刺五加糖基转移酶基因的表达及其对皂苷含量的影响

Expression of Glycosyltransferase Gene in Eleutherococcus senticosus and Its Influence on Saponins Content

为了探明刺五加糖基转移酶基因(glycosyltransferase,GT)的表达特点及其对刺五加总皂苷含量的影响。以GAPDH基因为内参照基因,采用实时定量PCR技术分析了不同产地、不同生长发育时期、不同器官刺五加中GT基因的表达规律及茉莉酸甲酯(MeJA)对其表达的影响。并采用浓硫酸-香草醛比色法测定刺五加总皂苷的含量,利用SPPS17.0软件进行相关性分析。结果表明,GT基因在根、幼茎、叶片和叶柄中均有表达,但表达量差异不显著。刺五加的GT基因在叶片完全展开期的表达量最高,盛花期和果实基本成熟期的表达量最低,仅为叶片完全展开期表达量的66.9%。MeJA处理可显著提高GT基因的表达量(p<0.05)。不同产地刺五加的GT基因表达量和总皂苷含量差异显著,但GT基因的表达量与总皂苷含量同升同降,存在极显著的正相关关系(p<0.01)。初步判定,GT基因的表达量决定了刺五加中总皂苷的含量,GT是决定刺五加中总皂苷含量的关键酶。

The purpose of our experiment is to ascertain the characteristics of the expression and the influence for total saponins content of Glycosyltransferase（GT） gene from Eleutherococcus senticosus.Taking GAPDH for reference gene,quantitative real time PCR was developed to analyze the expression of E.senticosus GT gene from different origins,during different growth periods and in different organs.The influence of methyl jasmonate（MeJA）on E.senticosus GT gene expression was analyzed by quantitative real time PCR.The content of saponins in E.senticosus was measured by the thick sulphuric acid-vanillin colorimetric method.SPSS 17.0 software was performed to analysis the datum.The result indicated that there were no significant differences about the expression of E.senticosus GT gene in different organs including petiole,tender stems,root and blade.The expression of E.senticosus GT gene was the highest during the leaf fully extended stage and the lowest during flowering stage and fruit elementary mature stage,which was only 66.9% as much as that in the highest stage.The MeJA could improve the expression of E.senticosus GT gene（p0.05）.The expression of E.senticosus GT gene from different origins and saponins content had differed significantly,shared the same changing trend,had significantly positive correlation（p0.01）.According to our initial judgment,the level of GT expression determined the E.senticosus saponins content,and E.senticosus GT played a key enzyme gene in the determined content of saponins.