LACK OF EXPRESSION OF THE GAMMA-45 GLIADIN GENE IN A DURUM-WHEAT GENOTYPE

Electrophoretic analysis of seed proteins of a durum wheat accession (MG 41392) showed the absence of ?-45 gliadin, whereas the ?-gliadin and low molecular weight glutenin subunits usually associated with it were present. Polymerase chain reaction (PCR) analysis of genomic DNA from this genotype showed the presence of the amplification band typically found in type-45 durum wheat cultivars. This observation was confirmed by Southern blot analysis, which showed the presence of all ?-gliadin hybridizing bands usually found in type-45 durum wheat cultivars. The gene for ?-45 gliadin is present, therefore, but not expressed.