陆地棉法尼基焦磷酸合酶基因的克隆及表达分析

Cloning and Expression Analysis of an Upland Cotton Farnesyl Pyrophosphate Synthase Gene

棉酚是棉花重要的次生代谢产物之一,具有抗虫及抗病害的作用。法尼基焦磷酸合酶是杜松烯合酶的上游酶,催化合成法尼基焦磷酸,该物质是棉酚等次生代谢物生物合成的前体。本文依据亚洲棉法尼基焦磷酸合酶基因序列,采用同源RT-PCR技术,克隆了陆地棉法尼基焦磷酸合酶基因,对其序列和编码产物结构进行了分析。荧光定量PCR分析表明,该基因在棉花植株叶片表达量最高,根部最低,在花、铃、蕾、茎中的表达水平接近。以上工作为棉花异戊二烯基途径的分析及相关次生代谢的途径工程研究奠定了一定的理论基础。

Gossypol is one of the most important secondary metabolites in cotton plants, which mediates insect and disease resistance. Farnesyl pyrophosphate synthase is a key enzyme in the biosynthesis pathway of gossypol and is an upstream enzyme of δ-cadinene synthase. Farnesyl pyrophosphate is a common precursor of diverse metabolites, such as gossypol. In this report, a cDNA encoding a farnesyl pyrophosphate synthase gene, designated GhFPPS, was cloned from Gossypium hirsutum L. by a homology RT-PCR method. Bioinformatics analyses methods, including secondary structure prediction and 3-D modeling, were adopted to predict the structure of the putative protein product. Expression pattern in different organs of cotton plant was revealed by a SYBR Green I real-time RT-PCR method. GhFPPS showed the highest expression level in cotton leaves and the lowest in roots. Similar expression levels were detected in cotton flower, boll, bud, and stem tissues, respectively. These efforts may be useful for further study on tuning of biosynthesis of some terpenoid metabolites by the pathway engineering strategy .