Isolation and characterization of key genes that promote flavonoid accumulation in purple-leaf tea (Camellia sinensisL.)

Abstract

There were several high concentrations of flavonoid components in tea leaves that present health benefits. A novel purple-leaf tea variety, 'Mooma1', was obtained from the natural hybrid population of Longjing 43 variety. The buds and young leaves of 'Mooma1' were displayed in bright red. HPLC and LC-MS analysis showed that anthocyanins and O-Glycosylated flavonols were remarkably accumulated in the leaves of 'Mooma1', while the total amount of catechins in purple-leaf leaves was slightly decreased compared with the control. A R2R3-MYB transcription factor (CsMYB6A) and a novel UGT gene (CsUGT72AM1), that were highly expressed in purple leaf were isolated and identified by transcriptome sequencing. The over-expression of transgenic tobacco confirmed that CsMYB6A can activate the expression of flavonoid-related structural genes, especially CHS and 3GT, controlling the accumulation of anthocyanins in the leaf of transgenic tobacco. Enzymatic assays in vitro confirmed that CsUGT72AM1 has catalytic activity as a flavonol 3-O-glucosyltransferase, and displayed broad substrate specificity. The results were useful for further elucidating the molecular mechanisms of the flavonoid metabolic fluxes in the tea plant.

Anthocyanins: Natural Sources and Traditional Therapeutic Uses

“…Flowers Dp 3-(2-rhamnosyl-6-malonylglucoside) [23] Blue poppy Flowers Cy 3-(2-xylosyl-6-malonylglucoside)-7-glucoside [24,25] Blue bugle Flowers Dp 3-[2-(6-feruloylglucosyl)-6-p-coumaroylglucoside]-5-(6-malonylglucoside) [26,27] Tea tree Flowers and leaves Dp 3-(6-p-coumaroylgalactoside) [28,29] Ginger-leaf morning-glory…”

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

“…These medicinal properties derived from the various secondary metabolites in tea plants, such as catechins, anthocyanins, and theanine (Shi et al 2011). However, anthocyanins were trace amount detected in most of the tea varieties (He et al 2018). In recent years, purple foliage has attracted a lot attention by the tea plant breeding programmers.…”

“…The R2R3-MYB TFs CsAN1 could combine with CsGL3 and CsTTG1 and activate the expression of genes involve in anthocyanin biosynthesis (Sun et al 2016). In ectopic transgenic tobacco plant leaves, CHS and 3GT were activated by the CsMYB6A which result in the signi cantly increment of anthocyanins (He et al 2018). In transgenic tobacco lines, CsMYB5a and CsMYB5e were reported to play important role in the regulation of anthocyanins and proanthocyanidins (Jiang et al 2018).…”

“…In transgenic tobacco lines, CsMYB5a and CsMYB5e were reported to play important role in the regulation of anthocyanins and proanthocyanidins (Jiang et al 2018). The PAP1-like MYB gene was proposed as a key regulator in controlling anthocyanins metabolism (He et al 2018;Wei et al 2016). CsMYB75 promoted the biosynthesis of catechins and anthocyanins by up-regulated the expression of CsGSTF1 in transgenic tobacco (Wei et al 2019).…”