Search Results (5,421)

Given the potential hazards of enrofloxacin (ENR) residues to human health, establishing an accurate, rapid, and stable detection method is of importance. To enable the direct detection of ENR, an electrochemical sensor was constructed in this study. N- and S-doped carbon quantum dots (CQDs) with peroxidase-like activity were prepared using DL-malic acid, L-alanine, and L-cysteine as precursors and compounded with a tetrakis (4-carboxyphenyl) porphyrin (TCPP) and Fe(NO₃)₃·9H₂O to make novel N/S CQDs@Fe-TCPP composite carbon-based nanozymes to construct an electrochemical sensor, and the electrochemical behavior was investigated. Under optimal experimental conditions, the sensor exhibited a linear current response to ENR concentrations in the range of 1–1300 nM (I (μA) = 0.0106c (nM) + 2.9861, R² = 0.9962), with a calculated detection limit of 0.872 nM (S/N = 3). The recovery rate of this sensor in actual milk samples ranged from 99.02% to 100.9%. The reproducibility experiments demonstrated the high precision of the method, with a relative standard deviation (RSD) of 1.27%. Stability testing revealed a peak current retention rate of 93.51% on day 21, indicating excellent system stability. These findings indicate that the sensor shows great capability for ENR detection in food products. Full article

As plastic and heavy metal pollution continue to escalate, the co-occurrence of microplastics and heavy metals in the environment poses significant threats to ecosystems and human health. This study was designed to explore the combined effects of polyethylene microplastics (PE-MPs) and cadmium (Cd) pollution on wheat seedlings, focusing on antioxidant enzyme activity and Cd bioaccumulation. At low concentrations of PE ($1\mathrm{mg}·{\mathrm{L}}^{-1}$), peroxidase (POD) activity in wheat shoots slightly increased without significance, while at higher concentrations ($50\mathrm{mg}·{\mathrm{L}}^{-1}$ and $100\mathrm{mg}·{\mathrm{L}}^{-1}$) of PE, POD activity was significantly inhibited compared to $0\mathrm{mg}·{\mathrm{L}}^{-1}$ PE treatment. At Cd exposure activity, with POD activity in the shoots increasing by 73.7% at $50\mathsf{\mu }\mathrm{mol}·{\mathrm{L}}^{-1}$${\mathrm{Cd}}^{2+}$ compared to $0\mathsf{\mu }\mathrm{mol}·{\mathrm{L}}^{-1}$ Cd treatment. When wheat seedlings were exposed to a combination of $50\mathrm{mg}·{\mathrm{L}}^{-1}$ PE and Cd at different concentrations Cd, significant differences in POD activity were observed in the shoots compared to the control group, showing an upward trend with increasing Cd concentration. However, the addition of PE suspension generally reduced POD activity in wheat shoots compared to Cd treatment alone. Specifically, the presence of $50\mathrm{mg}·{\mathrm{L}}^{-1}$ PE did not significantly alter POD activity in the wheat shoots ($p>0.05$). Furthermore, exposure to different concentrations of Cd resulted in a general increase in POD activity of roots, with significant differences observed at $5\mathsf{\mu }\mathrm{mol}·{\mathrm{L}}^{-1}$ and $25\mathsf{\mu }\mathrm{mol}·{\mathrm{L}}^{-1}$ Cd ($p<0.05$). Regarding Cd bioaccumulation, at Cd low concentrations ($1\mathsf{\mu }\mathrm{mol}·{\mathrm{L}}^{-1}$ and $5\mathsf{\mu }\mathrm{mol}·{\mathrm{L}}^{-1}$), PE significantly promoted Cd accumulation in the shoots. However, at high Cd concentrations ($50\mathsf{\mu }\mathrm{mol}·{\mathrm{L}}^{-1}$), PE microplastics reduced Cd accumulation in the shoots but promoted its accumulation in the roots.These results suggest that PE microplastics influence the bioavailability of Cd, mitigating the toxic effects of high Cd concentrations. This paper scientifically elucidates the ecotoxicological effects of co-contamination for microplastics and heavy metals, also their potential impacts on agricultural production are discussed. Full article

Korla fragrant pear (Pyrus sinkiangensis), valued for its unique flavor, suffers from freezing damage in its native Xinjiang. Previous studies indicated a strong correlation between low-temperature stress and the expression of LEA genes, particularly PsLEA4. This study cloned PsLEA4 from P. sinkiangensis and overexpressed it in paper mulberry (Broussonetia papyrifera). The encoded 368-amino-acid protein is localized to the endoplasmic reticulum. Under −4 °C stress, the proline and soluble protein contents in the overexpressing lines increased to 1.21-fold and 1.36-fold, respectively, compared to the wild type, while relative water content (RWC) reached 1.58-fold. And catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) activities increased by 9%, 16%, and 38%, respectively. During overwintering, the transgenic line exhibited soluble protein content and RWC at 1.78-fold and 1.49-fold compared to those of the wild type, respectively. Malondialdehyde (MDA) and relative electrolyte leakage (REL) levels were only 66% and 63% of the wild type, while CAT and POD activities reached 1.87-fold, and SOD activity peaked at 2.49-fold. These adaptations were associated with improved cold tolerance and with bud break occurring 7–10 days earlier than in WT the following year. These findings could help to understand the molecular mechanisms of P. sinkiangensis for overwintering and provide new genetic resources to breed varieties of pear that can resist cold temperatures. Full article

The study investigates the use of silver nanoparticles (AgNPs) in agriculture, focusing on their potential to enhance the immune response of potato (Solanum tuberosum L.) plants against phytopathogenic attacks. The research highlights how AgNPs, stabilized by biologically active polymers polyhexamethylene biguanide and tallow amphopolycarboxyglycinate, can induce oxidative stress. Triple foliar application of 0.1–9.0 g/ha silver nanoparticles at the budding and later stages demonstrated significant efficacy in suppressing diseases caused by Phytophthora infestans and Alternaria solani (over 60%). This effect was linked to the increased activity of peroxidase—over 30–50%—and the decreased catalase activity, indicative of a well-coordinated oxidative stress response to the invasion of P. infestans and A. solani. The results suggest that AgNPs in low concentrations can prime the plant’s innate immune system, enhancing its resistance without detrimental effects on growth parameters, thus contributing to the improved crop yield. These findings underscore the potential of AgNPs not as traditional biocides, but as intelligent elicitors of plant-induced resistance, positioning them as next-generation tools for sustainable crop protection and yield optimization, which can be applied at extremely low doses (less than 10 g/ha of active substance). Full article

Understanding the molecular basis of heat tolerance in microalgae is crucial for developing resilient strains for industrial biotechnology. This study identified two desert Chlorella strains, XDA024 (thermotolerant) and XDA121 (heat-sensitive), through short-term thermal screening. The thermotolerant strain XDA024 survived exposure to 50 °C for 3 h, whereas XDA121 succumbed within 1 h at 40 °C. Physiological analyses revealed that the superior heat resistance of XDA024 was associated with enhanced activities of key antioxidant enzymes, including superoxide dismutase, catalase, and peroxidase, which effectively mitigated oxidative damage, alongside an elevated proline content contributing to osmoregulation. Transcriptomic profiling under acute heat stress (45 °C, 3 h) revealed that the unique thermotolerance of XDA024 was underpinned by the upregulation of genes related to photosystem stability and lipid synthesis, processes supported by activated calcium signaling and antioxidant pathways. In contrast, XDA121 exhibited significant downregulation of photosynthesis-related genes and promoted lipid degradation, resulting in membrane instability. Exogenous application of phosphatidylethanolamine (PE) and monoethanolamine (MEA) markedly increased the survival rate of XDA121 by more than threefold, primarily by alleviating membrane damage through enhanced membrane integrity and modulated antioxidant enzyme activities. These findings indicate that thermotolerance in desert Chlorella (Chlorophyta) is governed by the integrated coordination of antioxidant defense mechanisms, lipid metabolism, and photosystem protection. This research provides crucial insights and practical strategies for engineering heat-resistant microalgal strains for sustainable biofuel and bioproduct production. Full article

Selenium-Binding Protein 1 (SBP1), involved in selenium metabolism, contributes to plant stress response. However, it is currently unknown whether the SBP1 protein from Liriodendron hybrid (LhSBP1) plays a role in response to cold stress. In this study, transgenic overexpression lines of LhSBP1 in Arabidopsis thaliana and Populus deltoides × P. euramericana cv. ‘Nanlin 895’, were used as materials to conduct phenotypic observations and physiological and biochemical determinations under cold stress. The results showed that the full-length CDS sequence of LhSBP1 gene was cloned, with a length of 1467 bp, encoding 488 amino acids. Under cold stress, physiological and biochemical indexes showed that the contents of reactive oxygen species (ROS) and malondialdehyde (MDA) in transgenic Arabidopsis were lower, with the contents of hydrogen peroxide (H₂O₂) and superoxide anion (O₂⁻) being 0.72 and 0.71 times those of the wild type, respectively, and the MDA content was 0.53 times that of the wild type. Compared with the wild type, the activities of antioxidant enzymes including superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) increased by 1.2, 1.75, and 1.48 times respectively, and the soluble protein content increased by 1.41 times, which significantly improved the cold tolerance of Arabidopsis. The contents of H₂O₂, O₂⁻, and MDA in LhSBP1 transgenic ‘Nanlin 895’ poplar were 0.63 and 0.67 times and 0.6 times those of wild type, respectively. The activities of SOD, POD and CAT were increased by 1.37, 1.48, and 1.44 times, and the soluble protein was increased by 1.28 times, which significantly improved the cold tolerance of ‘Nanlin 895’ poplar. Taken together, this study utilized two model plant systems to demonstrate the positive and conserved functions of LhSBP1 in plant cold tolerance defense response, which provided valuable genetic resources for the breeding of cold-tolerance woody plants. Full article

This study addresses the issues of poor stability and difficulty in recovery of free horseradish peroxidase (HRP) by developing a multi-level composite immobilized carrier that combines high loading capacity with long-term stability. The SiO₂@MnO₂@MAF-7 core–shell structured carrier was prepared via a solvothermal self-assembly method. Three immobilization strategies—adsorption, covalent cross-linking, and encapsulation—were systematically compared for their immobilization efficacy on HRP. The material structure was analyzed using techniques such as specific surface area analysis (BET), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) to characterize the material structure. Enzyme kinetic parameter determination experiments were conducted to systematically evaluate the performance advantages of the immobilized enzyme. BET analysis showed that SiO₂@MnO₂@MAF-7 had a specific surface area of 251.99 m²/g and a mesoporous area of 12.47 nm, and its HRP loading was 50.37 U/mg (immobilization efficiency 85.03%). Compared with free HRP, the Km value of the immobilized enzyme was decreased by 42%, the activity retention rate was increased by 35–50% at 80 °C and pH 4–9, and the activity was maintained by 65% after five repeated uses. In this study, MAF-7 was combined with MnO₂/SiO₂ for HRP immobilization for the first time, and the triple effect of rigid support-catalytic synergy-confined protection synergistically improved the stability of the enzyme, providing a new strategy for the industrial application of oxidoreductases. Full article

Straw returning, a core practice in conservation tillage, promotes sustainable intensification; however, it faces challenges such as inefficient decomposition, nutrient competition, and pathogen accumulation. To address these limitations, this study aimed to develop a multifunctional microbial consortium specifically designed for straw-incorporating cropping systems. The consortium comprises four Bacillus strains with complementary enzymatic systems, isolated from diverse ecological niches. It exhibited robust lignocellulolytic enzyme production, with manganese peroxidase (7709.33 U/L), laccase (450.65 U/L), endo-β-1,4-glucanase (154.67 U/mL), and filter paper activity (309.18 U/L). The consortium significantly enhanced rice straw degradation by 37.18% and increased nitrogen (N) release by 16.13% compared to the control. Moreover, the consortium exhibited a 67.56% inhibition rate against Magnaporthe oryzae and reduced both the incidence rate and disease index of leaf blast and panicle blast. Field trials revealed increases in the rice grain yield of 9.63% and 6.94% when applied alone and 6.75% and 5.18% when co-applied with straw residues. These findings highlight the multifunctional agricultural potential of the consortium and provide a sustainable strategy to overcome the limitations of straw-incorporating farming systems. Full article

Thai eggplant (Solanum melongena L. cv. Chao Phraya), a widely cultivated vegetable with increasing global demand, is highly susceptible to salinity stress, which can severely impair seed germination and early seedling development. This study investigated the effects of sodium nitroprusside (SNP), a nitric oxide (NO) donor, on seed germination and seedling growth under salt stress conditions. Seeds were pre-treated with SNP at concentrations of 0, 0.05, 0.1, and 0.2 mM for 24 h and subsequently germinated under saline conditions with NaCl solutions (0, 100, and 200 mM). SNP pre-treatment, particularly at 0.05 and 0.1 mM, significantly improved germination percentage and germination rate in seeds exposed to 200 mM NaCl compared to untreated controls. Increased NaCl concentrations induced oxidative stress in seedlings, as evidenced by elevated hydrogen peroxide (H₂O₂) accumulation, which in turn caused lipid peroxidation, reflected by higher malondialdehyde (MDA) levels. Salt stress significantly increased ascorbate peroxidase (APX) activity, whereas catalase (CAT) activity showed no significant change across treatments. Correlation analysis revealed that APX activity was positively correlated with oxidative stress markers (H₂O₂) and delayed germination (T₅₀/MGT), whereas CAT activity showed no significant correlation with these parameters. In contrast, elevated APX activity was strongly and negatively correlated with overall seedling growth and vigor (SVI/GI), indicating that the underlying stress condition had a detrimental effect on plant performance. Overall, SNP pre-treatment, particularly at 0.05 and 0.1 mM, significantly enhanced salt tolerance by promoting germination (increasing GP and reducing T₅₀/MGT) and improving seedling growth (SL and RL). This protective effect is associated with improved redox regulation and partial mitigation of oxidative damage, as reflected by changes in H₂O₂, MDA, and APX; however, excessive SNP concentrations may exert phytotoxic effects, highlighting the importance of optimal dosing. Full article

This study aimed to evaluate the effect of stress attenuators on the tolerance and antioxidant activity of watermelon cultivars under water deficit. The experiment was conducted in two stages, Stage I corresponding to water deficit levels (N1 = 0; N2 = −0.1; N3 = −0.2 MPa) and six watermelon cultivars. Stage II comprises two cultivars selected in Stage I (one sensitive and one tolerant) and the combination of water restriction with attenuators (T1 = 0.0 MPa (control), T2 = −0.2 MPa (water deficit), T3 = −0.2 MPa + hydropriming, T4 = −0.2 MPa + gibberellic acid, T5 = −0.2 MPa + salicylic acid, and T6 = −0.2 MPa + hydrogen peroxide). The concentration and exposure times of the attenuators were determined through preliminary tests. In Stage I, physiological and biochemical analyses were performed. In Stage II, in addition to these tests, hydrogen peroxide content, malondialdehyde levels, and the activity of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) were assessed. Water deficit impaired germination and seedling vigor of watermelon, with Crimson Sweet, Omaru, Charleston Gray, and Congo being the most sensitive cultivars, while Fairfax was the most tolerant. For Crimson Sweet, pre-germination treatments reduced oxidative stress and enhanced tolerance by stimulating antioxidant enzyme activity, with GA and H₂O₂ providing the most effective results. For Fairfax, greater tolerance was associated with osmotic adjustment through the accumulation of compatible solutes, a mechanism further enhanced by the use of attenuators. Full article

Fucoidan improves host health by enriching beneficial taxa such as Bacteroides and Parabacteroides, yet the underlying mechanisms remain unclear. This study validated the association between these two genera and fucoidan-mediated mitigation of intestinal inflammation in mice. Subsequently, the effects of Parabacteroides goldsteinii and Bacteroides finegoldii were evaluated in colitis mice, and the contributions of microbiota-associated metabolites spermidine and betaine were investigated in vitro. Both strains reduced IL-6 (32–36%), TNF-α (30–37%), and IL-1β (40–45%) levels and increased levels of catalase (25–35%) and glutathione peroxidase (31–45%) in the colon. Mechanically, these strains suppressed activation of the NF-κB and MAPK pathways and preserved tight junction integrity by inhibiting myosin light chain kinase activation. These effects were associated with alterations of gut microbiota, characterized by decreased Proteobacteria and increased Bacteroidota, resulting in increased betaine (45–60%) and spermidine (90–112%). In vitro, betaine and spermidine alleviated LPS-induced inflammation and oxidative damage by regulating macrophage polarization. These results suggest that Bacteroides and Parabacteroides contribute to fucoidan-induced improvement of host health through betaine- and spermidine-related pathways. Future studies should clarify the origins of key metabolites and validate their causality and translational relevance using approaches such as fecal microbiota transplantation, metabolite tracing, and human-relevant systems. Full article

Betaphycus gelatinus, a member of the Eucheumatoideae, serves as the primary source for carrageenan extraction and has significant economic value. The growth and reproduction of B. gelatinus are significantly impacted by seasonal fluctuations in seawater temperature. To explore its adaptive mechanisms under temperature stress, we cultured the algae at 15 °C (Low temperature, LT), 27 °C (Medium temperature, MT), and 36 °C (High temperature, HT) for 2 h and conducted subsequent physiological, transcriptomics, and metabolomics analyses. The photosynthetic performance of B. gelatinus significantly declined under both LT and HT stress conditions. Carotenoid content increased significantly under LT conditions, while chlorophyll a showed no significant change. Phycocyanin and phycoerythrin decreased significantly under LT conditions, but there was no significant difference under HT conditions. Under LT stress, glutathione (GSH) levels, ascorbate peroxidase (APX) activity, and catalase (CAT) activity all increased significantly. Under HT stress, APX and CAT activities increased significantly, while superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels remained unchanged. Transcriptomics and metabolomics analyses suggested that photosynthesis, carbohydrate metabolism, amino acid biosynthesis, porphyrin metabolism, and vitamin B6 metabolism are involved in the acute temperature stress response of B. gelatinus. Under both HT and LT, most genes in the targeted metabolic pathways were significantly downregulated (p < 0.05), while only a few were upregulated. Specifically, in carbohydrate metabolism, only nine genes were upregulated, while all others were downregulated. Moreover, all the genes involved in photosynthesis, photosynthetic carbon fixation, arginine biosynthesis, and porphyrin metabolism were downregulated. In contrast, only four genes involved in GSH metabolism, alanine, aspartate, and glutamate metabolism, and glycine, serine, and threonine metabolism were upregulated. These results suggest that temperature stress markedly suppresses the transcription of key genes in these pathways and that the few upregulated genes in these pathways may contribute to compensatory mechanisms or regulatory network reprogramming during stress responses. These findings help clarify how B. gelatinus adapts to different temperature stresses and provide a basis for developing improved germplasm to support stable production under climate variability. Full article

The primary objective of this study was to investigate the mechanism through which small peptides regulate the productive performance and egg quality of laying hens during the late-laying period. A total of 200 Lohmann Pink laying hens, aged 400 days, were randomly assigned into a control treatment (CON) and a small peptide treatment (SP) for a 120-day treating period. Productive performance, egg quality, serum antioxidant capacity, intestinal morphology, microbial community, and hepatic gene expressions were measured. Results showed that SP supplementation significantly increased eggshell strength and albumen height, while reducing the rate of abnormal eggs (p < 0.05). SP notably enhanced the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and hepatic lipase (p < 0.05). Additionally, SP supplementation significantly increased microbial α-diversity (p < 0.05) and elevated the relative abundances of Ruminococcus, Lactobacillus, and Faecalibacterium (p < 0.05). Hepatic transcriptomic analysis revealed that up-regulated genes in the SP treatment were primarily enriched in steroid biosynthesis, while down-regulated genes were mainly associated with the Yersinia infection pathway. In conclusion, small peptide supplementation efficiently improved eggshell strength and albumen height while reducing the rate of abnormal eggs by modulating the interactions between gut microbiota and hepatic gene expressions. Our findings may provide an effective option for enhancing egg quality in the late-laying period. Full article

The growth and development of breast cancer are accompanied by an increase in oxidative stress. A close relationship is known to exist between the biological activity of several antioxidant enzymes and the regulation of estrogen-mediated signaling in breast cancer. The aim of this study was to study the activity of salivary antioxidant enzymes and the level of lipid peroxidation products in breast cancer before and after surgical treatment. The study included 115 patients with breast cancer (58.7 ± 10.9 years) and 60 healthy volunteers (51.8 ± 12.1 years). Saliva samples were obtained again from 53 patients 4 weeks after surgery. The content of lipid peroxidation products, catalase activity, total antioxidant activity (AOA) and total peroxidase activity (TPA) in saliva were analyzed before and after breast cancer surgery. An increase in lipid peroxidation products in saliva was observed with positive estrogen receptor expression. For the first time, it was shown that in patients with breast cancer, the levels of salivary TPA and AOA increased, which is likely due to the important role of the salivary glands in antioxidant protection. It can be speculated that the effectiveness of antioxidant defense was associated with estrogen and progesterone receptor expression and was reduced in prognostically unfavorable breast cancer phenotypes (non-luminal and triple-negative breast cancer). Full article

During exercise, increased oxygen consumption results in elevated production of reactive oxygen species (ROS). If the antioxidant system is unable to counteract this surge in ROS, oxidative stress occurs. Physical activity modulates both the generation and clearance of ROS through dynamic interactions between metabolic and antioxidant systems, and also influences the oxidative burst activity of phagocytes, a key component of the innate immune response. To investigate the acute physiological responses to high-intensity interval training (HIIT), we assessed the effects of a single HIIT session on oxidative stress markers and the oxidative burst activity of phagocytes in young professional athletes and non-athlete individuals. Blood samples were collected before and after a HIIT session from eleven male athletes (mean age: 22.1 ± 4.5 years) and ten male non-athlete university students (mean age: 21.6 ± 2.3 years). Participants performed a single treadmill HIIT session of ten 45-s intervals at 75–85% of heart rate reserve, separated by 45-s low-intensity recovery periods, with target intensities individualized using the Karvonen formula. Total antioxidant capacity, activities of catalase, superoxide dismutase and glutathione peroxidase enzymes, total serum nitrite/nitrate levels, lipid peroxidation products, and oxidative burst activity of phagocytes were evaluated before and after exercise. In athletes, a significant increase was observed in the activity of superoxide dismutase (from a median of 2.09 to 2.21 U/mL; p = 0.037) and catalase (from a median of 32.94 to 45.45 nmol/min/mL; p = 0.034) after exercise, whereas no significant changes were found in the control group. Total serum nitrite/nitrate levels significantly increased in both groups after exercise (athletes: from a median of 8.70 to 9.95 µM; p = 0.029; controls: from a median of 10.20 to 11.50 µM; p = 0.016). Oxidative burst capacity of peripheral blood phagocytes was significantly higher in athletes both before (median: 10,422 vs. 6766; p = 0.029) and after (median: 9365 vs. 7370; p = 0.047) the HIIT session compared to controls. Our findings demonstrate that training status markedly influences oxidative stress responses, with athletes exhibiting more effective long-term antioxidant adaptations. These results emphasize the necessity of tailoring exercise regimens to baseline fitness levels in order to optimize oxidative stress management across different populations. Full article