The function and regulatory mechanism of tea plant transcription factor CsMYB116 in drought stress response

The MYB transcription factor family plays a crucial regulatory role in the growth and quality development of tea plants. Building upon previous drought-related transcriptome data, this study systematically investigated the function and regulatory mechanisms of the tea plant transcription factor CsMYB116 in response to drought stress, employing physiological and molecular biology methods. Through heterologous overexpression and gene silencing experiments, CsMYB116 was demonstrated to positively regulate drought resistance in tea plants. Under drought conditions, overexpression lines exhibited increased lateral root development, enhanced photosystem stability, elevated antioxidant enzyme activity, higher proline content, and a significant reduction in membrane lipid peroxidation. Conversely, gene silencing resulted in photosystem damage, diminished antioxidant capacity, and disrupted hormone signaling in tea seedlings. Transcriptome sequencing revealed significant alterations in key metabolic pathways-including hormone signal transduction, cell wall synthesis, phenylpropanoid metabolism, and ABC transporter activity—in silenced plants subjected to drought stress. Furthermore, yeast two-hybrid assays confirmed interactions between CsMYB116 and both ABC transporters and IAA-related proteins. This study is the first to demonstrate that CsMYB116 enhances drought adaptability in tea plants by positively regulating gene expression. These findings contribute to a deeper understanding of the molecular regulatory mechanisms underlying tea plant responses to drought and identify CsMYB116 as a promising target for molecular breeding aimed at improving drought tolerance in tea plants.