Altered starch structure is associated with endosperm modification in Quality Protein Maize.
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.
Gibbon
Bryan C
BC
Department of Plant Sciences, University of Arizona, Tucson, AZ 85741, USA.
Wang
Xuelu
X
Larkins
Brian A
BA
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*
D010940:Plant Proteins; D020543:Proteome; C108912:endosperm specific protein, Zea mays; D013213:Starch; D000687:Amylopectin