Genome-wide identification, phylogeny and expression analysis of HSF gene family in barley during abiotic stress response and reproductive development

Adverse environmental conditions are major threats to cereal crop production. For crop improvement, it is crucial to know the molecular responses of cereals to abiotic stresses. Heat shock factors (HSF) not only regulate the stress responses but also the developmental processes of plants. In the present study, we performed a comprehensive investigation of barley HSF genes. A total of 23 genes were identified in the HvHSF gene family and classified into three characteristic classes on the basis of phylogenetic analysis. Stress response, hormone signaling, and development specific cis-regulatory elements co-existed in the promotor region of many HvHSF genes. The expression analysis showed expression of HvHSFs under major abiotic stresses in both vegetative and reproductive tissues. All the HSFs of class A showed response to heat shock except for A1 and A8.vHvHSFA1a, the only member of subclass A1 showed constitutive expression in all the selected tissues and conditions. Up-regulation of class B and C genes, suggests their putative role in drought stress, development and recovery post heat stress. Our study extends the understanding of HSF genes in barley and reveals the candidate HSFs responsive to heat, drought and seed development, which can be used for molecular breeding based crop improvement.