Amino Acid Variation in the 10 kDa <i>Oryza</i> Prolamin Seed Storage Protein

Abstract

The deduced amino acid variability for the 10 kDa prolamin was determined for 16 Oryza species, both cultivated (rice) and wild. Prolamin, a seed storage protein and site of nitrogen and sulfur accumulation, is sequestered in the subaleurone layer of the starchy endosperm for use during seedling germination. The 10 kDa prolamin amino acid distribution for the cultivated species (O. sativa and O. glaberrima) was determined and compared to those of wild and, hitherto unknown, noncultivated Oryza species. Four wild species (O. granulata, O. australiensis, O. brachyantha, and O. meyeriana) exhibited the greatest residue heterogeneity in both the signal and mature peptide regions. A breakdown of the essential amino acid variance among three Central/South American and one African endemic wild species is also presented and compared with those of rice.