Transgenic tobacco plants overexpressing cotton glutathione S-transferase (GST) show enhanced resistance to methyl viologen.
A GST (EC 2.5.1.18) gene (Gst-cr 1) from cotton was introduced into Nicotiana tabacum by Agrobacterium tumefaciens-mediated transformation. Transgenic tobacco plants overexpressing Gst-cr1 were normal in growth and mature compared with control, but had much higher levels of GST and GPx activities and showed an enhanced resistance to oxidative stress induced by a low concentration of methyl viologen (MV). Six antioxidant enzymes, glutathione S-transferase, glutathione peroxidase (EC 1.11.1.9), superoxide dismutase (EC 1.15.1.1), peroxidase (EC 1.11.1.7), catalase (EC 1.11.1.6), and ascorbate peroxidase (EC 1.11.1.11) were monitored in transgenic lines and non-transgenic control during MV treatments. When they were treated with 0.03 mmol/L of MV, both transgenic lines and control showed a rapid increase in the activities of GST, GPx, SOD, POD, APx, while the activity of CAT seemed to be irregular. The percent of the increase in SOD and POD activities was much higher in control than in transgenic plants. When treated with 0.05 mmol/L of MV, both control and transgenic plants were severely damaged, and the activities of the six enzymes decreased sharply.
Yu
Tao
T
Key Laboratory for Plant Development Biology of Ministry of Education, College of Life Sciences, Wuhan University, Wuhan, 430072, P.R. China.
Li
Yang Sheng
YS
Chen
Xue Feng
XF
Hu
Jing
J
Chang
Xun
X
Zhu
Ying Guo
YG
D060387:Ascorbate Peroxidases; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D004351:Drug Resistance / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism; D005982:Glutathione Transferase / Q000235:genetics* / Q000378:metabolism; D003368:Gossypium / Q000201:enzymology*; D006540:Herbicides / Q000378:metabolism / Q000494:pharmacology*; D010269:Paraquat / Q000378:metabolism / Q000494:pharmacology*; D009195:Peroxidase / Q000235:genetics / Q000378:metabolism; D010544:Peroxidases / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics*
D006540:Herbicides; D010544:Peroxidases; D060387:Ascorbate Peroxidases; D002374:Catalase; D009195:Peroxidase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase; D010269:Paraquat