Genome-wide analysis of the heat shock transcription factor family in Triticum urartu and Aegilops tauschii

Heat shock proteins (Hsps) are believed to play essential roles in developmental processes and in responses to heat stress. Heat shock transcription factors (Hsfs) are important Hsp regulators, but their functions are poorly understood, especially in wheat. In this study, a comprehensive bioinformatics analysis was conducted in wheat A and D genome donors, Triticum urartu and Aegilops tauschii, the genomic sequences of which were published recently. The results showed that 13 Hsf proteins were identified in both T. urartu and Ae. tauschii, and they could be classified into three groups according to structure; seven Hsfs belonged to group A, two to group B, and three to group C. Expression analyses of these Hsf genes in different tissues of T. urartu and in the response to heat stress were conducted using quantitative RT-PCR. Several Hsf genes in group A (Tuhsf03, Tuhsf05, Tuhsf06, Tuhsf10) had 19–292-fold increases in transcript levels versus the control in different tissues of T. urartu and could be induced by heat stress, while the transcripts of group B and group C Hsf genes could hardly be detected. These results provide important information for cloning, expression, and functional studies of Hsfs in wheat.