Search Results (762)

Methyl jasmonate (MeJA) is a key regulator of plant defense and abiotic stress responses, while terpenoids are important secondary metabolites. However, the effects of MeJA on floral volatiles in Lagerstroemia indica and the underlying mechanisms remain unclear. In L. indica ‘Whit III’, MeJA treatment rapidly increased the emission of monoterpenes (e.g., citronellol) and sesquiterpenes (e.g., trans-farnesol) and advanced the peak emission time. We identified 34 LiTPS and 22 LiMYC genes in the genome, with promoter regions enriched in JA-responsive cis-elements. Expression analysis showed that LiMYC genes encoding putative JA repressors were transiently upregulated, whereas LiTPS genes located in a chromosome 11 cluster and LiTPS13 (7.33-fold induction) were strongly activated. These results suggest that MeJA may promote an early scent production through the coordinated activation of specific LiMYC and LiTPS gene sets, pointing to a potential mechanism by which jasmonate signaling modulates floral volatile emission. Full article

Jasmonate ZIM-domain (JAZ) proteins are pivotal repressors in the jasmonate (JA) signaling pathway, yet their specific roles in garlic (Allium sativum) remain largely unexplored. In this study, 28 AsJAZ genes were identified through a genome-wide analysis. The expansion of this family was primarily driven by whole-genome duplication events, with a significant majority (71.43%) of members belonging to a lineage-specific clade, Subfamily E. While AsJAZ proteins harbor conserved TIFY and Jas domains, they exhibit diverse gene structures and subcellular localization patterns. Notably, AsJAZ17 is strictly localized to the nucleus, whereas AsJAZ16 shows a nucleocytoplasmic distribution, suggesting potential functional compartmentalization within the family. Transcriptomic and qRT–PCR analyses revealed that most AsJAZ genes are responsive to heat, salt, and methyl jasmonate (MeJA) treatments. Protein–protein interaction (PPI) modeling and yeast two-hybrid (Y2H) assays confirmed that AsJAZ17 physically interacts with the MYC2 transcription factor, identifying it as a key regulator within the conserved COI1-JAZ-MYC2 signaling module. Functional validation demonstrated that overexpression of AsJAZ17 in Arabidopsis significantly enhances salt tolerance. This improvement is attributed to an optimized growth-defense trade-off and a reinforced antioxidant defense system, as evidenced by the increased activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), which collectively maintain reactive oxygen species (ROS) homeostasis under stress. These findings provide comprehensive insights into the evolutionary and functional landscape of the garlic JAZ family and identify AsJAZ17 as a promising candidate gene for molecular breeding to improve abiotic stress resilience in Allium crops. Full article

Panax ginseng is a medicinal plant with diverse pharmacological effects; its primary active components are ginsenosides. The biosynthesis of ginsenosides can be regulated by the plant hormone methyl jasmonate (MeJA) during in vitro culture of ginseng. The PYL proteins, which serve as abscisic acid (ABA) receptors, play a crucial role in plant hormone signaling transduction. However, there are no reports on the response of PYL genes to MeJA in ginseng. In this study, we identified 49 members of the PYL gene family in the ginseng genome and transcriptome from databases and conducted a systematic analysis. The results indicated that these PYL genes were unevenly distributed across the chromosomes and exhibited significant synteny. Gene Ontology (GO) functional annotation revealed considerable functional diversity in the PYL gene family in ginseng. Analysis of the promoter cis-acting elements showed that these genes are involved in various biological processes, including growth, development, and metabolic regulation. After treating ginseng adventitious roots with MeJA, we found that four PgPYL genes (PgPYL13, PgPYL17-01, PgPYL17-02, and PgPYL23) containing abundant MeJA-responsive elements exhibited distinct expression patterns and were negatively correlated with protopanaxadiol-type ginsenoside content. This study systematically elucidated the characteristics and functions of the ginseng PYL gene family, revealing its potential role in MeJA signal transduction and the regulation of ginsenoside biosynthesis. Our findings provide a theoretical basis for optimizing the in vitro culture of ginseng plant cells and enhancing ginsenoside production. Full article

The use of nanotechnology-based delivery systems along with growth regulators of plants is a promising approach to increase the quality of fruits postharvest. This experiment was aimed at determining the impact of sonicated nanoemulsions containing methyl jasmonate (MeJA) and 1-naphthaleneacetic acid (NAA) on the quality of postharvest Tango mandarin. The findings showed the samples treated improved fruit weight, diameter, firmness and juice percentage significantly compared to the control sample. TMJ4 (10.0 µM L⁻¹) was the most effective treatment at preserving the fruit firmness, whereas TMJ3 (7.5 µM L⁻¹) was the best treatment at improving the internal quality characteristics, such as total soluble solids, sugar–acid ratio, phenolics, flavonoids, flavonols, and antioxidant activity. Reduction in titratable acidity and a subsequent increase in sugar-to-acid ratio indicated a better maturation behavior and flavor profile of the fruit. The augmented retention of bioactive compounds implies the stimulation of secondary metabolite pathways and stress tolerance. The results suggest that nanoemulsion delivery of methyl jasmonate and NAA by sonication is an efficient method of enhancing the quality of the postharvest and prolonging the shelf life of Tango mandarin. Full article

DNA-binding with one finger (Dof) transcription factors are plant-specific regulators of growth, development, and stress responses. Despite extensive characterization in various species, Dof genes in flax (Linum usitatissimum L.), an important oil and fiber crop, remain largely uncharacterized. Through genome-wide identification and comprehensive characterization of the Dof gene family in flax, this study identified 47 LuDof genes in the high-oil Longya-10 variety, distributed non-uniformly across 15 chromosomes. Phylogenetic analysis grouped these genes into 12 distinct clusters, reflecting evolutionary conservation and lineage-specific characteristics, including the absence of LuDof members in Group XII. Gene structure and conserved motif analyses revealed strong structural conservation, particularly within the canonical zf-Dof domain. Segmental duplication was identified as the primary driver of LuDof family expansion, with all paralogous pairs evolving under strong purifying selection. Collinearity analysis revealed that 80.9% of LuDof genes have homologs in other species, highlighting strong evolutionary conservation. Promoter analysis identified multiple hormone- and stress-responsive elements, and qRT-PCR under drought, heat, cold, and methyl jasmonate (MeJA) treatments confirmed their roles in environmental stress responses. Transcriptome profiling indicated their involvement in stem and capsule development. This study represents the first systematic characterization of the evolution, structure, and functional potential of the flax Dof gene family, establishing a foundation for functional studies and for developing genetically superior, stress-tolerant flax varieties. Full article

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. Full article

Jacalin-related lectins play crucial roles in plant adaptation to abiotic and biotic stresses. The rice genome encodes four putative jacalin-related lectin kinase genes (OsJacLKs), but their functions toward environmental stresses remain largely uncharacterized. This study demonstrates that a putative jacalin-related lectin kinase, OsJacLK1, conferred resistance to the rice blast fungus Magnaporthe oryzae rather than salt stress. OsJacLK1 protein exhibited agglutination activities and affinity toward chitin, fungal cell wall, and mannose. OsJacLK1 was transcriptionally activated by stress-related phytohormones salicylic acid (SA), methyl jasmonate (MeJA), abscisic acid (ABA), and indoleacetic acid (IAA), as well as salinity, chitin, and M. oryzae inoculation, suggesting its involvement in broad stress-responsive signaling pathways. Overexpression of OsJacLK1 in rice led to reduced susceptibility to rice blast disease, whereas loss-of-function osjaclk1 lines showed no significant phenotypic difference from wild-type plants upon infection. Enhanced resistance in OsJacLK1-overexpressing lines was associated with a stronger reactive oxygen species (ROS) burst and elevated hydrogen peroxide accumulation, accompanied by the up-regulation of defense-related genes (OsRac1, OsSGT1, OsMAPK6, OsPAL1, OsNAC4, OsPBZ1, OsAOS2, and OsJAZ8). Collectively, our findings establish that OsJacLK1 acts as a positive regulator of rice immunity against M. oryzae, modulating the cellular redox state, highlighting its potential as a candidate for genetic improvement of disease resistance in rice. Full article

Acibenzolar-S-methyl (ASM), a salicylic acid (SA) analog, and jasmonic acid (JA) are chemical inducers of plant defenses, yet crosstalk between SA- and JA-associated pathways may result in antagonistic outcomes. Here, we assessed how ASM and JA, applied alone or in combination, are associated with rice blast severity and defense-related responses in an upland rice cultivar. Plants of rice (Oryza sativa L., cv. Primavera) were treated with JA, ASM or JA + ASM and subsequently challenged with Magnaporthe oryzae. ASM treatment was associated with reduced leaf blast severity (LBS), whereas JA treatment was associated with increased LBS. Antagonistic outcomes were observed in the combined treatment: LBS in JA + ASM plants was higher than in ASM-treated plants but lower than in JA-treated plants. Lipoxygenase (LOX) activity was induced by JA and positively correlated with LBS, indicating that higher LOX activity aligned with greater susceptibility under the tested conditions. In contrast, ASM-treated plants showed higher peroxidase (POX) activity, which was associated with lower LBS. Disease outcomes were also linked to secondary defense metabolism and phenylpropanoid-related components, including phenylalanine ammonia-lyase (PAL), salicylic acid (SA) and phenolic compounds (PC). Overall, these results provide an integrated biochemical profile of how ASM, JA and their combination are associated with contrasting blast outcomes in upland rice, consistent with antagonistic interactions between JA- and SA-associated defense responses. These findings may inform the use of defense inducers and the interpretation of defense markers in upland rice systems where blast management is a major constraint. Full article

Epigenetic regulation plays a central role in modulating plant immune responses and interactions with beneficial microbes. In this study, we investigated the contribution of RNA-directed DNA methylation (RdDM) components—DCL3; AGO9; DCL1; and the de novo DNA methyltransferases CMT3, DRM1, and DRM2—to the interaction between Arabidopsis thaliana, Trichoderma atroviride, and foliar pathogens. We show that DCL3 and AGO9 differentially regulate basal and inducible immunity, negatively affecting resistance to the necrotrophic fungus Botrytis cinerea, while promoting defense against the hemibiotrophic bacterium Pseudomonas syringae pv. tomato DC3000. Transcriptional analyses revealed that RdDM components modulate the balance between jasmonic acid/ethylene (JA/ET) and salicylic acid (SA) signaling pathways, influencing the amplitude and coordination of defense responses. In addition, DCL3 and DCL1 appear to be required for the full expression of T. atroviride-mediated systemic resistance, whereas AGO9 and DNA methyltransferases contribute to efficient root colonization. Notably, mutants in these pathways displayed enhanced basal resistance but impaired responsiveness to beneficial microbial signals, revealing a trade-off between constitutive defense activation and inducible systemic protection. Consistent with this, alterations in RdDM components were also associated with changes in plant growth dynamics under specific conditions, supporting a role for epigenetic regulation in coordinating growth–defense trade-offs. Together, our findings support a model in which epigenetic regulation controls defense responsiveness, enabling plants to balance immune activation, growth and compatibility toward beneficial microbes. Full article

Caladium bicolor is an important ornamental foliage plant; however, its tropical origin makes it highly sensitive to environmental stresses such as drought and low temperature, which limits its cultivation and industrial development. Basic helix–loop–helix (bHLH) transcription factors play key roles in plant responses to abiotic stresses, but their functions in C. bicolor remain largely unknown. Here, a bHLH transcription factor gene, CbbHLH35, was cloned from C. bicolor, and its sequence characteristics, subcellular localization, expression patterns, and potential roles in stress responses were analyzed. The results showed that CbbHLH35 contains a conserved bHLH domain and is localized in the nucleus. qRT-PCR analysis revealed that CbbHLH35 is expressed in different tissues, with the highest expression in tubers, and is significantly induced by methyl jasmonate (MeJA), abscisic acid (ABA), drought, and low-temperature treatments. Transgenic C. bicolor plants overexpressing CbbHLH35 were generated and subjected to drought and cold stress. Compared with control plants, the overexpression lines showed higher chlorophyll content and POD activity but lower electrolyte leakage and MDA content, indicating enhanced drought and cold tolerance. These results suggest that CbbHLH35 plays a positive role in regulating drought and cold tolerance in C. bicolor and represents a promising candidate gene for the molecular breeding of stress-resistant cultivars. Full article

Background/Objectives: The Arabidopsis thaliana GDS1 (Growth, Development and Splicing 1) gene has recently been identified as a key regulator linking nitrate signaling to leaf senescence. However, a systematic analysis of the GDS1 gene family in maize (Zea mays L.) is lacking. This study aims to identify and characterize the ZmGDS1 gene family in maize, providing a foundation for functional studies on their roles in growth, development, and low-nitrogen-induced leaf senescence. Methods: Putative ZmGDS1 family members were identified by searching the maize B73 reference genome using BLASTP (version 2.11.0+) and HMMER (version 3.4), with the Arabidopsis GDS1 protein sequence as the query. Candidate sequences were verified for the presence of the conserved zf-CCCH domain using NCBI CD-Search and SMART. Phylogenetic relationships, gene structures, conserved motifs, chromosomal distribution, collinearity, and promoter cis elements were comprehensively analyzed using MEGA 11, TBtools (version 1.098), MEME (version 5.5.9), and PlantCARE. Phylogenetic trees were constructed using the maximum likelihood (ML) method with the LG+G+I model and 1000 bootstrap replicates. Results: Thirteen ZmGDS1 genes were identified, distributed unevenly across eight maize chromosomes. Phylogenetic analysis classified the ZmGDS1 proteins into four distinct groups (A–D), revealing a lineage-specific expansion in group D. While all members contained the conserved zf-CCCH domain, their motif compositions varied considerably; ZmGDS1.1 exhibited the most complex structure, whereas ZmGDS1.12 had the most simplified. Subcellular localization predictions indicated that most ZmGDS1 proteins are targeted to the nucleus, consistent with a potential role as transcription factors. Promoter analysis revealed an abundance of cis elements associated with light response, hormone signaling (methyl jasmonate, abscisic acid, auxin), and stress responses. Notably, phylogenetically related genes tended to share similar cis-element profiles. Conclusions: This genome-wide analysis provides the first characterization of the ZmGDS1 gene family in maize. The observed structural conservation and diversity, together with regulatory elements linked to senescence-associated signals, support the hypothesis that ZmGDS1 genes may contribute to leaf senescence, particularly under low-nitrogen conditions. These findings provide a basis for future functional validation studies. Full article

Background: Wild jujube (Ziziphus jujuba var. spinosa) exhibits remarkable tolerance to saline-alkali stress, yet its molecular mechanisms remain poorly understood. 3-ketoacyl-CoA synthase (KCS) is a key enzyme involved in the biosynthesis of very-long-chain fatty acids (VLCFAs), which constitute pivotal precursors for membrane lipids involved in stress adaptation. Methods: Through genome-wide analysis and molecular biology techniques, 20 ZjKCS genes were identified. Results: The ZjKCS genes were grouped into nine subfamilies, exhibiting highly conserved gene structures, motifs, and functional domains within each subfamily. Two pairs of collinear gene pairs were identified, with the ZjKCS12-ZjKCS18 pair retaining core conserved functions despite intense purifying selection. ZjKCS genes are rich in cis-acting elements associated with light transduction, phytohormone responses, and abiotic stress adaptation. Tissue-specific expression patterns of ZjKCS under light, ABA (abscisic acid), and MeJA (methyl jasmonate) treatments were analyzed by quantitative real-time PCR (qRT-PCR). Under saline-alkali stress, ZjKCS genes were significantly upregulated, with most showing strong sustained induction during later treatment stages. Conclusions: These findings indicate that the ZjKCS family participates in saline-alkali stress and abiotic stress adaptation, potentially by enhancing VLCFA synthesis to reinforce and remodel membrane lipid structure. This study provides a foundation for elucidating lipid-mediated stress resistance mechanisms in stress-tolerant fruit trees. Full article

Background: Protein phosphatase 2Cs (PP2Cs) constitutes the largest phosphatase family in plants, playing a pivotal role in signal transduction. Within this family, the PP2C.D subfamily exerts significant influence on cell elongation and stress adaptation by mediating the ‘SAUR-PP2C.D-H+-ATPase’ regulatory module in the auxin signaling pathway. In rice, OsPP2C61 is a PP2C member whose molecular features and potential regulatory context remain unclear. Methods: Our study conducted a preliminary characterization of OsPP2C61 through integrated bioinformatics analysis, spatiotemporal expression profiling, and subcellular localization experiments in tobacco leaf cell. Results: OsPP2C61 encodes a 377-amino-acid protein predicted to be hydrophilic, basic, and structurally unstable. Secondary-structure prediction identified three major elements with random coils as the predominant component, whereas 3D modeling indicated alternating α-helices and β-sheets consistent with a canonical PP2C fold. Phylogenetic inference placed OsPP2C61 within the PP2C.D clade and revealed conserved motifs shared with OsPP2C25, OsPP2C28, and OsPP2C39. Promoter analysis showed enrichment of abscisic acid (ABA)- and methyl jasmonate (MeJA)-responsive elements along with multiple stress-related cis-regulatory motifs. Spatiotemporal expression analysis showed that OsPP2C61 is highly expressed in roots. Subcellular localization assays further demonstrated that the OsPP2C61-GFP fusion protein localizes to the nucleus and the plasma membrane when transiently expressed in epidermal cells of Nicotiana benthamiana. Conclusions: This work delivers the first comprehensive characterization of OsPP2C61, establishing a foundation for mechanistic studies and positioning OsPP2C61 as a candidate gene for rice improvement. Full article

The diamondback moth (Plutella xylostella) severely threatens global oilseed rape (Brassica napus L.) production. This study demonstrates that CRISPR/Cas9-mediated knockout of two homologous BnaFAH, involved in tyrosine degradation, confers enhanced Brassica napus resistance to Plutella xylostella under a 2-day short-day (SD2) photoperiod. Multi-omics analyses revealed that this resistance is associated with a coordinated response: BnaFAH deficiency triggers reactive oxygen species (ROS) accumulation, which is closely associated with activating the jasmonic acid (JA) biosynthetic and signaling pathways. This led to significant upregulation of key JA biosynthetic genes and accumulation of JA, its precursors (OPDA, OPC-4, and OPC-6), and bioactive conjugates (JA-Ile and JA-Phe). Pharmacological analyses support the central role of JA, as exogenous application of methyl jasmonate (MeJA) enhanced insect resistance, whereas the JA biosynthesis inhibitor DIECA suppressed resistance. Scavenging ROS with sodium selenite prevented both JA pathway upregulation and insect resistance, suggesting that ROS may act upstream to activate the JA biosynthetic and signaling pathways. These findings support a previously unrecognized “photoperiod-dependent ROS-JA” defense module, revealing how metabolic perturbation under specific environmental cues can be co-opted to enhance plant immunity, offering new targets for breeding resistant rapeseed varieties. Full article

Yellow pitahaya (Selenicereus megalanthus Haw.) is increasing in popularity and is considered to be an exotic fruit with great potential for consumption due to its content of both nutritive and bioactive compounds with health-related properties. Pitahaya plants, grown in Ecuador, were treated with two elicitors: methyl jasmonate (MeJA) and methyl salicylate (MeSA), both at a 0.1 mM concentration. After harvesting, the fruits were transported to Spain and stored at two temperatures, 2 and 10 °C, for 55 days. The analytical determinations were physiological parameters (ethylene and respiration rates), organoleptic traits [firmness, color, total soluble solids (TSSs) and total acidity (TA)], and phytonutrients (total phenolics, carotenoids and total antioxidant activity). The results show that all the parameters evolved more rapidly at 10 °C than at 2 °C, which is due to storage temperature effects on fruit metabolism. For TSSs, reductions were observed at the two temperatures, while, for TA, a major reduction was obtained at 2 °C. Regarding storage, the respiration rates increased, especially at 2 °C. At the end of storage, total phenolics were higher in treated pitahayas. Moreover, fruits developed chilling injury (CI) at 2 °C based on the highest respiration rate and accelerated softening. Collectively, all the data suggest that both MeJA and MeSA could modulate yellow pitahaya ripening without detrimental effects on quality during postharvest storage. Full article