Characterization of the R2R3-MYB Transcription Factor CsMYB113 Regulates Anthocyanin Biosynthesis in Tea Plants (Camellia Sinensis)

Abstract

Tea plant(Camellia sinensis) has very long history of cultivation and abundant germplasm resources in China. Purple bud is a characteristic variety, which has attracted the attention of breeding researchers because it accumulated a large number of anthocyanins naturally. In many species, R2R3-MYBtranscription factors (TFs)wereprovedto be involved in the regulation of anthocyanin biosynthesis.Research on anthocyanin metabolism has been relatively clear in some species, but that needs to be further elucidated in tea plants. In this research, anR2R3-MYB transcriptionfactor CsMYB113 relate to the anthocyanin accumulation regulation was identified from tea plants. Spatial and temporal expressionanalysis revealed differential expression of CsMYB113among different tissues and organs, with highest expression occurringin the roots.Subcellular localization assays showed that CsMYB113 localizedin the nucleus.Ectopic expression of CsMYB113increased pigmentation and anthocyanin contentsby the up-regulationof theexpression levelsof genes in anthocyanin biosynthesis pathwayamongdifferent tissues of Arabidopsis.Moreover, transient overexpressionof 35S::CsMYB113in tea plant increased the anthocyanin contents in the leaves.Our results indicated that CsMYB113 play important role in the anthocyaninbiosynthesis regulation in tea plants. It will also provide useful candidate gene for the modification of anthocyanin metabolism by genetic engineeringin plants.