Wheat is a major staple food crop worldwide because of the unique properties of wheat flour. High molecular weight glutenin subunits (HMW-GSs), which are among the most critical determinants of wheat flour quality, are responsible for the formation of glutenin polymeric structures via interchain disulfide bonds. We herein describe the identification of a new HMW-GS Dy10 allele (Dy10-m619SN). The amino acid substitution (serine-to-asparagine) encoded in this allele resulted in a partial post-translational cleavage that produced two new peptides. These new peptides disrupted the interactions among gluten proteins because of the associated changes to the number of available cysteine residues for interchain disulfide bonds. Consequently, Dy10-m619SN expression decreased the size of glutenin polymers and weakened glutens, which resulted in wheat dough with improved cookie-making quality, without changes to the glutenin-to-gliadin ratio. In this study, we clarified the post-translational processing of HMW-GSs and revealed a new genetic resource useful for wheat breeding.

由于小麦粉的独特特性，小麦是世界范围内的主要主粮作物。高分子量麦谷蛋白亚基 (HMW-GS) 是小麦面粉质量最关键的决定因素之一，负责通过链间二硫键形成麦谷蛋白聚合结构。我们在此描述了新的 HMW-GS Dy10等位基因 ( Dy10-m619SN )的鉴定。该等位基因编码的氨基酸取代（丝氨酸至天冬酰胺）导致部分翻译后裂解，产生两个新肽。这些新肽破坏了麸质蛋白之间的相互作用，因为链间二硫键的可用半胱氨酸残基数量发生了相关变化。因此，Dy10-m619SN 的表达降低了麦谷蛋白聚合物的大小并削弱了面筋，从而提高了小麦面团的饼干制作质量，而不会改变麦谷蛋白与麦醇溶蛋白的比例。在这项研究中，我们阐明了 HMW-GS 的翻译后加工，并揭示了一种可用于小麦育种的新遗传资源。