Microstructure and Ultrastructure of High-Amylose Rice Resistant Starch Granules Modified by Antisense RNA Inhibition of Starch Branching Enzyme

• Published in: Journal of agricultural and food chemistry Vol. 58; no. 2; pp. 1224 - 1232
• Main Authors: Wei, Cunxu, Qin, Fengling, Zhu, Lijia, Zhou, Weidong, Chen, Yifang, Wang, Youping, Gu, Minghong, Liu, Qiaoquan
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 27.01.2010
• Subjects: 1,4-alpha-Glucan Branching Enzyme - genetics; 1,4-alpha-Glucan Branching Enzyme - metabolism; amylose; Amylose - analysis; antisense RNA; Biological and medical sciences; Cereal and baking product industries; enzyme inhibition; enzyme inhibitors; Food Chemistry/Biochemistry; Food industries; Fundamental and applied biological sciences. Psychology; high-amylose rice resistant starch granules; microstructure; modified starch; Oryza - chemistry; Oryza - enzymology; Oryza - genetics; Oryza - ultrastructure; Plant Proteins - genetics; Plant Proteins - metabolism; Plants, Genetically Modified - chemistry; Plants, Genetically Modified - enzymology; Plants, Genetically Modified - genetics; Plants, Genetically Modified - ultrastructure; resistant starch; rice starch; RNA, Antisense - genetics; Starch - chemistry; Starch - metabolism; Starch - ultrastructure; Starch and starchy product industries; starch branching enzyme; starch granules; ultrastructure; Rice (Oryza sativa L.); semicompound starch granule; high-amylose resistant starch granule; microstructure; ultrastructure; Monocotyledones; RNA; Enzyme; Resistant starch; Starch granule; Oryza sativa; Amylose; Gramineae; Ultrastructure; Angiospermae; Cereal; Spermatophyta; Inhibition; Dietary fiber; Microstructure; Polysaccharide; Rice starch; Rice
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf9031316

A high-amylose transgenic rice line (TRS) modified by antisense RNA inhibition of starch branching enzymes revealed a resistant starch-rich quality. Compound starch granules in whole grains of the regular rice cultivar Teqing (TQ) were readily split during fracturing, whereas the starch granules in TRS were structurally intact and showed large voluminous, non-angular rounded bodies and elongated, filamentous structures tolerant of fracturing. In isolated preparation, TQ starch granules broke up into separate polygonal granules, whereas TRS starch granules kept their intactness. TRS starch granules consisted of packed smaller subgranules, some of which located at the periphery of starch granules were fused to each other with adjacent ones forming a thick band or wall encircling the entire circumference of the granules. TQ starch granules had a high concentration of amylose in the concentric hilum, whereas TRS starch granules showed a relatively even distribution of amylose with intense amylose in both hilum and band.