摘要
Arsenic affects plants by disrupting their growth and metabolism while selenium, an essential micronutrient has beneficial role in stress tolerance. Owing to the antioxidative capacity of selenium, it can counteract detrimental effects of arsenic induced stress in plants. The interactive influence of arsenate and selenate on the growth, arsenic and selenium accumulation, activities of non-enzymatic and enzymatic antioxidants, levels of ascorbate, α-tocopherol, total glutathione and activities of glutathione regulatory enzymes along with characterization and quantification of phytochelatins in growing wheat (Triticum aestivum L.) seedlings were investigated. Rate of arsenic accumulation was increased in arsenate treated seedlings while in seedlings treated jointly with arsenate and selenate, arsenic accumulation decreased. Arsenate stress resulted decrease in ascorbate and total glutathione contents, activities of the glutathione metabolism enzymes while significantly increased the levels of α-tocopherol and phytochelatins (PC2 and PC4), along with activities of ascorbate peroxidase and ascorbic acid oxidase in the test seedlings. The effects were more pronounced in roots than in shoots. Joint application of arsenate along with selenate was able to overcome the adverse effects caused by arsenic alone to variable extents by exhibiting significant alterations of all parameters tested, imparting better growth and thiol metabolism in the test seedlings. Our results conclude that application of selenium fertilizer in arsenic contaminated soil might be favourable to improve growth and defense ability in wheat against arsenic toxicity.
Arsenic affects plants by disrupting their growth and metabolism while selenium, an essential micronutrient has beneficial role in stress tolerance. Owing to the antioxidative capacity of selenium, it can counteract detrimental effects of arsenic induced stress in plants. The interactive influence of arsenate and selenate on the growth, arsenic and selenium accumulation, activities of non-enzymatic and enzymatic antioxidants, levels of ascorbate, α-tocopherol, total glutathione and activities of glutathione regulatory enzymes along with characterization and quantification of phytochelatins in growing wheat (Triticum aestivum L.) seedlings were investigated. Rate of arsenic accumulation was increased in arsenate treated seedlings while in seedlings treated jointly with arsenate and selenate, arsenic accumulation decreased. Arsenate stress resulted decrease in ascorbate and total glutathione contents, activities of the glutathione metabolism enzymes while significantly increased the levels of α-tocopherol and phytochelatins (PC2 and PC4), along with activities of ascorbate peroxidase and ascorbic acid oxidase in the test seedlings. The effects were more pronounced in roots than in shoots. Joint application of arsenate along with selenate was able to overcome the adverse effects caused by arsenic alone to variable extents by exhibiting significant alterations of all parameters tested, imparting better growth and thiol metabolism in the test seedlings. Our results conclude that application of selenium fertilizer in arsenic contaminated soil might be favourable to improve growth and defense ability in wheat against arsenic toxicity.
