Biotic and/or abiotic stressors dampen crop productivity and affect sustainability worldwide. To address these challenges, it is crucial to associate the desired stress-responsive genes with specific stress-inducible promoters for developing plant varieties with broad-spectrum stress tolerance. In this study, the promoter region of the anthocyanidin synthase (ANS) gene from banana was thoroughly analysed, and its tissue-specific expression, in response to various environmental insults was delineated. Comprehensive analyses such as transcript abundance-based expression profiling and evaluation of ProANS-GUS activity in transgenic lines was performed and the expression patterns thus obtained were corroborated with the presence of corresponding cis-elements in the promoter region. Transcription of the ANS gene was strongly altered by the imposition of environmental stresses or signaling molecules. MusaANS transcripts in banana were significantly suppressed by exposure to high salinity, salicylic acid or abscisic acid, while its expression was stimulated by methyl jasmonate as well as drought. In PMusaANS-GUS transformed tobacco lines, PMusaANS activity was mainly observed in the vascular tissue under control conditions. Drought, salinity, MeJA, salicylic acid and ABA strongly activated PMusaANS whereas, ethephon suppressed its activity. Thorough scrutiny of PMusaANS showed the presence of a diverse array of stress and phytochemical response-associated cis-elements, such as ARR1AT (cytokinin), ACGTATERD1 (drought), DPBFCOREDCDC3 (ABA), ABREOSRAB21 (ABA), ASF1MOTIFCAMV (salicylic acid), ERELEE4 (ethylene) and BIHD1OS (pathogen response). Based on the results, PMusaANS is differentially activated under stress and hence is an excellent stress-inducible candidate promoter for producing resilient transgenic crop varieties.

Rootstock-enhanced gray mold resistance through phytohormonal crosstalk and transcriptional reprogramming.

Exogenous methyl jasmonate enhances maize resistance by modulating secondary metabolites and suppressing Spodoptera frugiperda performance

Polygala tenuifolia Willd. (P. tenuifolia) is one of the source plants of the traditional Chinese medicine 'Yuanzhi' and is widely used in clinical practice. As a meso-xerophytic medicinal plant with strong environmental adaptability, it is listed as a nationally protected wild medicinal species in China. However, the molecular mechanisms underlying its drought tolerance remain unclear. Therefore, a genome-wide identification of the ERF subfamily inP. tenuifoliawas conducted to provide candidate genes for drought adaptation research and functional validation. Ethylene-responsive factors (ERFs) play important roles in plant responses to drought stress. In this study, 78 PtERF genes were systematically identified for the first time in P. tenuifolia. Phylogenetic analysis classified these genes into five subgroups (B1-B5), with members within the same subgroup exhibiting similar gene structures and conserved motifs. Collinearity analysis revealed that segmental duplication was the primary driving forceunderlying PtERF family evolution. Cis-acting element analysis revealed that PtERF promoter regions were enriched with drought-responsive cis-elements, including abscisic acid and methyl jasmonate (MeJA)-responsive elements. Transcriptome analysis combined with RT-qPCR verification identified five core drought-responsive genes, among which PtERF33 expression exhibited the highest level of upregulation. Further investigation showed that PtERF33 produced two alternatively spliced transcripts: the full-length PtERF33.1 transcript and the intron-retained PtERF33.2 transcript. These two transcripts exhibited opposite expression patterns under drought stress, suggesting that they may regulate drought responses through functional antagonism. These findings provide a systematic basis for identifying drought-resistant ERF genes in P. tenuifolia and establish a foundation for clarifying the role of alternative splicing in drought adaptation in this species.

LgHYH targets and upregulates thetranscription ofLgUGPase1/2, which in turn indirectly activate LgHYH expression through the polysaccharide metabolic pathways, thereby forming a positive feedback loop. Uridine diphosphate glucose pyrophosphorylase (UGPase) catalyzes the conversion of glucose-1-phosphate to uridine diphosphate glucose, a key precursor for cellulose and callose synthesis which is essential for plant cell wall integrity and wood formation. In previous work, we identified two orthologs of UGPase from Larix gmelinii, named LgUGPase1 and LgUGPase2, and demonstrated that their overexpression enhances vegetative growth of transgenic arabidopsis; however, the regulatory mechanisms upstream of LgUGPase transcription remain largely unknown. This study aims to clarify the transcriptional regulatory network of LgUGPase and to characterize its function in woody plants. Expression profiling revealed that LgUGPase1 is broadly expressed in roots, stems, and young leaves, whereas LgUGPase2 is predominantly expressed in apical buds; their expression is induced by phytohormones including gibberellins, methyl jasmonate, and ethylene. Overexpression of LgUGPase in transgenic 84K poplar significantly elevated contents of soluble sugar, lignin, and cellulose, thereby accelerating vegetative growth. RNA-sequencing analysis showed that differentially expressed genes (DEGs) between non-transgenic and LgUGPase-overexpressing lines were markedly enriched in starch and sucrose metabolism, plant hormone signal transduction, and flavonoid biosynthesis pathways. Notably, Gene Ontology (GO) enrichment analysis revealed a significant alteration in "DNA-binding transcription factor activity," with four PagHY5/HYH homologs exhibiting pronounced upregulation. Further dual-luciferase reporter and electrophoretic mobility shift assays (EMSA) confirmed that LgHYH directly binds to the promoter regions of LgUGPase1/2 and positively regulates their expression, thereby establishing a positive feedback regulatory loop mediated by LgHYH. Collectively, these findings provide potential regulatory targets for future genetic improvement of forest trees and crops.

Cadmium (Cd) contamination in Jasminum sambac threatens food safety and aroma quality. We compared titanium dioxide nanoparticle (nTiO2) and methyl jasmonate (MeJA) effects singly or combined using sensory evaluation, HS-SPME-GC-MS, inductively coupled plasma mass spectrometry (ICP-MS), and transcriptome analysis. Cd stress reduced pleasant floral and fruity notes, increased irritating odors, elevated floral Cd accumulation, and shifted volatiles to defense-related sesquiterpenes (e.g., α-cadinol, γ-/d-cadinene). MeJA enriched α-farnesene, enhancing fresh green attributes. ICP-MS revealed nTiO2 and MeJA each reduced floral Cd by approximately 50%, while their combination achieved 88.3% reduction. Transcriptomics showed Cd upregulated phenylpropanoid/flavonoid genes (PAL, 4CL, CHS, DFR, ANS) and activated ABC transporters and salicylic acid (SA) axis (NPR1-TGA-PR1). nTiO2 attenuated ABCB and ABCG expression, and MeJA enhanced α-linolenic acid metabolism and jasmonate signaling (via COI1-JAZ-MYC2). Weighted gene coexpression network analysis (WGCNA) and gene set enrichment analysis (GSEA) indicated energy, redox, and terpenoid pathways (e.g., TPS4, CYP76A26) were involved. This study provides a theoretical basis for synergistic safety and flavor of aromatic crops in heavy-metal-contaminated areas.

Methyl jasmonate (MeJA) plays a key role in enhancing plant resistance to a wide range of diseases. However, the specific defense responses it induced and the underlying molecular mechanisms remain incompletely understood in many plant-pathogen systems. This study aimed to determine whether exogenous MeJA enhances resistance to leaf spot disease caused by Alternaria tenuissima in peony (Paeonia lactiflora) and to elucidate the associated molecular and biochemical mechanisms through integrated transcriptomic and biochemical analyses. Compared with the control (CK), pretreatment with 25-75 µmol L- 1 MeJA significantly reduced disease severity, with 75 µmol L- 1 identified as the optimal concentration. Peony leaves pretreated with this concentration exhibited a stronger hypersensitive response than the CK, with initial differentiation observed at 24h after inoculation. Transcriptome sequencing analysis identified 1,017 differentially expressed genes between the MeJA-pretreated and CK groups, primarily associated with cell wall organization, phenylpropanoid biosynthesis, terpenoid backbone biosynthesis, and flavonoid biosynthesis pathways. MeJA pretreatment up-regulated the genes involved in phenylpropanoid and lignin biosynthesis, including peroxidase 27 (POD27) and caffeic acid 3-O-methyltransferase (COMT), as well as flavonoid-related genes such as chalcone isomerase (CHI). Genes regulating pectin methylesterification, including pectin methylesterase (PME) and PME inhibitor (PMEI), were also modulated. In addition, transcription factors such as basic leucine zipper (bZIP) and heat shock transcription factor (HSF) were activated. Biochemical analyses confirmed increased levels of major cell wall components (lignin, cellulose, hemicellulose, and pectin) and total flavonoids were significantly higher in MeJA-pretreated plants compared with CK plants. A putative model of MeJA-induced defense responses against A. tenuissima was proposed. Exogenous MeJA pretreatment enhances resistance to leaf spot disease caused by A. tenuissima in peony by promoting cell wall reinforcement and flavonoid accumulation. These findings highlight the potential of MeJA as a strategy for managing leaf spot disease in peony cultivation.

Trehalose 6-phosphate and hormone signalling crosstalk.

P. massoniana is an important native economic and ecological tree species in southern China, where seasonal drought has emerged as a critical factor limiting its productivity. The SAUR gene family, recognized as core early auxin-responsive genes, plays a crucial role in balancing plant growth, development, and stress adaptation; however, research related to this family in conifers remains limited. Utilizing the chromosome-level genome of P. massoniana, this study identified 73 SAUR genes (PmSAUR1~73) through bioinformatics methods, systematically analyzing the physicochemical properties of the encoded proteins, chromosomal localization, phylogenetic relationships, gene structures, and cis-acting elements. Combined with transcriptome sequencing and molecular experiments, the drought stress response patterns of these genes were further elucidated. The results indicated that PmSAUR genes predominantly encode alkaline proteins, primarily localized in mitochondria and nuclei, with an uneven distribution across nine chromosomes, where tandem duplication serves as the primary mechanism driving family expansion. Phylogenetic analysis classified these genes into seven subfamilies, which include both conserved clades homologous to angiosperms and branches specific to P. massoniana. All members contain the Auxin_inducible conserved domain, with motif1 identified as the core essential motif. Promoter regions were enriched with MeJA (methyl jasmonate)-responsive (56%), ABA-responsive, and drought stress-related cis-elements. Under drought stress, 38 PmSAUR genes exhibited diverse temporal expression patterns. Four key genes (PmSAUR14, PmSAUR28, PmSAUR54, and PmSAUR73), which are localized in the nucleus and exhibit high expression specifically in male cones or roots, were identified. These genes exhibit an expression pattern consistent with an auxin-negative response (i.e., repressed by IAA and induced by drought) and display a distinctive response pattern characterized by drought-induced upregulation coupled with IAA-mediated downregulation. This mechanism may contribute to the drought adaptation strategies of P. massoniana, involving regulatory processes for aboveground reproduction and adaptation of the underground root system. This study represents the first effort to elucidate the evolutionary characteristics and drought response patterns of the SAUR gene family in P. massoniana, thereby addressing the existing research gap regarding the functions of SAUR genes in coniferous trees. Furthermore, it offers candidate gene resources and theoretical support for the molecular breeding of stress resistance in P. massoniana. In addition, two auxin-induced SAUR genes (PmSAUR22 and PmSAUR37) were identified as contrasting examples, but the main focus of this study is on the four auxin-repressed genes.

Recurrent drought events are becoming increasingly frequent under climate change, yet how perennial clonal grasses adjust their functional traits and recovery trajectories across repeated drought-recovery cycles remain poorly understood. Here, we examined whether exogenous application of methyl jasmonate (MeJA) modifies physiological performance, biomass allocation, and recovery dynamics of the clonal grass Festuca rubra under recurrent drought. Plants were exposed to three consecutive drought-recovery cycles in a controlled growth-chamber experiment with factorial drought and MeJA treatments. We quantified physiological traits (chlorophyll concentration, maximum quantum efficiency of PSII), structural traits (specific leaf area, leaf dry matter content), and performance-related traits (ramet number and biomass allocation). Recurrent drought progressively reduced photosynthetic performance and ramet production, with recovery becoming increasingly incomplete across cycles. In contrast, MeJA treatment mitigated drought-induced declines in chlorophyll concentration and PSII efficiency and stabilized recovery responses. MeJA also altered biomass allocation patterns, increasing aboveground biomass and reducing root-to-shoot ratios under drought, in contrast to drought-only plants, which showed enhanced belowground investment. Post-hoc analyses revealed that MeJA + drought plants differed significantly from drought-only plants for aboveground biomass and several functional traits. Overall, our results demonstrate that MeJA modulates drought responses and recovery trajectories in F. rubra, promoting conservative trait expression and improved performance under recurrent drought. These findings highlight the potential role.

Plastid stromules are frequently observed under stress, yet their function remains enigmatic. In the current study, we tested two alternative hypotheses: stromules might channel metabolic flux from plastids to peroxisomes during jasmonate biosynthesis, or they might serve as conduits for plastid-nucleus retrograde signaling. We used Nicotiana tabacum BY-2 cells to investigate stromulation in non-photosynthetic plastids. Fluorescent markers for stroma, plastid outer membrane, peroxisomes, and the OPDA exporter were combined with confocal visualization and AI-based quantification of stromule frequency and length. Exogenous methyl jasmonate (MeJA) and salicylic acid (SA) each triggered a rapid (∼60 min) ∼3-fold increase in stromule frequency. This increase primarily resulted from more initiation events, rather than elongation. Disrupting microtubules with oryzalin stopped MeJA from causing stromule formation, while actin depolymerization had no effect. Inhibition of jasmonate biosynthesis with phenidone prevented SA-triggered stromule formation. Induction of genes for jasmonate biosynthesis (AOC) and response (JAZ1, JAZ3) by MeJA was amplified when stromulation was suppressed by oryzalin, suggesting that stromules act as modulators of jasmonate-dependent gene expression. The GFP-fusion of the OPDA exporter JASSY showed a significant preference for stromules, and over 80% of them associated with peroxisomes. Stromule frequency was highest during the cell-expansion phase. We discuss our findings in the context of a role for stromules in stress-dependent retrograde signaling from plastids to the nucleus.

Lead (Pb2+) toxicity disrupts cellular redox homeostasis and photosynthesis, highlighting the need to uncover the mechanisms underlying Pb2+ tolerance in phytoremediation. In this study, we characterized SlABH15, an α/β-hydrolase gene enhancing Pb2+ tolerance in tomato. SlABH15 was strongly Pb2+-induced (∼30-fold at 24 h) and was localized to the plasma membrane, acting as a methyl jasmonate esterase converting methyl jasmonate (MeJA) to jasmonic acid (JA). Co-immunoprecipitation (Co-IP) revealed that SlABH15 interacts with KAT2, a key peroxisomal enzyme in JA biosynthesis, and this interaction was strongly enhanced by Pb2+ and JA. SlABH15 overexpression improved Pb2+ tolerance, reduced ROS accumulation, sustained photosynthesis, and decreased tissue Pb2+ content. Conversely, silencing SlABH15 reduced JA levels, exacerbated oxidative damage, and repressed genes involved in JA and chlorophyll biosynthesis. Collectively, our results demonstrate that SlABH15 acts as a critical positive regulator integrating MeJA hydrolysis and JA biosynthesis to maintain plant defense and photosynthetic homeostasis under Pb2+ stress.

Biochar-assisted copper removal and metabolic responses of Hydrocotyle vulgaris in a hydroponic system: Insights from untargeted metabolomics and computational modeling.

Plant-induced defences against herbivores have the potential to modify plant growth, fitness, and the outcome of plant–herbivore interactions. Plants use a variety of cues to initiate the induction of defences, including physical tissue damage, cues released by damaged plant tissues of neighbouring plants (e.g. methyl jasmonate, MeJA), and cues that indicate herbivore presence but are not associated with herbivore damage (e.g. locomotion mucus of herbivorous molluscs). Evidence shows that both herbivore-damage and herbivore-presence cues can generate induced defences in herbaceous plants over relatively short time periods. However, the immediate and long-term effects of these cues on seedlings of deciduous broad-leaved woody plants remain poorly understood. Here, we compare the effects of two cues, MeJA and locomotion mucus of the dusky slug Arion subfuscus, on the growth and defence traits of sugar maple, Acer saccharum, seedlings at multiple timepoints. Specifically, we exposed 4-week-old seedlings to these cues in a greenhouse experiment and quantified their effects on seedling growth, total phenolics, and growth of spongy moth Lymantria dispar across the seedlings’ growing season. As expected, MeJA had a negative effect on seedling growth, a positive effect on total phenolics, and no effect on the growth of L. dispar. In contrast, the slug locomotion mucus did not negatively affect growth or change total phenolic levels. Our results highlight that herbivore cues can induce responses in seedling growth and defence in deciduous broad-leaved woody plant seedlings; however, these responses vary with cue type and the induced responses decay for some seedling traits but not others.

Arnica montana L. is a valuable medicinal plant with strong anti-inflammatory properties attributed to its high levels of antioxidants and specific metabolites. The species is endemic to Europe, and its natural populations are threatened by habitat disturbance and poor management. In vitro plant cultures are an alternative method for rapid plant multiplication and the controlled synthesis of biologically active substances. Elicitation is a common strategy for inducing physiological changes and defense responses in plants, thereby increasing their antioxidant potential and the synthesis of specialized metabolites. Methyl jasmonate, a plant growth regulator involved in the modulation of plant growth and development at morphological and molecular levels, has gained increasing attention as an elicitor. In the present study, three concentrations of MeJA (50, 100, and 200 μM) were applied for 3 and 7 days to evaluate their effects on growth, antioxidant capacity, and accumulation of caffeoylquinic acids in in vitro shoots of arnica. Seven-day MeJA treatment reduced growth parameters and was accompanied by increased activities of antioxidant enzymes SOD and APX, as well as elevated levels of water-soluble antioxidants, which correlated with the enhanced accumulation of caffeoylquinic acids, total phenolics, and flavonoids. The results demonstrate that MeJA affected shoot growth and antioxidant potential of A. montana, with concentration and treatment duration playing a critical role in response magnitude.

Sulforaphane (SFN) is widely recognized for its health-promoting benefits. While several studies have reported that methyl jasmonate (MeJA) enhances SFN accumulation, the role of epigenetic regulation remains unclear. Here, we performed an integrated analysis of transcriptome, whole-genome bisulfite sequencing, and small RNA-seq data from broccoli florets and leaves under MeJA treatment and control conditions. Our results revealed that MeJA-responsive differentially methylated regions (DMRs) predominantly occurring in the CHG context. Integrative analysis of methylation and siRNA data indicated that changes in MeJA-responsive CHH methylation were associated with 24-nucleotide siRNA clusters. Furthermore, inhibiting DNA methylation using 5-azacytidine treatment in broccoli seedlings increased SFN content, validating the role of DNA hypomethylation in this process. By combining transcriptional regulatory network analysis with DMR data, we identified the MeJA-responsive CHG-hypomethylated gene BoCYP83A1. The McrBC-PCR assay confirmed reduced methylation in the BoCYP83A1 promoter region. The function of BoCYP83A1 in MeJA-induced SFN biosynthesis was validated using RNA interference in broccoli. Further evidence demonstrated that the transcription factors BoMYB68 and BoIAA18 promote BoCYP83A1 expression by directly binding to its promoter. Our findings not only provide novel insights into the epigenetic regulation underlying MeJA-induced SFN accumulation in plants but also facilitate molecular breeding for the development of high-SFN crops.

Dipsacoside B alleviates experimental colitis by reshaping gut microbiota and metabolically regulating the balance of macrophage polarization.

The supply of the anticancer drug paclitaxel is limited by its low natural abundance and complex chemical structure. We previously reported the development of a cultured Taxus cambial meristematic cell (CMC) system, where methyl jasmonate enhances paclitaxel production. In this report, we describe a comprehensive analysis to identify potential master regulators of paclitaxel biosynthesis. We report that the combined expression of two myeloblastosis transcription factors can cooperatively activate a subset of paclitaxel biosynthetic genes in stable transgenic CMCs, resulting in a 121-fold increase in paclitaxel and a 364-fold increase in its valuable precursor baccatin III. Our findings provide a powerful approach to enhancing production of this vital compound and can also be applied to other valuable products.

Climate change is currently affecting chemical grape composition and, consequently, grape quality. The foliar application of biostimulants has emerged as a promising approach to mitigate these effects. This study investigated the effects of foliar applications of calcium (Ca), methyl jasmonate (MeJ), and their combination (Ca + MeJ) on the enological parameters and amino acid composition of Tempranillo grapes over two successive growing seasons (2022 and 2023). The effect of applying the treatments once or twice at post-veraison and 1 week later was also evaluated. Foliar applications showed season-dependent effects on Tempranillo musts, generally increasing pH, malic acid, and total phenol content. Differences between seasons were attributed to climatic variability. In all samples, arginine was the predominant amino acid in grapes, followed by proline and glutamine. All foliar treatments modified the amino acid profile, although the effects varied between seasons. The observed increases in asparagine, glutamine, valine, methionine, isoleucine, ornithine, and leucine following foliar calcium application suggest stimulation of nitrogen assimilation and amino acid biosynthesis pathways. In 2022, Ca + MeJ1 and MeJ2 were the most effective treatments, whereas in 2023, MeJ1 and Ca2 produced the highest amino acid content in musts. Foliar application of these biostimulants may represent a useful strategy to improve grape nitrogen composition and mitigate the effects of climate change. The observed increase in amino acid content may also contribute to improved yeast assimilable nitrogen (YAN), supporting yeast metabolism and potentially improving fermentation performance. © 2026 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Functional characterization of type I chalcone isomerase AmCHI from Astragalus mongholicus and its response mechanism to exogenous hormones.