植物淀粉合成的调控酶

淀粉是植物中最普通的碳水化合物，是人类最主要的食品来源与重要的工业原料。植物淀粉的生物合成主要涉及了4种酶—ADPG焦磷酸化酶、淀粉合成酶、淀粉分支酶和淀粉去分支酶，它们在淀粉的生物合成中发挥着不同作用。近年来，随着基因工程技术的迅速发展及与这些酶有关的众多突变体的发现，使人们对这些酶的结构、特性、功能及表达调控等方面的研究取得了重要进展。并且，人们已开始利用基因工程技术调控植物淀粉的数量与特性，取得了一定成效。在此，文章介绍了调控植物淀粉合成关键酶的生化特性、基因调控及利用基因工程改良植物淀粉等方面所取得进展。

Key Enzymes in Starch Synthesis in Plants

Starch, the most common form of stored carbon in plants, is both the major food source for mankind and important raw material for many industries. It is composed of two types of alpha-1,4-linked glucan polymer: essentially unbranched amylose and regularly branched amylopectin, and synthesized in photosynthetic and non-photosynthetic organs. Starch is synthesized via four committed enzyme steps: ADP-Glc pyrophosphorylase, which synthesizes sugar nucleotide precursors; starch synthase, which extends the alpha-1,4-linked glucan chains using ADP-Glc; starch-branching enzymes, which introduce alpha-1,6 branch points to form amylopectin; and starch debranching enzymes, which hydrolyze alpha-1,6 branches in glucans. In this paper, recent advances in biochemical characterizations and gene engineering concerning these enzymes were reviewed, and the achievements in gene engineering involved in manipulation of starch amount and quality were also cited.