title: Dosage effect of high-amylose modifier gene(s) on the starch structure of maize amylose-extender mutant.
abstract: The objective of this study was to investigate how dosages of high-amylose modifier (HAM) gene(s) affected the structure of maize amylose extender (ae) mutant starch. GEMS-0067 (G), a homozygous mutant of ae and the HAM gene(s), and H99ae (H), an ae single mutant, were self-pollinated or inter-crossed to produce maize endosperms of G/G, G/H, H/G, and H/H with 3, 2, 1, and 0 doses of HAM gene(s), respectively. Endosperm starch was fractionated into amylopectin, amylose, and intermediate component (IC) of large and small molecular weights using 1-butanol precipitation of amylose followed by gel-permeation chromatography. Increases in the dosage of HAM gene(s) from 0 to 3 decreased the amylopectin content. The HAM-gene dosage significantly changed the branch chain-length of small-molecular-weight IC, but had little effect on the branch chain-length distributions of amylopectin and large-molecular-weight IC and the molecular structure of amylose.
authors.affiliation: Department of Food Science and Human Nutrition, Iowa State University , Ames, Iowa 50011, United States.
authors.forename: Hongxin
authors.initials: H
authors.lastname: Jiang
authors.forename: Mark
authors.initials: M
authors.lastname: Campbell
authors.forename: Yusheng
authors.initials: Y
authors.lastname: Wu
authors.forename: Shuangkui
authors.initials: S
authors.lastname: Du
authors.forename: Sathaporn
authors.initials: S
authors.lastname: Srichuwong
authors.forename: Jay-Lin
authors.initials: JL
authors.lastname: Jane
mesh_terms: D018628:Gene Dosage; D060045:Genes, Modifier; D015394:Molecular Structure; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D013213:Starch / Q000737:chemistry* / Q000378:metabolism; D003313:Zea mays / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D013213:Starch
keywords: high-amylose maize starch; high-amylose modifier gene; resistant starch; starch structure