印度紫檀DXS基因的克隆及表达分析

Identification and Gene Expression Analysis of DXS Gene from Pterocarpus indicus

为了探讨印度紫檀(Pterocarpus indicus)萜类化合物的生物合成,本研究通过对合成萜类物质的MEP途径的第一个限速酶(1-脱氧-D-木酮糖-5-磷酸合酶, DXS)基因进行克隆,获得了印度紫檀DXS的全长cDNA PiDXS基因(NCBI登录号:MK959226),并对其进行生物信息学和组织表达特异性分析。结果显示:PiDXS基因cDNA开放阅读框长2 025 bp,编码674个氨基酸,Blast比对发现,PiDXS具有一个二磷酸硫胺结合位点和一个转酮醇酶结构域;系统进化分析显示,PiDXS基因与大豆DXS和狭叶羽扇豆DXS聚为一类;组织表达特异分析结果显示PiDXS在茎、叶、树皮和根中均能表达,主要在幼嫩的组织中表达。研究结果为确定印度紫檀中DXS的基因功能以及揭示印度紫檀萜类化合物的生物合成提供了基础。

In order to explore the biosynthesis process of terpenes in Pterocarpus indicus, the full-length cDNA of Pterocarpus indicus DXS(PiDXS) gene was obtained by cloning the first rate-limiting enzyme(1-deoxy-d-xyloxe-5-phosphate synthase, DXS) gene in the MEP pathway for the synthesis of terpenes, and bioinformatics analysis was performed. The results showed that DXS gene cDNA(PiDXS) had an open reading frame length of 2 025 bp and encoded 674 amino acids(NCBI accession number: MK959226). Blast comparison revealed that PiDXS had a thiamine diphosphate binding site and a transketoolase domain. Phylogenetic analysis showed that PiDXS gene was closely related to glycine max DXS and Lupinus angustifolius DXS gene. The results of tissue specific expression showed that PiDXS was expressed in stem, leaf, bark and root, mainly in young tissues. The results provide a reference basis for determining the gene function of DXS and revealing the biosynthesis of terpenes in Pterocarpus indicus.