油料作物种子维生素E基因工程研究进展

Progress in Genetic Engineering Improving Vitamin E Contents in Oilseeds

通过对维生素E代谢深入研究,人们已经基本弄清维生素E的合成途径。在植物不同组织维生素E的含量和组成各异。维生素E具有多种重要功能:是人类和动物维持生殖系统和免疫系统正常功能所必需的微量营养元素;维生素E因其抗氧化性能保护生物膜免受氧化而与预防多种疾病以及抗衰老有关;维生素E还能抑制油脂的自动氧化和酸败,延长食用植物油贮存期。维生素E的活性和抗氧化性与其组成和含量相关。对维生素E的基因工程研究主要从改变总量和各成分比重入手,通过单点和多点调控调节代谢,改变油料作物维生素E的组成。综述了维生素E合成代谢途径以及当今利用基因工程改变维生素E的策略和途径。

Almost all the steps in vitamin E biosynthesis have been revealed through the past decades of research on vitamin E metabolism. The content of vitamin E and the proportion of individual tocochromanol species differ in seeds and leaves of plants. Vitamin E performs lots of indispensable functions in vivo. It was originally discovered as an essential element for reproduction. It has also been found to be related to maintaining the immune system. As an effective oxidant, vitamin E plays an important role in protecting membranes from being oxidated by free radicals, which contributes greatly to slowing aging and to fighting against diseases. The sufficient source of vitamin E is supplied in edible plant oil, the stability of which benefit from the vitamin E antioxidation. The bioactivity and antioxidation are correlated to the content and the composition of vitamin E. These beneficial effects of vitamin E have aroused more researches on vitamin E gene engineering. To date, researches to improve vitamin content in oilseed crops have been mainly focused on the tow following strategies, enhancing the total volume of vitamin E and increasing the percentage of α-tocopherol, the form of vitamin E displaying the greatest efficacy. This review is giving a brief introduction about the biosynthesis and functions of vitamin E, the strategies and methods of vitamin E gene engineer.