文献类型： 外文期刊

作者： Han, Huaxin ¹ ; Yang, Chuantian ¹ ; Zhu, Jihui ¹ ; Zhang, Lixia ³ ; Bai, Yeming ⁴ ; Li, Enpeng ¹ ; Gilbert, Robert G. ¹ ;

作者机构： 1.Yangzhou Univ, Coll Agr, Jiangsu Key Lab Crop Genet & Physiol, Key Lab Plant Funct Genom,Minist Educ, Yangzhou 225009, Jiangsu, Peoples R China

2.Yangzhou Univ, Coinnovat Ctr Modern Prod Technol Grain Crops, Yangzhou 225009, Jiangsu, Peoples R China

3.Shanghai Acad Agr Sci, Crop Breeding & Cultivat Res Inst, Shanghai 201403, Peoples R China

4.Univ Queensland, Ctr Nutr & Food Sci, Queensland Alliance Agr & Food Innovat, Brisbane, Qld 4072, Australia

关键词： Starch; Biosynthesis; Enzyme actions; Rice; Structural characterization

期刊名称：RICE （ 影响因子：4.783； 五年影响因子：5.23 ）

ISSN： 1939-8425

年卷期： 2019 年 12 卷 1 期

页码：

收录情况： SCI

摘要： Background Starch branching enzymes (SBE) and granule-bound starch synthase (GBSS) are two important enzymes for starch biosynthesis. SBE mainly contributes to the formation of side branches, and GBSS mainly contributes for the synthesis of amylose molecules. However, there are still gaps in the understanding of possible interactions between SBE and GBSS. Results Nineteen natural rice varieties with amylose contents up to 28% were used. The molecular structure, in the form of the chain-length distribution (CLDs, the distribution of the number of monomer units in each branch) was measured after enzymatic debranching, using fluorophore-assisted carbohydrate electrophoresis for amylopectin and size- exclusion chromatography for amylose. The resulting distributions were fitted to two mathematical models based on the underlying biosynthetic processes, which express the CLDs in terms of parameters reflecting relevant enzyme activities. Conclusions Finding statistically valid correlations between the values of these parameters showed that GBSSI and SBEI compete for substrates during rice starch biosynthesis, and synthesis of amylose short chains involves several enzymes including GBSSI, SBE and SSS (soluble starch synthase). Since the amylose CLD is important for a number of functional properties such as digestion rate, this knowledge is potentially useful for developing varieties with improved functional properties.