The low-molecular-weight glutenin subunit proteins of primitive wheats. I. Variation in A-genome species.

A Tris-Tricine gel-electrophoresis system (Schaegger and von Jagow 1987), combined with a gradient gel, has been employed to provide an improved resolution of the B and C low-molecular-weight glutenin subunits (LMW-GSs) found in the endosperm of wheat grain. The gel system was used to document the variation in the gluten subunit proteins present in A-genome diploid wheats. The majority of LMW-GSs found in the A-genome diploid wheats were not present in normal bread wheats; the data suggest that they represent a rich source of new variation for the LMW-GSs which are considered to be very important in modulating wheat flour-processing properties. The analysis of variation in the nature of the LMW-GS genes, using PCR, demonstrated that the subclass of C-subunits assayed by primers from a previously published sequence did not show as much variation as the proteins. However, the data collected suggest that sufficient variation may exist in the LMW-GS genes of A-genome diploid wheats to use them as a source of genes for altering the flour-processing properties of hexaploid wheat. [ABSTRACT FROM AUTHOR]