High-molecular-weight glutenin subunit (HMW-GS) is a key factor affecting dough-processing quality. 1Sty13 is a novel HMW-GS found in the tetraploid species, Elymus sibiricus L. 1Sty13 has faster electrophoretic mobility than the 1Dy12 subunit on sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis. The gene encoding the 1Sty13 subunit was composed of 1803 nucleotide base pairs with an open reading frame that was 599 amino acids in length. Analysis of the predicted amino acid sequence of 1Sty13 indicated that the N-terminal domain was similar to the y-type subunit, whereas the C-terminal domains were similar to the x-type subunit. Five cysteine residues were found in 1Sty13, which is one less than the published HMW-GS in the St genome. The 1Sty13 protein was purified at a scale sufficient for incorporation into flour for the SDS sedimentation test, which indicated that incorporating 1Sty13 improved dough quality.

High-molecular-weight glutenin subunit (HMW-GS) of endosperm is mainly correlated with dough quality of bread wheat. In wheat cultivars, the HMW-GS genes with good processing quality are limited. However, there are an amount of excellent HMW-GS genes presenting in wheat-related species. In this work, two novel HMW-GS genes located on 1 M chromosome from Aegilops comosa have been cloned, designated as 1Mx2.1 and 1My12.1, respectively. The molecular structure of 1Mx2.1 and 1My12.1 showed high similarity with the published HMW-GS, but containing unique structures. 1Mx2.1 contained an extra cysteine residue in the repetitive domain, and 1My12.1 lost the conservative cysteine residue in the C-terminal domain. In vitro mixing test has indicated that 1Mx2.1 contributes excellent dough quality. The Ae. comosa can be used as an important genetic resource for wheat quality improvement.