Molecular characterization of a novel waxy allele (Wx-A u 1a) from Triticum urartu Thum. ex Gandil.

Abstract

Granule Bound Starch Synthase I, or waxy protein, is the sole enzyme responsible for the accumulation of amylose during the development of starch granules in wheat. The full coding region of the waxy (Wx) gene was sequenced in Triticum urartu, (a wild diploid species) and is related to the A genome of polyploid wheats. The Wx gene of T. urartu (Wx-Au1) showed a homology of *88.0 % with Wx-A1 from polyploid wheats. A greater homology was found with Wx-Am1 from the diploid cultivated wheat einkorn. Most of the differences were found in introns although several changes were also detected in exons that led to amino acid changes in the transit peptide and mature protein. These results show the potential of T. urartu as a source of new alleles that could be used in the breeding of durum and common wheat in order to synthesize starches with different properties.