Search Results (337)

In this study, we combine experimental and computational approaches to elucidate a density functional theory (DFT)-derived mechanism for superoxide scavenging by resveratrol, piceatannol, and oxyresveratrol. Using rotating ring–disk electrode (RRDE) hydrodynamic voltammetry, the superoxide radicals are generated in situ, allowing direct measurement of antioxidant activity. Data show that the catechol-containing piceatannol is approximately four times more active than resveratrol, while resveratrol and oxyresveratrol exhibit similar efficiencies, indicating that the additional 2′-OH group in oxyresveratrol has minimal impact. Vitamin C (ascorbic acid) facilitates scavenging by acting as a proton donor for resveratrol, piceatannol, and 4′-OH oxyresveratrol, but it is unable to deprotonate the 2′OH group of oxyresveratrol. The experimental results suggest a superoxide dismutase (SOD)-like mechanism, obtained from energetically feasible DFT calculations, in which these stilbenes convert two superoxide anions into H₂O₂ and O₂, helped by vitamin C. Mechanistically, the first superoxide is reduced by abstracting a hydroxyl-group hydrogen atom, while the second undergoes oxidation via π–π interaction with the aromatic system, releasing O₂. Notably, resveratrol can be regenerated through a catalytic cycle involving vitamin C. These data underscore the SOD-mimicking properties of dietary polyphenols and suggest a need to reevaluate resveratrol’s clinical utility regardless of its low bioavailability. Full article

Understanding the dynamics of root zone soil water content is crucial for precision irrigation scheduling in protected strawberry cultivation. The HYDRUS-3D model is capable of simulating three-dimensional water flow and root water uptake. Although the model has been tested in various settings, its validation under realistic greenhouse cultivation rack systems with direct soil moisture measurements remains limited. In this study, a HYDRUS-3D model was developed to simulate root zone soil water dynamics in a greenhouse U-shaped strawberry cultivation system under both irrigated and non-irrigated conditions, with and without plastic mulch. In the first year, the model’s accuracy was evaluated using a newly developed line-scale dielectric soil moisture sensor. The simulated volumetric soil water content showed good agreement with sensor measurements across all scenarios (R² ≥ 0.8302, RMSE ≤ 0.0309, NSE ≥ 0.5979). In the following two years, we utilized the established model to schedule irrigation and investigated its water-saving effects. Model-scheduled irrigation reduced water use by 8.45–13.36% compared with conventional irrigation scheduling. No significant differences were observed in most morphological, physiological, fruit quality, or yield indicators (p > 0.05). However, occasional improvements were detected in chlorophyll content, root activity, ascorbic acid and total soluble solids. These findings demonstrate that HYDRUS-3D effectively simulates root zone water content dynamics throughout the strawberry growth cycle and serves as a practical tool for precision soil water management in greenhouse cultivation rack systems. Full article

Niacin contents vary significantly among fresh-cut potato cultivars with different browning sensitivities, whereas its role as a browning inhibitor for fresh-cut produce has not been previously reported. In this study, potato slices were soaked in distilled water (control) or 1% food-grade niacin solution for 5 min, then stored at 4 ± 1 °C for 8 days with sampling every 2 days for physiological and molecular analyses. In particular, the optimal niacin (1%) treatment showed higher brightness and lower color change than the control. The activities of polyphenol oxidase (PPO), peroxidase (POD), and phenylalanine ammonia lyase (PAL), and phenol content were reduced. Higher activities of superoxide dismutase (SOD) and catalase (CAT), and greater glutathione accumulation, were observed following niacin treatment. Meanwhile, lower levels of malondialdehyde and reactive oxygen species (ROS), and lower nicotinamide adenine dinucleotide phosphate oxidase (NOX) activity, indicated lower oxidant damage. The contents of NADP and NAD, and activities of nicotinamide adenine dinucleotide kinase (NADK) and glucose-6-phosphate dehydrogenase (G6PDH) were improved. Furthermore, the gene expression patterns of StRBOH, StPPO, and StG6PDH also supported the hypothesis that niacin regulates pyridine nucleotide and ROS homeostasis. Full article

Nitric oxide (NO) and hydrogen sulfide (H₂S) are key gasotransmitters that regulate multiple aspects of plant growth, development, and stress adaptation. Although their individual signaling pathways have been extensively investigated, the integrated mechanisms underlying NO–H₂S crosstalk and its potential agronomic applications remain unclear. This review summarizes current advances in understanding the biochemical interplay between NO and H₂S in plants, emphasizing their synergistic roles in redox regulation, antioxidant activation, ion homeostasis, and photosynthetic protection under abiotic and biotic stresses. Special attention has been given to recent progress in nanotechnology-based delivery systems that enable the controlled, localized, and sustained release of gasotransmitters, thereby improving bioavailability and minimizing environmental losses. Studies on foliar, seed, and nutrient-solution applications have demonstrated that combined NO/H₂S treatments increase stress tolerance by activating the ascorbate–glutathione (AsA–GSH) cycle, reducing the expression of oxidative markers such as hydrogen peroxide (H₂O₂) and malondialdehyde (MDA), and improving both short-term (Fv/Fm, antioxidant enzyme activity) and long-term (biomass, SPAD index, yield) physiological outcomes. By integrating molecular insights with applied strategies, this review outlines the emerging potential of NO–H₂S signaling as a sustainable tool for crop management in the context of climate change and food security. Full article

Allelopathy means that one plant produces chemical substances to affect the growth of other plants. Crop rotation is considered as a potential strategy to alleviate the allelopathic inhibition. So, it is important to identify rotation crops with wide availability and low inhibitory effects. In this study, the allelopathic potential of soil extracts was investigated on the germination, seedling growth, biomass, and biochemical parameters (malondialdehyde, photosynthetic pigments, and antioxidant enzyme activities) of five crops, by a series of laboratory experiments. Firstly, both soil water extracts (SWE) and soil ethanol extracts (SEE) exhibited allelopathic inhibition on the seed germination and the root length of all seedlings in a dose-dependent relationship. The SWE significantly promoted the shoot length of bok choy and Chinese lettuce, while the SEE had no significant effect in bok choy. The application of SEE resulted in a significant increase in the dry weight of bok choy and rocket. In contrast, SWE had a negligible effect on bok choy and lettuce. Both of them caused decrease in the dry weight of the other seedlings. Then, the allelopathic synthetic effect index of water/ethanol extracts was chemo-inhibitory, and the inhibitory effect increased with increasing extract concentration. The SWE had the strongest inhibition on rocket and the SEE on lettuce. Both of them had the weakest effect on bok choy. The extracts significantly inhibited the photosynthetic capacity in five crops, manifested as decrease in photosynthetic pigments and dose-dependent effects. The malondialdehyde (MDA) content in all crops increased in a dose-dependent manner, confirming that the extracts caused lipid peroxidation. However, the defense strategies of different crops vary significantly. There is crop with active defense, such as bok choy treated with SWE. It delayed oxidative damage by continuously upregulating the activities of superoxide dismutase (SOD) and catalase (CAT). This is the key physiological mechanism for tolerance. There is also the oxidative stress failure type, as follows: CAT activity of rocket and cabbage increased, but the SOD activity did not increase by SEE. This reveals the physiological essence of their sensitivity—the lack of persistent scavenging ability for reactive oxygen species. Based on the inhibition of peroxidase (POD) and ascorbic acid peroxidase (APX), it is speculated that the extracts may inhibit the hydrogen peroxide scavenging pathway, which centered on the ascorbate–glutathione cycle. It is the fundamental reason why the continuous accumulation of MDA though SOD/CAT is up. This study confirmed the allelopathic effects of the water and ethanol extracts on five vegetable crops, and found that bok choy was less affected by them. The soil extracts affected the growth and development of seedlings by regulating their oxidative metabolism and photosynthetic capacity. These results support recommending pak choi as a rotation crop. This provides crops for subsequent field experiments and a new direction for next-step research on continuous cropping obstacles. Full article

The search for a healthy diet has increased the consumption of kale, a vegetable recognized for its high nutritional value, mineral content, and antioxidant properties. Phosphorus is an essential nutrient in this context, acting in energy transfer and root development, which favors productivity and product quality. This study evaluated the effect of two phosphorus sources, bone meal (BM) and thermophosphate Yoorin^® (TY), and five phosphorus (P₂O₅) doses (0, 160, 320, 480, and 640 kg ha⁻¹) on kale yield and quality. The experiment used a randomized complete block design with four replications and ten treatments in a 2 × 5 factorial arrangement in a protected environment over a cycle of 155 days after transplanting. Marketable yield with BM reached an estimated maximum of 1.54 kg plant⁻¹ at 525 kg ha⁻¹ P₂O₅ (54% over control), while TY showed a linear increase up to 1.57 kg plant⁻¹ (59%). Photosynthetic pigments, antioxidant activity, ascorbic acid, and total phenolic compounds fitted quadratic models, with gains of up to 36%, 73%, 51%, and 57%, respectively. Contents of P, K, Ca, and Fe increased significantly with P doses, with Fe gains reaching 110–180%. Phosphate fertilization with BM, a renewable P source, increases kale yield and nutritional quality, highlighting its potential for organic farming systems. Full article

Light combined with refrigeration is an effective strategy for preserving postharvest fruit and vegetable quality. This study explored the effects of various red–blue (R/B) light-emitting diode (LED) light/dark (L/D) cycles on pak choi during refrigeration. Pak choi exposed to a 4/20 h L/D cycle exhibited greater freshness, along with the highest levels of total phenolic compounds, chlorophyll, and ascorbic acid, particularly after 6 days of refrigeration. Transcriptomic analysis showed that this lighting regime upregulated genes associated with phenylpropanoid and flavonoid biosynthesis (PAL, C4H, ANS, CHS, FLS) and ascorbate metabolism (VTC2_5, VTC4, APX), boosting phenolic and ascorbic acid content. It also reduced chlorophyll degradation by increasing the expression of genes in the porphyrin metabolism pathway (CRD1, POR, DVR). These findings highlight the benefits of R/B light with a 4/20 h L/D cycle for enhancing pak choi quality during refrigeration storage. This approach provides an efficient approach for vegetable preservation. Full article

Soil salinity as a major abiotic stressor has significantly affected crop production worldwide. However, plants have developed complex signaling networks that enable them to adapt and cope with such environmental shifts. Recent research has demonstrated the involvement of hydrogen sulfide (H₂S) in signaling cascades that link plant development with stress tolerance management. Similarly, glutathione (GSH), a non-enzyme antioxidant, and a vital tripeptide, has been found to protect plants from oxidative damage and regulate metabolic functions under abiotic stress. As a potential scavenger of ROS, GSH maintains cellular redox homeostasis through the ascorbate-GSH cycle and acts as a signaling molecule for the sulfur-status of plants. This review focusses on: (i) revisiting the concept and current status of soil salinity; (ii) highlighting its impact at cellular and whole-plant levels; (iii) elucidating the role of a H₂S and GSH in plant salt stress tolerance; and (iv) exploring the potential interactive roles of H₂S and GSH in mitigating salinity impacts. This review will provide valuable insights into the complex network involving H₂S and GSH, suggesting pathways for developing climate-resilient crops. Full article

Light availability is a key environmental factor regulating nitrogen assimilation, carbon metabolism, and nutritional quality in leafy vegetables grown in controlled environments. However, how practical lighting regimes used in plant factories with artificial lighting (PFALs) influence the coordination between nitrogen assimilation and central carbon metabolism across different lettuce cultivar types remains insufficiently understood. This study investigated how moderate differences in photosynthetic photon flux density (PPFD) influence nitrogen metabolism and metabolic coordination in hydroponically cultivated lettuce. Two cultivars representing contrasting morphological types, iceberg lettuce (‘Celebration’) and leaf lettuce (‘Sunny’), were grown under LED light intensities of 150 and 200 µmol·m⁻²·s⁻¹. Nitrate, nitrite, and ammonium concentrations were measured together with the activities of nitrate reductase (NRA) and nitrite reductase (NiRA), as well as ascorbic acid content. Metabolomic profiling was additionally performed to characterize broader metabolic responses. Higher light intensity enhanced nitrate reduction capacity in both cultivars, but the resulting patterns of nitrogen accumulation were strongly genotype-dependent. The leaf lettuce cultivar ‘Sunny’ exhibited increased NRA and reduced nitrate accumulation under higher light intensity, whereas the iceberg lettuce cultivar ‘Celebration’ accumulated more nitrate under the same conditions. Ammonium responses further suggested differences in downstream nitrogen assimilation processes. Elevated light intensity also increased ascorbic acid levels in both cultivars. Metabolomic analysis revealed contrasting cultivar-specific shifts in central carbon metabolism, particularly involving soluble sugars and tricarboxylic acid cycle intermediates, indicating differential coordination between carbon metabolism and nitrogen utilization. Overall, these findings demonstrate that moderate changes in light intensity within the practical PFAL cultivation range can significantly influence the integration of carbon and nitrogen metabolism in lettuce. Importantly, cultivar-specific physiological traits determine how these metabolic responses translate into nitrate accumulation and nutritional quality in controlled-environment production systems. Full article

Bangia fuscopurpurea is a marine alga with significant commercial value. Although a high-light adapted species, the productivity of its commercial cultivation is frequently limited by environmental light attenuation, resulting in the algae operating under energy-limiting, sub-saturating conditions. This study investigated its physiological responses and antioxidant defense mechanisms across a sub-saturating light gradient (20, 40, and 80 µmol photons m⁻² s⁻¹). We employed exogenous ascorbic acid (AsA) supplementation to evaluate the dynamic response of the ascorbate-glutathione (AsA-GSH) cycle. Without AsA supplementation, the 40 µmol photons m⁻² s⁻¹ condition supported redox homeostasis and the highest soluble protein accumulation. In contrast, the lowest irradiance (20 µmol photons m⁻² s⁻¹) restricted physiological performance. At 80 µmol photons m⁻² s⁻¹, which remained below the light saturation point, the algae experienced oxidative stress, indicated by elevated lipid peroxidation and hydrogen peroxide levels. The efficacy of exogenous AsA depended on these energy states. Under the highest tested irradiance (80 µmol photons m⁻² s⁻¹), AsA reduced malondialdehyde (MDA) and maintained electron transport capacity, but these effects were accompanied by a significant degradation of photosynthetic pigments. These findings imply an altered partitioning of cellular reducing power, where the demand for AsA regeneration might limit the resources available for biosynthetic pathways. The study highlights that antioxidant efficacy is constrained by the cellular energy availability, which limits simultaneous stress mitigation and growth in light-limited aquaculture environments. Full article

Saline-alkaline (SA) soils pose a serious threat to soybean production worldwide. Although severe saline-alkaline stress can reduce yield by up to 30%, the mechanisms underlying saline-alkaline-induced inhibition of root growth remain unclear. In this study, two soybean cultivars with contrasting tolerance, Chang Nong 26 (CN26) and Jiyu 441 (JY441), were exposed to saline-alkaline stress induced by NaHCO₃ and Na₂CO₃ at Na⁺ concentrations of 0, 21, and 45 mmol·L⁻¹. The effects on seed germination, early seedling growth, antioxidant responses, and root DNA damage were systematically examined. High-level saline-alkaline stress significantly inhibited germination and root elongation in both cultivars. Superoxide dismutase (SOD) and peroxidase (POD) activities increased markedly under stress, indicating activation of antioxidant defenses. Catalase (CAT) and ascorbate peroxidase (APX) to scavenge ROS and maintain cellular redox balance. Nevertheless, oxygen-free radicals (OFRs) accumulated to a significantly greater extent in the root tips of CN 26 than in JY441, suggesting lower tolerance in CN 26. Random amplified polymorphic DNA (RAPD) analysis revealed pronounced DNA damage in root tips under saline-alkaline stress, with more polymorphic bands detected in CN 26 than in JY441. Furthermore, qRT-PCR analysis demonstrated that the expression of DNA damage repair-related genes (RAD51, OGG1, RAD4, and ATM) was downregulated in CN 26 roots under stress, whereas E2FA and WEE1 expression was upregulated. In contrast, these DNA repair genes in JY441 were significantly induced during the early stage of stress exposure and subsequently declined. Collectively, this study demonstrates that saline-alkaline stress inhibits soybean growth through the induction of oxidative DNA damage and cell cycle arrest in roots. The reduced capacity for DNA repair in CN 26 likely contributes to its greater sensitivity to saline-alkaline stress. This study provides mechanistic insights into saline-alkaline stress-induced growth inhibition in soybean and offers a theoretical basis for breeding stress-tolerant cultivars. Full article

Background: Citrus components potentially suppress adipogenic differentiation and lipid accumulation, and exhibit anti-inflammatory and antioxidant effects. We hypothesized that the bioactive compounds in Citrus junos Sieb ex Tanaka (yuzu) fruit peel can alter the systemic metabolism and productivity of beef cattle. Methods: Japanese Brown (JBR) steers were fed with a diet supplemented with 2.5% yuzu peel during the last month of the finishing period. To investigate the effect of dietary yuzu supplementation (DYS) on beef and liver metabolism, we explored the metabolomic profiles of longissimus thoracis (LT, loin) muscle at 14 d postmortem using capillary electrophoresis (CE-TOF/MS) and high-performance liquid chromatography time-of-flight mass spectrometry (LC-TOF/MS). Results: The DYS treatment enhanced the beef fat score compared to that recorded in beef in the no-DYS (None) group (p = 0.050); however, the other carcass quality traits were not significantly different between the DYS and None groups. CE-TOF/MS and LC-TOF/MS revealed 242 and 107 annotated peaks, respectively, for the LT muscle. DYS significantly increased 9(S)-hydroxyoctadecadienoic acid (9-HODE, a beef flavor precursor), cyclo(-Leu-Pro), spermidine, asymmetric dimethylarginine, and 7α-hydroxycholesterol levels and reduced 2-ethylhydracrylic acid (2-EHAA), γ-tocopherol, coenzyme Q10 (CoQ10), sphingomyelin(d18:1/16:0), Cys-Gly, Tyr-Arg, and palmitoylcarnitine levels in postmortem LT muscle (p < 0.050). Concomitantly, in the fresh liver, DYS increased acetyl-CoA, 6-phosphogluconic acid, S-methylglutathione, ATP, ribulose 5-phosphate, and ADP levels and suppressed the content of thiamine, Ala-Ala, riboflavin, and ascorbate 2-sulfate (p < 0.050). Conclusion: Collectively, yuzu ingredients activated ATP production in the liver through the elevation of hepatic energy metabolism primarily in the citrate cycle and β-oxidation, and potentially altered muscle metabolism, including linoleic acid oxidation, FAD-mediated electron transport chain, and isoleucine catabolism, as demonstrated in the reduced accumulation of 2-EHAA and CoQ10 in DYS beef. Moreover, DYS likely affects the gut microbiome by enhancing the production of cyclo(-Leu-Pro), an antimicrobial dipeptide. Full article

The development of efficient and non-toxic fuels for direct liquid fuel cells has highlighted ascorbic acid (AA) as a sustainable energy source. This study presents a combined theoretical and experimental investigation of ascorbate oxidation on an Au-Pt electrode in alkaline medium. Density functional theory (DFT) calculations reveal that Au deposition on Pt creates a more homogeneous and active surface, significantly enhancing the adsorption energy of ascorbate (−7.54 eV vs. −5.80 eV on bare Pt). Electrochemically, this translates to a superior performance, where the Au-Pt electrode achieves a 38% reduction in charge-transfer resistance, a higher current density, and a lower Tafel slope of 77 mV dec⁻¹, indicating accelerated kinetics. The electrode also retains its activity over 1000 cycles, confirming exceptional durability. This synergistic combination of theoretical and experimental results establishes Au-Pt as a premier catalyst for sustainable ascorbate-based energy conversion. Full article

Abiotic stresses disrupt redox homeostasis and reduce crop productivity. Antioxidant networks support resilience by limiting excess reactive oxygen species (ROS) and maintaining redox signalling for stress perception, gene expression, and metabolic reprogramming. We summarize advances (2000–2025) in ROS generation, detoxification mechanisms, and signalling across organelles, including chloroplasts, mitochondria, peroxisomes, and the apoplast. This includes compartmentalized enzymes—superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), and glutathione reductase (GR)—as well as the peroxiredoxin–thioredoxin system and non-enzymatic buffers like ascorbate, glutathione, tocopherols, carotenoids, and flavonoids. We uniquely synthesize these findings in a compartment-resolved “redox rheostat” model, linking ROS concentration–time windows (signaling vs. damage) to antioxidant network design (kinetic tiers, compartmentation, and trade-offs) and identifying intervention points for breeding, genome editing, and field-scale priming. We emphasize constraints, such as NADPH supply and antioxidant recycling capacity, that lead to context-dependent outcomes. We evaluate omics, transgenic strategies, genome editing (CRISPR and Cas systems), exogenous applications, and plant–microbe associations. This synthesis clarifies how antioxidant systems protect photosynthetic and respiratory machinery while supporting signalling, thus outlining routes to climate-resilient, yield-stable crops across varied environments and stresses. Full article

Taxifolin, a natural flavonoid, consistently exerts cytoprotective effects against various oxidative stresses. In this study, we systematically evaluated its photoprotective efficacy and underlying mechanisms against ultraviolet B (UVB)-induced injury in human immortalized keratinocytes (HaCaT). Cell viability and apoptosis were assessed by MTT, fluorescence staining, and flow cytometry, while integrative transcriptomic and proteomic analyses were employed to identify core pathways and key mediators. Taxifolin exhibited antioxidant capacity comparable to that of ascorbic acid under identical in vitro radical-scavenging assays. Moreover, it displayed a strong absorption peak at 289 nm that overlaps the UVB spectrum (280–320 nm), enabling it to act as a chemical sunscreen. In UVB-challenged HaCaT cells, taxifolin markedly reduced intracellular reactive oxygen species (ROS) and attenuated JNK/p38 MAPK activation, as evidenced by Western blot, thereby breaking the ROS-MAPK vicious cycle. Multi-omics revealed that taxifolin was associated with attenuation of UVB-imposed G1/S arrest concomitant with restored Cyclin expression, while up-regulating MYC, FOXQ1, HMOX1 and AP-1 components c-Jun/c-Fos and thereby switching on a pro-survival transcriptional program. Consequently, apoptosis was suppressed and survival was significantly improved. Collectively, taxifolin integrated chemical filtration, ROS scavenging and signaling modulation to support a multi-target photoprotective network, which provides mechanistic insight into taxifolin-mediated cytoprotection and identifies candidate molecular nodes for further validation. Full article