Abstract

Kusolwa PM and Myers JR.

Proteomic analysis of the expression of seed storage proteins was performed in wild tepary beans (P. acutifolius) accession G40199. The interspecific backcross progenies were obtained from the cross between G40199 and cultivated common bean (Phaseolus vulgaris) cultivars ICA Pijao and/or Rojo. Mature seeds from interspecific backcross progenies and G40199 were used to isolate seed storage proteins. Seed storage profiles obtained by SDS-PAGE, and bands were isolated and used for MS/MSES peptide sequencing and analysis. Peptide peaks and their amino acids sequences demonstrated that both the interspecific backcross progenies and G40199 contain arcelins and arcelin-like (ARL2) proteins that are co-expressed with other proteins of the arcelin,
-amylase inhibitor and phytohemagglutinin (APA) locus. Arcelin and ARL2 proteins previously obtained from a wild tepary bean accession of this APA were the predominant types detected in the wild tepary bean accession G40199 demonstrating the presence of multiple arcelin-like proteins as the major seed storage proteins. The occurrence of multiple variants of the APA seed storage proteins in a single accession presents an important opportunity for exploration of antibiosis proteins in breeding for resistance to bean bruchids, major storage pests in common beans in the tropics