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 Fundamental Research Funds for the Central Universities and the State Key Development Program for Basic Research of China(2007CB714304)
文摘维生素 E succinate 作为催化剂用修改 Novozym-435 在器官的溶剂被综合。以便改进 Novozym-435 的催化表演,酶用醋性的酐被修改, propionic 酐并且琥珀酸酐独立。我们发现 hydrolytic 活动和修改 Novozym-435 的热稳定性与未修改的酶相比被提高。修改 Novozym-435 催化剂被用来综合维生素 E 的 succinate 衍生物。与本国的 Novozym-435 相比,在支持维生素 E succinate 的合成的修改 novozym-435 的催化活动戏剧性地被增加,与修改与的 novozym-435 琥珀酸酐(N435-S ) 作为最活跃的催化剂。为维生素 E succinate 的合成的条件也被优化。tert-butanol 和 DMSO 的混合物(2 的体积比率:3 ) 是反应的最合适的媒介,而维生素 E 到的适当臼齿的比率琥珀酸酐和反应温度是 1:5 和 40 (C 分别地。在这些反应条件下面,维生素 E succinate 的收益到达了 94.4% 。N435-S 能为五批被再使用。
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.