A long noncoding RNA modulates anthocyanin biosynthesis in Camellia sinensis

Tea, derived from the leaves of Camellia sinensis, is a globally consumed beverage with considerable nutritional and economic value. Specific cultivars exhibit a striking purple leaf coloration due to anthocyanin accumulation, yet the molecular mechanisms governing this trait remain incompletely understood. In this study, we identified a sense-intronic long non-coding RNA, Cs_lncRNA.18443.6, that is co-expressed with CsUFGT (UDP-glucose: flavonoid 3-O-glucosyltransferase) and is predicted to act in cis on this gene. Together with the transcription factor CsMYB12, these components form a hypothesized three-tier regulatory module that contributes to anthocyanin accumulation in purple tea leaves. CsUFGT emerges as a potential regulatory hub in anthocyanin biosynthesis. Weighted gene co-expression network analysis (WGCNA), combined with the construction of a competing endogenous RNA network construction reveals Cs_lncRNA.18443.6 as a cis-acting lncRNA associated with CsUFGT expression. This association was supported by RNA fluorescence in situ hybridization (FISH), transient expression assays in transgenic tobacco, and RT-qPCR analysis. Dual-luciferase reporter assays provided preliminary evidence that Cs_lncRNA.18443.6 influences CsUFGT transcription by affecting CsMYB12-dependent promoter activation. These findings uncover a previously uncharacterized lncRNA association with anthocyanin biosynthesis and offer new hypotheses and provide candidate targets for the molecular breeding of anthocyanin-enriched tea cultivars.