Enhanced Catalytic Synthesis of Flavonoid by UV-B Radiation in Artemisia argyi

Enzymatic synthesis of specific active substances is an important foundation for biological adaptations to various stresses. In this study, we investigated the metabolic response of the medicinal herb Artemisia argyi to UV-B radiation through transcriptome and metabolome analysis. In all tested samples, there were 544 shared differentially expressed genes, most of which were linked to the metabolism of flavonoids and fatty acids. A total of 283 differential metabolites were identified and classified into 10 categories, with flavonoids being the largest category. Through an integrated analysis of genes and metabolites involved in flavonoid biosynthesis, flavonoids were predicted to be critical for the adaptation of A. argyi to UV radiation. The increased plant hormones methyl jasmonate and salicylic acid were considered as key regulatory approaches for catalyzing the large-scale synthesis of flavonoids. We explored this by investigating the flavonoid production of A. argyi grown at different altitudes. It showed that total flavonoid content of A. argyi planted in high-altitude areas was 45% higher than that in low-altitude areas. These findings not only deepen our understanding of flavonoid anabolism and its regulation but also provide a reliable strategy for improving flavonoid content in the genus Artemisia.