Peroxide Anion Research Articles

The physiological response of oriental river prawn Macrobrachium nipponense to starvation-induced stress

Environmental stresses play critical roles in the physiology of crustaceans. Food deprivation is an important environmental factor and a regular occurrence in both natural aquatic habitats and artificial ponds. However, the underlying physiological response mechanisms to starvation-caused stress in crustaceans are yet to be established. In the present study, the hepatopancreas tissue of Macrobrachium nipponense was transcriptome analyzed and examined for starvation effects on oxidative stress, DNA damage, autophagy, and apoptosis across four fasting stages (0 (control group), 7, 14, and 21 days). These results indicated that a ROS-mediated regulatory mechanism is critical to the entire fasting process. At the initial stage of starvation (fasting 0 d ~ 7 d), ROS concentration increased gradually, activating antioxidant enzymes to protect the cellular machinery from the detrimental effects of oxidative stress triggered by starvation-induced stress. ROS content production (hydrogen peroxide and superoxide anion) then rose continuously with prolonged starvation (fasting 7 d ~ 14 d), reaching peak levels and resulting in autophagy in hepatopancreas cells. During the final stages of starvation (fasting 14 d ~ 21 d), excessive ROS induced DNA damage and cell apoptosis. Furthermore, autophagolysosomes and apoptosis body were further identified with transmission electron microscopy. These findings lay a foundation for further scrutiny of the molecular mechanisms combating starvation-generated stress in M. nipponense and provide fishermen with the theoretical guidance for adopting fasting strategies in M. nipponense aquaculture.

Plant growth regulators mitigate oxidative damage to rice seedling roots by NaCl stress.

The aim of this experiment was to investigate the effects of exogenous sprays of 5-aminolevulinic acid (5-ALA) and 2-Diethylaminoethyl hexanoate (DTA-6) on the growth and salt tolerance of rice (Oryza sativa L.) seedlings. This study was conducted in a solar greenhouse at Guangdong Ocean University, where 'Huanghuazhan' was selected as the test material, and 40 mg/L 5-ALA and 30 mg/L DTA-6 were applied as foliar sprays at the three-leaf-one-heart stage of rice, followed by treatment with 0.3% NaCl (W/W) 24 h later. A total of six treatments were set up as follows: (1) CK: control, (2) A: 40 mg⋅ L-1 5-ALA, (3) D: 30 mg⋅ L-1 DTA-6, (4) S: 0.3% NaCl, (5) AS: 40 mg⋅ L-1 5-ALA + 0.3% NaCl, and (6) DS: 30 mg⋅ L-1 DTA-6+0.3% NaCl. Samples were taken at 1, 4, 7, 10, and 13 d after NaCl treatment to determine the morphology and physiological and biochemical indices of rice roots. The results showed that NaCl stress significantly inhibited rice growth; disrupted the antioxidant system; increased the rates of malondialdehyde, hydrogen peroxide, and superoxide anion production; and affected the content of related hormones. Malondialdehyde content, hydrogen peroxide content, and superoxide anion production rate significantly increased from 12.57% to 21.82%, 18.12% to 63.10%, and 7.17% to 56.20%, respectively, in the S treatment group compared to the CK group. Under salt stress, foliar sprays of both 5-ALA and DTA-6 increased antioxidant enzyme activities and osmoregulatory substance content; expanded non-enzymatic antioxidant AsA and GSH content; reduced reactive oxygen species (ROS) accumulation; lowered malondialdehyde content; increased endogenous hormones GA3, JA, IAA, SA, and ZR content; and lowered ABA content in the rice root system. The MDA, H2O2, and O2- contents were reduced from 35.64% to 56.92%, 22.30% to 53.47%, and 7.06% to 20.01%, respectively, in the AS treatment group compared with the S treatment group. In the DS treatment group, the MDA, H2O2, and O2- contents were reduced from 24.60% to 51.09%, 12.14% to 59.05%, and 12.70% to 45.20%. In summary, NaCl stress exerted an inhibitory effect on the rice root system, both foliar sprays of 5-ALA and DTA-6 alleviated damage from NaCl stress on the rice root system, and the effect of 5-ALA was better than that of DTA-6.

Synthesis, characterization, and antioxidant efficiency of CoCu/(βCDhis) complex

This report describes the synthesis of a bimetallic cobalt-copper complex of histidine-containing β-cyclodextrin (βCDhis) capable of efficiently scavenging superoxide radicals and peroxide anions. A blue-violet CoCu/(βCDhis) complex was prepared in mole ratios of 0.165:0.25:1:1 of Co:Cu:his:βCD in water and characterized using UV–vis, TGA-DTA, EDX, powder XRD and FT-IR analytical techniques. TGA analysis and XRD patterns showed that histidine was incorporated within the β-cyclodextrin ring. UV–Vis and FT-IR spectroscopy confirmed that the histidine CO group interacts with copper and cobalt metals. The results of antioxidant activity tests showed that CoCu/(βCDhis) complex has the highest catalase (88 %), and peroxidase activity (87 %) per 0.005 g of the complex. The imidazole group in histidine increases the solubility of the synthesized complexes and the ability to scavenge hydroxyl radicals, therefore histidine enhances their antioxidant potential.

Oxidative replication stress induced by long-term exposure to hydroxyurea in root meristem cells of Vicia faba.

Low concentrations of hydroxyurea, an inhibitor of DNA replication, induced oxidative and replicative stress in root apical meristem (RAM) cells of Vicia faba. Plant cells are constantly exposed to low-level endogenous stress factors that can affect DNA replication and lead to DNA damage. Long-term treatments of Vicia faba root apical meristems (RAMs) with HU leads to the appearance of atypical cells with intranuclear asynchrony. This rare form of abnormality was manifested by a gradual condensation of chromatin, from interphase to mitosis (so-called IM cells). Moreover, HU-treated root cells revealed abnormal chromosome structure, persisting DNA replication, and elevated levels of intracellular hydrogen peroxide (H2O2) and superoxide anion (O2∙-). Immunocytochemical studies have shown an increased number of fluorescent foci of H3 histones acetylated at lysine 56 (H3K56Ac; canonically connected with the DNA replication process). We show that continuous 3-day exposure to low concentrations (0.75mM) of hydroxyurea (HU; an inhibitor of DNA replication) induces cellular response to reactive oxygen species and to DNA replication stress conditions.

Nitric oxide alleviates mercury toxicity by changing physiological and biochemical pathways in maize (Zea mays L.) seedlings

Like all life forms, plants suffer from high levels of mercury (Hg), known as one of the most harmful heavy metals in soil. The present study was performed to explore the effects of exogenous nitric oxide (NO) on Hg toxicity in maize (Zea mays L., cv. Arifiye-2) seedlings. Plants were grown in a hydroponic system containing 1/2 diluted Hoagland at 16 h day length, 25/20 °C (day/night) and 60% relative humidity. Eight day-old maize seedlings were first treated with NO (as 0.1 µM sodium nitroprusside) and then they were exposed to Hg toxicity (as 100 µM HgCl2) after 24 h. The toxic Hg decreased seedling growth, chlorophyll content, proline content, calcium and manganese contents, non-enzymatic antioxidant contents, cell membrane viscosity, and antioxidant enzyme activities (superoxide dismutase, catalase, peroxidases, and glutathione reductase) while it increased the generation of reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) and super oxide anion (O2.-), and lipid peroxidation (as malondialdehyde, MDA) content and the amount of sodium ion (Na+) in the seedlings. However, NO treatment markedly enhanced the growth parameters (dry and fresh weight, and plant height) and manganese and potassium contents as well as contents of antioxidants and chlorophyll thus alleviating the negative effects caused by the Hg stress. Also, it decreased the generation of ROS and lipid peroxidation level by activating the antioxidant enzymes. These results show that NO in maize seedlings under Hg toxicity may improve stress response and mitigate oxidative stress by stimulating the antioxidant system and modulating ion homeostasis.

Redox-signalling and Redox Biomarkers in Cardiovascular Health and Disease.

Overproduction of reactive nitrogen and oxygen species (RNS and ROS) has been linked to the pathogenesis of diabetes, hypertension, hyperlipidemia, stroke, angina, and other cardiovascular diseases. These species are produced in part by the mitochondrial respiratory chain, NADPH oxidase, and xanthine oxidase. RNS and ROS both contribute to oxidative stress, which is necessary for the development of cardiovascular disorders. In addition to ROS species like hydroxyl ion, hydrogen peroxide, and superoxide anion, RNS species like nitric oxide, peroxynitrous acid, peroxynitrite, and nitrogen dioxide radicals have also been linked to a number of cardiovascular conditions. They promote endothelial dysfunction, vascular inflammation, lipid peroxidation, and oxidative damage, all of which contribute to the development of cardiovascular pathologies. It's crucial to understand the mechanisms that result in the production of RNS and ROS in order to identify potential therapeutic targets. Redox biomarkers serve as indicators of oxidative stress, making them crucial tools for diagnosing and predicting cardiovascular states. The advancements in proteomics, metabolomics, genomics, and transcriptomics have made the identification and detection of these small molecules possible. The following redox biomarkers are notable examples: 3-nitrotyrosine, 4-hydroxy-2-nonenal, 8- iso-prostaglandin F2, 8-hydroxy-2-deoxyguanosine, malondialdehyde, Diacron reactive oxygen metabolites, total thiol, and specific microRNAs (e.g. miRNA199, miRNA21, miRNA1254, miRNA1306-5p, miRNA26b-5p, and miRNA660-5p) are examples. Although redox biomarkers have great potential, their clinical applicability faces challenges. Redox biomarkers frequently have a short half-life and exist in small quantities in the blood, making them challenging to identify and measure. The interpretation of biomarker data may also be influenced by confounding factors and the complex interplay of various oxidative stress pathways. Therefore, in-depth validation studies and the development of sensitive and precise detection methods are needed to address these problems. In the search for redox biomarkers, cutting-edge techniques like mass spectrometry, immunoassays, and molecular diagnostics are applied. New platforms and technologies have made it possible to accurately detect and monitor redox biomarkers, which facilitates their use in clinical settings. Our expanding knowledge of RNS and ROS involvement in cardiovascular disorders has made it possible to develop redox biomarkers as diagnostic and prognostic tools. Overcoming the challenges associated with their utility and utilizing advanced detection techniques, which will improve their clinical applicability, will ultimately benefit the management and treatment of cardiovascular conditions.

Physiological and Biochemical Aspects of Silicon-Mediated Resistance in Maize against Maydis Leaf Blight.

Maydis leaf blight (MLB), caused by the necrotrophic fungus Bipolaris maydis, has caused considerable yield losses in maize production. The hypothesis that maize plants with higher foliar silicon (Si) concentration can be more resistant against MLB was investigated in this study. This goal was achieved through an in-depth analysis of the photosynthetic apparatus (parameters of leaf gas exchange chlorophyll (Chl) a fluorescence and photosynthetic pigments) changes in activities of defense and antioxidative enzymes in leaves of maize plants with (+Si; 2 mM) and without (-Si; 0 mM) Si supplied, as well as challenged and not with B. maydis. The +Si plants showed reduced MLB symptoms (smaller lesions and lower disease severity) due to higher foliar Si concentration and less production of malondialdehyde, hydrogen peroxide, and radical anion superoxide compared to -Si plants. Higher values for leaf gas exchange (rate of net CO2 assimilation, stomatal conductance to water vapor, and transpiration rate) and Chl a fluorescence (variable-to-maximum Chl a fluorescence ratio, photochemical yield, and yield for dissipation by downregulation) parameters along with preserved pool of chlorophyll a+b and carotenoids were noticed for infected +Si plants compared to infected -Si plants. Activities of defense (chitinase, β-1,3-glucanase, phenylalanine ammonia-lyase, polyphenoloxidase, peroxidase, and lipoxygenase) and antioxidative (ascorbate peroxidase, catalase, superoxide dismutase, and glutathione reductase) enzymes were higher for infected +Si plants compared to infected -Si plants. Collectively, this study highlights the importance of using Si to boost maize resistance against MLB considering the more operative defense reactions and the robustness of the antioxidative metabolism of plants along with the preservation of their photosynthetic apparatus.

E3 Ubiquitin Ligase PUB23 in Kiwifruit Interacts with Trihelix Transcription Factor GT1 and Negatively Regulates Immune Responses against Pseudomonas syringae pv. actinidiae.

Kiwifruit bacterial canker caused by Pseudomonas syringae pv. actinidiae (Psa) is the most serious disease threatening kiwifruit production. Our previous study found genes encoding the U-box containing proteins were significantly regulated by Psa infection. Here, we report a U-box type E3 ubiquitin ligase PUB23 in kiwifruit which acts as a negative regulator of immune responses against Psa. PUB23 was found to physically interact with GT1, a trihelix transcription factor, in vitro and in vivo. The expression of GT1 was up-regulated in PUB23-silenced plants, indicating that interacting with PUB23 may directly or indirectly suppress GT1 expression. The silencing of PUB23 led to enhanced immune responses of PAMP-triggered immunity (PTI), including a higher expression level of defense marker genes PR1 and RIN4, and increased accumulation of hydrogen peroxide and superoxide anion. Our results reveal a negative role PUB23 plays in kiwifruit immune responses against Psa and may regulate gene expression by interacting with GT1.

Oxygen‐18 Labeling Reveals a Mixed Fe−O Mechanism in the Last Step of Cytochrome P450 51 Sterol 14α‐Demethylation

AbstractThe 14α‐demethylation step is critical in eukaryotic sterol biosynthesis, catalyzed by cytochrome P450 (P450) Family 51 enzymes, for example, with lanosterol in mammals. This conserved three‐step reaction terminates in a C−C cleavage step that generates formic acid, the nature of which has been controversial. Proposed mechanisms involve roles of P450 Compound 0 (ferric peroxide anion, FeO2−) or Compound I (perferryl oxygen, FeO3+) reacting with either the aldehyde or its hydrate, respectively. Analysis of 18O incorporation into formic acid from 18O2 provides a means of distinguishing the two mechanisms. Human P450 51A1 incorporated 88 % 18O (one atom) into formic acid, consistent with a major but not exclusive FeO2− mechanism. Two P450 51 orthologs from amoeba and yeast showed similar results, while two orthologs from pathogenic trypanosomes showed roughly equal contributions of both mechanisms. An X‐ray crystal structure of the human enzyme showed the aldehyde oxygen atom 3.5 Å away from the heme iron atom. Experiments with human P450 51A1 and H218O yielded primarily one 18O atom but 14 % of the formic acid product with two 18O atoms, indicative of a minor contribution of a Compound I mechanism. LC–MS evidence for a Compound 0‐derived Baeyer–Villiger reaction product (a 14α‐formyl ester) was also found.

Oxygen-18 Labeling Reveals a Mixed Fe-O Mechanism in the Last Step of Cytochrome P450 51 Sterol 14α-Demethylation.

The 14α-demethylation step is critical in eukaryotic sterol biosynthesis, catalyzed by cytochrome P450 (P450) Family 51 enzymes, for example, with lanosterol in mammals. This conserved three-step reaction terminates in a C-C cleavage step that generates formic acid, the nature of which has been controversial. Proposed mechanisms involve roles of P450 Compound 0 (ferric peroxide anion, FeO2 - ) or Compound I (perferryl oxygen, FeO3+ ) reacting with either the aldehyde or its hydrate, respectively. Analysis of 18 O incorporation into formic acid from 18 O2 provides a means of distinguishing the two mechanisms. Human P450 51A1 incorporated 88 % 18 O (one atom) into formic acid, consistent with a major but not exclusive FeO2 - mechanism. Two P450 51 orthologs from amoeba and yeast showed similar results, while two orthologs from pathogenic trypanosomes showed roughly equal contributions of both mechanisms. An X-ray crystal structure of the human enzyme showed the aldehyde oxygen atom 3.5 Å away from the heme iron atom. Experiments with human P450 51A1 and H2 18 O yielded primarily one 18 O atom but 14 % of the formic acid product with two 18 O atoms, indicative of a minor contribution of a Compound I mechanism. LC-MS evidence for a Compound 0-derived Baeyer-Villiger reaction product (a 14α-formyl ester) was also found.

Hypoxia-Mediated Upregulation of Xanthine Oxidoreductase Causes DNA Damage of Colonic Epithelial Cells in Colitis.

Xanthine oxidoreductase (XOR) serves as the primary source of hydrogen peroxide and superoxide anions in the intestinal mucosa. However, its specific contribution to the progression of colonic disease remains unclear. In this study, we investigated the role of XOR in ulcerative colitis (UC) and attempted to identify the underlying mechanisms. We used the dextransulfatesodium (DSS)-induced mouse model to mimic UC and observed that XOR inhibitors, allopurinol and diphenyleneiodonium sulfate (DPI), significantly alleviated UC in mice. In addition, treatment with cobalt chloride (CoCl2) and 1% O2 increased the expression of XOR and induced DNA oxidative damage in colonic epithelial cells. Furthermore, we identified that XOR accumulation in the nucleus may directly cause DNA oxidative damage and regulates HIF1α protein levels. In addition, allopurinol effectively protected colon epithelial cells from CoCl2-induced DNA damage. Altogether, our data provided evidence that XOR could induce DNA damage under hypoxic conditions, indicating a significant role of XOR in the initiation and early development of colitis-associated colorectal cancer (CAC).

Epigallocatechin gallate (EGCG) nanoselenium application improves tea quality (Camellia sinensis L.) and soil quality index without losing microbial diversity: A pot experiment under field condition

Applying selenium (Se) fertilizer is the only way to alleviate soil Se deficiency. Although effects of nanoselenium foliar application on plant growth and stress resistance have been extensively investigated, soil application of nanoselenium on soil microorganisms and their relationship with crop quality and soil health remains unclear. In this study, a steady-state homogeneous nanoparticle of epigallocatechin gallate Se (ESe) was synthesized, and a pot experiment was conducted applying ESe at five concentrations (0, 1, 10, 50, and 100 mg kg−1) to the tea planattion soil. The study revealed a significant increase in Se concentration in soil and tea with ESe application and identified 2.43–7.8 mg kg−1 as the safe and optimal range for soil application. Specifically, the moderate dose of ESe improved the tea quality [reduced tea polyphenols (TP), increased free amino acids (AA), and reduced TP/AA] and soil quality index (SQI). Besides, in marure tea leaves, antioxidant enzyme activities [promote catalase (CAT) superoxide dismutase (SOD), and peroxidase (POD)] increased, while level of oxidative stress [malondialdehyde (MDA), hydrogen peroxide (H2O2) and superoxide anion (O2−)] decreased with ESe application. The 16S rRNA of the soil bacteria showed that ESe application significantly changed the community structure of soil bacteria but did not alter the diversity of the bacteria and the abundance of dominant taxa (phylum and genus levels). Statistical analysis of the taxonomic and functional profiles (STAMP) detected 21 differential taxa (genus level), mainly low-abundance ones, under the ESe application. Linear regression and random forest (RF) modeling revealed that the low-abundance bacterial taxa were significantly correlated with SQI (R2 = 0.28, p < 0.01) and tea quality (R2 = 0.23–0.37, p < 0.01). Thus, the study's findings suggest that ESe application affects soil and tea quality by modulating the low-abundance taxa in soil. The study also highlights the crucial role of low-abundance bacterial taxa of the rhizosphere in regulating soil functions under the ESe application.

A Critical Analysis of Chemical and Electrochemical Oxidation Mechanisms in Li-Ion Batteries.

Electrolyte decomposition limits the lifetime of commercial lithium-ion batteries (LIBs) and slows the adoption of next-generation energy storage technologies. A fundamental understanding of electrolyte degradation is critical to rationally design stable and energy-dense LIBs. To date, most explanations for electrolyte decomposition at LIB positive electrodes have relied on ethylene carbonate (EC) being chemically oxidized by evolved singlet oxygen (1O2) or electrochemically oxidized. In this work, we apply density functional theory to assess the feasibility of these mechanisms. We find that electrochemical oxidation is unfavorable at any potential reached during normal LIB operation, and we predict that previously reported reactions between the EC and 1O2 are kinetically limited at room temperature. Our calculations suggest an alternative mechanism in which EC reacts with superoxide (O2-) and/or peroxide (O22-) anions. This work provides a new perspective on LIB electrolyte decomposition and motivates further studies to understand the reactivity at positive electrodes.

High-throughput computational materials screening of transition metal peroxides.

Semiconductor materials of abnormal stoichiometric ratio often exhibit unique properties, yet it is still a challenge to determine the structures of such materials in an efficient way. Herein, we propose a method for structurally biased screening according to the coordination numbers and the numbers of Wyckoff positions, balancing the atom local environment and the global symmetry of structures. Based on first-principles calculations, we have predicted two metastable peroxides P21/c-ScO2 and Pmmn-TiO3 with more than six coordination points. For these two structures, the most stable intrinsic defect is the oxygen vacancy (VO) at the peroxide anion (O2-2), which induces the absence of antibonding orbital formed by O2-2 near the valence band maximum. With the introduction of VO, the decrease of coordination numbers leads to charge recombination, and results in the appearance of an ordered phase TiO2.5 with stronger Ti-O orbital hybridization. The proposed method presents a promising and feasible approach for the screening of novel compounds.

Advances of curcumin in nervous system diseases: the effect of regulating oxidative stress and clinical studies.

In recent years, researchers have highly observed that neurological disorders (NSDs) with the aging of the population are a global health burden whose prevalence is increasing every year. Previous evidence suggested that the occurrence of neurological disorders is correlated with predisposing factors such as inflammation, aging, and injury. Particularly, the neuronal cells are susceptible to oxidative stress, leading to lesions caused by high oxygen-consuming properties. Oxidative stress (OS) is a state of peroxidation, which occurs as a result of the disruption of the balance between oxidizing and antioxidizing substances. The oxidative intermediates such as free radicals, hydrogen peroxide (H2O2), and superoxide anion (O2-) produced by OS promote disease progression. Curcumin, a natural diketone derived from turmeric, is a natural antioxidant with a wide range of neuroprotective, anti-inflammatory, anti-tumor, anti-aging, and antioxidant effects. Fortunately, curcumin is recognized for its potent antioxidant properties and is considered a promising candidate for the prevention and treatment of neurological diseases. Consequently, this review elucidates the mechanisms by which curcumin mitigates oxidative stress and emphasizes the potential in treating nervous system disorders, including depression, Alzheimer's disease, Parkinson's disease, epilepsy, subarachnoid hemorrhage, and glioblastoma. We aim to provide a new therapeutic option for the management of neurological diseases.

Nitric Oxide Promoted the Seed Germination of Cynanchum auriculatum under Cadmium Stress

Cynanchum auriculatum, an early food-medicine homologous plant native to Asia, possesses significant nutritional and health benefits. However, the presence of cadmium (Cd) in the soil poses a hazard to the germination and growth of C. auriculatum. As nitric oxide (NO) plays a vital role in plant resistance to heavy metal stress, we used three different concentrations of SNP treatment during the germination phase, aiming to alleviate the inhibitory effects of Cd stress on the seed germination of C. auriculatum. The results indicated that when compared to seeds treated with SNP concentrations of 0.2 mM and 0.8 mM, C. auriculatum seeds treated with 0.4 mM SNP exhibited an improved germination rate and germination index, as well as longer hypocotyl. Furthermore, in comparison to NOS-like, the SNP application stimulated the production of endogenous NO through NR catalysis. Additional investigations showed that the ABA level decreased while the GA level increased under normal conditions, while the SNP application enhanced the accumulation of both ABA and GA in C. auriculatum seeds under Cd stress. Histochemical staining and biochemical indicators demonstrated that SNP treatment enhanced the enzymatic activity of SOD, POD, and CAT, while inhibiting the production of hydrogen peroxide and superoxide anion. Moreover, SNP treatment resulted in increased α-amylase activity, which facilitated starch hydrolysis and the generation of soluble sugar. Ultimately, the seed vitality of C. auriculatum under Cd stress was promoted. Our findings present a theoretical framework for the application of SNP in the seed germination mechanism of C. auriculatum and establish the groundwork for comprehending the physiological role of NO under Cd stress.

Intercropping and appropriate nitrogen application control faba bean Fusarium wilt by improving physiological and biochemical resistance and protein expression of faba bean

AbstractThis study set up four nitrogen application levels (0, 45, 90 and 135 kg/ha) and two planting systems (faba bean monocropping and faba bean and wheat intercropping) to investigate the incidence of faba bean Fusarium wilt under different treatments and determine the resistance enzyme activities and gene expression, protein expression, and other indexes of faba bean plants. At all N levels, faba bean and wheat intercropping controlled faba bean Fusarium wilt by decreasing the content of hydrogen peroxide and superoxide anion in faba bean roots, increasing the enzyme activity and gene expression of the superoxide dismutase and the gene expression of pathogenesis‐related protein 1 (VfPR1), VfPR2, VfPR5 and VfPR10 disease resistance proteins in the roots, with the most significant effects at the N2 level (90 kg/ha). Further investigation of the impact of intercropping on faba bean roots using the N2 treatment showed that faba bean–wheat intercropping upregulated 288 proteins and downregulated 179 proteins compared with monocropping, and the functions of the upregulated proteins were mainly related to energy metabolism, antioxidant enzymes, stress and DNA repair. GO functional analysis showed that the upregulated proteins were mainly focused on the involvement in amide biological processes. KEGG enrichment analysis revealed that faba bean–wheat intercropping upregulated proteins involved in glutathione metabolism and ascorbic acid metabolism. In summary, at the N2 level, faba bean–wheat intercropping effectively mitigated root oxidative stress by enhancing antioxidant and disease resistance mechanisms in faba bean roots.

POST-VACCINATED COVID-19 OXIDATIVE STRESS IN MENOPAUSE FEMALES

After 12 months of amenorrhea (absence of menses) and the irreversible termination of ovarian activity, menopause is identified. Menopause has a number of physiological implications, including increased abdominal obesity and a higher risk of cardiovascular and metabolic illness. Hot flashes (HF), headaches, back discomfort, stiff joints, weariness, and difficulty sleeping are all signs of menopause. Menopause begins around the age of 51. Menopause occurs prematurely in 0.3–1.1% of women. During menopause, oxidant stress (hydrogen peroxide and superoxidant anion) increases the formation of free radicals. Intermediates in enzymatic reactions that occur during cell metabolism (reactive oxygen species and reactive nitrogen) sometimes leak from enzyme molecules and interact with molecular oxygen, creating free oxygen free radicals. The molecular basis of cancer, neurodegenerative and cardiovascular diseases, diabetes, and autoimmune disorders is oxidative stress caused by free oxygen radicals. HF and irregular menses are common complaints among women, as seen in many blog entries, so there may be some research to be done. Oxidative stress causes COVID-19 post-vaccination side effects. Antioxidant supplements and menopausal hormonal treatment may lower oxidative stress and inflammation. The focus of this research is to see how oxidative stress and quality of life levels change after receiving the COVID-19 vaccination, which is used to treat HF associated with menopause.

Antifungal effects of carvacrol, the main volatile compound in Origanum vulgare L. essential oil, against Aspergillus flavus in postharvest wheat

Plant volatile organic compounds (VOCs) with antimicrobial activity could potentially be extremely useful fumigants to prevent and control the fungal decay of agricultural products postharvest. In this study, antifungal effects of volatile compounds in essential oils extracted from Origanum vulgare L. against Aspergillus flavus growth were investigated using transcriptomic and biochemical analyses. Carvacrol was identified as the major volatile constituent of the Origanum vulgare L. essential oil, accounting for 66.01 % of the total content. The minimum inhibitory concentrations of carvacrol were 0.071 and 0.18 μL/mL in gas-phase fumigation and liquid contact, respectively. Fumigation with 0.60 μL/mL of carvacrol could completely inhibit A. flavus proliferation in wheat grains with 20 % moisture, showing its potential as a biofumigant. Scanning electron microscopy revealed that carvacrol treatment caused morphological deformation of A. flavus mycelia, and the resulting increased electrolyte leakage indicates damage to the plasma membrane. Confocal laser scanning microscopy confirmed that the carvacrol treatment caused a decrease in mitochondrial membrane potential, reactive oxygen species accumulation, and DNA damage. Transcriptome analysis revealed that differentially expressed genes were mainly associated with fatty acid degradation, autophagy, peroxisomes, the tricarboxylic acid cycle, oxidative phosphorylation, and DNA replication in A. flavus mycelia exposed to carvacrol. Biochemical analyses of hydrogen peroxide and superoxide anion content, and catalase, superoxide dismutase, and glutathione S-transferase activities showed that carvacrol induced oxidative stress in A. flavus, which agreed with the transcriptome results. In summary, this study provides an experimental basis for the use of carvacrol as a promising biofumigant for the prevention of A. flavus contamination during postharvest grain storage.

Sodium nitroprusside (SNP) treatment increases the postharvest resistance of apple fruit to Alternaria alternata by enhancing antioxidant enzyme activity

Black spot disease, caused by the fungal pathogen Alternaria alternata, commonly infects apple (Malus domestica) during postharvest storage and transportation, diminishing fruit quality, contaminating the fruit with toxins, and causing significant economic losses. Here, we investigated the effect of 0.1 mmol L−1 sodium nitroprusside (SNP), a nitric oxide donor, on lesion diameter, fruit quality, and reactive oxygen species (ROS) metabolism in A. alternata-inoculated apples. SNP not only effectively decreased lesion diameter but also maintained fruit quality and cell membrane integrity. Additionally, SNP enhanced antioxidant enzyme activity and genes encoding of peroxidase (POD), glutathione reductase (GR), superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT), and decreased hydrogen peroxide (H2O2) and superoxide anion (O2•−) production, malondialdehyde (MDA) concentration, and membrane permeability. Collectively, these results demonstrate that SNP inhibits ROS accumulation and increases antioxidant enzyme activity, and that the mechanism of SNP-induced resistance is related to the regulation of ROS metabolism.