中文摘要：

【目的】暗黑鳃金龟Holotrichia parallela通过气味结合蛋白（odorant binding protein,OBP）识别性信息素和植物挥发物准确而迅速地定位配偶、寄主植物。本研究通过克隆暗黑鳃金龟气味结合蛋白15a（Hpar OBP15a）基因,解析该基因的编码蛋白特征、组织表达模式及与寄主植物气味等化合物的结合特性方面的研究,为阐明暗黑鳃金龟基于嗅觉识别的寄主植物选择机理奠定理论基础。【方法】根据暗黑鳃金龟成虫触角转录组测序的结果,利用RT-PCR克隆了Hpar OBP15a基因;Real-time PCR方法分析了该基因在成虫不同部位的表达量差异;荧光竞争结合测定了Hpar OBP15a蛋白和58种候选化合物的结合特征。【结果】暗黑鳃金龟Hpar OBP15a基因全长534 bp,编码147个氨基酸,Gen Bank登录号为AK1834747。Hpar OBP15a在触角中特异表达,且在雌虫触角中表达量显著高于雄虫。在被测的58种化合物中,Hpar OBP15a与46种气味化合物具有较好的亲和性,其中与十二烷、十二醇结合能力最强,其解离常数分别为8.5和11.3μmol/L;同时,对性信息素（L-异亮氨酸甲酯和R-芳樟醇）也有一定的结合能力（解离常数分别为21.0和18.5μmol/L）。【结论】Hpar OBP15a具有广泛的气味结合谱,其中对榆树挥发物十二烷的结合能力最强,因此该蛋白可能在暗黑鳃金龟对榆树的定位过程中具有重要作用。

英文摘要：

【Aim 】 The dark black chafer, Holotrichia parallela, locates the mate and host plant accurately and rapidly by binding of the odorant binding proteins（ OBPs） with sex pheromones and plant volatiles. This study aims to clone the open reading frame（ ORF） of odorant binding protein 15a（ Hpar OBP15a） gene from H. parallela,as well as to gain insight into the characteristics of its encoding protein,its expression patterns,and characterize the binding profiles of OBP15 a with a number of plant volatiles,and will provide a theoretical basis for a better understanding of the chemosensory mechanism of H. parallela. 【Methods】Based on transcriptome sequencing of the adult antenna of H. parallela,reverse transcription-polymerase chain reaction（ RT-PCR） was used to amplify the ORF of Hpar OBP15 a. The mRNA levels of Hpar OBP15 a in different tissues of adults were assayed by real-time quantitative PCR（ qRT-PCR）. Binding affinities of Hpar OBP15 a towards 58 compounds,which are probably associated with the chemosensation of H. parallela,were measured by fluorescent competitive binding assay.【Results】 Hpar OBP15 a has a full-length c DNA of 534 bp,encoding 147 amino acids,and its corresponding sequence was submitted to Gen Bank under the accession number AK1834747. The qRTPCR assay indicated that Hpar OBP15 a mRNA was specifically expressed in the antennae of female adults. Among the 58 chemicals tested,Hpar OBP15 a exhibited a good affinity to 46 kinds of ligands.Notably,it was found that Hpar OBP15 a had the strongest binding affinity to dodecane and 1-dodecanol,with the dissociation constant of 8. 5 and 11. 3 μmol / L,respectively. Hpar OBP15 a had a certain binding affinity toward the sex pheromone components methyl L-isoleucinate and（-）-linalool,with the dissciation constant of 21. 0 and 18. 5 μmol / L,respectively. 【Conclusion 】Hpar OBP15 a protein shows a broad odorant-binding spectrum and has a strong binding affinity toward dodecane,a volatile from host elm leaves. This protein