Sesquiterpenoids play an import role in the direct or indirect defense of plants. Farnesyl pyrophosphate synthases (FPSs) catalyze the biosynthesis of farnesyl pyrophosphate, which is a key precursor of farnesol and (E)-β-farnesene. In the current study, two FPS genes in Gossypium hirsutum, GhFPS1 and GhFPS2, were heterologously cloned and functionally characterized in a greenhouse setting. The open reading frames for full-length GhFPS1 and GhFPS2 were each 1 029 nucleotides, and encoded two proteins of 342 amino acids with molecular weights of 39.4 kDa. The deduced amino acid sequences of GhFPS1–2 showed high identity to FPSs of other plants. Quantitative real-time PCR analysis revealed that GhFPS1 and GhFPS2 were highly expressed in G. hirsutum leaves, and were upregulated in methyl jasmonate (MeJA)-, methyl salicylate (MeSA)- and aphid infestation-treated cotton plants. The recombinant proteins of either GhFPS1 or GhFPS2 plus calf intestinal alkaline phosphatase could convert geranyl diphosphate (GPP) or isopentenyl diphosphate (IPP) to one major product, farnesol. Moreover, in electrophysiological response and Y-tube olfactometer assays, farnesol showed obvious attractiveness to female Aphidius gifuensis, which is an important parasitic wasp of aphids. Our findings suggest that two GhFPSs are involved in farnesol biosynthesis and they play a crucial role in indirect defense of cotton against aphid infestation.

倍半萜在植物的直接或间接防御中起重要作用。法呢基焦磷酸合酶（FPSs）催化法呢基焦磷酸的生物合成，法呢基焦磷酸是法呢醇和（E）-β-法呢烯的关键前体。在当前的研究中，在温室中异源克隆了陆地棉中的两个FPS基因GhFPS 1和GhFPS2。全长GhFPS 1和GhFPS2的开放阅读框分别为1,029个核苷酸，编码了342个氨基酸的两个蛋白质，分子量为39.4 kDa。推测的GhFPS 1-2氨基酸序列与其他植物的FPS具有高度同一性。实时定量PCR分析表明GhFPS1和GhFPS2在陆地棉叶片中高表达，并在茉莉酸甲酯（MeJA）-，水杨酸甲酯（MeSA）-和蚜虫侵染处理的棉株中上调。GhFPS1或GhFPS2的重组蛋白加上小牛肠碱性磷酸酶可以将香叶基二磷酸酯（GPP）或异戊烯基二磷酸酯（IPP）转化为一种主要产品法尼醇。此外，在电生理反应和Y-管嗅觉测定中，法尼醇对雌性蚜虫蚜虫（Aphidius gifuensis）具有明显的吸引力，这是蚜虫的重要寄生蜂。我们的发现表明，两种GhFPS参与了法尼醇的生物合成，它们在棉花抗蚜虫侵害的间接防御中起着至关重要的作用。