Evidence from Amino Acid Analysis for the Constancy of Composition of Storage Proteins Accumulated in Maize Seed

Summary Amino acid analysis of maize seeds ranging from very low to very high protein content (1 to 3 per cent of nitrogen on a dry basis) enabled the characterization of extra proteins accumulated in more or less high protein seeds.The extra proteins were rich in high nitrogen amino acids.The amino acid composition of the extra proteins was constant, depending neither on genotype nor on phenotype (in particular on seed protein content} of normal maize plants.They only contained the two main storage protein fractions: zeins and glutelins.These data indicate that the rate of zein biosynthesis is twice that of glutelins.This implies that storage protein biosynthesis is controlled by a very accurate regulation system.