镉胁迫下能源甜菜BvGST基因在酵母中的功能分析

Functional Analysis of Energy Beet BvGST in Yeast under Cadmium Stress

植物谷胱甘肽转移酶(GSTs)在正常生长条件下的细胞代谢以及由于重金属胁迫所带来的解毒过程中,都发挥着重要作用。为了进一步研究BvGST基因在能源甜菜镉逆境胁迫中的功能,本研究利用RT-PCR的方法,从能源甜菜体内克隆获得了Beta vulgaris glutathione S-transferase(BvGST,LOC104898671)基因。利用酵母表达载体构建pYES2-BvGST重组质粒,并转化到酵母InVSc1中。SqRT-PCR结果表明,与内参基因ACT1相比,BvGST基因可以受到半乳糖的诱导从而适量表达。当施加0.5 mmol/L CdCl2逆境胁迫后,适量表达BvGST重组菌的生长状态和趋势要明显优于对照菌株(转化pYES2的酵母),并具有相对更高的Cd耐受性。因此可以推断,能源甜菜BvGST基因在镉逆境胁迫过程中发挥着重要的作用,并有可能通过GST介导的氧化逆境的活性解毒,从而参与到细胞对重金属镉离子的代谢平衡调控过程中。

Plant glutathione transferases(GSTs)play important role in both cell metabolism under normal growth conditions and detoxification due to heavy metal stress.In order to further study the function of BvGST gene in energy beet under cadmium stress,the Beta vulgaris glutathione S-transferase(BvGST,LOC104898671)gene was cloned from energy beet by RT-PCR.The recombinant plasmid of pYES2-BvGST was constructed through yeast expression vector system,and transformed into Saccharomyces cerevisiae InVSc1.Semi-quantitative RCR showed that BvGST as suitably induced by galactose and expressed in moderation compared with the reference gene ACT1.Under 0.5 mmol/L CdCl2 stress,the growth status and trend of the recombinant strain expressing BvGST were better than that of the control yeast,and had relatively higher Cd tolerance.Therefore,it could be concluded that BvGST gene played an essential role in the process of cadmium stress response,and might be involved in the regulation of cell metabolism of cadmium through the active detoxification of oxidative stress mediated by GST.