The heat stress transcription factor family in Aegilops tauschii: genome-wide identification and expression analysis under various abiotic stresses and light conditions.

Heat stress transcription factors (Hsfs) are known to play a vital role in protecting plants against various abiotic stresses. Among the wild wheat relatives, Aegilops tauschii offers an excellent source of abiotic stress tolerance genes for improvement of bread wheat. However, little is known about its stress tolerance mechanisms. In this study, 22 AetHsf genes were identified in the genome of Aegilops tauschii and their chromosomal location, exon-intron structures, sub-cellular localization, phylogenetic and syntenic relationship were analyzed. Based on the conserved motif analysis, these Hsfs were further divided into group A, B and C. The interaction network analysis and expression profile of AetHsfs in different tissues predicted their interaction with diverse types of proteins and suggested their involvement in different developmental processes of the plant. The promoter analysis of AetHsfs showed the presence of abiotic stress-responsive, phytohormone-responsive, plant development-related and light-related cis-elements. Thus, we investigated the expression of Hsfs in Aegilops tauchii seedlings under various abiotic stress conditions and irradiated with different monochromatic lights. Most of the AetHsfs were found to be upregulated by heat stress, while some showed expression in drought, salinity and high light stress as well. Notably, the expression pattern of various AetHsfs showed their responsiveness toward dark and various light conditions (blue red and far-red) as well. Thus, this study provides novel insights into the potential role of AetHsfs in stress and light signaling pathways, which can further facilitate understanding of the stress tolerance mechanisms in Aegilops tauschii.