title: Altered starch structure is associated with endosperm modification in Quality Protein Maize.
abstract: The biochemical basis of modified kernel texture in Quality Protein Maize (QPM) is poorly understood. Proteomic analysis of several QPM lines indicated increased levels of granule-bound starch synthase I in the soluble nonzein protein fraction of these genotypes. Increased extraction of this enzyme reflected a change in starch structure, which was manifested as shorter amylopectin branches and increased starch-granule swelling. In mature kernels, these alterations in starch structure were associated with interconnections between starch granules that resulted in a vitreous kernel phenotype. Understanding the molecular basis for this previously uncharacterized starch structure will accelerate the development of QPM.
authors.affiliation: Department of Plant Sciences, University of Arizona, Tucson, AZ 85741, USA.
authors.forename: Bryan C
authors.initials: BC
authors.lastname: Gibbon
authors.forename: Xuelu
authors.initials: X
authors.lastname: Wang
authors.forename: Brian A
authors.initials: BA
authors.lastname: Larkins
mesh_terms: D000687:Amylopectin / Q000737:chemistry / Q000302:isolation & purification; D015180:Electrophoresis, Gel, Two-Dimensional; D010940:Plant Proteins / Q000302:isolation & purification / Q000502:physiology*; D020543:Proteome; D013213:Starch / Q000737:chemistry* / Q000302:isolation & purification; D014961:X-Ray Diffraction; D003313:Zea mays / Q000737:chemistry / Q000502:physiology*
chemical_list: D010940:Plant Proteins; D020543:Proteome; C108912:endosperm specific protein, Zea mays; D013213:Starch; D000687:Amylopectin