Optimization of Adventitious Root Suspension Culture in Valeriana fauriei and GC-MS-Based Metabolomics of Responses to Methyl Jasmonate

To overcome the depletion of wild resources and limited seed propagation of Valeriana fauriei, an adventitious root suspension culture system was established and optimized, and methyl jasmonate (MeJA)-elicited metabolic responses were then evaluated using gas chromatography-mass spectrometry (GC-MS)-based untargeted metabolomics. Culture conditions were optimized using a single-factor medium screening experiment combined with a uniform design for four culture-condition factors. The results showed that the optimized culture system increased the 28 d proliferation coefficient of Valeriana fauriei adventitious roots to 27.07. A total of 181 significant differential metabolites were identified and classified into four clusters according to their changing trends. The first cluster increased and then decreased, reaching the maximum value at 80 mg·L−1 MeJA. The second cluster decreased and then increased, reaching the minimum value at 80 mg·L−1 MeJA. The third cluster increased, then decreased, and then increased again, reaching the maximum value at 40 mg·L−1 MeJA and the minimum value at 160 mg·L−1 MeJA. The fourth cluster increased continuously with increasing MeJA concentration. Subsequently, KEGG pathway enrichment analysis was performed for the metabolite sets of the four clusters. Combined analysis indicated that 80 mg·L−1 MeJA was the treatment concentration that most strongly affected the metabolic biosynthesis of V. fauriei adventitious roots. Under this treatment, pathways related to membrane transport, amino acid metabolism, translation, nucleotide metabolism, and the biosynthesis of other secondary metabolites were the most significantly enriched.