岗梅转录组及其乌索烷型三萜皂苷生物合成相关酶基因的发掘  

Transcriptomic Analysis and Systematic Mining of Genes Involved in Biosynthetic Pathway of Triterpenoid Saponins in Ilex Asprella

作　　者：郑夏生[1] 罗秀秀[1] 徐晖[1] 詹若挺[1] 陈蔚文[1] 

机构地区：[1]广州中医药大学中药资源科学与工程研究中心/岭南中药资源教育部重点实验室,广州510006

出　　处：《世界科学技术-中医药现代化》2014年第7期1505-1512,共8页Modernization of Traditional Chinese Medicine and Materia Medica-World Science and Technology

基　　金：财政部中央财政支持地方高校发展专项资金项目(粤财教[2010]358号):南药可持续利用研究与综合开发利用;负责人:陈蔚文;广东省科技厅广东省科技计划项目(2012A030100006):三九胃泰和感冒灵中岭南中药材规范化种植关键技术研究;负责人:韩正洲

摘　　要：目的:发掘与岗梅乌索烷型三萜皂苷生物合成相关的酶基因。方法:利用Illumina测序平台对岗梅根进行转录组测序,通过基因注释、同源分析、系统发生分析等生物信息学手段,发掘可能参与合成的单基因簇(Unigenes)。结果:在岗梅根转录组中发现了272条与萜类生物合成相关的Unigenes。这其中包括72条可能参与萜类生物合成上游途径的Unigenes,以及26条可能与三萜合成途径下游母核合成、氧化和糖基化相关的Unigenes。对其中部分Unigenes进行系统发生分析,进一步揭示了这些Unigenes与同源基因间的进化关系。利用酵母表达系统,鉴定了两个香树酯醇合酶IaAS1和IaAS2,其中IaAS1为少数以α-香树脂醇为主要产物的香树酯醇合酶之一。结论:本文从岗梅根转录组数据库中发掘到一系列可能与岗梅乌索烷型三萜皂苷生物合成相关的酶基因。对这些基因的进一步研究,有助于从分子水平揭示岗梅中乌索烷型三萜皂苷的生物合成途径。This study was aimed to screen candidate genes involved in the triterpenoid saponins biosynthetic pathway of the Ilex asprella root. The Illumina platform was applied to perform transcriptomic sequencing of I. asprella root, followed by a series of bioinformatics analysis. The results showed that a total of 272 candidate unigenes were annotated to be involved in the biosynthetic pathway of terpenoid in the transcriptome of I. asprella root, including 72 unigenes for the upstream pathway and 26 unigenes for cyclization, oxidation and glycosylation in the downstream pathway. Phylogenetic analysis was carried out to further analyze the evolution relationship of some candidate unigenes and their homologous genes. Two genes IaA S1 and IaA S2 were proved to be mixed amyrin synthases in yeast expression system. Moreover, IaA S1 was identified to one of the rare ASs with α-amyrin as the major product. It was concluded that a series of candidate genes, which might be involved in the biosynthetic pathway of triterpenoid saponins, were screened out from the transcriptome of I. asprella root. Further investigation of these candidate genes will provide insight into their actual functions in the triterpenoid saponins biosynthetic pathway in I. asprella.

关 键 词：岗梅 转录组 三萜皂苷 生物合成 基因发掘 

分 类 号：R282.5[医药卫生—中药学]