An improved SDS-PAGE method for the analysis of wheat endosperm storage proteins

Abstract

An improved one-dimensional, one-step SDS polyacrylamide gel electrophoresis (SDS-PAGE) technique was developed for the analysis of wheat endosperm storage proteins (glutenins and gliadins). SDS-PAGE then was used to re-evaluate the glutenin and gliadin composition of intervarietal chromosomal substitution lines of wheat ( Triticum aestivum L.). Glutenins and gliadins were extracted from reciprocal substitution lines involving group 1 and group 6 chromosomes of the cultivars ‘Cheyenne’ and ‘Wichita’. Molecular-weight estimates were made for all proteins unique to each cultivar. Variation among lines was found to be greater for group 1 chromosome-encoded proteins, especially gliadins and low-molecular-weight subunits of glutenin, than for group 6 chromosome-encoded proteins. Both highmolecular-weight and putative low-molecular-weight glutenin subunits were found to be slightly soluble in aqueous ethanol solutions. Substituted chromosomes of the cultivars Cheyenne and Wichita produced simultaneous changes in polypeptide composition of both gliadin and glutenin fractions of the recipient cultivars. Thus, correlations between end-use quality changes (associated with substituted chromosomes) and endosperm storage proteins are reliable only when proteins of both gliadin and glutenin fractions are analyzed.