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.