Search Results (844)

In this study, an artificially simulated enhanced UV-B radiation treatment of 96 kJ/m²·d⁻¹ was applied with natural sunlight as the control. By observing changes in biological tissue damage, peroxidase (POD) enzyme activity, and hormone content, combined with transcriptome analysis and quantitative fluorescence PCR validation, this study preliminarily elucidated the physiological mechanisms of plant-specific peroxidase (POD) in responding to enhanced UV-B radiation stress. Enhanced UV-B treatment significantly inhibited biological tissue growth, particularly during the rapid growth stage. At this stage, the treatment exhibited higher malondialdehyde (MDA) content, indicating increased oxidative stress due to the accumulation of reactive oxygen species (ROS). Despite the inhibition in growth, the treatment showed improvements in the accumulation of organic nutrients as well as the contents of abscisic acid (ABA), salicylic acid (SA), and methyl jasmonate (MeJA). Additionally, an increase in POD activity and lignin content was observed in the treatment, especially during the middle period of the rapid growth period. Transcriptome analysis revealed that two POD multigene family members, LOC123198833 and LOC123225298, were significantly upregulated under enhanced UV-B radiation, which was further validated through qPCR. In general, enhanced UV-B radiation triggered a defence response in biological tissue by upregulating POD genes, which can effectively help to scavenge excess ROS. Full article

Pinus massoniana Lamb. is an economically important conifer native to China. However, it is highly susceptible to the pine wood nematode (Bursaphelenchus xylophilus, PWN), the causal agent of pine wilt disease (PWD), resulting in substantial ecological and economic losses. To elucidate potential molecular defense mechanisms, 50 NAC (NAM, ATAF1/2, and CUC2) transcription factors (PmNACs) were identified in the P. massoniana genome. Phylogenetic analysis divided these PmNACs into seven subfamilies, and motif analysis identified ten conserved motifs associated with stress responses. Twenty-three genes were selected for expression analysis in various tissues and under exogenous salicylic acid (SA), methyl jasmonate (MeJA), and PWN infection. Six genes (PmNAC1, PmNAC8, PmNAC9, PmNAC17, PmNAC18, and PmNAC20) were significantly up-regulated by both hormonal treatment and PWN infection, implying their involvement in JA/SA-mediated immune pathways. Functional characterization showed PmNAC8 is a nuclear-localized transcription factor with autoactivation activity. Furthermore, transient overexpression of PmNAC8 in Nicotiana benthamiana induced reactive oxygen species (ROS) accumulation and necrotic lesions. Collectively, these results elucidate NAC-mediated defense responses to PWN infection in P. massoniana and identify candidate genes for developing PWD-resistant pine varieties. Full article

Cutting propagation is a commonly employed technology for vegetative reproduction in agricultural, forestry, and horticultural practice. The success of cutting propagation depends on adventitious root (AR) formation—a process whereby roots regenerate from stem cuttings or leaf cuttings. In this review, we summarize the distinct stages of cutting-induced AR formation and highlight the pivotal roles of plant hormones and age in this process. Jasmonic acid (JA) acts as a master trigger for promoting AR formation, while auxin serves as the core regulator, driving AR formation. Furthermore, plant age is a crucial factor determining the regenerative competence of cuttings. Notably, age and JA collaboratively modulate auxin synthesis in cutting-induced AR formation. Overall, this review not only elucidates the molecular mechanisms underlying AR formation but also provides valuable insights for improving efficiency of cutting propagation in various plant species. Full article

The worldwide agriculture industry is facing increasing problems due to rapid population increase and increasingly unfavorable weather patterns. In order to reach the projected food production targets, which are essential for guaranteeing global food security, innovative and sustainable agricultural methods must be adopted. Conventional approaches, including traditional breeding procedures, often cannot handle the complex and simultaneous effects of biotic pressures such as pest infestations, disease attacks, and nutritional imbalances, as well as abiotic stresses including heat, salt, drought, and heavy metal toxicity. Applying phytohormonal approaches, particularly those involving hormonal crosstalk, presents a viable way to increase crop resilience in this context. Abscisic acid (ABA), gibberellins (GAs), auxin, cytokinins, salicylic acid (SA), jasmonic acid (JA), ethylene, and GA are among the plant hormones that control plant stress responses. In order to precisely respond to a range of environmental stimuli, these hormones allow plants to control gene expression, signal transduction, and physiological adaptation through intricate networks of antagonistic and constructive interactions. This review focuses on how the principal hormonal signaling pathways (in particular, ABA-ET, ABA-JA, JA-SA, and ABA-auxin) intricately interact and how they affect the plant stress response. For example, ABA-driven drought tolerance controls immunological responses and stomatal behavior through antagonistic interactions with ET and SA, while using SnRK2 kinases to activate genes that react to stress. Similarly, the transcription factor MYC2 is an essential node in ABA–JA crosstalk and mediates the integration of defense and drought signals. Plants’ complex hormonal crosstalk networks are an example of a precisely calibrated regulatory system that strikes a balance between growth and abiotic stress adaptation. ABA, JA, SA, ethylene, auxin, cytokinin, GA, and BR are examples of central nodes that interact dynamically and context-specifically to modify signal transduction, rewire gene expression, and change physiological outcomes. To engineer stress-resilient crops in the face of shifting environmental challenges, a systems-level view of these pathways is provided by a combination of enrichment analyses and STRING-based interaction mapping. These hormonal interactions are directly related to the United Nations Sustainable Development Goals (SDGs), particularly SDGs 2 (Zero Hunger), 12 (Responsible Consumption and Production), and 13 (Climate Action). This review emphasizes the potential of biotechnologies to use hormone signaling to improve agricultural performance and sustainability by uncovering the molecular foundations of hormonal crosstalk. Increasing our understanding of these pathways presents a strategic opportunity to increase crop resilience, reduce environmental degradation, and secure food systems in the face of increasing climate unpredictability. Full article

Uncaria rhynchophylla, a medicinal plant extensively used in traditional Chinese medicine, is an important plant source of terpenoid indole alkaloids (TIAs), but the mechanism of TIA biosynthesis at molecular level remains unclear. Geraniol synthase (GES) serves as a crucial enzyme in catalyzing the formation of geraniol from geranyl pyrophosphate (GPP) in various plants, but the functional characterization of the GES gene in U. rhynchophylla has not been investigated. In this study, a GES was identified and characterized through genome mining and bioinformatic analysis. Functional validation was performed via a protein catalysis experiment, transient expression in Nicotiana benthamiana, and methyl jasmonate (MeJA) induction experiments. The full-length UrGES gene was 1761 bp, encoding a protein product of 586 amino acids with an estimated 67.5 kDa molecular weight. Multiple sequence alignments and phylogenetic analysis placed UrGES within the terpene synthase g (TPS-g) subfamily, showing high similarity to known GESs from other plants. Enzymatic assays confirmed that recombinant UrGES catalyzed GPP conversion to a single product of geraniol. The transient expression of UrGES resulted in geraniol accumulation in N. benthamiana, further confirming its function in vivo. UrGES expression was observed in leaves, stems, and roots, where leaves had the highest transcript levels. Moreover, MeJA treatment significantly upregulated UrGES expression, which positively correlated with an increase in alkaloid content. This study functionally characterizes UrGES as a geraniol synthase in U. rhynchophylla, contributing to the current knowledge of the TIA biosynthetic pathway. These findings may offer insights for future metabolic engineering aiming to enhance TIA yields for pharmaceutical and industrial applications. Full article

WRKY transcription factors play key roles in plant immune responses, including resistance to fungal pathogens. In the present study, we identified a flax resistance-related gene Lus10021999, named LuWRKY39. Here, to identify the role of WRKY transcription factor in resistance of flax against Septoria linicola, we cloned and analyzed the gene LuWRKY39 via homologous cloning using bioinformatics methods and localized the encoded protein. Quantitative real-time PCR (qRT-PCR) was used to explore the response of this gene to S. linicola. The results showed that the gene that is 948 bp long exhibited the closest genetic relationship to WRKY in castor (Ricinus communis), as revealed by phylogenetic analysis, and the encoded protein was localized in the nucleus. The LuWRKY39 gene showed higher expression levels in resistant flax materials than in susceptible ones, and higher in roots and stems than in leaves. Furthermore, gene expression showed an upward trend following treatment with salicylic acid (SA) and methyl jasmonate (MeJA), indicating that LuWRKY39 is involved in the regulation of SA and JA signals. By silencing LuWRKY39 in flax using virus-induced gene silencing (VIGS), the processed plants were more sensitive to S. linicola than untreated plants. Gene expression analysis and disease index statistics confirmed that the silenced plants were more susceptible, highlighting the crucial role of LuWRKY39 in flax disease resistance. This study provides a foundation for functional investigations of WRKY genes in flax and the identification of disease resistance genes. Full article

Grafting involves complex hormonal interactions at graft interfaces that are not yet fully understood. In this study, we analyzed hormone fluctuations and gene expression during callus proliferation and vascular tissue differentiation in hickory (Carya cathayensis Sarg.) grafts. Cytokinin and ethylene precursor ACC levels steadily increased after grafting. The biosynthetic genes for these hormones (IPT3, ACS1, ACO1, and ACO5) exhibited heightened expression. Genes related to cytokinin signaling (RR3, ARR4, and ZFP5) and ethylene signaling (MKK9, ESE1, and ESE3) were similarly upregulated. Conversely, genes associated with jasmonic acid, abscisic acid, and strigolactone pathways were downregulated, including synthesis genes (AOC4 and AOS) and those involved in signal transduction (NAC3, WRKY51, and SMAX1). Correspondingly, JA-Ile and 5-deoxystrigol levels significantly decreased. Indole-3-acetic acid (IAA) levels also dropped during the early stages of graft union formation. These results suggest that low auxin concentrations may be essential in the initial stages after grafting to encourage callus proliferation, followed by an increase at later stages to facilitate vascular bundle differentiation. These findings imply that maintaining a balance between low auxin levels and elevated cytokinin and ethylene levels may be critical to support cell division and callus formation during the initial proliferation phase. Later, during the vascular differentiation phase, a gradual rise in auxin levels, accompanied by elevated ethylene, may facilitate the differentiation of vascular bundles in hickory grafts. Full article

Clubroot, caused by Plasmodiophora brassicae Woronin, poses a major threat to Chinese cabbage (Brassica rapa subsp. pekinensis) production worldwide, significantly impacting crop yield, quality, and economic value. Biological control represents a promising approach since it is non-toxic and eco-friendly, and it reduces the risk of pathogen resistance development. In this study, our objective was to screen for actinomycetes that can effectively inhibit clubroot. We screened 13 actinomycete strains, identifying 2, XDS3-6 and CD1-1, with substantial in vivo inhibitory effects, achieving infection suppression rates above 64% against P. brassicae. Phylogenetic analysis classified XDS3-6 and CD1-1 as Streptomyces virginiae and Streptomyces cinnamonensis, respectively. Both strains exhibited protease and glucanase production capabilities, essential for pathogenic suppression. Additionally, these strains induced host defense responses, as evidenced by increased jasmonic acid (JA) and salicylic acid (SA) accumulation and elevated activities of defense-related enzymes. Colonization studies of XDS3-6 and CD1-1 mutant strains in cabbage roots indicated sustained root colonization, with peak colony-forming units (CFUs) at 20 days post-inoculation, reaching 11.0 × 10⁴ CFU/g and 8.5 × 10⁴ CFU/g, respectively, and persisting for at least 30 days. Overall, these findings underscore the potential of Streptomyces strains XDS3-6 and CD1-1 as effective biocontrol agents, providing a theoretical foundation for their application in managing clubroot in Chinese cabbage. Full article

Salt stress is a major constraint to seed germination and early seedling growth in rice, affecting crop establishment and productivity. To understand the mechanisms underlying salt tolerance, we investigated two rice varieties with contrasting responses as follows: salt-tolerant sea rice 86 (SR86) and salt-sensitive P559. Germination assays under increasing NaCl concentrations (50–300 mM) revealed that 100 mM NaCl induced clear phenotypic divergence. SR86 maintained bud growth and showed enhanced root elongation under moderate salinity, while P559 exhibited significant growth inhibition. Transcriptomic profiling of buds and roots under 100 mM NaCl identified over 3724 differentially expressed genes (DEGs), with SR86 showing greater transcriptional plasticity, particularly in roots. Gene ontology enrichment revealed tissue- and genotype-specific responses. Buds showed enrichment in photosynthesis-related and redox-regulating pathways, while roots emphasized ion transport, hormonal signaling, and oxidative stress regulation. SR86 specifically activated genes related to photosystem function, DNA repair, and transmembrane ion transport, while P559 showed activation of oxidative stress-related and abscisic acid (ABA)-regulated pathways. Hormonal profiling supported transcriptomic findings as follows: both varieties showed increased gibberellin 3 (GA3) and gibberellin 4 (GA4) levels under salt stress. SR86 showed elevated auxin (IAA) and reduced jasmonic acid (JA), whereas P559 maintained stable IAA and JA levels. Ethylene precursor and salicylic acid levels declined in both varieties. ABA levels rose slightly but not significantly. These findings suggest that SR86’s superior salt tolerance results from rapid growth, robust transcriptional reprogramming, and coordinated hormonal responses. This study offers key insights into early-stage salt stress adaptation and identifies molecular targets for improving stress resilience in rice. Full article

Salinization severely impairs crop growth by inducing oxidative stress and disrupting cellular homeostasis. This study systematically investigates the synergistic effects of salt-tolerant plant-growth-promoting rhizobacteria (ST-PGPR) and foliar silicon fertilizer spraying (FSFS) on antioxidant responses in Pak choi under salt stress. Two-season pot experiments were carried out to evaluate key indicators, including antioxidant enzyme activities (superoxide dismutase: SOD; peroxidase: POD; catalase: CAT), oxidative stress (malondialdehyde: MDA), osmolyte accumulation (proline, soluble protein), and hormones (Jasmonic Acid: JA; Salicylic Acid: SA; Abscisic acid: ABA). The results demonstrate that combining ST-PGPR with FSFS significantly enhances SOD (6.18–2353.85%), POD (3.44–153.29%), and CAT (25.71–319.29%) activities while reducing MDA content (8.12–35.87%). Proline and soluble protein levels increased by 1.56–15.71% and 5.03–188.87%, respectively. Hormonal regulation increased JA, SA, and ABA levels by 1.05–31.81%, 2.09–34.29%, and 3.18–30.09%, respectively. Notably, ST-PGPR treatments at 10⁴ and 10⁶ cfu·mL⁻¹, combined with foliar silicon application, consistently ranked highest in overall antioxidant performance across both seasons based on a principal component analysis. These findings provide novel insights into microbial–mineral interactions for sustainable saline agriculture. Full article

Piriformospora indica is a beneficial endophytic fungus that promotes plant growth and root development by colonizing plant roots. In order to investigate whether P. indica could promote the growth of tissue-cultured Cerasus humilis seedlings, in this study, we co-cultivated P. indica colony segments (P+) and P. indica spore suspensions (P++) in the rooting medium, and plant biomass as well as chlorophyll and root hormone contents of ‘3-19-3’ tissue-cultured C. humilis seedlings were determined under P+, P++, and CK (without fungus inoculation) treatments. The results showed that above-ground biomass and chlorophyll content of P+-and P++-treated tissue-cultured seedlings were significantly increased, and root peroxidase (POD), indole-3-acetic-acid (IAA) content, and root activities were significantly enhanced, while jasmonic acid (JA) and 1-aminocyclopropane-1-carboxylic acid (ACC) contents were reduced. Moreover, the growth-promoting effects of P++ treatment were found to be stronger than those of P+ treatment. Our results confirmed that P. indica was able to promote the growth of tissue-cultured C. humilis seedlings and effectively promoted root development by regulating hormone content. Therefore, the application of P. indica in the production of C. humilis is promising, especially in the cultivation of elite varieties. Full article

Bisphenol A (BPA) is a widely used chemical to produce raw materials in plastic production, which has led to its ubiquity in the natural environment and toxicity to both plants and humans. In this study, we evaluated the phytotoxic effects of BPA on the growth and physiology of pepper (Capsicum annuum L.), a globally cultivated horticultural plant. Our high-performance liquid chromatography (HPLC) result revealed that 0.5 mg/kg of BPA treatment did not lead to the accumulation of BPA in the leaves and fruits of pepper plants. The exogenous application of 5 mg/kg of BPA prominently inhibited pepper growth, while 0.5 mg/kg of BPA had no obvious effects on pepper growth. Additionally, our transcriptomic assay revealed that BPA-regulated gene expression is associated with photosynthesis and reactive oxygen species (ROS) signaling. Physiological and qRT-PCR assays further demonstrated that BPA reduced chlorophyll content and increased ROS levels by regulating the expression of genes related to chlorophyll synthesis and ROS production. Our transcriptomic data also elucidated the potential role of plant hormones, including brassinolides (BR), salicylic acid (SA), jasmonic acid (JA), and strigolactone (SL) in mediating BPA-induced phytotoxicity. Furthermore, BPA activated the N⁶-methyladenosine (m⁶A) modification to exert its toxicity. Collectively, our findings offer additional insights into the mechanisms through which BPA attenuates pepper plant growth, which might contribute new knowledge toward a better scientific assessment of BPA exposure risks in horticultural species. Full article

Clubroot disease, caused by the soil-borne pathogen Plasmodiophora brassicae, poses a severe threat to the global production of Brassicaceae crops, including radish (Raphanus sativus L.). Although resistance breeding is an important method for sustainable disease management, the molecular mechanism underlying clubroot resistance remains elusive in radish compared to other Brassicaceae species. In this study, 52 radish inbred lines were screened for disease responses following P. brassicae inoculation, with the resistant line T6 and the susceptible line T14 selected for transcriptome analysis. RNA-Seq was performed at 10, 20, and 30 days post inoculation (DPI) to elucidate transcriptional responses. The susceptible line T14 exhibited a higher number of differentially expressed genes (DEGs) and persistent upregulation across all time points, indicating ineffective defense responses and metabolic hijacking by the pathogen. In contrast, the resistant line T6 displayed temporally coordinated defense activation marked by rapid induction of core immune mechanisms: enhanced plant–pathogen interaction recognition, MAPK cascade signaling, and phytohormone transduction pathways, consistent with effector-triggered immunity priming and multilayered defense orchestration. These findings indicate that resistance in T6 could be mediated by the rapid activation of multilayered defense mechanisms, including R gene-mediated recognition, MAPK-Ca²⁺-ROS signaling, and jasmonic acid (JA) pathway modulation. The outcomes of this study would not only facilitate clarifying the molecular mechanism underlying clubroot resistance, but also provide valuable resources for genetic improvement of clubroot resistance in radish. Full article

The effects of a fungal elicitor from Trichothecium roseum on signal pathways of salicylic acid (SA), jasmonic acid (JA), and Ca²⁺ in potato tubers were investigated. The results showed that fungal elicitor treatment effectively inhibited the lesion diameter of Fusarium sulphureum in vivo, which was 17.5% lower than that of the control. In addition, fungal elicitor treatment triggered an increase in O₂⁻ production and H₂O₂ content. The fungal elicitor enhanced the activities and gene expression levels of isochorismate synthase (ICS), phenylalanine ammonia lyase (PAL), allene oxide cyclase (AOC), allene oxide synthase (AOS), lipoxygenase (LOX), and Ca²⁺-ATPase. Furthermore, the fungal elicitor promoted an increase in calmodulin (CaM) content. Protective enzymes (dismutase (SOD), catalase (CAT), polyphenol oxidase (PPO), chitinase (CHI), and β-1,3-glucanase (Glu)) and disease-resistance-related genes (PR1, PR2, and PDF1.2) were induced to be upregulated by elicitor treatment. These results indicated that the fungal elicitor induced disease resistance by accelerating the accumulation of reactive oxygen species (ROS), activating SA, JA, and Ca²⁺ signaling, and upregulating resistance genes. The results of this study revealed the molecular mechanism of fungal elicitor-induced resistance in the potato, which provides a theoretical basis for the mining of new, safe, and efficient elicitor-sourced antifungal agents and is of great importance for the effective control of potato dry rot disease. Full article

Abiotic stresses are the major factors limiting grape production in the world. They significantly impede grape growth and production. However, during the grape production stage, plant growth regulators play a crucial role in regulating grape developmental progress, especially methyl jasmonate (MeJA). The exogenous MeJA participates in different crop production, gene expression, signaling transduction, natural defense, stress resistance, hormone balance, osmotic regulation, cellular metabolic process, and thermostatic regulation. Grape crop resilience to different abiotic and biotic stresses was overall fascinated by exogenous applications of MeJA. Therefore, in this review, we focus on the MeJA hormone in abiotic stress relief and discovery, application, significance, occurrence, growth via development, stress responses, interaction, molecular modulation, and biological signaling in the grape. Exogenous MeJA in abiotic stress responses explained the physiological change and the signaling pathway has emerged as one of the key plant metabolic processes vs. photosynthetic productivity, playing a substantial role in gene expression, quality parameters, fruit attribution, protein differentiation, cellular programming, and reprogramming, and tolerance mechanism. MeJA hormone has been discovered after a broader study as abiotic stress-responsive methyl jasmonate/Jasmonic acid, which could be a pivotal target not only for grape production but also for other crops. Full article