The key determinants of dough elasticity, extensibility, and other processing properties are gluten proteins stored in wheat grains. For decades, breeders have recognized the importance of several high-molecular-weight glutenin subunits for strong-gluten quality.

However, the genes encoding gluten proteins are highly repetitive, structurally complex, and clustered within the wheat genome, making many important genomic regions difficult to fully resolve. This limits the discovery of key quality-related variants, the understanding of the molecular and evolutionary basis of superior wheat quality, and the development of efficient and precise breeding strategies.

Recently, a team led by LU Fei from the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences, along with CAO Xinyou's team from Shandong Academy of Agricultural Sciences, successfully assembled a high-quality reference genome of the widely cultivated strong-gluten wheat variety Jimai 44, providing key insights into the evolution and formation of wheat quality traits.

The study was published in Nature Plants, and the journal also published a Research Briefing.

Using "Jimai 44", one of the most widely cultivated strong-gluten wheat varieties in China, the researchers generated a high-quality reference genome that fully resolved the fine-scale structure of gluten protein loci. Combining this genome with a whole-genome variation map from 485 wheat and related accessions, they reconstructed the adaptive evolutionary history of wheat processing quality across domestication, polyploidization, Eurasian dissemination, and modern Chinese breeding.

The researchers revealed how strong-gluten wheat quality traits have evolved during breeding and adaptation. Importantly, they showed that wheat quality improvement is not simply driven by the accumulation of a few "favorable genes." Instead, it is shaped by both highly variable gluten protein genes and extensive epistatic interaction networks among these genes.

The findings of this study provide a new perspective on how wheat has been shaped into a crop suitable for diverse food-processing purposes, and offer new directions for future breeding-by-design strategies. Breeders should explore the trait-shaping potential of highly variable genes such as low-molecular-weight glutenins and gliadins, while incorporating combinational and epistatic effects among gluten genes into breeding programs.