Background: Secondary metabolites not only constitute the material basis for plant responses to multiple environmental stresses but are also extensively utilized in the pharmaceutical industry. Methods: In the present work, we investigated the metabolic response of Artemisia argyi to UV-A irradiation through transcriptomic and metabolomic analyses. Results: After 16 h of UV-A treatment with an intensity of 2.5 μmol m−2 s−1 and 8 h of dark cultivation, a total of 4343 differentially expressed genes were identified, most of which were associated with fatty acid metabolism, biosynthesis of secondary metabolites, and ribosome. Of the 1959 metabolites detected in samples exposed to a 16/8 h UV-A/dark cycle for 6 days, a total of 223 differentially accumulated metabolites were identified and classified into 12 subgroups, with phenolic acids and flavonoids representing the largest subgroups. Comprehensive analyses indicated that polyphenols and terpenes play critical roles in the adaptation of A. argyi to UV-A irradiation. The phytohormone methyl jasmonate was identified as a key regulator of the enhanced synthesis of these secondary metabolites, through activation of transcription factors from the MYB and bHLH families. Conclusions: This study deepens our understanding of secondary metabolic regulation in response to UV-A stress and provides a simple and reliable method to promote the accumulation of specific secondary metabolites in Artemisia species.
Li et al. (Thu,) studied this question.