谷物淀粉分支酶研究进展

Research Progress on Cereal Starch Branching Enzymes

摘要

修饰淀粉合成相关酶对改良谷物籽粒营养品质至关重要。淀粉主要由直链淀粉和支链淀粉组成，其中高直链淀粉是膳食抗性淀粉（Resistant Starch，RS）的重要来源。抗性淀粉能够改善肠道健康，有利于预防和改善某些慢性病。淀粉分支酶（Starch branching enzyme，SBE）是支链淀粉合成的关键酶，在改善食品质地、增加食品稳定性、开发功能性食品、提高不同作物直链淀粉含量等方面具有重要的应用潜力，通过下调 SBE基因的表达水平，可显著抑制支链淀粉的生物合成途径，进而促进直链淀粉的积累并提高抗性淀粉含量，为培育高直链淀粉及抗性淀粉含量的谷物新种质提供创新育种策略。本文综述了淀粉分支酶的功能、抗性淀粉功能、 SBE基因分类、结构和表达特点、以及对SBE改良在创制高抗性淀粉种质方面的国内外研究进展，旨在为利用基因工程技术调控谷物淀粉的组分、结构和特性及培育高抗性淀粉谷物新品种提供相关信息。

Abstract

Modification of starch synthesis-related enzymes is important for improving the nutritional quality of cereal grains. Starch is mainly composed of amylose and amylopectin, with high-amylose starch being a significant source of dietary resistant starch (RS). Resistant starch helps improve gut health and contributes to the prevention and alleviation of certain chronic diseases. The starch branching enzyme (SBE) is a key enzyme in amylopectin synthesis, playing a vital role in enhancing food texture, increasing food stability, developing functional foods, and boosting amylose content in various crops. By downregulating the expression levels of SBE genes, the biosynthesis pathway of amylopectin can be significantly inhibited, thereby promoting amylose accumulation and increasing resistant starch content. This provides an innovative breeding strategy for developing novel cereal germplasms with high amylose and resistant starch content. This paper reviews the functions of starch branching enzymes, the benefits of resistant starch, the classification, structure, and expression characteristics of SBE genes, as well as domestic and international research progress in modifying SBE for creating high-resistant starch germplasms. The aim is to provide relevant insights for regulating the composition, structure, and properties of cereal starch through genetic engineering techniques and for breeding new cereal varieties with high resistant starch content.

关键词

谷物淀粉 / 淀粉分支酶 / 抗性淀粉 / 淀粉结构及分类

Key words

Grain starch / starch branching enzymes / resistant starch / starch structure and classification

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基金资助

山东省重点研发计划（竞争性创新平台外专项目）(2025CXPTWZ001)

山东省重点研发计划（乡村振兴科技创新提振行动计划）(2023TZXD08601)