Cloning and molecular characterization of two novel LMW-m type glutenin genes from Triticum spelta L.

Spelt wheat (Triticum spelta L., 2n=6x=42, AABBDD), as a hexaploid wheat species, is important sources of food and feed in Europe. It also serves as an important genetic resource for improvement of wheat quality and resistance. In this study, two novel m-type low molecularglutenin subunit (LMW-GS) genes, named as TsLMW-m1 and TsLMW-m2 were cloned by allelic specific polymerase chain reaction (AS-PCR)from German spelt wheat cultivars Rochbergers fruher Dinke and Schwabenkorn, respectively. The complete open reading frames (ORFs) of both genes contained 873 bp encoding 290 amino acid residues, and had typical LMW-GS structural features. Two same deletions with 24 bp at the position of 707-730 bp were present in both genes, while TsLMW-m1 had two nonsynonymous single-nucleotide polymorphism (SNP) variations at the positions of 434 bp (C-A transversion) and 857 bp (G-A transition). Phylogenic analysis revealed that both LMW-m genes were closely related to those from wheat A genome, suggesting that both subunits are encoded by the Glu-A3 locus. Secondary structure prediction showed that TsLMW-m1 and TsLMW-m2 subunits had more α-helices than other wheat LMW-GS including superior quality subunit EU369717, which would benefit to form superior gluten structures and dough properties. The authenticity and expression activity of TsLMW-m1 and TsLMW-m2 genes were verified by prokaryotic expression in E. coli. Our results indicated that two newly cloned TsLMW-m genes could have potential values for wheat quality improvement.