Characterisation of a ω-gliadin gene in Triticum tauschii

A omega-gliadin gene at the Gli-D(1)1 locus of Triticum tauschii accession AUS18913 was isolated using PCR primers, designed from published sequences of w-gliadin genes of bread wheat cv Cheyenne, and deduced sequences of the N-terminal amino acids of omega-gliadin proteins. Further, the derived protein was isolated from A-PAGE and was sequenced. The protein sequence contained a signal peptide of 19 amino acids followed by a short N-terminal sequence of I I amino acids, a central repetitive domain that covers approximately 90% of the sequence and a short C-terminal domain of 12 amino acids. The sequence comparison with other omega-gliadins showed a high level of similarities between them. Further analysis of the omega-gliadins using A-PAGE revealed that there are three omega-gliadin proteins in AUS18913 accession. Comparison of N-terminal sequences of these proteins revealed that two of these proteins have very high homologies with omega-gliadins of Cheyenne while the third one was significantly different. (c) 2007 Elsevier Ltd. All rights reserved.