甜叶菊中9种甜菊醇糖苷积累与其生物合成关键基因表达量的相关性

为了研究甜叶菊中主要甜菊醇糖苷积累特点与其生物合成关键基因表达量的关系,本研究选取3个品种甜叶菊(普赛科3号、中山2号、同心)为试验材料,定期在幼苗期、营养生长期、花蕾期采收植株的上位3对叶片,采用液相色谱-质谱法(LC-MS)检测9种甜菊醇糖苷,即莱宝迪苷A、B、C、D、E、F(RA、RB、RC、RD、RE、RF)、...

Correlation Between the Accumulations of 9 Steviol Glycosides and the Expressions of the Key Genes Involved in Their Biosynthesis in Stevia rebaudiana

In order to study the correlation between the accumulations of main steviol glycosides(SGs)and the expressions of the key genes that are involved in their biosynthesis in Stevia rebaudiana,three cultivars(Pusaike3,Zhongshan2,and Tongxin)were selected as materials.The upper three layer leaves were harvested at 3 growth stages,including the young seedling stage,vegetative stage,and flower budding stage.The contents of 9 SGs,such as rebaudioside A,B,C,D,E,F(RA,RB,RC,RD,RE,RF),stevioside(ST),rubusoside(RBS),dulcoside A(DA),were test by liquid chromatography mass spectrometry(LC-MS),and the expression levels of 3 key genes encoding uridine diphosphate-glycosyltransferases(UGTs),SrUGT91D2e,SrUGT74G1 and SrUGT76G1,were analyzed by quantitative real-time PCR.The results showed that the contents of the sweet SGs,RA was the highest at vegetative stage(1.60 mg·g^-1),and RD was the highest at flower budding stage(1.58 mg·g^-1)in Pusaike3;the contents of bitter SGs,St(0.50 mg·g^-1),RC(0.26 mg·g^-1)and DA(0.01 mg·g^-1)were significant lower in Pusaike3 than those in Zhongshan 2 or Tongxin,thus Pusaike3 was considered as a candidate cultivar for high yield of sweet SGs.The correlation analysis between the contents of SGs and the expressions levels of the key genes involved in their biosynthesis showed that the contents of sweet SGs,RD and RA were remarkably correlated with the expression levels of SrUGT91D2e and SrUGT76G1,while the contents of bitter SGs,RC,ST,DA were remarkably correlated with the expression level of SrUGT74G1.This research provides a scientific basis for Stevia rebaudiana breeding and suitable harvest time selection.