Metabolism of Acetate-[2-14C] in Hard Endosperm Opaque-2 Maize

Abstract

Summary Acetate-[2-14C] metabolism by developing normal, modified opaque and opaque-2 maize endosperm showed considerable differences in incorporation of label into protein and free amino acids, organic acids and sugar. Protein synthesizing efficiency in modified opaque and normal maize endosperm was higher as compared to opaque-2 at 20 and 25 days post-pollination while at 30 day stage, it was similar. Considerably higher label appeared in organic acids fraction in modified opaque maize endosperm at 30 day stage as compared to normal and opaque-2 maize endosperm. Greater label appeared in free amino acids in opaque-2 maize and protein amino acids in normal endosperm during early stage of maturity. Differences in the proportion of label in different organic acids were also evident. The specific activity in protein lysine was the highest in opaque-2, intermediate in modified opaque and the least in normal maize endosperm at early stage. Distribution of label and specific activity of other amino acids also differed during development. Based on incorporation of label from acetate it is concluded that modified opaque endosperm differ from that of normal maize endosperm in their metabolism.