Search Results (575)

Root-knot nematodes (RKNs; Meloidogyne spp.) are among the most destructive plant parasites, causing severe yield losses in diverse crops. Reactive oxygen species (ROS), particularly superoxide radicals (O₂•⁻) and hydrogen peroxide (H₂O₂), are central regulators of plant–RKN interactions. This review synthesizes current molecular, biochemical, genetic, transcriptomic, and translational evidence showing that the outcome of infection is determined by the spatiotemporal regulation of H₂O₂ rather than by ROS abundance alone. In resistant interactions, nematode perception activates PTI-associated signaling through selected cell-surface receptor complexes, including some BAK1/SERK3-associated pathways, together with BIK1, Ca²⁺ signaling, and RBOHD/F, generating a sustained oxidative activity associated with salicylic acid-dependent immune signaling and reduced H₂O₂-scavenging capacity and coupled to hypersensitive response, lignin and callose deposition, and feeding site restriction. In susceptible interactions, RKNs deploy ROS-targeting effectors such as Mi-CRT, MjTTL5, CATLe, Mj-NEROSs, and CMII to suppress ROS production, enhance antioxidant scavenging, or weaken SA-dependent defense. Evidence from a cyst-nematode system suggests that RBOH-derived ROS can restrict excessive cell death around syncytia; whether an analogous lower-redox requirement exists in RKN-induced giant cells remains unresolved. Finally, redox-based strategies, including CRISPR/Cas editing, host-induced gene silencing, chemical priming, and biocontrol, are discussed as promising approaches for durable and sustainable nematode resistance. Full article

Hydrogen peroxide (H₂O₂) is a key reactive oxygen species involved in both cellular signaling and oxidative stress, making its reliable detection essential in biological and environmental systems. Electrochemical sensing has emerged as a promising approach for H₂O₂ monitoring due to its high sensitivity, rapid response, and suitability for in situ analysis. This review provides a comprehensive overview of nanostructured metal oxide electrodes for non-enzymatic electrochemical detection of H₂O₂. The effects of material composition, nanostructure morphology, and synthesis strategies (particularly hydrothermal methods) on sensor performance are critically discussed. Special attention is given to our previously reported studies, enabling a consistent comparison of structure–property relationships under similar experimental conditions. Furthermore, the application of these sensors in plant stress analysis is examined, including both the monitoring of oxidative stress and the evaluation of stress mitigation strategies using metal oxide nanoparticles. The role of nanoparticles as reactive oxygen species scavengers and enhancers of plant antioxidant systems is highlighted, demonstrating their ability to reduce H₂O₂ levels and improve plant physiological status under adverse environmental conditions. Overall, this work emphasizes the dual functionality of nanostructured materials as both sensing platforms and active agents for stress mitigation, highlighting their potential in agricultural and environmental applications. Full article

Septic shock is a life-threatening manifestation of sepsis characterized by dysregulated immune responses, excessive inflammation, oxidative stress, and progressive multi-organ dysfunction. Despite advances in antimicrobial therapy and supportive care, mortality remains high, highlighting the need for therapeutic strategies that target immune dysregulation in addition to infection control. The review evaluates the potential of hollow nanoparticles as immunomodulatory therapies for septic shock, focusing on lipid-based, polymeric, protein-based, biomimetic, inorganic, carbon-based, and hybrid nanoparticle platforms. Current evidence suggests that these systems can modulate key pathological processes through reactive oxygen and nitrogen species (RONS) scavenging, regulation of inflammatory signaling, macrophage modulation, neutralization of bacterial toxins and antigens, and, in some cases, direct antimicrobial activity. Among the available platforms, lipid-based and biomimetic nanoparticles appear to possess the greatest translational potential owing to their favorable immunomodulatory properties and improved biocompatibility. Nonetheless, several challenges continue to limit clinical translation, including nanoparticle-associated systemic and organ toxicity, unintended immunogenicity, limited long-term safety data, and the lack of standardized comparative studies across nanoparticle classes. Despite these limitations, the progression of VBI-S, a phospholipid nanoparticle formulation, to Phase III clinical evaluation highlights the growing clinical feasibility of such nanoparticle-based approaches for septic shock. Future research should focus on optimizing nanoparticle design, improving safety profiles, and establishing standardized preclinical and clinical evaluation frameworks. Collectively, the available evidence suggests that hollow nanoparticles represent a promising antibiotic-independent strategy for restoring immune homeostasis and improving outcomes in septic shock. Full article

Bacterial infections and excessive reactive oxygen species (ROS) severely impede wound healing. However, traditional hydrogels often lack the integrated antibacterial and antioxidant properties required for effective treatment. To overcome these limitations, a natural thioctic acid (TA)-based multifunctional composite hydrogel (PTA-Arg/SAS) was developed. Arginine (Arg) served as a green inducer for the aqueous ring-opening polymerization of TA. Concurrently, salicylic acid-grafted sericin (SAS) was introduced to inhibit poly(thioctic acid) (PTA) depolymerization via the formation of stable sulfur-aryl (S-Ar) bonds. The hydrogel exhibits self-healing capability, injectability, and robust tissue adhesion to porcine skin (1877 Pa dry; 1663 Pa wet). Furthermore, SAS endowed the system with potent antibacterial (99.1% against E. coli, 97% against S. aureus) and antioxidant activities (98.2% ABTS and 72.7% DPPH radical scavenging rates). In vitro evaluations confirmed the viability of L929 cells (>98% over 3 days) and a negligible hemolysis ratio (<5%). Consequently, this study provides a strategy for fabricating next-generation bioactive dressings for complex wound management. Full article

Daidzein is a naturally occurring isoflavone phytoestrogen, mainly found in leguminous plants. This component exerts anti-inflammatory effects by regulating inflammatory cells via multiple targets, blocking core inflammatory pathways, and inhibiting the release of inflammatory factors. It also scavenges reactive oxygen species, activates the antioxidant enzyme system, and regulates antioxidant signaling pathways to achieve antioxidant effects. By regulating these two core pathological processes, it exerts protective effects in diseases such as cancer, cardiovascular disease, and acute kidney injury, based on preclinical evidence. The development of nanodelivery systems has effectively improved the physicochemical properties of daidzein, enhanced its bioavailability, and enabled disease-targeted delivery. Most previous reviews have either focused exclusively on daidzein or broadly covered the pharmacological activities of isoflavones, yet have largely overlooked the dual anti-inflammatory and antioxidant mechanisms specific to daidzein. This review summarizes these mechanisms and their preclinical effects on various diseases, including cancer, cardiovascular diseases, and acute kidney injury. It also reviews the pharmacokinetic limitations of daidzein and recent progress in nanodelivery strategies aimed at enhancing its bioavailability and bioactivity. Overall, this review serves as a reference for the future standardized comparison of nanocarriers, targeted therapies, and clinical applications. Full article

Grapevine downy mildew, caused by the oomycete pathogen Plasmopara viticola (P. viticola), is one of the most devastating diseases threatening the global grape industry. The pathogen invades host plants through stomata, triggering a series of highly coordinated physiological disorders and biochemical defense events. This review systematically summarizes the dynamic changes in morphological structures (stomatal characteristics), physiological functions (photosynthesis, membrane system integrity, and carbon metabolism), and multi-level biochemical defense systems (reactive oxygen species (ROS) scavenging enzyme system, phenylpropanoid metabolic pathway, pathogenesis-related proteins, and phenolic compounds) in grapevines following infection. It focuses on analyzing the differences in the timing, intensity, and metabolic reprogramming of defense responses between resistant and susceptible cultivars, pointing out that the essence of disease resistance lies in early pathogen recognition and rapid defense induction. The conflicting conclusions regarding indicators such as soluble sugars, peroxidase (POD), and superoxide dismutase (SOD) are discussed from the perspectives of experimental systems, cultivar genetic backgrounds, and pathogen physiological race differences. Furthermore, the known physiological and biochemical alterations are linked to upstream signaling pathways, including salicylic acid and jasmonic acid (SA/JA), calcium signaling, and mitogen-activated protein kinase (MAPK) cascades. Recent advances in revealing resistance mechanisms in the omics era are also introduced. Finally, future research directions are proposed, including constructing multi-indicator dynamic evaluation models, verifying key gene functions using gene editing, exploring the potential of epigenetic regulation, and developing integrated control strategies combined with microbiome research. This review aims to provide theoretical support for grapevine downy mildew resistance breeding and sustainable disease management. Full article

Salinity stress severely inhibits crop growth and reduces yield. Exogenous selenium (Se) enhances plant abiotic stress tolerance, but how different selenium forms exert their impacts and pathways in mitigating salinity remains ambiguous. Under salt stress, this work compared two Se forms, selenate [Se(VI)] and selenite [Se(IV)], regarding their impacts on development, photosynthetic performance, antioxidative system, osmotic regulators, Se buildup, and stress-related gene expression in Nicotiana tabacum L. Both Se species significantly promoted tobacco growth. (1) Under 150 mmol/L NaCl stress, biomass, net photosynthetic rate and antioxidant enzyme activities decreased significantly, while soluble sugar, free proline, Na⁺/K⁺, Na⁺/Ca²⁺, H₂O₂, MDA contents and NtROS2a, NtLEA5 expression increased significantly. (2) Exogenous Se increased biomass, photosynthetic parameters; antioxidant enzyme activities and NtNAC2, NtCDPK12, NtROS2a expression; elevated Se deposition in roots and leaves; and reduced oxidative damage, ion imbalance and NtLEA5 expression in salt-stressed tobacco, suggesting that Se may improve salt tolerance by regulating these physiological processes and stress-related gene expression. (3) Compared with Se(IV), Se(VI) significantly increased root length, chlorophyll content, stomatal conductance, K⁺ content, SOD/CAT activities, leaf and root Se accumulation as well as and NtNAC2, NtCDPK12 expression, while Se(IV) resulted in higher root diameter, free proline content, Na⁺/K⁺ ratio and NtROS2a expression. In conclusion, both sodium selenate and sodium selenite effectively enhanced tobacco salt tolerance. The salt stress alleviation effect of Se(VI) may be associated with upregulating NtNAC2 and NtCDPK12 to improve antioxidant capacity and photosynthesis, thereby potentially maintaining cell membrane integrity and ion balance, while Se(IV) may exert its effect through upregulating NtROS2a to promote root thickening, reactive oxygen species scavenging and osmotic adjustment. At the tested concentrations, selenate was more effective. Full article

Copper is an essential trace element for plant growth; however, in excessive amounts, it can cause severe toxicity by inducing bursts of reactive oxygen species and disrupting metabolic balance. As a root-based medicinal plant and food, Platycodon grandiflorus has its roots in direct contact with the soil. Its ability to accumulate copper is the most pronounced among various heavy metals; consequently, it is particularly susceptible to copper stress, which in turn affects its normal growth and medicinal quality. This paper focuses on the intrinsic stress potential and possible response pathways of Platycodon grandiflorus to copper stress. Drawing on existing research and relevant literature, it conducts an integrated analysis of its defence mechanisms across four levels: physical barriers, non-enzymatic antioxidants, conserved physiological and biochemical pathways, and transcriptional regulation. Regarding physical barriers, the cell wall forms the first line of defence through pectin adsorption and lignin deposition; in terms of endogenous antioxidant defence, secondary metabolites such as polysaccharides and saponins can directly participate in the scavenging of reactive oxygen species; regarding conserved pathways, the glutathione–phytochelate system acts in concert with antioxidant enzymes such as SOD and CAT to participate in copper ion chelation and the alleviation of oxidative stress, with hormone signalling regulation also playing a crucial coordinating role in this process; regarding transcriptional regulation, transcription factors such as PgWRKY may mediate the perception of stress signals and the expression of downstream genes. These pathways act in a coordinated and sequential manner, collectively forming a multi-level defence network through which Platycodon grandiflorus responds to copper stress. At the same time, this paper highlights the functional limitations of this defence system, summarises the shortcomings in current research, and proposes directions for future studies, with a view to guiding the safe cultivation and quality assurance of Platycodon grandiflorus in copper-polluted areas, as well as for the breeding of heavy-metal-tolerant medicinal plants. Full article

Many rhizobia use quorum sensing (QS) systems to detect their population density and modify their symbiotic behavior with the legume host. There are three LuxRI-type QS systems in Rhizobium etli CFN42, and CinR plays a key role in symbiotic performance. However, the details of how CinR regulates the symbiotic process remain unknown. In this study, we employed the RNA-Seq method to screen differentially expressed genes between the wild-type strain and the ΔcinR mutant of R. etli CFN42. We found that most of the genes related to reactive oxygen species (ROS) were expressed at lower levels in the ΔcinR mutant than in CFN42. We also found that the ΔcinR mutant was more sensitive to H₂O₂ than to CFN42. We then showed that CinR positively regulated katG expression and possessed an affinity to bind the katG promoter in the absence of the AHL ligand. The addition of AHLs promoted CinR binding to the katG promoter and enhanced katG expression. Accumulation of H₂O₂ and O₂^•− was observed in root nodules formed by the ΔcinR mutant. Crucially, katG overexpression rescued the H₂O₂-sensitive phenotype in vitro and partially restored defective symbiotic performance in nodules formed by the ΔcinR mutant on the common bean. These results suggest that CinR globally regulates ROS scavenging gene expression in order to balance oxidative stress within root nodules, promoting nitrogenase activity of R. etli CFN42. Full article

Intervertebral disk degeneration (IVDD) is widely recognized as a major contributor to discogenic low back pain (LBP), imposing a substantial burden on global public health and socioeconomic systems. Growing evidence confirms that disrupted redox homeostasis, excessive reactive oxygen species (ROS) accumulation, and oxidative stress act as major convergent mechanisms that propagate inflammatory cascades, nucleus pulposus cell dysfunction, and extracellular matrix degradation. Although conventional conservative therapies and surgical interventions are clinically effective in relieving macrostructural compression, they remain limited in resolving localized molecular dysregulation. In recent years, nanotechnology has emerged as a promising strategy for overcoming the limitations of traditional therapy for IVDD. This review provides an analysis of four categories of antioxidant nanotherapies for IVDD, including inorganic functional nanozymes, bioactive nanomaterials, stimuli-responsive nanosystems, and nanocomposite scaffolds. We elaborate on their mechanisms in scavenging excessive ROS, restoring redox equilibrium, protecting mitochondrial function, and ameliorating oxidative stress-induced degeneration. Integrating structural biomimicry with microenvironmental responsiveness enables the engineering of composite nanosystems with multi-pathway ROS-scavenging capabilities. Therefore, these platforms emerge as promising therapeutic strategies for arresting IVDD progression. Finally, we discuss the key obstacles to clinical translation. Overall, this review provides insights into the development of redox-targeted therapies. Full article

Ubiquitous environmental endocrine-disrupting chemicals (EDCs), including bisphenols, phthalates, and heavy metals, pose a severe and persistent threat to mammalian reproductive health worldwide. Oxidative stress acts as the pivotal mediator which drives epigenetic dysregulation in germ cells upon EDC exposure, including aberrant DNA methylation, abnormal histone post-translational modifications and dysregulated non-coding RNA networks. EDC-induced oxidative stress damages endogenous antioxidant defense systems and inactivates key epigenetic regulators, forming a self-reinforcing cycle of redox imbalance and epigenetic dysregulation, which ultimately leads to impaired gametogenesis, reduced fertility, and transgenerational reproductive abnormalities. This review summarizes current evidence indicating that multiple antioxidants, including melatonin, vitamin C, resveratrol, and epigallocatechin gallate, alleviate EDC-induced reproductive toxicity by targeting epigenetic dysregulation. Their protective effects encompass scavenging excessive reactive oxygen species, activating endogenous antioxidant signaling cascades, restoring activity of epigenetic enzymes, and rectifying aberrant histone modification profiles, contributing to the maintenance of epigenetic homeostasis in germ cells. This review clarifies the intrinsic mechanistic link among EDC exposure, oxidative stress, epigenetic dysregulation and reproductive toxicity, which provides a theoretical basis for formulating reproductive health protection strategies against EDC exposure and guides the exploration of clinical epigenetic biomarkers. Full article

Diabetic foot ulceration is a severe and common chronic complication of diabetes, accompanied by excessive reactive oxygen species (ROS) accumulation, persistent bacterial infection, prolonged inflammation, and insufficient angiogenesis. Traditional single-function wound dressings fail to simultaneously resolve these pathological barriers, leading to unsatisfactory healing outcomes. In this study, we developed a multifunctional composite hydrogel (E/MGel) by introducing mussel adhesive protein (MAP) into methacrylated hyaluronic acid (mHA) to construct an antibacterial and antioxidant delivery system, which was further loaded with epidermal growth factor (EGF) to promote angiogenesis. The as-prepared E/MGel exhibited a uniform porous structure, favorable rheology, high swelling ratio, and sustained protein release behavior. In vitro results demonstrated that E/MGel exerted potent antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E.coli), high ROS scavenging efficiency, good cytocompatibility, and remarkable pro-angiogenic effect on endothelial cells. In a mouse model of diabetic MRSA-infected full-thickness skin defect, E/MGel significantly accelerated wound closure, reduced bacterial burden, downregulated pro-inflammatory cytokines, promoted collagen deposition, and enhanced neovascularization. Meanwhile, no obvious systemic toxicity was observed. Taken together, this multifunctional hydrogel integrates antibacterial, antioxidant, and pro-angiogenic capacities to break the pathological vicious cycle of diabetic wounds, providing a promising and safe strategy for the clinical treatment of diabetic infected wounds. Full article

Background/Objectives: Sunflower (Helianthus annuus L.) is one of the four major oil crops worldwide and possesses strong stress tolerance. However, salt stress remains limiting in the improvement of sunflower yield and quality. Methods: In this study, the salt-tolerant cultivar P50 and salt-sensitive cultivar P29 were used as experimental materials to conduct transcriptome sequencing on root and leaf samples treated with NaCl. Subsequently, the molecular mechanisms underlying salt tolerance in sunflower were revealed through assembly and splicing, functional annotation, differential expression analysis, enrichment analysis, and transcription factors (TFs) prediction. Results: Results showed that 54,860,184 and 60,601,572 high-quality clean reads were obtained from the two cultivars, respectively. A total of 110,751 all-unigenes were generated after assembly and clustering, of which 77,536 were functionally annotated. A total of 21,332 differentially expressed genes (DEGs) were identified, including 10,306 upregulated and 11,026 downregulated genes. Quantitative real-time PCR validation of 15 DEGs showed a 93.33% consistency rate with the sequencing data. GO enrichment analysis indicated that DEGs were significantly enriched in pathways related to antioxidant enzyme activities. KEGG enrichment analysis demonstrated that DEGs were primarily involved in 15 carbohydrate metabolism pathways, especially starch and sucrose metabolism. In addition, 67 differentially expressed TF families containing 528 DEGs were identified, including bHLH, AP2/ERF-ERF, MYB, C3H, WRKY, EREBP, B3-ARF, and NAC. Conclusions: Our study constructed a comprehensive transcription map of the sunflower response to salt stress and systematically elucidated the molecular mechanisms underlying salt tolerance. The salt-tolerant sunflower cultivar P50 exhibits an efficient salt stress defense system via three core strategies: (i) activating the antioxidant system to rapidly scavenge excess reactive oxygen species and mitigate oxidative damage; (ii) regulating carbohydrate metabolism through starch and sucrose redistribution to provide energy and osmotic protection against physiological drought; and (iii) mobilizing multiple TF families to establish a complex regulatory network for the precise control of downstream functional genes. Full article

Xanthophylls are oxygenated carotenoids widely distributed in photosynthetic microorganisms, plants, algae, and certain invertebrates, where they function as key photoprotective and antioxidant pigments. Among them, xanthophylls containing vicinal 1,2-diol moieties exhibit unique chemical reactivity that enables reversible coordination with boron species naturally present in marine and terrestrial environments. The formation of cyclic borate esters between boron and diol-containing xanthophylls induces structural and electronic modifications that may enhance pigment stability and functional performance. Emerging evidence suggests that boron–xanthophyll complexes display improved resistance to photooxidative degradation, enhanced singlet oxygen quenching capacity, and increased radical-scavenging activity compared with their uncomplexed counterparts. In addition, boron coordination can influence molecular conformation, polarity, and supramolecular organization within lipid bilayers, thereby promoting membrane stabilization under conditions of high light exposure and oxidative stress. Together, these effects indicate a cooperative role of boron complexation in amplifying the intrinsic photoprotective and antioxidant properties of xanthophylls. A deeper understanding of the structural basis and biological implications of boron–xanthophyll interactions may provide new insights into adaptive stress tolerance in marine and photosynthetic organisms, as well as guide the development of advanced photoprotective systems for biomedical and technological applications. Full article

Oxidative stress, caused by the excessive production of reactive oxygen and nitrogen species, contributes to cellular damage and chronic diseases. Fermented foods are increasingly recognized for their antioxidant properties, which are strongly influenced by microbial metabolism during fermentation. This review examines three major microbial mechanisms involved in antioxidant enhancement in fermented foods: exopolysaccharide (EPS) production, release of matrix-bound bioactive compounds, and microbial modulation of redox conditions. Microbial EPS contribute through radical scavenging and metal chelation, while microbial enzymes increase the bioavailability of phenolic compounds, peptides, and other antioxidant molecules. In addition, microbial metabolic activity influences the redox environment of fermented systems through electron-transfer processes and reducing metabolites. By integrating these complementary mechanisms, this review provides a comprehensive framework linking microbial biotransformation and redox modulation to the antioxidant properties of fermented foods, and highlights their potential for the development of functional fermented products. Full article