摘要：

为了探索马铃薯小G蛋白StRab5b与花青素合成之间的关系,利用农杆菌介导的遗传转化,将StRab5b基因在马铃薯中超表达后,研究StRab5b基因对马铃薯花青素含量和PAL 活性的影响。结果表明,超表达StRab5b基因显著增加了马铃薯叶片、茎段和薯块中的花青素含量。与对照相比,转基因马铃薯植株StRab5b-L2、StRab5b-L3和StRab5b-L5叶片花青素含量分别增加了42%,24%,54%,茎段中花青素含量分别增加了59%,37%,32%,薯块中花青素含量分别增加了118%,82%,105%;同时,StRab5b基因对植物花青素合成关键酶PAL活性也有促进作用,与对照相比,转基因马铃薯植株StRab5b-L2、StRab5b-L3和StRab5b-L5叶片PAL活性分别增加了88%,63%,66%,茎段中PAL活性分别增加了48%,38%,31%,薯块中PAL活性分别增加了98%,78%,64%。综上所述,小G蛋白StRab5b通过调控PAL活性,增加了马铃薯中花青素的含量。

关键词: 马铃薯, 花青素, 小G蛋白, StRab5b基因, 遗传转化, PAL活性

Abstract:

Small GTPases Rabs is a kind of monomer GTP binding protein,which can act as a molecular switch involve in variety of physiological and biochemical reactions in plant cells. In order to explore the relationship between potato small G protein StRab5b and anthocyanin synthesis,the StRab5b gene was overexpressed in potato by Agrobacterium mediated genetic transformation,try to study the effects of StRab5b gene on anthocyanin content and PAL activity. The result showed that overexpression of StRab5b gene significantly increased the anthocyanin content in potato leaves,stems and tubers. Compared with the control,the anthocyanin content in leaves of transgenic potatoes StRab5b-L2,StRab5b-L3 and StRab5b-L5 increased by 42%,24% and 54%,respectively;in stems was increased by 59%,37% and 32%,respectively;in tubers was increased by 118%,82% and 105%,respectively. At the same time,StRab5b gene also promoted the PAL activity,a key enzyme of plant anthocyanin synthesis. Compared with the control,the PAL activity in leaves of transgenic potatoes StRab5b-L2,StRab5b-L3 and StRab5b-L5 increased by 88%,63% and 66%,respectively;in stems increased by 48%,38% and 31%,respectively;in tubers increased by 98%,78% and 64%,respectively. In summary,small GTPases StRab5b increased the content of anthocyanin in potato by regulating PAL activity.

Key words: Potato, Anthocyanin, Small GTPases, StRab5b gene, Genetic transformation, PAL activity