Glutenin and gliadin proteins are key determinants of wheat dough functionality and end-use traits. However, the multiplicity and extensive genetic variation of these proteins have made it very difficult to study their individual and combined effects on dough and end-use properties. To address this knowledge gap, we have combined mutagenetic, functional genomic and rheological approaches to investigate the spectrum of glutenin and gliadin proteins expressed in two Chinese winter wheat cultivars (Xiaoyan 54 and Xiaoyan 81) and their single and interactive effects on dough and breadmaking performance. In high-molecular-weight glutenin subunits (HMW-GSs), we developed knockout mutants lacking one or more subunits or one or more of the three homoeologous Glu-1 loci. These mutants have been successfully used to demonstrate functional differences among HMW-GSs and in between different Glu-1 loci. In low-molecular-weight glutenin subunits (LMW-GSs), we identified the LMW-GSs accumulated in both cultivars, and found a positive correlation between the number of actively expressed LMW-GS genes and the potency of the contribution of LMW-GSs to gluten and dough strength. In gliadins, combined transcriptomic and proteomic analysis showed that Xiaoyan 81 grains accumulated at least 38 gliadin proteins

- - - -gliadins. Lastly, we studied the structure and function of Gli-D2 locus located on 6D

chromosome, and found that the null allele of Gli-D2 is useful for improving the breadmaking and health-related (e.g., lysine content) traits of common wheat. Our work shows that the complexity of glutenin and gliadin genes can be tackled by combining genetic and genomic approaches. The implications of our research on further studies of glutenin and gliadin genes and their functions in end-use quality control will be discussed.