Peroxide Concentration Research Articles

HcLEA113, a late embryogenesis abundant protein gene, positively regulates drought-stress responses in kenaf.

Late embryogenesis abundant (LEA) proteins have been widely recognized for their role in various abiotic stress responses in higher plants. Nevertheless, the specific mechanism responsible for the function of LEA proteins in plants has not yet been explored. This research involved the isolation and characterization of HcLEA113 from kenaf, revealing a significant increase in its expression in response to drought stress. When HcLEA113 was introduced into yeast, it resulted in an improved survival rate under drought conditions. Furthermore, the overexpression of HcLEA113 in tobacco plants led to enhanced tolerance to drought stress. Specifically, HcLEA113-OE plants exhibited higher germination rates, longer root lengths, greater chlorophyll content, and higher relative water content under drought stress compared to wild-type (WT) plants, while their relative conductivity was significantly lower than that of WT plants. Further physiological measurements revealed that the proline content, soluble sugars, and antioxidant activities of WT and HcLEA113-OE tobacco leaves increased significantly under drought stress, with greater changes in HcLEA113-OE plants than WT. The increase in hydrogen peroxide (H2O2), superoxide anions (O2 -), and malondialdehyde (MDA) content was significantly lower in HcLEA113-OE lines than in WT plants. Additionally, HcLEA113-OE plants can activate reactive oxygen species (ROS)- and osmotic-related genes in response to drought stress. On the other hand, silencing the HcLEA113 gene through virus-induced gene silencing (VIGS) in kenaf plants led to notable growth suppression when exposed to drought conditions, manifesting as decreased plant height and dry weight. Meanwhile, antioxidant enzymes' activity significantly decreased and the ROS content increased. This study offers valuable insights for future research on the genetic engineering of drought resistance in plants.

Molybdenum oxide catalyst for wastewater treatment studied by faradaic efficiency

The measurements of gas volumes evolved during electrochemical wastewater treatment provide the information on the process faradaic efficiency. This work demonstrates how it enables identification of the water oxidation pathway (2 or 4 electron) in flow electrolysis process through the application of the formulae suggested in the study. This way, the real wastewater oxidation strength, i.e. production of hydrogen peroxide can be determined based on calculations. These provide more accurate results than direct measurements of accumulated hydrogen peroxide concentration after the electrolysis process, as its instability may lead to its immediate decomposition and false results. As an example provided in the paper, the application of MoO3 as a catalyst in the carbon composite electrode indicates almost no hydrogen peroxide detected after the process, whereas its oxidative properties owing to production of hydroxyradicals demonstrate complete decomposition of wastewater analogue (methylene blue). The calculations point to high production of H2O2. Using pure carbon material without the catalyst in the same experiment, decomposition occurs at much lower rate. The possible mechanisms behind the processes are discussed. The approach presented in the work can aid to efficient development of catalysts towards two-electron water oxidation.

Exploring the therapeutic potential of the oxygenated monoterpene linalool in alleviating saline stress effects on Allium cepa L.

Sodium chloride (NaCl) can cause oxidative stress in plants, which represents a potential obstacle to the development of monocultures worldwide. Onion (Allium cepa L.) is a famous vegetable consumed and used in world cuisine. In the present study, we analyzed the influence of soil physicochemical profile and the remedial capacity of linalool on seed emergence, roots, and leaf growth in onions subjected to salt stress, as well as its in vivo and in vitro antioxidant potential, Fe2+chelating activity, and reducing power of Fe3+. The outcome of the soil analysis established the following order of abundance: sulfur (S) > calcium (Ca) > potassium (K) > magnesium (Mg) > sodium (Na). NaCl (150 mM) significantly reduced the emergence speed index (ESI), leaf and root length, while increasing the peroxidation content. The length of leaves and roots significantly increased after treatment with linalool (300 and 500 μg/mL). Our data showed negative correlations between seed emergence and K+ concentration, which was reversed after treatments. Linalool (500 μg/mL) significantly reduced oxidative stress, but increased Fe2+ concentration and did not show potential to reduce Fe3+. The in vivo antioxidant effect of linalool is thought to primarily result from an enzymatic activation process. This mechanism underscores its potential as a therapeutic agent for oxidative stress-related conditions. Further investigation into this process could unveil new avenues for antioxidant therapy.

Grafting increases superoxide dismutase and catalase activity to overcome the impact of the two-spotted spider mite on eggplant growth and productivity

Grafting vegetable crops is considered a valuable tool for improving the yield and quality of fruits under various stress conditions. This study aimed to assess the influence of grafting eggplant Solanum melongena (cv. A338) onto Solanum torvum rootstock (cv. STT3) on the incidence of the two-spotted spider mite Tetranychus urticae (TSSM). An experimental study was conducted to investigate the defense response elicited, as assessed by measuring the activities of antioxidant enzymes like superoxide dismutase (SOD) and catalase (CAT), as well as hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) and chlorophyll contents in grafted and non-grafted eggplants under different TSSM infestation levels (10, 30 and 50 adults per plant). In addition, the effect of grafting on plant growth and yield of eggplant was evaluated. According to the findings of the present study, grafted plants had a lower density of TSSM than non-grafted plants. The number of eggs, nymphs, and adults on grafted plants was 40.11%, 31.71%, and 27.54%, respectively, lower than on non-grafted plants. With increasing TSSM density, the activities of CAT and SOD were increased at varying degrees. In terms of SOD activity, the grafted plants outperformed both the non-grafted scion and rootstock at all TSSM densities. In addition, the results demonstrated that plants with greater CAT activity were able to maintain a lower H<sub>2</sub>O<sub>2</sub> content and vice versa. The lower negative impacts on photosynthetic pigments demonstrated that grafted plants on S. torvum were more resistant to mite-induced damage to chlorophyll and carotenoids as mite density elevated. The grafted plants were superior in vegetative growth, and the total fruit weight was found to be two times higher than non-grafted plants. The features modified by grafting, such as the increased activities of SOD and CAT, can alleviate the impact of TSSM. Therefore, grafting could constitute a valuable tool when combined with other strategies of Integrated Pest Management (IPM) in the two-spotted spider mite control programs.

Investigating the impact of plasma plume length of atmospheric pressure plasma jet on ampicillin degradation efficiency and toxicity

Emerging pharmaceutical micropollutant: ampicillin-degradation in water using atmospheric pressure plasma jets (APPJs) is examined, and its environmental impact is evaluated. To this end, comprehensive plasma characterization techniques, including electrical and optical analyses, are used, to supplement existing research that primarily focused on degradation outcomes. The results of these techniques provide deeper insights into the degradation process. Additionally, the solution properties are assessed by examining the treated liquids and quantifying the corresponding hydrogen peroxide and nitrite concentrations, clarifying the role of reactive species in the degradation process. High-performance liquid chromatography analysis provides essential insights into degradation kinetics and rate constants. A comprehensive framework is developed for understanding the degradation of ampicillin by APPJs, combining plasma diagnostics, solution characterization, chemical assays, degradation kinetics, and toxicity analysis. Our study, grounded in these multidisciplinary approaches, contributes to both the fundamental understanding of plasma-based degradation and optimization of plasma plume length. Our findings highlight the potential of plasma jet technologies in addressing pharmaceutical pollution and promoting sustainable wastewater management practices. This research can advance efforts to enhance the efficiency of pharmaceutical waste treatment, ultimately safeguarding the health and well-being of aquatic ecosystems and human populations.

OsAlR3 regulates aluminum tolerance through promoting the secretion of organic acids and the expression of antioxidant genes in rice

In acidic soils, aluminum (Al) toxicity inhibits the growth and development of plant roots and affects nutrient and water absorption, leading to reduced yield and quality. Therefore, it is crucial to investigate and identify candidate genes for Al tolerance and elucidate their physiological and molecular mechanisms under Al stress. In this study, we identified a new gene OsAlR3 regulating Al tolerance, and analyzed its mechanism from physiological, transcriptional and metabolic levels. Compared with the WT, malondialdehyde (MDA) and hydrogen peroxide (H2O2) content were significantly increased, superoxide dismutase (SOD) activity and citric acid (CA) content were significantly decreased in the osalr3 mutant lines when exposed to Al stress. Under Al stress, the osalr3 exhibited decreased expression of antioxidant-related genes and lower organic acid content compared with WT. Integrated transcriptome and metabolome analysis showed the phenylpropanoid biosynthetic pathway plays an important role in OsAlR3-mediated Al tolerance. Exogenous CA and oxalic acid (OA) could increase total root length and enhance the antioxidant capacity in the mutant lines under Al stress. Conclusively, we found a new gene OsAlR3 that positively regulates Al tolerance by promoting the chelation of Al ions through the secretion of organic acids, and increasing the expression of antioxidant genes.

Enhancing catalyst stability: Immobilization of Cu–Fe catalyst in sodium alginate matrix for methyl orange removal via Fenton-like reaction

This study aims to enhance the stability and effectiveness of heterogeneous catalysts in Fenton-like reactions, explicitly addressing the acidity limitations inherent in traditional Fenton processes. Copper-iron was synthesized through co-precipitation, and a catalyst bead was produced from hydrogel formation. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) confirm phases in the bimetallic Copper-iron, aligning with the intended composition. Modification with alginate led to reduced metal leaching compared to the bare bimetallic counterpart, as confirmed by atomic absorption spectroscopy (AAS). Additionally, Fourier-transform infrared spectroscopy (FTIR) revealed the deactivation of alginate through the disappearance of carboxyl groups, indicating the depolymerization of the catalyst bead. Under the suggested conditions (Methyl Orange concentration of 25 mg/L, initial solution pH of 7, 2 g/L catalyst loading, concentration of hydrogen peroxide 100 mM in a 120-min reaction time), the catalyst demonstrated remarkable decolorization efficiency of Methyl Orange, achieving 97.67 %. Further highlighting its practicality, the catalyst exhibited outstanding reusability over four cycles under identical conditions, showcasing robust immobilization capabilities and sustained performance. Notably, the catalyst's magnetic properties facilitated easy separation using an external magnet. In conclusion, the developed catalyst beads offer a solution with high reusability, magnetic separability, and reduced iron leaching. The advantageous characteristics underscore its potential as a heterogeneous catalyst for wastewater treatment applications, warranting further exploration under practical conditions.

Oczyszczanie ścieków z wytłoczyn z oliwek poprzez elektrokoagulację peroksydacyjną z wykorzystaniem arkuszy aluminiowych

The extraction of olive pomace oil is a significant aspect of the edible oil industry in Mediterranean regions where olives are widely cultivated. The resulting wastewater generated from this industry is known to harbor pollutants, including residual solvents, oils, and chemicals from the refining process, that can have adverse effects on the environment and public health. Peroxy-electrocoagulation (PEC) is a method that can be used to treat wastewater from the olive pomace oil extraction industry. The purpose of the work was to reduce the concentration of pollutants in the effluent through the use of PEC with aluminum electrodes as a method of treatment. The Box-Behnken Design was used to study the relationship between hydrogen peroxide dosage (10, 20, and 30 g L-1), electric current density (5, 20 and 35 mA cm-2), and the initial pH (2.5, 3.5, and 4.5), in the PEC process, and the removal of chemical oxygen demand (COD) and total phenolic compounds (TPh). The highest removal was obtained with hydrogen peroxide dosage of 30 g L-1, and 20 mA cm-2, and with 29% of TPh removal at pH 2.5, and with 84% COD removal at pH 4.5. The procedure removed an average of 22% COD and 82% TPh. The concentration of hydrogen peroxide was one of the most significant factors in the process. Pre-treatment with other techniques is necessary to reduce harmful elements in the effluent before undergoing biological treatment.

Evaluating Ecological Nano-Calcium from Eggshells: Effects on Calcium Nutrition and Oxidative Stress in Lettuce Under Saline and Boron Toxicity

AbstractNano-fertilizers with higher efficacy compared to conventional fertilizers can provide advantage for plant cultivation in both productive and problematic soils. Therefore, this study aimed to determine the effect of nano-calcium (nano-Ca) on lettuce plants grown in saline-boron toxic soil. Nano-calcium fertilizer was prepared from eggshells. Functional and structural properties of nano-Ca was determined by scanning electron microscopy (SEM), x-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR) before plant experiment. The treatments was; control, 40 mM NaCl and 20 mg kg−1 B (NaCl + B), and 40 mM NaCl and 20 mg kg−1 B with 4 mM Nano-Ca (NaCl + B + nano-Ca). The nano-Ca significantly increased the dry weight and calcium (Ca) concentration of lettuce plants under saline-B toxic conditions. Although there was a decrease in the concentrations of sodium (Na), chloride (Cl), and boron (B) with nano-Ca treatment, it was not statistically significant. Salinity and boron toxicity lead to increased lipid peroxidation. In the present study, the production of malondialdehyde (MDA) as a marker for lipid peroxidation, along with a significant decrease in hydrogen peroxide (H2O2) concentration, was observed with the application of nano-Ca. There was no significant alteration in superoxide dismutase activity (SOD) observed in lettuce grown under saline and boron toxic conditions. However, catalase activity (CAT) increased with nano-Ca application, while the activity of ascorbate peroxidase (APX) decreased. The study results suggest that nano-Ca serves a protective function for lettuce plants cultivated under saline and boron toxic conditions.

Comprehensive evaluation of drought tolerance of six Chinese chestnut varieties (clones) based on flavonoids and other physiological indexes

Flavonoids are crucial secondary metabolites that possess the ability to mitigate UV damage and withstand both biotic and abiotic stresses. Therefore, it is of immense significance to investigate the flavonoid content as a pivotal indicator for a comprehensive assessment of chestnut's drought tolerance. This study aimed to determine the flavonoid content and drought tolerance-related physiological and biochemical indices of six chestnut varieties (clones) grafted trees—Qianxi 42 (QX42), Qinglong 45 (QL45), Yanshanzaofeng (YSZF), Yanzi (YZ), Yanqiu (YQ), and Yanlong (YL)-under natural drought stress. The results were used to comprehensively analyze the drought tolerance ability of these varieties. The study revealed that the ranking of drought tolerance indices in terms of their ability to reflect drought tolerance was as follows: superoxide (oxide) dismutase (SOD) activity, ascorbate peroxidase (APX) activity, flavone content, catalase (CAT) activity, proline (PRO) content, soluble sugar content, peroxidase (POD) activity, betaine content, flavonol content, hydrogen peroxide (H2O2) content, soluble protein content, superoxide ion (OFR) content, superoxide (ion OFR) production rate, malondialdehyde (MDA) content, chlorophyll content. Through principal component analysis, the contents of flavonoids and flavonols can be used as indicators for comprehensive evaluation of drought tolerance of chestnut. The comprehensive evaluation order of drought tolerance of grafted trees of 6 chestnut varieties (Clones) was: QL45 > QX42 > YQ > YZ > YSZF > YL.

Basidiomycetes Polysaccharides Regulate Growth and Antioxidant Defense System in Wheat.

Higher-fungi xylotrophic basidiomycetes are known to be the reservoirs of bioactive metabolites. Currently, a great deal of attention has been paid to the exploitation of mycelial fungi products as an innovative alternative in crop protection. No data exist on the mechanisms behind the interaction between xylotrophic mushrooms' glycopolymeric substances and plants. In this study, the effects of basidiomycete metabolites on the morphophysiological and biochemical variables of wheat plants have been explored. Wheat (Triticum aestivum L. cv. Saratovskaya 29) seedlings were treated with extracellular polysaccharides (EPSs) isolated from the submerged cultures of twenty basidiomycete strains assigned to 13 species and 8 genera. The EPS solutions at final concentrations of 15, 40, and 80 mg/L were applied to wheat seedlings followed by their growth for 10 days. In the plant samples, the biomass, length of coleoptile, shoot and root, root number, rate of lipid peroxidation by malondialdehyde concentration, content of hydrogen peroxide, and total phenols were measured. The peroxidase and superoxide dismutase activity were defined. Most of the EPS preparations improved biomass yields, as well as the morphological parameters examined. EPS application enhanced the activities of antioxidant enzymes and decreased oxidative damage to lipids. Judging by its overall effect on the growth indices and redox system of wheat plants, an EPS concentration of 40 mg/L has been shown to be the most beneficial compared to other concentrations. This study proves that novel bioformulations based on mushroom EPSs can be developed and are effective for wheat growth and antioxidative response. Phytostimulating properties found for EPSs give grounds to consider extracellular metabolites produced in the xylotrophic basidiomycete cultures as an active component capable of inducing plant responses to stress.

Oxidative stress dynamics revealed the role of H2O2 in citrus rootstocks sensitivity to Phytophthoranicotianae

Phytophthora nicotianae is a devastating pathogen in citrus and tolerant rootstocks are required for its management. Seven Jatti Khatti (JK, a rough lemon strain; susceptible) × Poncirus trifoliata (PT; tolerant) hybrids were screened against P. nicotianae. In feeder root rot based evaluation, three hybrids were found moderately tolerant (MT) while four were moderately susceptible (MS). The H2O2 in plant pathogen interactions contributes in resistance/susceptibility to the biotrophic/necrotrophic pathogens. To comprehend its role in citrus against Phytophthora (a hemi-biotrophic pathogen), H2O2, lipid peroxidation, and peroxidase (POD) activity were determined in Phytophthora inoculated and non-inoculated roots of JK, PT, three MT and one MS hybrids at 10, 20 and 30 days post inoculation (dpi). The tolerant parent, PT and MT hybrids exhibited lower or stable H2O2 content in Phytophthora inoculated plants at 20 or 30-dpi. Their POD activity increased at 10-dpi, depicting its role in H2O2 homoeostasis. At 30-dpi, JK and MS hybrid showed significantly higher H2O2 content (4.10 and 3.62 μmol g−1 FW), compared to 1.88 μmol g−1 FW in PT. The lipid peroxidation content significantly increased in JK or MS hybrid at 20 or 30-dpi. The susceptible or MS individuals displayed significantly higher (18–25 % higher) electrolyte leakage than their control. A strong positive association (r = 0.89) was found between electrolytes leakage and H2O2 accumulation at 30-dpi. The POD activity and H2O2 at 10-dpi showed strong negative correlation (r = −0.86). Results infer that high H2O2 causes cellular death and contributes to Phytophthora susceptibility in citrus. It can serve as a biomarker for predicting relative sensitivity to Phytophthora.

Modelling thermal characteristics of cocoa butter using a feed‐forward artificial neural network based on multilayer perceptron

SummaryCocoa butter is the most important ingredient of chocolate, which determines its melting behaviour. Variations in the melting characteristics of cocoa butter can profoundly affect the performance and suitability for their industrial utilisation. Over time, researchers have been attempting to establish a logical relationship between cocoa butter's unique thermal properties and the amount of saturated to unsaturated fatty acids in mono, di and triglycerides, and fatty acids (as major components), and free fatty acids, soap, primary oxidation products, minerals, moisture, phospholipids, tocopherols, unsaponifiable matters and metals (as minor components) found in cocoa butter. In this research, the thermal behaviours of thirteen samples of cocoa butter with different origins were investigated using isothermal differential scanning calorimetry. The cocoa butters starting temperature of crystallisation, temperature of maximum heat release, temperature of completed crystallisation and the enthalpy of heat release during recrystallisation were evaluated. In addition, the chemical composition (moisture, acidity, peroxide, minerals and soap content), fatty acid and triacylglycerol composition were used to establish an MLP‐ANN with fourteen input neurons connected by two flexible, sigmoid activation function layers. The back‐propagation was used to train the artificial neural network (ANN) structure and optimise the error of prediction. The study showed that the MLP algorithm can predict the thermal behaviour of CB samples with trace error, regardless of plant growth and extract process condition.

Unleashing the Power of Fungi: Utilizing the Arbuscular Mycorrhizal Fungi Rhizophagus clarus to Mitigate Salinity Stress and Boost Cowpea Bean Productivity for Food Security

The increasing demands for food, driven by shrinking arable land areas and a growing population, underscore the need for innovative agricultural practices to mitigate the effects of soil degradation due to salinity and promote food security, particularly in regions heavily impacted by salinity. In this study, we investigated the effects of inoculating the arbuscular mycorrhizal fungus (AMF) Rhizophagus clarus on the productivity of Vigna unguiculata cv. BRS Imponente plants in response to salinity (0, 25, 50, 75, and 100 mM). We found that NaCl concentrations ≥ 50 mM were phytotoxic, reducing plant growth and productivity. However, inoculation with AMF reduced plant oxidative stress (hydrogen peroxide concentration and lipid peroxidation) and ionic stress (Na+/K+ ratio). Inoculated plants exhibited increased antioxidant enzyme activity (ascorbate peroxidase and catalase), higher P and K concentrations, and lower Na concentrations in their leaves. As a result, salt did not interfere with grain production in the AMF-inoculated plants. For the first time, we demonstrate that inoculation with R. clarus can counteract the harmful effects of NaCl in V. unguiculata plants, ensuring their grain yields. Therefore, amid the escalating soil salinization globally, the AMF R. clarus emerges as a practical approach to ensure cowpea yields and enhance production in deteriorating agricultural lands, especially in saline areas. This can significantly contribute to promoting food security.

The Potential of Using Bisr Date Powder as a Novel Ingredient in Biscuits Made of Wheat Flour Only or Mixed with Barley.

An overproducing date fruit with limited industrial utilization leads to significant waste and losses, especially in the early stage of date maturity known as bisr. This study aimed to investigate the potential use of bisr date powder (BDP) at different concentrations (25%, 50%, and 100%) as a natural sweetener instead of sugar and barley flour as a source of dietary fiber, vitamins, and minerals instead of wheat flour (50%) in biscuit production over storage periods of 7, 14, and 21 days. The analysis revealed that the bisr Al-Khalas powder sample had a moisture content of 11.84%, ash content of 2.30%, and crude fiber content of 10.20%. Additionally, it had a low protein (2.50%) and fat (0.77%) content, with total carbohydrates at 82.59%. The gradual substitution of bisr Al-Khalas in biscuit production resulted in an increased moisture, ash, fat, protein, crude fiber, and iron content, as well as a decrease in total carbohydrate percentage. A chemical analysis of bisr Al-Khalas powder demonstrated high levels of antioxidants, with 248.49 mg gallic acid/g of phenolic compounds, 31.03 mg quercetin/g of flavonoids, and an antioxidant activity ranging from 42.30%, as shown by the DPPH test. The peroxide content was 0.009 mg equivalent/kg. Biscuit samples with different proportions of bisr Al-Khalas showed an improved resistance to oxidation compared to samples without bisr Al-Khalas, with increased resistance as the percentage of replacement increased during storage. Physical properties such as the diameter, height, and spread percentage, as well as organoleptic properties like color, flavor, aroma, and taste, were significantly enhanced with higher levels of bisr Al-Khalas in the mixture. Biscuit samples fortified with 100% pure bisr Al-Khalas powder were found to be less acceptable, while samples with a 25% substitution did not negatively impact sensory properties. In addition, acrylamide and hydroxymethylfurfural (HMF) were not detected in bisr powder and biscuit samples prepared at different concentrations (25%, 50%, and 100%). In conclusion, the study suggests that bisr Al-Khalas powder, an underutilized waste product, has the potential to add value to commercial biscuit production due to its high nutritional value and extended storage period resulting from its potent antioxidant activity.

A novel plant growth regulator B2 mediates drought resistance by regulating reactive oxygen species, phytohormone signaling, phenylpropanoid biosynthesis, and starch metabolism pathways in Carex breviculmis

Drought is one of the most common environmental stressors that severely threatens plant growth, development, and productivity. B2 (2,4-dichloroformamide cyclopropane acid), a novel plant growth regulator, plays an essential role in drought adaptation, significantly enhancing the tolerance of Carex breviculmis seedlings. Its beneficial effects include improved ornamental value, sustained chlorophyll content, increased leaf dry weight, elevated relative water content, and enhanced root activity under drought conditions. B2 also directly scavenges hydrogen peroxide and superoxide anion contents while indirectly enhancing the activities of antioxidant enzymes (superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase) to detoxify reactive oxygen species (ROS) oxidative damage. Transcriptome analysis demonstrated that B2 activates drought-responsive transcription factors (AP2/ERF-ERF, WRKY, and mTERF), leading to significant upregulation of genes associated with phenylpropanoid biosynthesis (HCT, POD, and COMT). Additionally, these transcription factors were found to suppress the degradation of starch. B2 regulates phytohormone signaling related-genes, leading to an increase in abscisic acid contents in drought-stressed plants. Collectively, these findings offer new insights into the intricate mechanisms underlying C. breviculmis' resistance to drought damage, highlighting the potential application of B2 for future turfgrass establishment and management with enhanced drought tolerance.

Short‐Term Soil Waterlogging Improves Cotton Tolerance to High Temperature by Triggering Antioxidant Defence System in Cotton Seedlings

ABSTRACTSoil waterlogging and high temperature (HT) are serious abiotic stresses that negatively affect cotton growth and yield. Yet effects of prewaterlogging to HT subsequently in cotton seedlings have not been obtained. To address this, two temperature conditions (30/20°C and 35/25°C) and two soil waterlogging levels (0 and 3 days) were established during the cotton seedling stage. Results showed that indexes of plant performance were decreased markedly under HT. Unexpectedly, plant performance for the treatment of HT combined with 3 days of soil waterlogging (HW) was better than HT treatment (specifically, increase of 7.9%, 9.0%, 10.2%, 5.4% and 4.6% in leaf area, plant height, belowground biomass, aboveground biomass and root‐to‐shoot ratio was detected). Decreases in MDA (malondialdehyde), H2O2 (hydrogen peroxide) contents and (superoxide radicals) generation rate under HW treatment were observed by 14.1%, 7.7% and 14.1%, respectively, compared with HT. Moreover, ASA (ascorbic acid) content and DHAR (dehydroascorbate reductase) activity were improved by 19.7% and 13.8% for HW treatment relative to HT, however, the opposite situation for activities of APX (ascorbate peroxidase) and GR (glutathione reductase). Besides, activities of SOD (superoxide dismutase), CAT (catalase) and POD (peroxidase) in HW treatment were increased by 16.7%, 8.3% and 18.4%, separately. Thus, we concluded that short‐term soil waterlogging improved cotton cross‐tolerance to the continued high‐HT stress by enhanced SOD, CAT, POD and DHAR activities, increased ASA content in cotton seedlings. These results were expected to provide a theoretical basis for understanding cotton's cross‐tolerance to abiotic stress.

Antioxidants are ineffective at quenching reactive oxygen species inside bacteria and should not be used to diagnose oxidative stress.

A wide variety of stresses have been proposed to exert killing effects upon bacteria by stimulating the intracellular formation of reactive oxygen species (ROS). A key part of the supporting evidence has often been the ability of antioxidant compounds to protect the cells. In this study, some of the most-used antioxidants-thiourea, glutathione, N-acetylcysteine, and ascorbate-have been examined. Their ability to quench superoxide and hydrogen peroxide was verified invitro, but the rate constants were orders of magnitude too slow for them to have an impact upon superoxide and peroxide concentrations invivo, where these species are already scavenged by highly active enzymes. Indeed, the antioxidants were unable to protect the growth and ROS-sensitive enzymes of E. coli strains experiencing authentic oxidative stress. Similar logic posits that antioxidants cannot substantially quench hydroxyl radicals inside cells, which contain abundant biomolecules that react with them at diffusion-limited rates. Indeed, antioxidants were able to protect cells from DNA damage only if they were applied at concentrations that slow metabolism and growth. This protective effect was apparent even under anoxic conditions, when ROS could not possibly be involved, and it was replicated when growth was similarly slowed by other means. Experimenters should discard the use of antioxidants as a way of detecting intracellular oxidative stress and should revisit conclusions that have been based upon such experiments. The notable exception is that these compounds can effectively degrade hydrogen peroxide from environmental sources before it enters cells.

Development of a microfluidic wearable electrochemical sensor for the non-invasive monitoring of oxidative stress biomarkers in human sweat

Oxidative stress is widely recognized as a pivotal factor contributing to numerous Central Nervous System (CNS) ailments. The concentrations of hydrogen peroxide (H2O2) and phosphorylated proteins within the human body serve as crucial indicators of oxidative stress. As such, the real-time monitoring of H2O2 and phosphorylated proteins in sweat is vital for the early identification, diagnosis, and management of diseases linked to oxidative stress. In this context, we present a novel microfluidic wearable electrochemical sensor by modifying the electrode with Prussian blue (PB) and loading sulfur-rich vacancy-containing molybdenum disulfide (MoS2-X) onto Multi-walled carbon nanotube (CNTs) to form coaxially layered CNTs/MoS2-X, which was then synthesized with highly dispersed titanium dioxide nanoparticles (TiO2) to synthesize CNTs/MoS2-X/TiO2 composites for the detection of human sweat H2O2 and phosphorylated proteins, respectively. This structure, with its sulfur vacancies and coaxial layering, significantly improved sensitivity of electrochemical sensors, allowing it to detect H2O2 in a range of 0.01–1 mM with a detection limit of 4.80 μM, and phosphoproteins in a range of 0.01–1 mg/mL with a threshold of 0.917 μg/mL. Furthermore, the miniature sensor demonstrates outstanding performance in detecting analytes in both simulated and real sweat. Comprehensive biosafety assessments have validated the compatibility of the electrode material, underscoring the potential of sensor as a reliable and non-invasive method for tracking biomarkers linked to CNS disorders. This microfluidic wearable electrochemical biosensor with high performance and biosafety features shows great promise for the development of cutting-edge wearable technology devices for tracking CNS disease indicators.

Unraveling the Hippocampal Molecular and Cellular Alterations behind Tramadol and Tapentadol Neurobehavioral Toxicity.

Tramadol and tapentadol are chemically related opioids prescribed for the analgesia of moderate to severe pain. Although safer than classical opioids, they are associated with neurotoxicity and behavioral dysfunction, which arise as a concern, considering their central action and growing misuse and abuse. The hippocampal formation is known to participate in memory and learning processes and has been documented to contribute to opioid dependence. Accordingly, the present study assessed molecular and cellular alterations in the hippocampal formation of Wistar rats intraperitoneally administered with 50 mg/kg tramadol or tapentadol for eight alternate days. Alterations were found in serum hydrogen peroxide, cysteine, homocysteine, and dopamine concentrations upon exposure to one or both opioids, as well as in hippocampal 8-hydroxydeoxyguanosine and gene expression levels of a panel of neurotoxicity, neuroinflammation, and neuromodulation biomarkers, assessed through quantitative real-time polymerase chain reaction (qRT-PCR). Immunohistochemical analysis of hippocampal formation sections showed increased glial fibrillary acidic protein (GFAP) and decreased cluster of differentiation 11b (CD11b) protein expression, suggesting opioid-induced astrogliosis and microgliosis. Collectively, the results emphasize the hippocampal neuromodulator effects of tramadol and tapentadol, with potential behavioral implications, underlining the need to prescribe and use both opioids cautiously.