Genome-Wide Identification and Expression Analysis of Heat Shock Transcription Factors in Camellia sinensis Under...

The tea plant (Camellia sinensis) is an economically important crop that plays an important role not only in the beverage industry but also in the pharmaceutical industry. The environment has a great influence on the quality of the tea plant. Heat shock factors (Hsfs) are transcriptional regulators that control the plant response to adversity. However, only a limited number of studies have reported the Hsf gene in Camellia sinensis, and most of these reports involve high-temperature, drought, and salt stress. Research on light, dark, and cold stress is limited. In this study, 22 CsHsf genes were obtained by whole genome sequencing and found to be located on 11 chromosomes. In addition, the gene structure, protein motif, and phylogeny were studied. We classified the genes into three major subfamilies: CsHsfA, CsHsfB, and CsHsfC. Interestingly, we found that there was more alignment between CsHsf and Hsf genes in dicotyledons, including Arabidopsis thaliana and Solanum lycopersicum, than in the monocotyledon Oryza sativa. The expression of many CsHsf genes was affected by low-temperature, light, and dark abiotic stresses. Notably, CsHsf15 and CsHsf16 showed high induction rates under both light and cold stress, and both genes carried cis-acting elements associated with light and low-temperature responses. These results lay a solid groundwork for further investigations into the involvement of CsHsf genes in the response of Camellia sinensis to abiotic stresses.