茉莉花JsGGPPS基因的克隆及生物信息学与表达分析

牻牛儿基牻牛儿基焦磷酸合酶(Geranylgerany pyrophosphate synthase,GGPPS)是萜烯类香气物质合成途径中的关键酶。采用RT-PCR和RACE相结合的方法,克隆了茉莉花牻牛儿基牻牛儿基焦磷酸合酶基因的全长cDNA(命名为JsGGPPS,GenBank登录号AIY24421.1),采用实时荧光定量PCR技术分析JsGGPPS基因在茉莉花开放过程中的表达模式。结果表明,JsGGPPS全长cDNA为1 410bp,含1 083bp完整的开放阅读框(ORF),其推导的氨基酸序列包含360个氨基酸,属于trans-isoprenyl diphosphate synthases(IPPS)和class I terpene cyclases家族,含链长控制区(CLDR)、2个天冬氨酸富集区以及其他保守区。JsGGPPS基因与独行菜Lepidium apetalum、橡胶草Taraxacum kok-saghyz的同源性分别为91%、86%。实时荧光定量PCR结果表明,茉莉花开放过程中JsGGPPS基因在晚上18:00时表达量较低,呈上调趋势,在22:00时达到最高,呈下调趋势,在翌日2:00时表达量最低,与茉莉花释香趋势相似,为深入研究茉莉花萜烯类香气物质代谢途径奠定基础。

Cloning,Molecular Characterization,and Expression of JsGGPPs Gene from Jasminum sambac

Geranylgerany pyrophosphate synthase (GGPPS ) catalyzes the biosynthesis of geranylgeranyl diphosphate,which is a key precursor of the aromatic terpenes in jasmine flowers.The full-length cDNA sequence of GGP PS gene in the terpenoid backbone biosynthesis was cloned from J asminum sambac by RT-PCR combined with RACE,and subsequently named J sGGP PS with a GenBank Accession number of AIY24421.1. The expression of J sGGP PS during jasmine blooming was detected by quantitative real-time PCR.The results showed that the full-length of the cDNA sequence was 1 410 bp with a 1 083 bp open reading frame.The deduced protein consisted of 360 amino acids,and shared 91% identity with GGPPS from Lepidium apetalum and 84% from Taraxacum kok-saghyz .J sGGP PS had one chain length determination region,two highly conserved aspartate-rich motifs,and other conserved domains,which belonged to the trans-isoprenyl diphosphate synthases and class I terpene cyclases superfamily.The quantitative real-time PCR showed that the J sGGP PS expression at 18:00 was low,and began to rise and reached a maximum at 20:00 followed by a steady decline to a minimum at 2:00.The observation significantly correlated with the aroma release pattern of J.sambac in nature.The results provided a basis for further study on the terpene biosynthetic pathway of the flower.