CsMYB5 regulates anthocyanin accumulation and stress responses through responding to hormone signaling of Camellia sinensis

Background Anthocyanins are major secondary metabolites that determine tea quality and contribute to plant stress adaptation. However, the transcriptional mechanisms coordinating their biosynthesis in response to environmental cues remain largely unclear. Result In this study, we characterized the R2R3-MYB transcription factor CsMYB5 from tea plant ( Camellia sinensis ) and investigated its role in hormone-responsive secondary metabolism regulation. Expression analyses revealed that CsMYB5 is preferentially expressed in anthocyanin-rich tea cultivars and leaf tissues and is strongly induced by SA, MeJA and multiple abiotic stresses. Genome-wide DNA affinity purification sequencing revealed that CsMYB5 binding sites are enriched in promoter regions of genes associated with transcriptional regulation and secondary metabolism, including flavonoid and caffeine biosynthetic pathways. Notably, CsMYB5 directly targets CsTCP15 , a TCP transcription factor potential regulation of anthocyanin synthesis and accumulation, suggesting the existence of a CsMYB5–CsTCP15 regulatory module.Heterologous overexpression of CsMYB5 in Arabidopsis thaliana resulted in enhanced vegetative growth and pronounced anthocyanin accumulation. Conclusions Based on these findings, we propose that CsMYB5 acts as a central transcriptional hub linking hormone signaling with coordinated regulation of anthocyanin accumulation biosynthesis. This study provides new insights into the transcriptional integration of flavonoid metabolism and offers potential targets and research direction for improving tea quality and stress resilience through molecular breeding.