植物磷酸乙醇胺N-甲基转移酶的研究进展

甘氨酸甜菜碱是一种渗透调节物质，能够维持高盐浓度下细胞的渗透平衡和膜的有序性，并有效地稳定酶的结构；胆碱是甘氨酸甜菜碱生物合成的必要前体物质，而磷酸乙醇胺甲基转移酶（phosphoethanolamineN-methyltransferase，PEAMT）作为甲基转移酶，是催化磷酸乙醇胺三次甲基化生成胆碱的限速酶。近年来研究表明磷酸乙醇胺甲基转移酶不仅在植物生长发育过程发挥作用，而且通过参与渗调物质甜菜碱以及胁迫相关第二信使磷脂酸的合成从而使植物对盐胁迫产生应答反应。本文就植物磷酸乙醇胺甲基转移酶的反应作用机理、生物学功能及表达调控机制进行了归纳总结。

Research Advances on Phosphoethanolamine N-Methyltransferase in Plant

Glycine betaine, known aS an osmoprotectant, maintains cellular osmotic balance, keeps cell membrane integrity, and stabilizes the enzyme structure. Choline is the precursor necessary for the biosynthesis of glycine betaine. And phosphoethanolamine N-methyltransferase （PEAMT） functions as a rate-limiting enzyme for choline production, which methylates three ethanolamine phosphate as a methyl transferase enzyme. Recent studies have shown that PEAMT not only plays a certain role in plant growth and development, but also participates in the synthesis of osmo-regulation substance such as glycine betaine, and stress-associated second messenger such as phosphatidic acid under abiotic stress condition. In this paper, the reaction mechanism, biological function, and regulatory mechanisms ofphosphoethanolamine methyltransferase in plant were summarized and discussed.