Formation of (E)-nerolidol in tea (Camellia sinensis) leaves exposed to multiple stresses during tea manufacturing

- (E)-Nerolidol synthase was in the cytosol and synthesized (E)-nerolidol in tea.
- (E)-Nerolidol synthase was highly expressed at the turn over process of oolong tea.
- Continuous mechanical damage enhanced (E)-nerolidol and its synthase levels.
- Dual stresses had synergistic effect on (E)-nerolidol formation.

(E)-Nerolidol is a volatile sesquiterpene that contributes to the floral aroma of teas (Camellia sinensis). The unique manufacturing process for oolong tea involves multiple stresses, resulting in a high content of (E)-nerolidol, which is not known to form in tea leaves. This study aimed to determine the formation mechanism of (E)-nerolidol in tea exposed to multiple stresses during tea manufacture. C. sinensis (E)-nerolidol synthase (CsNES) recombinant protein, found in the cytosol, was found to transform farnesyl diphosphate into (E)-nerolidol. CsNES was highly expressed during the oolong tea turn over process, resulting in (E)-nerolidol accumulation. Continuous mechanical damage, simulating the turn over process, significantly enhanced CsNES expression level and (E)-nerolidol content. The combination of low temperature stress and mechanical damage had a synergistic effect on (E)-nerolidol formation. This is the first evidence of (E)-nerolidol formation mechanism in tea leaves and a characteristic example of plant volatile formation in response to dual stresses.