Towards an Understanding of Starch Biosynthesis and Its Relationship to Protein Synthesis in Plant Storage Organs

Starch biosynthesis is one of the most important metabolic processes of developing storage organs. The importance of this process in determining seed composition is illustrated by a number of mutations affecting genes in the biosynthetic pathway such as r and rb of pea and some of the high lysine lines of maize and barley. Lesions that limit starch quantity and quality also have effects on the accumulation of lipid protein. To understand the relationship between starch biosynthesis and the production of other storage products we have begun to isolate a number of the genes involved in starch biosynthesis. These genes allow us to define particular mutants biochemically, and by genetic engineering allow us to affect particular steps in starch production in transgenic plants. By analyzing these transgenic plants we hope to develop our understanding of the regulation of starch biosynthesis and its relationship to the determination of seed composition as a whole. We anticipate that these experiments will also produce a number of transgenic plants with modifications in starch quantity and quality.