利用与植物次生代谢产物糖基化相关的UDPG糖基转移酶的特征性保守区域 ,设计了同源简并引物 ,以甜菊基因组DNA为模板 ,PCR扩增获得甜菊糖基转移酶基因片段 .根据获得的基因片段设计引物GSTr和GSTf,分别与cDNA文库的T3 和T7通用引物扩增获得全长核苷酸序列的甜菊糖基转移酶基因 ,定名为sudpt 2 ,该基因全长 16 6 2bp ,包括poly(A)和一个 136 2bp的开放阅读框 ,编码 45 4个氨基酸 .与常见的糖基转移酶基因的相似性达 44 %～ 77% ,且具有UDPG糖基转移酶的特征性保守序列 .分子发育进化分析表明 ,此基因为类黄酮糖基转移酶基因家族成员By using two homologous degenerated primers, DNA fragments encoding steviol UDPG glucosyltransferase were amplified from the leaves of Stevia rebaudiana. The DNA fragment with strong homology to known flavonoid glucosyltransferases was used to design two primers to amplify upstream and downstream cDNA of stevia glucosyltransferase. The cDNA of stevia glucosyltransferase sudpg-2 was 1 662 bp in length, with a poly(A) tail and a 1 362 bp open reading frame which encoded 454 deduced amino acid residues. The deduced amimo acids sequence has 40%～60% identity to other plant glucosyltransferase and includes a part of the glucosyltransferase signature sequence. Molecular phylogenic relations of the deduced amino acids sequences with other plant glucosyltransferase suggested that the steviol UDPG glucosyltransferase belongs to family of flavonoid glucosyltransferases
