Tocopherols synthesized exclusively by photosynthetic organisms are major antioxidants in biomembranes.In plants,tocopherol cyclase(TC/VTE1) catalyzes the conversion of 2,3-dimethyl-5-phytyl-1,4-benzoquinone(DMPBQ) to...Tocopherols synthesized exclusively by photosynthetic organisms are major antioxidants in biomembranes.In plants,tocopherol cyclase(TC/VTE1) catalyzes the conversion of 2,3-dimethyl-5-phytyl-1,4-benzoquinone(DMPBQ) to γ-tocopherol.In the present study,OsVTE1,which encodes a rice tocopherol cyclase ortholog,was cloned and characterized.OsVTE1 was induced significantly by abiotic stresses such as high salt,H2O2,drought,cold and by the plant hormones ABA and salicylic acid.The tissue-specific expression pattern and OsVTE1-promoter GUS activity assay showed that OsVTE1 was mainly expressed in the leaf,and also could be detected in the root,stem and panicle.Compared with control plants,transgenic plants with OsVTE1 RNA interference(OsVTE1-RNAi) were more sensitive to salt stress whereas,in contrast,transgenic plants overexpressing OsVTE1(OsVTE1-OX) showed higher tolerance to salt stress.The DAB in vivo staining showed that OsVTE1-OX plants accumulated less H2O2 than did control plants.展开更多
基金supported by the National Basic Research Program of China (Grant No. 2006CB100102)National High-Tech Project (Grant No. 2006AA10Z18201)
文摘Tocopherols synthesized exclusively by photosynthetic organisms are major antioxidants in biomembranes.In plants,tocopherol cyclase(TC/VTE1) catalyzes the conversion of 2,3-dimethyl-5-phytyl-1,4-benzoquinone(DMPBQ) to γ-tocopherol.In the present study,OsVTE1,which encodes a rice tocopherol cyclase ortholog,was cloned and characterized.OsVTE1 was induced significantly by abiotic stresses such as high salt,H2O2,drought,cold and by the plant hormones ABA and salicylic acid.The tissue-specific expression pattern and OsVTE1-promoter GUS activity assay showed that OsVTE1 was mainly expressed in the leaf,and also could be detected in the root,stem and panicle.Compared with control plants,transgenic plants with OsVTE1 RNA interference(OsVTE1-RNAi) were more sensitive to salt stress whereas,in contrast,transgenic plants overexpressing OsVTE1(OsVTE1-OX) showed higher tolerance to salt stress.The DAB in vivo staining showed that OsVTE1-OX plants accumulated less H2O2 than did control plants.
