Molecular characterization of seven novel Glu-A1mx alleles from Triticum monococcum ssp. monococcum

Seven Glu-A1^m allelic variants of the Glu-A1^mx genes in Triticum monococcum ssp. monococcum, designated as 1Ax2.1^a, 1Ax2.1^b, 1Ax2.1^c, 1Ax2.1^d, 1Ax2.1^e, 1Ax2.1^f, and 1Ax2.1^g were characterized. Their authenticity was confirmed by successful expression of the coding regions in E. coli, and except for the 1Ax2.1^a with the presence of internal stop codons at position of 313 aa, all correspond to the subunit in seeds. However, all the active six genes had a same DNA size although their encoding subunits showed different molecular weight. Our study indicated that amino acid residue substitutions rather than previously frequently reported insertions/deletions played an important role on the subunit evolution of these Glu-A1^mx alleles. Since variation in the Glu-A1x locus in common wheat is rare, these novel genes at the Glu-A1^mx can be used as candidate genes for further wheat quality improvement.