Dough quality of bread wheat lacking α-gliadins with celiac disease epitopes and addition of celiac-safe avenins to improve dough quality

Abstract

Celiac disease is a T-cell mediated immune response in the small intestine of genetically susceptible individuals caused by ingested gluten proteins from wheat, rye, and barley. In the allohexaploid bread wheat (Triticum aestivum), gluten proteins are encoded by multigene loci present on the homoeologous chromosomes 1 and 6 of the three homoeologous genomes A, B, and D. The effect of deleting individual gluten loci was analyzed in a set of deletion lines of T. aestivum cv. Chinese Spring with regard to the level of T-cell stimulatory epitopes (Glia-α9 and Glia-α20) and to technological properties of the dough including mixing, stress relaxation, and extensibility.Deletion of loci encoding ω-gliadins, γ-gliadins, and LMW-glutenins located on the short arm of chromosome 1D, reduced the number of T-cell stimulatory epitopes and caused minor deterioration of dough quality by increase of elasticity. Deletion of loci encoding α-gliadins located on the short arm of chromosome 6D, resulted in a significant decrease in T-cell stimulatory epitopes. In parallel, the dough became more stiff and less elastic, which is an improvement for ‘Chinese Spring’ dough.We demonstrated that α-gliadins from wheat can largely be compensated by addition of avenins from oat to the flour to meet technological requirements.