Synthesis and Development of Starch Granules in High Lysine Barley Grains

Electron microscopy studies of developing endosperm have shown differences in the synthesis and development of starch granules between high lysine mutant Notch-2 and parent NP 113. The starch granules in Notch-2 were modified and did not develop into characteristic oval granules. Based on iodine absorption and phospholipids analysis, it is suggested that the presence of phospholipids impairs the development of starch granule in Notch-2. This is further confirmed by higher lipid density across starch granule in mutant Notch-2, and its absence in NP 113. Amylopectin from mutant differs from that of NP 113. The results indicate that the lack of geometry and smaller size of starch granules in Notch-2 is ultimately due to specific interaction of lipids with developing starch granules, and this leads to decreased yield.