Genome-wide identification, classification and expression profile analysis of the HSF gene family in Hypericum...

Heat shock transcription factors (HSFs) are critical regulators of plant responses to various abiotic and biotic stresses, including high temperature stress. HSFs are involved in regulating the expression of heat shock proteins (HSPs) by binding with heat stress elements (HSEs) to defend against high-temperature stress. The H. perforatum genome was recently fully sequenced; this provides a valuable resource for genetic and functional analysis. In this study, 23 putative HpHSF genes were identified and divided into three groups (A, B, and C) based on phylogeny and structural features. Gene structure and conserved motif analyses were performed on HpHSFs members; the DNA-binding domain (DBD), hydrophobic heptad repeat (HR-A/B), and exon-intron boundaries exhibited specific phylogenetic relationships. In addition, the presence of various cis-acting elements in the promoter regions of HpHSFs underscored their regulatory function in abiotic stress responses. RT-qPCR analyses showed that most HpHSF genes were expressed in response to heat conditions, suggesting that HpHSFs play potential roles in the heat stress resistance pathway. Our findings are advantageous for the analysis and research of the function of HpHSFs in high temperature stress tolerance in H. perforatum.