Transcriptomic analysis of the effect of shaking and tumbling degree on quality formation of Wuyi rock tea.

ABSTRACT

Shaking and tumbling are extremely important for the formation of the special flavor of Wuyi rock tea. In this study, we analyzed the effects of different shaking and tumbling degrees on the quality index content of tea leaves and determined changes in gene expression in tea leaves using RNA sequencing technology. On this basis, the correlation between gene expression intensities in tea leaves and tea quality index content was analyzed. The results showed that heavy shaking and tumbling (MW3) increased gene expression of metabolic pathways, biosynthesis of secondary metabolites, starch and sucrose metabolism, biosynthesis of amino acids, glycine, serine, and threonine metabolism, alpha-linolenic acid metabolism pathways and decreased gene expression of flavonoid biosynthesis, carbon fixation in photosynthetic organisms, phenylpropanoid biosynthesis, and plant hormone signal transduction pathways in tea leaves, which in turn increased the content of caffeine, soluble sugar, amino acid and decreased the content of flavone, tea polyphenol, catechin component in tea leaves; the opposite was true for light shaking and tumbling. Second, this study found that MW3 was more beneficial in improving the mellowness, sweetness, and fresh and brisk taste of tea leaves and reducing the bitterness of tea leaves. This study provides some references to guide the processing of Wuyi rock tea with different flavors. PRACTICAL APPLICATION Heavy shaking and tumbling was more beneficial in improving the mellowness, sweetness, and fresh and brisk taste of tea leaves and reducing the bitterness of tea leaves. Therefore, the degree of shaking and tumbling in Wuyi production can be appropriately improved to produce high-quality tea and improve the economic benefits of tea.