Functional Analysis of <i>CsHsf10</i> in Drought Stress Response in <i>Camellia sinensis</i>

Heat shock transcription factor (Hsf) plays a crucial role in the signal transduction pathways of plants in response to drought stress. However, studies exploring the specific functions and mechanisms of action of the Hsf family in tea plants (<i>Camellia sinensis</i> L.) remain limited. In this study, we identified 31 members of the CsHsf family from the <i>C. sinensis</i> genome. <i>CsHsf10</i> was determined to be a potential drought-resistant candidate gene by screening 10 highly expressed genes in mature leaves and confirming results through RT-qPCR. Correlation analysis indicates that <i>CsHsf10</i> may enhance the drought resistance of tea plants by participating in the tea polyphenol synthesis pathway and regulating the expression of antioxidant enzyme genes. Furthermore, overexpression experiments in <i>Arabidopsis</i> and antisense oligonucleotide experiments in tea plants corroborated that <i>CsHsf10</i> exerts a significant positive regulatory effect on drought resistance in tea plants. Yeast one-hybrid assays and dual luciferase reporter gene experiments demonstrated that <i>CsHsf10</i> can directly target <i>CsPOD17</i>, significantly promoting its transcriptional expression. Additionally, we found that the expression of <i>CsHsf10</i> contributes to the increased accumulation of catechin components in tea plants under drought stress. These findings suggest that, during the response of tea plants to drought stress, <i>CsHsf10</i> not only enhances antioxidant capacity by regulating the activity of antioxidant enzymes but also optimizes the physiological state of tea plants by influencing the accumulation of secondary metabolites, thereby significantly improving their drought resistance.