在植物基因工程中，需要用到选择标记基因以便筛选转化子。随着转基因植物的商品化，人们越来越关注其安全性问题，其中主要涉及选择标记的安全性。为了提高转基因植物的安全性，生物学家们开始寻找生物安全的选择标记。本文分别从糖代谢、氨基酸代谢、激素代谢、核苷酸代谢、蛋白质代谢等方面综述了当前以代谢关键酶基因作为转基因植物选择标记的研究进展，此类选择标记为解决转基因植物的安全性问题提供了一条有效途径。

In plant genetic engineering, selectable marker is needed to distinguish transformant. As the commercialization of transgenic plants, people are more and more paying close attention to their safety, among which refers to the safety of selectable marker. In order to increase the safety of transgenic plants, Biologists began to search for biosafe selectable marker. Here we overview current research progress of taking key enzyme in metabolic pathways，which include glycometabolism, amino acid metabolism, hormone metabolism ,nucleotide metabolism and protein metabolism et cetera, as selectable marker in transgenic plants.