洋常春藤β-AS基因的全长克隆与表达分析  

Cloning and Expression Analysis of β-AS Gene in Hedera helix L.

作　　者：孙化鹏 钟晓红[2] 徐子健 乔飞[1] Sun Huapeng 1, Zhong Xiaohong 2, Xu Zijian 1,3, Qiao Fei1(1 Key Laboratory of Crop Gene Resources and Germplasm Enhancement in Southern China, Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, 571737; 2 College of Horticulture and Landscape, Hunan Agricultural University, Changsha, 410128; 3 College of Horticulture and Landscape Architecture, Hainan University, Haikou, 570228)

机构地区：[1]中国热带农业科学院热带作物品种资源研究所农业部华南作物基因资源与种质创制重点开放实验室,儋州571737 [2]湖南农业大学园艺园林学院,长沙410128 [3]海南大学园艺园林学院,海口570228

出　　处：《分子植物育种》2018年第3期733-739,共7页Molecular Plant Breeding

基　　金：中央级公益性科研院所基本科研业务费(1630032018006);湖南省教育厅科研项目(15A089);国家自然科学基金面上项目(31570326)共同资助

摘　　要：β-香树素合成酶(β-AS)是三萜皂苷生物合成途径中关键酶基因,可以催化形成齐墩果烷型三萜皂苷类化合物的骨架结构。本研究利用RACE克隆技术克隆并分析了洋常春藤中的β-AS基因,结果表明:洋常春藤β-AS基因的c DNA全长2784 bp,命名为Hhβ-AS(Gen Bank登录号:KU942522),其包含编码763个氨基酸的开放阅读框。预测该基因编码的蛋白质分子量为87.8 k D,理论等电点为5.94。经过氨基酸序列比对,结果表明洋常春藤中的β-AS与刺楸的β-AS同源性最高,达到96%。通过RT-q PCR分析Hhβ-AS基因在洋常春藤中的时空表达规律,表明Hhβ-AS基因与常春藤皂苷含量之间存在明显的正相关性,为探讨其在常春藤皂苷生物合成途径中的作用以及深入的研究该基因的分子调控机制奠定基础。Beta-amyrin synthase（β-AS） gene is the key gene in triterpenoid saponins biosynthesis pathway, and it can catalyze to build the skeleton structure of olefins-type triterpenoid saponins. The β-AS gene of Hedera helix was cloned and analyzed by using the RACE cloning method in this study. The results showed that the length of cDNA sequence of β-AS H. helix gene has 2 784 bp, and the gene was named as Hhβ-AS and deposited in Gen Bank with accession number KU942522. Hhβ-AS contained an open reading frame（ORF） encoding a 763 amino acid sequence. Bioinformatics analysis predicted that protein molecular weight of encoding protein was predicted at 87.8kD with isoelectric point 5.94. Blast results of the amino acid sequence indicated that the β-AS gene of H. helix has highest homolog（96%） with Kalopanax septemlobus. Meanwhile, the time and space expression level of Hhβ-AS gene was analyzed by RT-q PCR, and the results showed that it had significant positive correlation between Hhβ-AS gene and content of triterpenoid saponins. All these results might provide a researching foundation on triterpenoid saponins biosynthesis pathway in H. helix and molecular regulation mechanism of Hhβ-AS gene.

关 键 词：洋常春藤 β-AS基因 常春藤皂苷 表达分析 

分 类 号：S567.19[农业科学—中草药栽培]