Molecular Characterization and Evolutionary Analysis of α-gliadin Genes from Eremopyrum bonaepartis (Triticeae)

Total 16 α-gliadin gene sequences ranged from 1186 to 1316bp were isolated from Eremopyrum bonaepartis byPCR based strategy. Analysis of deduced amino acid sequences indicated that 8 of 16 sequences displayed thetypical structure of α-gliadin genes with six cysteine residues, while the other 8 sequences contained in-framestop codon, and were therefore pseudogenes. Phylogenetic analysis based on the variation of α-gliadin genesequences indicated that the F genome of E. bonaepartis was apparently differed from the A, B and D genomesof wheat. Four peptides, Glia-α, Glia-α2, Glia-α9 and Glia-α20, which have been identified as T cell stimulatoryepitopes in celiac disease (CD) patients through binding to HLA-DQ2/8, were searched to the E. bonaepartisα-gliadin gene sequences. We firstly found that only Glia-α existed in 7 of 8 full sequences, the fact suggestingthat the occurrence of the stimulatory epitopes in α-gliadin genes was newly evolved in wheat.