Variation in polypeptide of the major albumin protein of pea (Pisum sativum L.)

The variation in the polypeptides of the major albumin (MA) protein of different pea genotypes was studied. The two MA polypeptides, MA-L and MA-S, behave as products of single Mendelian genes at a single locus. The band patterns of fragments of restricted genomic DNA of four pea genotypes, detected by hybridization with a cDNA encoding MA, revealed differences in the number and sizes of DNA fragments related to MA. This is discussed in relation to MA protein structure. The relative amount of MA protein in seeds appears to be strongly influenced by the total number of gene copies present in a genotype. Through molecular analysis at the protein, RNA and genomic DNA levels, a mutant line was identified which carries a deletion of the active MA structural genes.