Impact of Methyl Jasmonate on Terpenoid Biosynthesis and Functional Analysis of Sesquiterpene Synthesis Genes in Schizonepeta tenuifolia

This study investigates the impact of methyl jasmonate (MeJA) on the volatile oil composition of and elucidates the function of the gene, a key player in terpenoid biosynthesis. The effect of different concentrations of MeJA (0, 50, 100, 200, and 300 μmol/L) on the growth of adventitious bud clusters was analyzed over a 20 d period. Using gas chromatography-mass spectrometry (GC-MS), 17 compounds were identified from the adventitious bud clusters of . Significant changes in the levels of major monoterpenes, including increased contents of (+)-limonene and (+)-menthone, were observed, particularly at higher concentrations of MeJA. Analysis of transcriptome data from three groups treated with 0, 100, and 300 μmol/L MeJA revealed significant changes in the gene expression profiles following MeJA treatment. At 100 μmol/L MeJA, most terpene synthase (TPS) genes were overexpressed. Additionally, gene expression and functional predictions suggested that acts as germacrene D synthase. Therefore, was cloned and expressed in , and enzyme activity assays confirmed its function as a germacrene D synthase. Molecular docking and structural prediction of further suggested specific interactions with farnesyl diphosphate (FPP), aligning with its role in the terpenoid synthesis pathway. These findings provide valuable insights into the modulation of secondary metabolite pathways by jasmonate signaling and underscore the potential of genetic engineering approaches to enhance the production of specific terpenoids in medicinal plants.