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.

Cadmium (Cd) pollution poses significant threats to ecosystems and human health, with agricultural soils in China particularly affected. Ilex verticillata, a popular ornamental plant, has not been extensively studied for its response to Cd stress. This study investigated the physiological and molecular mechanisms underlying Cd stress tolerance in I. verticillata, focusing on auxin signaling pathways. Under Cd stress (500 mmol/kg soil), I. verticillata exhibited inhibited stem growth, reduced photosynthetic capacity, and elevated oxidative stress markers such as malondialdehyde, H₂O₂, ·O₂⁻, and antioxidant enzyme activities. Transcriptomic analysis revealed 3750 differentially expressed genes (DEGs) with significant enrichment in auxin signaling pathways. Six nucleus-localized IvIAA genes were identified and shown to interact with the transcription factor IvMYB77, suggesting a regulatory module in Cd stress responses. These findings highlight the role of auxin signaling in mediating Cd stress tolerance and provide insights into the molecular adaptation of I. verticillata to heavy metal pollution.

Ilex verticillata (winterberry) is a valuable ornamental shrub increasingly threatened by leaf blight, a disease that compromises its aesthetic and economic value. While fungal pathogens like Alternaria alternata are known to cause leaf blight in horticultural crops, their role in I. verticillata and the host’s defense mechanisms have not been fully characterized. Our study investigated the pathogen-host interaction by identifying the causal agent and examining the physiological and molecular defense mechanisms of I. verticillata. Through morphological and multi-locus molecular analyses (ITS, TEF1-α, G3PDH, RPB2), A. alternata was confirmed as the primary pathogen, fulfilling Koch’s postulates. Pathogenicity assays revealed distinct disease progression stages, from necrotic lesions to tissue degradation. Transcriptomic profiling uncovered dynamic host responses, with early upregulation of pattern recognition receptors (PRRs) and transcripts encoding antioxidant enzymes (SOD, CAT), followed by downregulation of metabolic pathway genes. Phytohormone analysis highlighted intricate crosstalk, with salicylic acid (SA) peaking during mid-infection and jasmonic acid (JA) rebounding later, reflecting a coordinated defense strategy. Additionally, the oxidative stress marker malondialdehyde (MDA), an indicator of membrane lipid peroxidation, surged early, indicating membrane damage, while sustained induction of antioxidant enzymes suggested adaptive responses. The key finding was distinct phytohormone crosstalk, characterized by a mid-infection SA peak followed by a late JA rebound, alongside an early oxidative burst marked by MDA accumulation and sustained antioxidant enzyme activity. These findings provide a framework for understanding I. verticillata’s defense mechanisms and offer insights for developing targeted disease management strategies, such as resistant cultivar breeding or hormone-mediated interventions.

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.

Grafting is an important method for pecans, while the molecular mechanisms underlying graft union formation still need in-depth analysis. In the current investigation, we identified 22 BGLU genes in Carya illinoinensis (pecan) and demonstrated that CiBGLU21, a β-glucosidase-encoding gene, plays an important positive role in graft healing. The overexpression of CiBGLU21 enhanced graft survival rates and accelerated tissue regeneration, while biochemical assays confirmed its role in cell wall reinforcement and sugar metabolism. Additionally, we identified that CiWOX13 formed heterodimers with CiWOX14 to directly and synergistically activate the transcription of CiBGLU21. The current investigation revealed a CiWOX13/14-CiBGLU21 module as an important modulator of graft union formation, offering insights into improving grafting efficiency in perennial crops and advancing the understanding of cell wall dynamics during tissue regeneration.