Low-molecular-weight glutenin subunit LMW-N13 improves dough quality of transgenic wheat

•Three wheat transgenic lines expressing LMW-N13 have been obtained.•Transgenic lines possess superior dough properties.•Transgenic lines showed higher contents of GMP and total protein than NT lines.•The protein matrix was continuous and tight in transgenic lines. In our previous study, a novel LMW-GS designated as LMW-N13 with a unique molecular structure was identified from Aegilops uniaristata. LMW-N13 has been characterized as the largest LMW-GS, so far, and possesses an extra cysteine residue compared with typical LMW-GS. In order to analyze the contribution of LMW-N13 to dough quality, in this work, three transgenic wheat lines overexpressing LMW-N13 were generated. Compared with non-transformation (NT) lines, transgenic (TG) lines demonstrated superior dough properties. These superior dough properties were accompanied by the higher contents of glutenin macropolymer (GMP) and total protein. The microstructure of the dough was further investigated by scanning electron microscopy; starch granules in NT lines were smaller than those in transgenic lines. The protein matrix in NT lines was relatively loose and discontinuous. Conversely, the protein matrix in transgenic lines was more continuous and tight. The application of LMW-N13 in wheat breeding is also discussed.