Abstract:In this study,107 and 126 NAC transcription factor family members in Triticum urartu L. and Aegilops tauschii L. genome were identified respectively by hmm profile search..They were further classified into two groups, consisting of 15 subgroups based on the classification method of Arabidopsis and rice. Phylogenetic analysis revealed that 5 TuNAC genes and 6 AetNAC genes were found to be similar in protein sequence with TaNAC2a, which had been reported involving in the response to diverse stresses in plant. Phyletic evolution, protein domains, gene structure, cis-acting elements in the promoter region and tissue-specific expression pattern of these 11 NAC genes were further analyzed. Results showed that these 11 NAC proteins possessed typical NAC domains and several pairs of genes with close evolutionary relationship had similar gene structure. Prediction of cis-acting elements revealed that they all had stress-responsive cis-acting elements in their promoter region. Gene expression pattern analysis revealed that the transcripts of TuNAC, AetNAC genes were detected in root, coleoptile and leaf of Triticum urartu and Aegilops tauschii, respectively, and exhibited obvious tissue-specific expression pattern. It was speculated from microarray data and expression patten under stress conditions that AetNAC2c had a role in the response to drought stress and AetNAC2b was more likely to be involved in the regulation of plant reaction to low temperature and drought stress. Our analysis lays a foundation for systematical research of gene family in bread wheat progenitors and provides an experimental basis for the identification of excellent functional genes.