Cloning and Sequence Analysis of New α-Gliadin Genes from Triticum monococcum

The α-gliadins were typically the most consumed storage proteins in human life,however,owing to the main toxic components they contained causing celiac disease(CD),the α-gliadins were also the most active proteins in triggering CD.So the objective of this study was to estimate the potential value in wheat quality breeding of the cloned α-gliadin sequences from the genomic DNA and to analyze the CD epitopes among them.One new α-gliadin gene with full-ORF(named as AA-6,GenBank accession No.JN831382) and three pseudogenes(named as AA-8,AA-9,AA-21,GenBank accession No.JN831383,JN831384 and JN831385,respectively) were cloned and sequenced.The three pseudogenes resulted from C to T base transitions,which leading to the alternative of a CAG codon for glutamine into a TAG stop codon at the position of 102 bp.Analysis on the deduced amino acid sequences of AA-6 revealed that AA-6 was characterized with the typical structure of α-gliadins,with the highest homology of 99%.Analysis on its CD epitops demonstrated that seven toxic peptides of the nine known epitops were present in AA-6 except for the absence of Glia-α2 and Glia-α in the A genome.Phylogenetic analysis among AA-6 and 86 genes from common wheat and its ancestral species showed that a clear cluster can be observed according to the origin of their genome.The homology of A genome and D genome was more close than that of B genome.