长春花激素自养型细胞株C_(20)hi中阿玛碱过量合成分子机制研究

Molecular Mechanism of Ajmalicine Over-Production in Catharanthus Roseus Cell Line C_(20)hi

通过RT-PCR半定量技术分析了长春花生物碱生物合成过程中7个关键酶基因在长春花激素自养型细胞株C20hi及其母株C20D中转录表达水平的差异,发现关键酶基因asat、dc、hmgr、g10h、scss、ss、sgd在C20hi中的转录表达水平高于C20D中的表达水平。推测,长春花激素自养型细胞株C20hi中阿玛碱的过量合成可能与2,4-D抑制了阿玛碱生物合成关键酶的表达水平有关。

To elucidate the putative molecular mechanism of ajmalicine over-production in C20hi, a novel Catharanthus roseus cell line producing large amount of ajmalicine which has been obtained through di- rectional induction from the mother cell line C20D in our lab, the reverse transcriptional polymerase chain reaction （RT-PCR） was applied to analyze the expression levels of seven key genes, named asa, tdc, hmgr, gl0h, scs, sss, and sgd, in the alkaloid biosynthesis pathway in C20hi and C20D. RT-PCR results revealed that all of the seven genes＇ expression level in C20hi is higher than that in C20D, respectively. Especially, gl0h, scs, and sss had much higher expression level in C20hi than in C20D. The over expression of the key genes maybe result from the negative control of 2,4-D in the media. We speculate that the over expression of the key genes led to the change of corresponding enzyme activities, which consequently resulted in the over-production of ajmalicine in cell line C20hi.