Abstract: Raw lacquer is a valuable natural coating material with exceptional properties, including heat, corrosion, and acid resistance, which make it an important resource in various industries. Revealing the changes in metabolites during its growth process of lacquer is the key to excavate its applications. We analyzed phloem sap samples of Toxicodendron vernicifluum at different developmental stages (based on the time of lacquer harvesting) using broad targeted metabolomic analysis technology, including principal component analysis, orthogonal partial least squares discriminant analysis, and cluster heat map analysis, to investigate the differences and changing patterns of metabolites. Our analysis identified 529 metabolites in raw lacquer, which can be classified into 13 major groups, including flavonoids, phenolic acids, alkaloids, tannins, sugars and alcohols, and lipids. Multivariate statistical analysis revealed that the metabolic characteristics of raw lacquer in the second, third, fourth, and fifth developmental stages were similar, but significantly different from those in the first stage. By comparing and analyzing the metabolites in raw lacquer at different developmental stages, we identified 92 common differentially abundant metabolites. Notably, flavonoid compounds primarily accumulated in raw lacquer during the first stage, while amino acids and their derivatives, sugars, and alcohols had relatively higher contents in raw lacquer at later stages. Our findings provide a comprehensive understanding of the metabolic characteristics of raw lacquer at different developmental stages, which could have significant implications for the development and utilization of lacquer resources.

Key words: Toxicodendron vernicifluum, metabolomics, raw lacquer, differentially abundant metabolites