Drought stress severely compromises the physiological integrity and secondary metabolism of medicinal plants. This study integrated physiological, biochemical, and ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) analyses to investigate the effects of exogenous methyl jasmonate (MeJA) on drought-stressed Ilex rotunda seedlings. Drought reduced relative water content by 29% and chlorophyll by >50%, while elevating H₂O₂ (76%) and malondialdehyde (120%). MeJA application mitigated these impairments, reducing oxidative markers by 25% and enhancing non-enzymatic antioxidant capacity, as shown by a 74% increase in DPPH radical scavenging activity and a 141% rise in total phenolic content. Hierarchical clustering analysis (HCA), principal component analysis (PCA), and orthogonal partial least squares-discriminant analysis (OPLS-DA), and pathway mapping confirmed a significant reprogramming of the phenolic metabolome, particularly within phenylpropanoid and benzoate biosynthesis pathways. Drought + MeJA-treated plants exhibited a distinct and enriched profile compared to both well-watered control and drought-stressed groups. This reprogramming specifically elevated key hydroxycinnamates, including verbascoside and neochlorogenic acid (increased by 50% and 52%, respectively), while suppressing alternative phenolic branches. These findings demonstrate that MeJA orchestrates a shift from enzymatic scavenging to a potent metabolite-based antioxidant system, positioning it as an effective elicitor for enhancing drought resilience and enriching the high-value phytochemicals in I. rotunda.

Drought stress imposes oxidative damage on plants, yet the tissue-specific roles of salicylic acid (SA) in modulating phenolic metabolism remain poorly understood in woody species. Using Ilex rotunda seedlings, we investigated whether exogenous SA (100 µM) mitigates drought-induced oxidative damage and reshapes phenolic profiles in different tissues. Drought alone increased leaf total phenolics by 32% but depleted root phenolics by 29%, whereas combined drought + SA (DSA) treatment partially restored root phenolic levels, coinciding with elevated malondialdehyde (MDA) (2.2-fold in leaves, 2.6-fold in roots) and H₂O₂. Leaf antioxidant capacity increased under drought (DPPH by 73%, •OH by 33%), whereas root DPPH declined by 27% despite a 26% rise in •OH scavenging. SA alone induced mild oxidative responses and selectively upregulated caffeoylquinic and galloyl derivatives, notably 1-Caffeoylquinic acid (log₂FC = 6.38) in leaves. DSA treatment mitigated oxidative damage—reducing leaf MDA by 44% and root H₂O₂ by 38%. Metabolomics revealed tissue-specific reprogramming leaves accumulated dicaffeoylshikimic acid (log₂FC = 10.66) and trilobatin D (log₂FC = 11.18) under DSA, whereas roots showed contrasting patterns with up-accumulation of vanillate (log₂FC = 5.77) and suppression of 3,5-dicaffeoylquinic acid (log₂FC = −7.21) under drought, with stronger metabolic reprogramming in leaves than roots. Our findings indicate that SA-mediated drought tolerance is associated with tissue-specific phenolic reprogramming, identifying candidate indicators that advance the mechanistic understanding of woody plant resilience to drought. These results provide a framework for translating metabolomic signatures into practical strategies for stress mitigation in medicinal perennials facing climate change.

Camphora officinarum (syn. Cinnamomum camphora) is an ecologically, medicinally, and economically important tree species widely known for its essential oils (EOs), timber, and long history of use in traditional medicine. In recent years, renewed interest in this species has been driven by taxonomic revision, the discovery of chemically distinct chemotypes, and advances in genomics, metabolomics, and biotechnological processing. This review summarizes current knowledge on the botany, distribution, phytochemistry, biological properties, agro-industrial value, and biotechnological potential of C. officinarum. Particular attention is given to the genetic and metabolic basis of terpene diversity, especially the role of terpene synthase (TPS) gene expansion in the formation of camphor-, linalool-, borneol-, cineole-, and citral-type profiles. We also discuss developments in essential oil extraction, the utilization of non-volatile constituents such as flavonoids and lignans, and the nutritional value of seed kernel oil rich in medium-chain fatty acids (MCFAs). In addition, recent progress in tissue culture, multi-omics analysis, metabolic engineering, and nano-enabled delivery systems is reviewed. The paper also considers important safety and ecological issues, including the dose-dependent toxicity of camphor and the contrasting status of the species as a protected native resource in East Asia and an invasive plant in some introduced regions. Overall, this review provides an updated and balanced overview of C. officinarum, identifies key knowledge gaps, and highlights future prospects for sustainable utilization, conservation of native genetic resources, and exploitative control of invasive populations.

Cryptomeria japonica var. sinensis Miquel (Chinese cedar) is an ecologically and economically vital evergreen conifer endemic to China. Renowned for its rapid growth and superior timber quality, the species has evolved from a traditional forestry resource into a multifaceted model species for phytochemistry and biotechnology. This review synthesizes recent advancements in its biology, chemical profiling, industrial utilization, and molecular breeding. Taxonomically and morphologically distinct from the Japanese variety, Chinese cedar exhibits robust physiological plasticity and complex transcriptomic responses to abiotic stresses. Phytochemically, the tree is a prolific reservoir of volatile essential oils, complex terpenoids, and flavonoids. These bioactive secondary metabolites demonstrate potent antimicrobial, antioxidant, and neuroprotective properties, driving broad applications in modern pharmacology and sustainable agrochemicals. Industrially, the timber is increasingly utilized in the fabrication of advanced engineered structural composites and circular bioenergy production. Concurrently, breakthrough biotechnological platforms including a chromosome-level reference genome assembly, multi-omics, somatic embryogenesis, and CRISPR/Cas9-mediated genome editing have advanced molecular breeding, accelerating the targeted development of climate-resilient and non-pollen-producing (hypoallergenic) elite cultivars. However, as global climate change and historical habitat fragmentation severely threaten ancient wild populations, this review advocates for integrated in situ and ex situ conservation strategies. By identifying critical research gaps in translational pharmacology, precision gene editing, and comparative genomics, this review provides a comprehensive foundation for understanding the biology, phytochemistry, biotechnology, and utilization of this invaluable botanical resource, offering a strategic roadmap for its sustainable management and commercial valorization.