Genome-Wide Identification, Classification, and Expression Analysis of the Hsf Gene Family in Carnation ( Dianthus caryophyllus )

Heat shock transcription factors (Hsfs) are a class of important transcription factors (TFs) which play crucial roles in the protection of plants from damages caused by various abiotic stresses. The present study aimed to characterize the genes in carnation ( ), which is one of the four largest cut flowers worldwide. In this study, a total of 17 non-redundant genes were identified from the genome. Specifically, the gene structure and motifs of each were comprehensively analyzed. Phylogenetic analysis of the family distinctly separated nine class A, seven class B, and one class C genes. Additionally, promoter analysis indicated that the promoters included various -acting elements that were related to stress, hormones, as well as development processes. In addition, -elements, such as STRE, MYB, and ABRE binding sites, were identified in the promoters of most genes. According to qRT-PCR data, the expression of varied in eight tissues and six flowering stages and among different , even in the same class. Moreover, revealed their putative involvement in the early flowering stages. The time-course expression profile of during stress responses illustrated that all the were heat- and drought-responsive, and almost all were down-regulated by cold, salt, and abscisic acid (ABA) stress. Meanwhile, , , were primarily up-regulated at an early stage in response to salicylic acid (SA). This study provides an overview of the gene family in and a basis for the breeding of stress-resistant carnation.