Frequent Absence of GBSS 1 B Isoprotein in Endosperm Starch of Canadian Wheat Cultivars

Abstract

Granule bound starch synthase 1 (GBSS 1) is an enzyme involved in amylose synthesis, and it is encoded at the waxy loci in wheat. Mutations have been reported for three GBSS1 loci in wheat. Mutations at wheat GBSS 1 loci result in the absence of GBSS 1 isoproteins with concomitant reduction in the amylose concentrations of endosperm starch. A recent survey of Canadian wheat cultivars detected the frequent absence of GBSS1 B isoprotein in endosperm starch granules. This was likely a result of many Canadian spring wheat cultivars having common parents, which have a mutation at the GBSS1 B locus.