Paraquat tolerance of transgenic Nicotiana tabacum with enhanced activities of glutathione reductase and superoxide dismutase.

Transgenic tobacco with enhanced cytosolic activities of glutathione reductase and superoxide dismutase were generated by cross-fertilization. Leaves of the hybrids exhibited further increased tolerance to a O2-.-generating herbicide paraquat than those of their parents. This result indicates the efficiency of manipulating more than one gene in improving resistance of plants to photooxidative stress.