Dynamics of ADH and related genes responsible for the transformation of C-aldehydes to C-alcohols during the postharvest process of oolong tea.

Aroma is an important index of tea quality. The volatile C-compounds formed from linoleic and linolenic acids in tea leaf lipids are essential components of tea. C-compounds are formed and transformed during the postharvest process of tea leaves. However, the metabolic flux of these C-compounds, the activities of related enzymes, and the transcription of related genes during the postharvest process of oolong tea remain unclear. In this study, the chemical profiles of C-aldehydes and C-alcohols, the pattern of ADH enzyme activity, and the level of gene expression during the postharvest process of oolong tea were investigated. We found that the turnover process had a positive effect on the accumulation of C-alcohols and simultaneously induced ADH activity, especially during the withering stage. The expression of peaked during the turnover stage. The relative expression level of CSA019598 typically increased during the postharvest process. Correlation analysis demonstrated that CSA019598 expression increased as ADH activity increased. This finding suggests that CSA019598 may play a prominent role in regulating ADH. These results advance our understanding of C-compound formation during the postharvest process of oolong tea. We aim to evaluate how green leaf volatiles affect the enzymatic formation and genetic transcription of aromatic compounds in oolong tea in future studies.