关键词: 拟南芥 维生素E 生育酚 启动子 表达

Abstract:

Vitamin E （Tocopherol）is a lipid-soluble antioxidant and essential for human health. Homogentisate phytyltransferase （HIT）, 2-methyl-6-phytyl-1, 4-benzo- quinol methyltransferase （MPBQMT/VTE3） and γ- tocopherol methyhransferase （γ-TMT/VTE4） are three key enzymes involved in the tocopherol biosynthetic pathway in plants. In this study, the expression patterns of the promoters of HPT1, VTE3 and VTE4 from Arabidopsis thaliana were characterized respectively under some environmental stress conditions, such as low-temperature, high salt content and non-light. GUS staining showed that the expression of HPT1 decreased dramatically at low-temperature and decreased slightly with high salt content. In the dark-grown transgenic seedlings, an evident expression shift was observed that there was an increase in hypocotyls, whereas a decrease in roots. The promoter of VTE3 was not responsive to low temperature, but displayed a significant reduction of expression at high salt content, with less expression in hypocotyls under non-light. The expression of VTE4 increased slightly at low-temperature, but decreased dramatically on high salt content condition, with a little of decrease in hypocotyls under non-light. The data showed that the above three genes involved in vitamin E pathway are regulated by environmental conditions.

Key words: Arabidopsis thaliana , vitamin E , tocopherols , promoter, expression