中文摘要：

棉花被植食性昆虫取食后大量释放的特异性萜烯挥发物，能够有效吸引天敌昆虫进行寄主搜索和定位。本文从陆地棉（中棉12）Gossypiumhirsutum叶片中克隆获得一个倍半萜合成酶基因的全长cDNA，命名为GhTPS1（GenBank登录号：JQ365627）。该基因编码545个氨基酸的蛋白，预测分子量为63．3ku，等电点为5．92。氨基酸序列比对分析表明该基因与其它被子植物倍半萜合成酶基因一致性为34％～60％，其中与欧洲葡萄（-）-germacrene D synthase一致性最高（60％）。聚类分析表明GhTPS1属于由被子植物倍半萜合成酶基因组成的TPSa亚家族。采用实时荧光定量PCR检测了GhTPS1mRNA在棉铃虫Helicoverpaarmigera（Htibner）幼虫为害棉花不同时间的表达谱，结果表明接虫24h该基因表达量显著上调。

英文摘要：

Cotton plants attacked by herbivorous insects emit large amounts of characteristic volatile terpenoids that are highly attractive to predatory insects and trigger specific behavioral reactions in these, such as detection and location of the chemical source. Here, we identified a novel sesquiterpene synthase gene GhTPS1 （GenBank accession no. JQ365627） from leaves of Gossypium hirsutum cv. Zhongmianl2. GhTPS1 encodes a protein comprised of 545 amino acid residues with a calculated molecular mass of 63.3 ku and an isoelectric point of 5.92. Multiple sequence alignment revealed that the deduced amino acid sequence has 34% --60% identity with the sesquiterpene synthases of other angiosperm species, and shared the highest identity with that of （ - ） - germacrene D synthase from Vitis vinifera. Phylogenetic analysis clustered GhTPS1 into the TPSa subfamily, which is predominantly comprised of angiosperm sesquiterpene synthase genes. We used real-time quantitative PCR to further investigate the temporal expression of GhTPS1 in G. hirsutum leaves induced by the feeding activity of Helicoverpa armigera （Htibner） larvae. The results indicate that the GhTPS1 transcription level significantly increased after 24 hours of larval feeding activity.