Plant Tannase: Evolutionary and Functional Divergence Features

In plants, α/β-hydrolase regulates the hydrolysis
of
ester compounds, enriching the types and functions of specialized
metabolites. In this study, three genesCsCSE, CsCXE3, and CsTAwhich
encode caffeoyl shikimate esterase (CSE), carboxylesterase (CXE),
and tannase (TA), respectively, were isolated from the tea plant genome
through multiomics correlation analysis. Evolutionary analysis showed
that CSE and CXE were ancient, whereas TA emerged in core eudicots
approximately 120 million years ago. Enzyme activity assays revealed
that CsCSE and CsCXE3 catalyze phenolic acid and acetate ester hydrolysis,
respectively. Interestingly, CsTA not only has the catalytic function
of CsCSE and CsCXE3 but also catalyzes the hydrolysis of galloylated
catechin, hydrolyzable tannin, and hormone ester. Overall, CsTA is
a newly derived α/β-hydrolase with evolutionary and functional
divergence features. This study expands our understanding of the physiological
significance of plant TA and provides insights into the potential
role of CsTA in the complex metabolic processes of
tea plants.