Metabolomic Analysis Provides Insights into Bud Paradormancy in Camellia sinensis cv. Huangdan

TL;DR

This study explores how bud dormancy is controlled in tea plants using metabolomic analysis, revealing changes in sugar and flavonoid levels during dormancy release.

Contribution

The study provides novel insights into paradormancy mechanisms in a perennial evergreen species using untargeted metabolomics.

Findings

Paradormant buds had lower glucose-1-phosphate and fructose but higher trehalose and raffinose.

Flavonoids like C-diglucosylapigenin and proanthocyanidins were enriched in paradormant buds.

Metabolite levels reversed during the transition from paradormancy to growth.

Abstract

Bud paradormancy has been widely studied in perennial deciduous woody species, but little attention has been paid to paradormancy set and release in perennial evergreen tree species. Here, shoot bud paradormancy in Camellia sinensis cv. Huangdan was studied by untargeted metabolomics. We found that after removing the axillary floral buds for one day, the paradormancy of the axillary shoot buds was released. The paradormant shoot buds had lower glucose-1-phosphate, fructose, and D-(-)-tagatofuranose content but higher trehalose, raffinose, galactinol, and α-D-xylopyranose content. Meanwhile, high levels of asparagine were accumulated. Flavonoids were differentially accumulated, and higher levels of three flavone glycosides (C-diglucosylapigenin, apigenin 6-C-glucoside 8-C-arabinoside, and prunin) and four proanthocyanidins (Procyanidin trimer isomer 1, Galloylprocyanidin dimer, Procyanidin trimer isomer 3, and Galloylated trimeric proanthocyanidin) were accumulated in paradormant shoot buds. During the paradormancy-to-growth transition, all these metabolites were reversed. These data suggest that the reconfiguration of carbon, nitrogen, and flavonoid metabolism could be an important aspect for the paradormancy set and release of tea axillary shoot buds. This study provided novel insights into shoot bud paradormancy set and release in a perennial evergreen tree species.

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