烟草牻牛儿基牻牛儿基焦磷酸合成酶小亚基基因的克隆及组织表达谱

Cloning and Tissue Expression Analysis of Geranylgeranyl Pyrophosphate Synthase Small Subunit Gene from Nicotiana tabacum

为揭示牻牛儿基牻牛儿基焦磷酸合成酶(GGPPS)小亚基在烟草(Nicotiana tabacum)中的生理功能,采用电子克隆的方法,结合RT-PCR和SMART RACE技术,从烟草中克隆到1个牛儿基牛儿基焦磷酸合成酶小亚基基因的cDNA序列,命名为NtGGPPS5(GenBank登陆号:KF316932)。该基因全长1320 bp,编码332个氨基酸,与番茄(Solanum lycopersicum,XP_004246572)及其野生种(Solanum pennellii,ADZ24721)的GGPPS小亚基的氨基酸序列一致性均为92%,具有一个特征性的异戊二烯合成酶保守的天门冬氨酸富集区。进化分析表明,植物GGPPS分为大亚基和小亚基两个分支,而且NtGGPPS5属于小亚基。实时荧光定量PCR试验表明,NtGGPPS5基因在烟草根、茎、叶和芽中均有表达,表达量为芽>叶>茎>根。

In order to reveal the physiological functions of the small subunit of geranylgeranyl pyrophosphate synthase （GGPPS）, a cDNA sequence encoding the small subunit of GGPPS was isolated from tobacco （Nicotiana tabacum） by in silico cloning combined with RT-PCR and SMART RACE technology, and designated as NtGGPPS5 （GenBank Number KF316932）, the gene was 1320 bp in length and encoded a putative protein of 332 amino acids, This deduced amino acid sequence shared 92% identity with Solanum lycopersicum （XP 004246572） and Solanum pennellii （ADZ24721）, and possessed a characterized Asp-rich motif of isoprenyl synthase family. Phylogenetic analysis revealed that the plant GGPPSs had two branches： large subunit and small subunit, NtGGPPS5 belonged in the latter. Meanwhile, the results of real-time quantitative PCR analysis indicated that NtGGPPS5 was transcribed in root, stalk, leaf and bud, the order of NtGGPPS5 expression level was bud〉leave〉stalk〉root.