Genetic variation in the subunits of globulin-1 storage protein of French bean

Abstract

Charge and molecular weight heterogeneity of globulin-1 (G1) polypeptides of the bean, Phaseolus vulgaris L., were revealed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Different bean cultivars were classified into three groups: ‘Tendergreen’, ‘Sanilac’, and ‘Contender’ on the basis of their protein subunit composition. Nine distinct major bands: α51,α49, α48.5,β48^T, β48^S, β47, γ45.5, γ45^S, and γ45^C, and two minor bands: γ46^T and γ46^S were found to account for the three profiles seen on one-dimensional SDS-PAGE. Two-dimensional analysis revealed these eleven protein bands to be composed of a minimum of fourteen distinct protein subunits. The ‘Tendergreen’ and ‘Sanilac’ types differ in their G1 polypeptide composition. The protein patterns of the ‘Contender’ types are intermediate, containing many protein subunits found in the patterns of the ‘Tendergreen’ and ‘Sanilac’ types suggesting a genetic and evolutionary relationship.