Molecular Characterization of Gene-Product Relationships in the Wheat Gluten Complex for Reduced Immunogenicity Wheat Development

Abstract

Immune-mediated reactions to wheat gliadins, including celiac disease and wheat allergies, affect ~1% of the U.S. population and are prevalent worldwide. Reducing the risk of inadvertent gluten exposure for individuals with celiac disease or wheat allergies requires the development of reduced immunogenicity wheat varieties which are suitable for human consumption. This study was designed with a view to improve our understanding of gene protein relationships at the complex wheat Gli1/Glu3 and Gli2 loci, and to develop genetic and molecular resources for breeding reduced-immunogenicity wheat lines. We conducted comprehensive genomic, biochemical, and immunological analyses of diverse wheat genetic resources, including aneuploid stocks, chromosome deficiency and interstitial deletion lines, Wasko omega null, the landrace San Pastore, Pegaso near isogenic lines lacking Gli1/Glu3/Gli2 loci, and progenies derived from a Wasko mega null X Pegaso(6A/6D) alpha null. Genomic characterization involved the targeted GlutEnSeq approach and PCR based DNA markers while biochemical and immunological analyses employed acid-urea PAGE, SDS PAGE, and ELISA. Integration of these complementary approaches resolved gliadin gene protein relationships at an unprecedented level. Notably, two F2; lines exhibited substantial reductions (both omega and alpha gliadins) due to the successful stacking of parental mutations. The resulting F2; progenies and associated DNA markers represent valuable resources for breeding wheat for reduced immunogenicity