Co-expression of Polygonum sibiricum Glutathione Transferase and Cysteine Synthase Genes in Saccharomyces cerevisiae
西伯利亚蓼谷胱甘肽转移酶和半胱氨酸合成酶基因在酿酒酵母中的共表达

Glutathione transferase (GST) and cysteine synthase (CS) play an important role in plant elimination of active oxygen (reactive oxygen species, ROS). RT-PCR analysis of GST and CS in Polygonum sibiricum Laxm. showed remarkable change in expression induced by 3% NaHCO3 stress. We transformed GST, CS and the GST+CS combination into yeast cells(Saccharomyces cerevisiae), designated transgenic yeast (ty) ty-gst, ty-cs and ty-gc. The survival rate of ty-gst, ty-cs and ty-gc was higher than that of wild-type yeast (wy) under 1 mol.L-1 Na2CO3 and 5 mol.L-1 NaCl stress, with essentially no difference in rate between the three tys. With 0.4 mol.L-1 NaCl, the activity of superoxide dismutase 1 (SOD1), SOD2, glutathione peroxidase 1 (GPX1) and GPX3 were lower and that of catalase 1 (CTA1) higher in ty than in wy. However, the activity of the ty-cs SOD, CAT and GPX showed the highest with 0.4 mol.L-1 NaCl stress.