China.
State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Research and Development Center for Fine Chemicals, Guizhou University, Guiyang, Guizhou, 550025, China.
Insect Biochem Mol Biol. 2022 Aug;147:103801. doi: 10.1016/j.ibmb.2022.103801. Epub 2022 Jun 15.
The oriental fruit fly (Bactrocera dorsalis) is a devastating fruit pest that infests more than 450 plant species. Methyl eugenol (ME) has been used as male attractant to monitor and eradicate B. dorsalis populations for 70 years, but the molecular basis of its activity remains largely unclear. Previously, BdorOBP83b and BdorOBP56f-2 as odorant binding proteins (OBPs) were identified responsible for ME perception. In this study, ME-induced expression profiles and in vitro binding assays revealed that BdorOBP69a is also produced in response to ME and binds directly to it with strong affinity (K = 9.54 μM). BdorOBP69a null mutants generated by CRISPR/Cas9 mutagenesis showed significantly lower electroantennogram and behavioral responses to ME than wild-type controls. Molecular docking analysis followed by site-directed mutagenesis showed that residues Leu89 and Phe145 are essential for the interaction between BdorOBP69a and ME. BdorOBP69a is therefore an important component involved in the perception of ME in B. dorsalis and a promising molecular target for the development of new male attractants. The molecular docking and binding assay data also provide an important reference for future OBP gene manipulation and ME chemical engineering to improve the efficiency of male attractants.
东方果实蝇（Bactrocera dorsalis）是一种极具破坏性的水果害虫，可侵害超过 450 种植物。甲基丁香酚（ME）已被用作监测和根除东方果实蝇种群的雄性引诱剂长达 70 年，但它的活性的分子基础在很大程度上仍不清楚。先前，BdorOBP83b 和 BdorOBP56f-2 作为气味结合蛋白（OBP）被鉴定为负责 ME 感知。在这项研究中，ME 诱导的表达谱和体外结合实验表明，BdorOBP69a 也是对 ME 产生反应并直接与之强烈结合（K=9.54μM）的蛋白。通过 CRISPR/Cas9 诱变产生的 BdorOBP69a 缺失突变体对 ME 的触角电位和行为反应明显低于野生型对照。分子对接分析随后的定点突变表明，残基 Leu89 和 Phe145 对于 BdorOBP69a 和 ME 之间的相互作用至关重要。因此，BdorOBP69a 是东方果实蝇感知 ME 的重要组成部分，也是开发新型雄性引诱剂的有前途的分子靶标。分子对接和结合实验数据也为未来的 OBP 基因操作和 ME 化学工程提供了重要参考，以提高雄性引诱剂的效率。
