甜叶菊中新KAH基因的克隆及表达模式分析

发布时间：2018-04-15 18:58

  本文选题：甜叶菊 + 甜菊糖苷　； 参考：《生物技术通报》2017年04期

【摘要】：为进一步揭示甜菊糖苷生物合成途径的分子调控机制,探究甜菊糖苷在甜叶菊叶片中积累差异原因。从不同甜叶菊材料中分别克隆关键分支点酶KAH的编码基因,并对获得的核苷酸序列进行生物学功能分析和预测。结果显示,最终共获得6条高度同源的核苷酸序列,个别关键碱基的突变造成序列开放读码框位置和大小的显著差异,共预测获得7个不同KAH编码基因。KAH1、KAH2同时存在于SR1、SR3、鑫丰3号、谱星1号和守田3号中,KAH3存在于江甜1号和守田3号中,KAH4存在于江甜3号中,KAH5、KAH6、KAH7均存在于SR2中且Sr KAHs在甜菊糖苷积累多的品种和组织部位中表达更高。7个KAH基因均含有P450保守结构域且均属于CYP716家族成员;亚细胞定位预测KAH2和KAH4定位于细胞质其他5个均定位在叶绿体中。甜叶菊中KAH编码基因的数目、氨基酸长度及在亚细胞结构的定位差异或许是导致甜叶菊不同品种和组织中Sr KAHs表达和功能差异的主要原因并最终糖苷的积累差异。
[Abstract]:In order to further reveal the molecular regulation mechanism of stevioside biosynthesis pathway, the reason of stevioside accumulation difference in stevia leaves was investigated.The coding genes of key branching enzyme KAH were cloned from different stevia materials, and the obtained nucleotide sequences were analyzed and predicted.The results showed that a total of 6 highly homologous nucleotide sequences were obtained. The mutation of some key bases resulted in significant differences in the position and size of the open reading frame.It is predicted that seven different KAH coding genes. KAH1 and KAH2 exist simultaneously in SR1, SR3, Xinfeng 3, Xinfeng 3, Xinfeng 3, Xinfeng 3.Peixing 1 and Shutian 3 were found in Jiangtian 1 and Shutian 3 respectively. Both of them were found in SR2, and Sr KAHs were expressed in the cultivars and tissues with more stevioside accumulation. All of the 7 KAH genes were expressed in all of them.It contains P450 conserved domain and belongs to CYP716 family.Subcellular localization predicted that KAH2 and KAH4 were located in the cytoplasm and the other 5 were located in chloroplasts.The differences in the number of KAH coding genes, amino acid length and subcellular structure in stevia may be the main reasons leading to the difference of Sr KAHs expression and function in different varieties and tissues of stevia, and ultimately the difference of glycoside accumulation.
【作者单位】： 江苏省农科院经济作物研究所;
【基金】：江苏省农业三新工程[SXGC(2015)213] 江苏省农业科学院科技服务项目[KF(16)1042]
【分类号】：S566.9;Q943.2
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本文编号：1755369