Integrated metabolomics and transcriptomics unravel the mechanism of shaking in regulating floral-honey aroma quality formation in black tea (Camellia sinensis)

Shaking is a critical process for enhancing the aroma quality of black tea, though its molecular regulatory mechanisms remain unclear. Through integrated metabolomics and transcriptomics, we found shaking significantly intensifies floral-honey attributes, with a 30–50 % higher market value than conventional black tea.Stir bar sorptive extraction/gas chromatography-mass spectrometry (SBSE/GC-MS) analysis identified 11 key volatile compounds, including methyl jasmonate, jasmine lactone, indole, and nerolidol，as primary contributors to the characteristic aroma profile. The critical biosynthetic window was determined to be the shaking-to-withering transition phase (W8-W15). Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) coupled with transcriptomic analysis revealed that shaking activated lipid hydrolysis mediated by CsPLDα1 and CsGPAT , releasing linoleic acid and α-linolenic acid, which subsequently regulated the synthesis of methyl jasmonate and jasmine lactone through CsLOX-5 , CsOPR3 , and CsJMT . Additionally, the newly discovered CsTSβ1L-1 gene was implicated in potential cooperation with CsTSβ2 for indole biosynthesis regulation, while CsNES-1 and CsNES-5 were established as principal regulators of nerolidol synthesis.These findings collectively elucidate how shaking modulates the lipid, shikimate, and mevalonate pathways to shape black tea aroma, providing concrete molecular targets for industrial optimization of premium floral-honey aroma tea production.