转基因水稻抗坏血酸-谷胱甘肽循环系统对锌镉互作的应答

Response of the Ascorbate-glutathione Cycle to Combined Cadmium and Zinc in Transgenic Rice

实验分析了转GST和CAT 1双抗氧化酶基因水稻和非转基因水稻(Oryza sativa L.中花11号)抗坏血酸-谷胱甘肽循环系统在锌、镉及锌镉复合处理条件下的变化。结果显示,在单一镉胁迫下,转基因水稻(T)地上部分的CAT和GST活性都比非转基因水稻(N)的高,而前者的DHAR活性和GSH氧还状态则低于后者的;T根系CAT、APX和GR的活性也高于N的,但其GST、SOD和DHAR的活性则低于N的。单一锌处理时,T地上部分的CAT、GST、DHAR、APX和GR活性及ASA氧还状态都比N的高;其根系CAT和APX的活性也高于N的,但GSH氧还状态则低于后者的。锌和镉复合处理时,T地上部分的CAT和GR活性都比N的高,其SOD和DHAR活性及ASA和GSH氧还状态却低于后者的;T根系的CAT、GST和APX活性都比N的高,而前者的SOD、GR和DHAR活性及GSH氧还状态则比后者的低。转基因水稻和非转基因水稻之间抗坏血酸-谷胱甘肽循环系统变化的差异,可能是外源基因和内源功能相关组分协同作用的结果。

An analysis of the change of ascorbate-glutathione cycle in single Cd or Zn and combined Cd and Zn treated transgenic and non-transgenic rice(Oryza sativa L.NO.11) was conducted.The results showed that CAT and GST activity in overground part of transgenetic rice(T) was higher than that of non-transgenetic rice(N) treated with single Cd.but DHAR activity and GSH redox of the former were lower than that of the latter.And the activity of CAT,APS and GR in shoot of T were higher than that of N,but the activity of GST,SOD and DHAR were lower than that of N.The activity of CAT,GST,DHAR,APX,GR and ASA oxidation state in overground part of T were higher than that of N,and the activity of CAT,APX in shoot were higher than that of N,but GSH redox state was lower than that of N treated with single Zn.Treated with Cd and Zn,the activity of CAT,GR in overground part of T were higher than that of N,and the activity of SOD,DHAR and redox state of ASA and GSH were lower than that of N.and the activity of CAT,GST,APX in shoot were higher than that of N,but the activity of SOD,GR,DHAR and redox state of GSH were lower than that of N.The aboved outcome indicated that the difference of ascorbate-glutathione cycle between transgenic rice and non-transgenic rice might come from the coordination of GST and CAT 1 and the function-linked components.