Changes in Activities of Enzymes of Nitrogen Metabolism in Seedcoats and Cotyledons during Embryo Development in Pea Seeds 1

摘要

In the seedcoats of developing pea seeds, the maximal activities of asparaginase (EC 3.5.1.1) and aspartate: α-ketoglutarate aminotransferase (EC 2.6.1.1) are attained early in development, before the embryo has expanded to fill the embryo sac. These two enzyme activities could account for the early absence of asparagine and aspartate from the fluid secreted by the seedcoats into the embryo sac.