CsMYB114 promoter variation leads to differential accumulation of galloylated cis-catechins in tea plants

Galloylated cis -catechins serve as characteristic bioactive metabolites in tea plants and significantly determine tea quality. However, the transcriptional regulatory mechanisms of galloylated cis -catechin biosynthesis and the genetic basis for their natural differential levels are largely unknown. In this study, we identified CsMYB114 as a candidate regulator of galloylated cis -catechin biosynthesis by performing a genome-wide association study on the basis of a natural population of Yunwu Tribute Tea plants. CsMYB114 expression was positively correlated with galloylated cis -catechin levels among different Yunwu Tribute Tea plant accessions, and similar co-expression patterns were observed under strigolactone, drought, and salt treatments. Functional validation through virus-induced gene silencing, transient overexpression, electrophoretic mobility shift assays, and transactivation assays demonstrated that CsMYB114 plays a positive regulatory role in galloylated cis -catechin biosynthesis through direct binding to and activation of the downstream biosynthetic gene CsSCPL11-IA . Natural variation in the CsMYB114 promoter was identified and demonstrated to modulate promoter activity and transcript level of CsMYB114 , as well as structural gene expression, resulting in the differential accumulation of galloylated cis -catechins among different Yunwu Tribute Tea plant accessions and other tested tea cultivars. Our findings demonstrate the critical function of CsMYB114 and the role of its promoter variation in regulating biosynthesis of tea plant galloylated cis -catechins, and provide a valuable target gene for precision breeding of tea cultivars with improved quality.