Oxidative stress is one of the major causative factors for injury to plants exposed to environmental stresses. Plants have developed diverse defense mechanisms for scavenging oxidative stress-inducing molecules. The antioxidative enzyme 2-cysteine peroxiredoxin (2-Cys Prx) removes peroxides and protects the photosynthetic membrane from oxidative damage. In this study, transgenic potato (Solanum tuberosum L. cv. Atlantic) expressing At2-Cys Prx under control of the oxidative stress-inducible SWPA2 promoter or enhanced CaMV 35S promoter (referred to as SP and EP plants, respectively) was generated using Agrobacterium-mediated transformation. The transgenic plants were tested for tolerance to stress.
Following treatment with 3 mM methyl viologen (MV), leaf discs from SP and EP plants showed approximately 33 and 15% less damage than non-transformed (NT) plants. When 300 mM MV was sprayed onto whole plants, the photosynthetic activity of SP plants decreased by 25%, whereas that of NT plants decreased by 60%. In addition, SP plants showed enhanced tolerance to high temperature at 42 C. After treatment at high temperature, the photosynthetic activity of SP plants decreased by about 7% compared to plants grown at 25 C, whereas it declined by 31% in NT plants. These results indicate that transgenic potato can efficiently regulate oxidative stress from various environmental stresses via overexpression of At2-Cys Prx under control of the stress-inducible SWPA2 promoter.