Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University, Yangzhou, Jiangsu, 225009, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD, 4072, Australia.
Department of Food Science & Engineering, Jinan University, Huangpu West Avenue 601, Guangzhou, Jiangsu Province, China.
Carbohydr Polym. 2020 Feb 15;230:115656. doi: 10.1016/j.carbpol.2019.115656. Epub 2019 Nov 22.
How various isoforms of rice-starch biosynthesis enzymes interact during amylose and amylopectin synthesis is explored. The chain-length distributions of amylopectin and amylose from 95 varieties with different environmental and genetic backgrounds were obtained using size- exclusion chromatography, and fitted with biosynthesis-derived models based on isoforms of starch synthase (SSI-SSIV), starch branching enzyme (SBE, including SBEI and SBEII) and granule-bound starch synthase (GBSS) that are involved in amylose and amylopectin synthesis. It is usually thought that these are synthesized by separate enzymes. However, the amount of longer amylopectin chains correlated with that of shorter amylose chains, indicating that GBSS, SBE and SS affect both amylose and amylopectin synthesis. Further, the activity of GBSS in amylose correlated with that of SS in amylopectin. This new understanding of which enzymes are suggested by the statistics to be involved in both amylose and amylopectin synthesis could help rice breeders develop cereals with targeted properties.
研究了在直链淀粉和支链淀粉合成过程中，水稻淀粉生物合成酶的各种同工型如何相互作用。使用凝胶渗透色谱法获得了来自 95 个具有不同环境和遗传背景的品种的支链淀粉和直链淀粉的链长分布，并根据参与直链淀粉和支链淀粉合成的淀粉合酶（SSI-SSIV）、淀粉分支酶（SBE，包括 SBEI 和 SBEII）和颗粒结合淀粉合酶（GBSS）的同工型拟合了生物合成衍生模型。通常认为这些是由不同的酶合成的。然而，较长的支链淀粉链的数量与较短的直链淀粉链的数量相关，表明 GBSS、SBE 和 SS 都影响直链淀粉和支链淀粉的合成。此外，直链淀粉中 GBSS 的活性与支链淀粉中 SS 的活性相关。这种对哪些酶被统计数据提示参与直链淀粉和支链淀粉合成的新认识，可以帮助水稻育种家开发具有目标特性的谷物。
