Medicinal Plant Research 2025, Vol.15, No.6, 274-282 http://hortherbpublisher.com/index.php/mpr 278 substantially increase the content of key metabolites, including tanshinone IIA, tanshinone I, and cryptotanshinone, while also improving root biomass and increasing microbial diversity. Intercropping with maize or soybean results in little benefit or is even deleterious (Zhang et al., 2024). These findings stress the importance of proper crop selection in rotation and intercropping systems for maintaining soil health toward enhancing metabolite accumulation. 5.4 Integrated optimization of cultivation patterns and agronomic management These integrated methods synergistically improve not only the yield but also the quality by optimum planting density, appropriate pruning, and beneficial intercropping. For instance, application of arbuscular mycorrhizae along with proper cultivation pattern shows increased root biomass and secondary metabolite production (Wu et al., 2021). Crop rotation and intercropping to manage inter-root secretions and microbial communities overcome obstacles in continuous cropping for sustainability in production (Zhang et al., 2024). 6 Growth Regulators and Inducers inSalvia miltiorrhiza 6.1 Induction of secondary metabolites by plant hormones (ABA, GA, JA, SA, etc.) Jasmonic acid and its derivative methyl jasmonate are the most potent elicitor for tanshinone and phenolic acid biosynthesis through transcriptional regulation of the biosynthetic genes by interaction with JAZ repressors and bHLH/ERF TFs (Lv et al., 2024). Gibberellin signals via induction of tanshinone accumulation mediated through GRAS TF, while abscisic acid and salicylic acid generally modulate the pathways of phenolic acid under stress conditions (Li et al., 2024). 6.2 Effects of ethylene and ROS signaling on metabolite synthesis Ethylene and ROS signaling are closely related to stress responses and secondary metabolism. Overexpression of some stress-responsive transcription factors, such as AtMYB2, reduces ROS accumulation by enhancing antioxidant enzyme activity and thus increases the tanshinone and phenolic acid content under salt stress (Zuo et al., 2025). These pathways often interplay with hormone signaling in order to fine-tune metabolite production. 6.3 Abiotic and biotic stress inducers Abiotic stresses, including drought, salinity, and UV irradiation, upregulate genes responsible for secondary metabolite biosynthesis mainly through hormone-dependent pathways, such as ABA and JA (Zhang et al., 2024). Biotic elicitors, like endophytic fungi and silver ions (Ag+), are also able to induce tanshinone and phenolic acid biosynthesis through the activation of key biosynthetic genes and transcription factors involved (Cheng et al., 2023; Zuo et al., 2025). 6.4 Synergistic effects of hormones and environmental factors Hormonal crosstalk and environmental signals act synergistically. For instance, MeJA and salt stress in concert regulate the SmJAZs-SmbHLH37/SmERF73-SmSAP4 module to balance biosynthesis of metabolites and tolerance to stresses (Lv et al., 2024). Such integration would ensure optimal secondary metabolite production and resilience of plants. 7 Multi-Omics Insights into Secondary Metabolite Regulation inSalvia miltiorrhiza 7.1 Transcriptomics revealing expression patterns of biosynthetic genes Transcriptomic analyses have identified thousands of DEGs associated with the biosynthesis of key secondary metabolites, such as tanshinones, phenolic acids, and flavonoids. For example, transcriptome profiling under drought and nutrient stress has disclosed the upregulation of genes in the phenylpropanoid and terpenoid pathways and their controlling transcription factors, including MYB, WRKY, and bHLH (Yu et al., 2025). Dynamic regulatory hubs, such as the SmWRKY48-SmTCP4-SmWRKY28 module, orchestrating responses to metabolic pathway perturbations, were further unraveled by time-series transcriptomics (Jiang et al., 2024; Liu et al., 2025) (Figure 2).
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