Greater protection against oxidative damages imposed by various environmental stresses in transgenic potato with higher level of reduced glutathione

摘要

Potato ( Solanum tuberosum L.) is the world’s number one non-cereal food crop and ranks fourth among most important crops grown worldwide in terms of acreage, yield and value. In order to maintain greater protection against environmental stresses, we developed transgenic potato overexpressing Arabidopsis thaliana glutathione reductase gene ( AtGR1 ). The transgenic potato maintained up to 6.5 folds higher GR activity, 5.8 folds glutathione (GSH) contents and up to 2.2 folds higher glutathione S -transferase activity compared to non transformed plants (NT). Interestingly, while the transgenic plants exhibited decreased dehydroascorbate reductase (DHAR) activity, the relative reduced ascorbate (AsA) contents were higher while the relative dehydroascorbate (DHA) were lower compared to NT which provide a support to the hypothesis that an active glutathione-independent pathway for DHA reduction might exists in vivo . The transgenic plants maintained an enhanced tolerance to methylviologen, and cadmium. When subjected to drought stress, the transgenic plants exhibited faster recovery with less visual injury compared to NT. These results suggest that manipulation of glutathione levels provides reliable strategy for the development of industrial transgenic potato plants with enhanced tolerance to multiple environmental stresses.