Molecular Characterization and Phylogenetic Analysis of Novel Α-Gliadin Genes From Triticum Dicoccoides L.

The quality traits of triticum dicoccoides ku-13441 (triticum turgidum l. var.dicoccoides (aabb, 2n= 4x= 28)) were analyzed by mixograph, and the results showedthat t. dicoccoides ku-13441 had desirable qualities in gluten strength and flour stirringtolerance. subsequently, seventeen novel full-orf α-gliadin genes and thirty-fivepseudogenes were cloned and sequenced from t. dicoccoides ku-13441. among the 17novel full-orf α-gliadin genes, the putative proteins of gli2-td-44 and gli2-td-46contained an extra cysteine residue, located in the first nonrepetitive region and nterminalrepetitive domain, respectively, rather than in the second nonrepetitive regionlike other α-gliadins. prokaryotic expression analysis and western-blotting indicated thatthese two α-gliadin genes could be successfully expressed under the control of t7promoter. according to the varying numbers of 4 typical coeliac disease toxic peptidesand glutamine residues in the two ployglutamine domains among the 17 α-gliadins, gli2-td-39, gli2-td-46 and gli2-td-47 genes were assigned to sub-genome b and other 14genes were assigned to sub-genome a. phylogenetic analysis including two s-genomespecies, aegilops longissima (s^l) and aegilops speltoides (s) revealed that the α-gliadinsequences of the b genome in t. dicoccoides had closer genetic relationship with thosefrom ae. speltoides. this implies that ae. speltoides might participate in the origin ofwheat b genome.