Development of wheat varieties with reduced contents of celiac-immunogenic epitopes through conventional and GM strategies

Cereals, especially wheat, may cause several food-related diseases, of which gluten intolerance (coeliac disease, CD) is the best defined: specific immunogenic epitopes, nine amino acid-long peptide sequences, have been identified from various gluten proteins. These may activate T cells, causing inflammation of the small intestine and a wide variety of other symptoms. Here, we review several breeding-related strategies aiming at reduction or elimination of such epitopes from wheat, including variety selection, re-synthesis of hexaploids, deletion of specific chromosomal fragments, RNA-interference, mutagenesis and genome editing using CRISPR/Cas9. The related issue of genetic modification (GM) is discussed. These strategies should lead to wheat food products to be used in gluten-free diets for diagnosed CD individuals and/or to strongly reduce the burden from immunogenic gluten to the non-diagnosed CD population.