关键词: 淀粉, 突变体, 基因工程, 生物合成

Abstract: 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 α–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 α–1,4-linked glucan chains using ADP-Glc; starch-branching enzymes, which introduce α–1,6 branch points to form amylopectin; and starch debranching enzymes, which hydrolyze α–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.