Genome-Wide Analysis of the Hsf Gene Family in Rosa chinensis and RcHsf17 Function in Thermotolerance.

Heat shock transcription factors (Hsfs) play an important role in response to high temperatures by binding to the promoter of the heat shock protein gene to promote its expression. As an important ornamental plant, the rose often encounters heat stress during the flowering process. However, there are few studies on the Hsf family in roses ( Rosa. chinensis ). In the current study, 19 Hsf genes were identified from R. chinensis and grouped into three main subfamilies (A, B, and C) according to their structural characteristics and phylogenetic analysis. The expression patterns of RcHsf genes were detected in different tissues by quantitative real-time PCR. The RcHsf genes exhibited distinct expression patterns at high temperatures, with RcHsf17 having the highest expression level. RcHsf17 was localized in the nucleus and had transcriptional activity. The overexpression of RcHsf17 increased thermotolerance in Arabidopsis , suggesting the potential role of RcHsf17 in the regulation of the high-temperature response. In addition, RcHsf17 overexpressed in Arabidopsis could enhance the response of transgenic Arabidopsis to methyl jasmonate. Collectively, this study identified and screened RcHsfs in response to high temperatures in roses, providing new insights into the functional divergence of RcHsfs and a basis for screening new varieties of rose.