Superoxide Research Articles

Drought priming improves tolerance of Alhagi sparsifolia to subsequent drought: A coordinated interplay of phytohormones, osmolytes, and antioxidant potential

Perennial trees are often stressed by drought more than once during their life cycle. Our study exposed three-month-old Alhagisparsifolia, with (drought-primed) or without (nonprimed) prior drought stress to subsequent drought for two months, aiming to reveal whether pre-exposure to drought could enhance seedling resistance to subsequent drought and investigated possible underlying mechanisms. Root biomass, leaf relative water content, chlorophyll a, and carotenoids were significantly higher in drought-primed than nonprimed seedlings. They also had reduced concentrations of malondialdehyde, hydrogen peroxide (H2O2), and superoxide anions (O2•−), indicating relief from oxidative stress. This relief was associated with a coordinated upregulation of enzymes scavenging O2•− and H2O2, particularly superoxide dismutase (SOD) and catalase (CAT), and the maintenance of the ascorbate-glutathione (AsA-GSH) redox pool and enzymatic activities (ascorbate peroxidase, mono- and dehydroascorbate reductase, and glutathione reductase), leading to the better regulation of reactive oxygen species. The failure of nonprimed seedlings to upregulate the SOD, CAT, and AsA-GSH cycles nevertheless made the seedlings susceptible to oxidative stress. The increased levels of strigolactones, jasmonic acid, and abscisic acid in drought-primed seedlings reveal their roles in subsequent stress. They also displayed higher gibberellic acid and indole acetic acid. A principal component analysis showed that the seedlings responded differently to drought if they had previously suffered a drought, mainly due to a higher capacity for pigment protection, oxidative scavenging, osmolytes, and anti-stress hormones. Our study provides insights into the benefits of stress memory induced in seedlings by early drought priming as a strategy for overcoming subsequent stress.

Huge redshift of absorption edge in a novel Z-type Bi2Sn2O7/α-Bi2O3 junction for highly efficiently visible light degradation of norfloxacin and bisphenol AF

Heterojunction was mainly used to realize the separation of charge carrier in current studies, but it did not bring about any other effect. In this paper, Bi2Sn2O7 was introduced into α-Bi2O3 to construct a direct Z-type Bi2Sn2O7/α-Bi2O3 heterojunction. It not only accelerated the rapid separation of electrons and holes, but also induced a huge redshift of absorption edge to enlarge the visible light absorption range. Such result led into the optimal sample being able to degrade 95% of norfloxacin and 92% of bisphenol AF for 90min of visible light irradiation. Under the same testing conditions, the removal efficiency of these two pollutants in the drinking water also attained 94% and 90% to demonstrate a good application. Moreover, the cycling test results indicated that the Bi2Sn2O7/α-Bi2O3 could be sustainably utilized. The electrons, holes, superoxide radical (•O2-) and hydroxyl radical (•OH) were the active substances in the process of degradation. The numbers of the Escherichia coli were 0.69×106 CFU/mL and 0.75×106 CFU/mL in the solutions after degradation to denote non-toxicity of the final products. Thus the Bi2Sn2O7/α-Bi2O3 composite could be applied in purification of various waste waters.

Fullerene derivatives barrier layer for efficient and stable perovskite solar cells through interfacial modification and removal of superoxide radicals

Superoxide radicals(O2•–)-induced decomposition of perovskite, which seriously impairs the photovoltaic performance and stability of perovskite solar cells (PSCs). Both TiO2 and perovskite produce O2•– that accelerates the rate of catalytic degradation at the interface and inherently poor interfacial contact, exacerbating charge recombination and efficiency loss. Adding fullerene phenol derivative (C60HTB) to the perovskite/TiO2 interface absorbs O2•– and improves poor interfacial communication. The PSCs' power conversion efficiency (PCE) is improved from 20.54 % to 21.63 %. The target devices retained 91.20 %, 94.86 %, and 89.36 % of their initial power conversion efficiencies after 48 h of aging under full-spectrum illumination, 240 h of aging under ultraviolet illumination, and dark storage in air for 500 h, respectively. In this work, efficient and stable TiO2-based-PSCs were realized by scavenging O2•–, which opens a new way to enhance the stability of PSCs in light and O2 environments (light/oxygen).

Network Pharmacology and Molecular Docking Reveal the Antioxidant Potential of Mangiferin from Mango Peel

Background: As one of the main by-products of mango production, the mango peel is rich in multiple polyphenols, such as mangiferin. Therefore, there is an urgent need to explore the potential mechanism of mangiferin for nutrition intervention of oxidative stress-related diseases. Methods: Mangiferin was extracted and purified from the mango peel and was identified by the reverse phase high-performance liquid chromatography. The antioxidant potential of mangiferin was determined in vitro (potassium ferricyanide reducing capacity, DPPH, hydroxyl radicals scavenging ability, and superoxide anion radicals reducing capacity). In order to explore the potential mechanism for the antioxidant activity of mangiferin, a combination of network pharmacology and molecular docking approaches was performed. Results: The purity of mangiferin from the mango peel was ≥ 95.0%, and its antioxidant activity was confirmed by different in vitro assays. ALB, ESR1, CASP8, CASP3, BCL2L1, CXCL8, AKT1, CTNNB, and EGFR were identified as the potential oxidative stress-related targets of mangiferin. These results suggested that mangiferin might play a key role in the antioxidant process through multi-targets. Conclusion: Integrated with network pharmacology and molecular docking methods, this work demonstrated the potential mechanism of mangiferin for nutrition intervention of oxidative stress-related diseases.

Eco-endocrinological dynamics: Unraveling dexamethasone's influence on the interrenal axis in juvenile carp Cyprinus carpio

This study delves into the eco-endocrinological dynamics concerning the impact of dexamethasone (DXE) on the interrenal axis in juvenile carp, Cyprinus carpio. Through a comprehensive analysis, we investigated the effects of DXE exposure on oxidative stress, biochemical biomarkers, gene expression, and bioaccumulation within the interrenal axis. Results revealed a concentration-dependent escalation of cellular oxidation biomarkers, including 1) hydroperoxides content (HPC), 2) lipid peroxidation level (LPX), and 3) protein carbonyl content (PCC), indicative of heightened oxidative stress. Concurrently, the activity of critical antioxidant enzymes, superoxide dismutase (SOD), and catalase (CAT), significantly increased, underscoring the organism's response to oxidative insult. Notable alterations were observed in biochemical biomarkers, particularly Gamma-glutamyl-transpeptidase (GGT) and alkaline phosphatase (ALP) activity, with GGT displaying a significant decrease with increasing DXE concentrations. Gene expression analysis revealed a significant upregulation of stress and inflammation response genes, as well as those associated with sensitivity to superoxide ion presence and calcium signaling, in response to DXE exposure. Furthermore, DXE demonstrated a concentration-dependent presence in interrenal tissue, with consistent bioconcentration factors observed across all concentrations tested. These findings shed light on the physiological and molecular responses of juvenile carp to DXE exposure, emphasizing the potential ecological implications of DXE contamination in aquatic environments. Understanding these dynamics is crucial for assessing the environmental impact of glucocorticoid pollutants and developing effective management strategies to mitigate their adverse effects on aquatic ecosystems.

Impact of Photo-remediation on Anthracene PAHs in treated wastewater using ZnO/TiO2/H2O2 Catalysis

The remediation of carcinogenic Polycyclic Aromatic Hydrocarbons )PAHs( such as Anthracene (3 Rings) in different sources of wastewater was examined using a mix of Zink Oxide, Titanium Oxide, and Hydrogen peroxide (ZnO/ TiO2/H2O2). Eleven wastewater sources were collected from different industrial wastewater and treated wastewater (5 Farms, Main treatment plant, Tanning factory treated wastewater, Tanning factory non-treated wastewater, Carton factories, Factories Lake, and Grease refining plants. Anthracene was extracted by QuEChERS methodology and Analyzed by GCMSMS/TQD. Remediation techniques were applied by using different UV wavelengths irradiation on photolysis of PAHs under two wavelengths (254 and 306 nm) UV irradiation with ZnO + TiO2+ H2O2catalysts for 10 h. Also, the influence of remediation time and several parameters on Anthracene photolysis have been studied. The results indicate that Tanning factory non-treated wastewater had the highest concentration of Anthracene PAHs. The average recovery of Anthracene ranged from 92-96% and Detection Limit (DL) was 5 µg/l. The results of Anthracene concentration in tested wastewater ranged from 21.09 -223.69 µg/l. Also, the results show the anthracene was not detected after 5, 8, and 10h after the remediation using UV 254nm ZnO + TiO2+ H2O2. On the other side, the Anthracene was not detected after 3, 5, and 8h after the remediation using UV 254nm/ZnO + TiO2+ H2O2. Generally, the results of Photoremediation were effective and sufficient for the Anthracen. The impact of photocatalytic illumination of ZnO + TiO2 + H2O2yields valence band holes and conduction band electrons, which interact with the surface adsorbed molecular oxygen to give superoxide radical anions, and finally, the water produces radicals of HO•. These radicals oxidize the target molecule (Anthracene) to Anthraquinone.

Photocatalytic degradation of Rhodamine B dye via Bi2O3 embedded BaO-P2O5-TeO2 glass nanocomposites: An ab initio study of structural, optical, and electrical transport properties

Bismuth incorporated glassy systems with composition xBi2O3-(1-x) [0.3BaO-0.3P2O5-0.4TeO2] (where x = 0.10, 0.15, 0.20, and 0.25) are synthesized by melt quenching technique. The glassy systems are examined for their structural, and surface morphological properties using XRD, SEM, and EDX analysis. A study of photocatalytic activity for the degradation of common organic dyes like Rhodamine B (RhB) dye under visible light is also carried out. From UV-vis absorbance data, the calculated optical band gap energy values declined from (2.99-2.56) eV, whereas the Urbach energy and refractive index values increased from (0.35 -0.52) eV, and (2.39 - 2.52), respectively with the rise of Bi2O3 content(x). Additionally, the fundamental processes of electrical conductivity have been studied within the framework of Jonscher's universal power law and the Almond-West formalism. The Mott and Greaves model asserts that the small polaron hopping model underlies DC conductivity; as Bi2O3 content increases, DC conductivity rises, but hopping distance (Rhop) and hopping energy (Whop) drop dramatically. The electrical conductivity study reveals the semi-conducting nature of the as-prepared samples. In our present study, we are focusing on the structural, optical, and electrical transportation properties, additionally, we investigated this class of glassy materials as a promising candidate for photocatalytic dye degradation. Our study reveals that RhB dye can degrade up to 75% within 340 min of visible light illumination. Moreover, the test demonstrates the production of superoxide radicals by the CB-electrons and hydroxyl radicals by the VB holes enables efficient photocatalytic dye degradation.

The Polysaccharides from Pinellia ternata and Their Derivatives: Preparation, Structure Characteristics, and Activities inVitro.

Three polysaccharides, PTC, PTH, and PTB, were extracted from Pinellia ternata using three different extraction conditions: room temperature water, hot water, and 2% Na2CO3 solution. PTC and PTH were composed of rhamnose, glucose, galactose, mannose, glucuronic acid, galacturonic acid, and arabinose, which combine to form complex structures. PTB was composed solely of glucose and rhamnose. Further analysis indicated that PTC and PTB exhibited triple-helix structures. PTC showed the highest scavenging capacity against DPPH, superoxide anion, and hydroxyl radicals, with half maximal inhibitory concentrations (IC50) of 1004.1, 1584.1, and 1584.1 μg/mL, respectively. Additionally, PTC, PTH, and PTB were subjected to sulfation, phosphorylation, and selenization, resulting in the production of nine derivates. The distinctive absorptive bands of these derivates were determined through infrared spectroscopy. Selenized and sulfated derivates have shown significant antitumor and immunoenhancing properties. Our findings revealed that at 400 μg/mL, the inhibition rate of selenated PTB on HeLa cells was 54.2% and that on HepG2 cells was 43.1%. Additionally, selenized PTC displayed significant immunoenhancing activity, with a proliferation rate of 63.7% at 400 μg/mL in RAW264.7 cells. These results provide valuable evidence supporting the consideration of polysaccharides from Pinellia ternata as a potential candidate for the development of antineoplastic drugs.

Withanolides production by the endophytic fungus Penicillium oxalicum associated with Withania somnifera (L.) Dunal.

Withanolides are steroidal lactones with diverse bioactive potential and their production from plant sources varies with genotype, age, culture conditions, and geographical region. Endophytic fungi serve as an alternative source to produce withanolides, like their host plant, Withania somnifera (L.) Dunal. The present study aimed to isolate endophytic fungi capable of producing withanolides, characterization and investigation of biological activities of these molecules. The methanolic fungal crude extract of one of the fungal isolates WSE16 showed maximum withanolide production (219mg/L). The fungal isolate WSE16 was identified as Penicillium oxalicum based on its morphological and internal transcribed spacer (ITS) sequence analysis and submitted in NCBI (accession number OR888725). The methanolic crude extract of P. oxalicum was further purified by column chromatography, and collected fractions were assessed for the presence of withanolides. Fractions F3 and F4 showed a higher content of withanolides (51.8 and 59.1mg/L, respectively) than other fractions. Fractions F3 and F4 exhibited antibacterial activity against Staphylococcus aureus with an IC50 of 23.52 and 17.39µg/ml, respectively. These fractions also showed antioxidant activity (DPPH assay with IC50 of 39.42 and 38.71µg/ml, superoxide anion scavenging assay with IC50 of 41.10 and 38.84µg/ml, and reducing power assay with IC50 of 42.61 and 41.40µg/ml, respectively) and acetylcholinesterase inhibitory activity (IC50 of 30.34 and 22.05µg/ml, respectively). The withanolides present in fraction 3 and fraction 4 were identified as (20S, 22R)-1a-Acetoxy-27-hydroxywitha-5, 24-dienolide-3b-(O-b-D-glucopyranoside) and withanamide A, respectively, using UV, FTIR, HRMS, and NMR analysis. These results suggest that P. oxalicum, an endophytic fungus isolated from W. somnifera, is a potential source for producing bioactive withanolides.

Annual rhythm in immune functions of blood leucocytes in an ophidian, Natrix piscator

Annual variations in animal’s physiological functions are an essential strategy to deal with seasonal challenges which also vary according to the time of year. Information regarding annual adaptations in the immune-competence to cope with seasonal stressors in reptiles is scarce. The present research plan was designed to analyze the presence of circannual immune rhythms in defense responses of the leucocytes in an ophidian, Natrix piscator. Peripheral blood leucocytes were obtained, counted, and superoxide anion production, neutrophil phagocytosis, and nitrite release were tested to assess the innate immune functions. Peripheral blood lymphocytes were separated by centrifugation (utilizing density gradient) and the cell proliferation was measured. The Cosinor rhythmometry disclosed the presence of significant annual rhythms in the number of leucocytes, superoxide anion production, nitric oxide production, and proliferation of stimulated lymphocytes. The authors found that respiratory burst activity and proliferative responses of lymphocytes were crucial immune responses that showed the annual rhythm. It was summarized that the immune function of the N. piscator is a labile attribute that makes the animal competent to cope with the seasonal stressor by adjustment in the potency of response.

Inositol-6-phosphate mitigates deoxynivalenol nephrotoxicity in pig kidney explants

Abstract Deoxynivalenol (DON) is a mycotoxin that frequently contaminates food crops and negatively impacts human and animal health. While inositol-6-phosphate (IP6) is known to counteract DON-induced intestinal damage, inflammation, and oxidative stress, its ability to alleviate DON-caused kidney injury is yet unexplored. This study assessed DON’s kidney effects and IP6’s protective capability using an ex vivo renal explants model. From 360 explants taken from six pigs, four groups were formed: control (culture medium), DON (10 μM equivalent to 3 mg/kg of feed), IP6 group (5 mM), and DON + IP6 (10 μM + 5 mM). DON elevated creatinine levels and γ-glutamyl transferase activity in the culture medium. It led to cytoplasmic vacuolation in convoluted tubular epithelial cells and tubular necrosis, a drop in antioxidant potential (ABTS) and a rise in interleukin (IL)-8 mRNA. The introduction of IP6 restored renal histological and functional parameters, bolstered antioxidant status, enhanced IL-10 gene expression, and reduced superoxide anion levels. These results indicate that within the model of renal explants, IP6 significantly alleviates the nephrotoxic effects of DON while efficiently regulating the antioxidative and anti-inflammatory response within the kidneys.

Electron Structure of α‐, β‐Te2MoO7 and Photocatalytic Decomposition of Antibiotics

AbstractTwo modifications of Te2MoO7 oxide have been prepared by different synthetic methods. The crystal structure and composition have been studied by X‐ray diffraction analysis and X‐ray microanalysis. The phase of α‐Te2MoO7 has been synthesized by solid‐state reaction from ammonium salts and characterized by monoclinic structure with P21/c. The β‐Te2MoO7 compound has been formed in hydrothermal conditions and has amorphous nature. The thermal behavior of β‐Te2MoO7 modification is characterized by the phase transition into α‐form, however after melting the amorphous state has restored. The electron structure has been investigated experimentally by X‐ray photoelectron spectroscopy and UV‐vis diffusion reflectance spectra and theoretically by approximation using atomic electronegativity. Despite the same composition, the band gap of β‐Te2MoO7 corresponds to visible light, whereas α‐Te2MoO7 adsorbs light in UV region. The both modifications are able to generate superoxide radicals in vacuum or air and hydroxyl radicals in water under irradiation. The HPLC‐MS analysis has shown the quite deep decomposition of dye and antibiotics by α‐Te2MoO7, whereas amorphous phase almost does not lead to any oxidation.

Exciton Dissociation into Charge Carriers in Porphyrinic Metal-Organic Frameworks for Light-Assisted Li-O2 Batteries.

Light-assisted Li-O2 batteries exhibit a high round-trip efficiency attributable to the assistance of light-generated electrons and holes in oxygen reduction and evolution reactions. Nonetheless, the excitonic effect arising from Coulomb interaction between electrons and holes impedes carrier separation, thus hindering efficient utilization of photo-energy. Herein, porphyrinic metal-organic frameworks with (Fe2Ni)O(COO)6 clusters were used as photocathodes to accelerate exciton dissociation into charge carriers for light-assisted Li-O2 batteries. The coupling of Ni 3d and Fe 3d orbitals boosts ligand-to-metal cluster charge transfer, and hence drives exciton dissociation and activates O2 for superoxide (•O2 -) radicals, rather than singlet oxygen (1O2) under photoexcitation. These enable the light-assisted Li-O2 batteries with a low total overvoltage of 0.28V and round-trip efficiency of 92% under light irradiation of 100mW cm-2. This work highlights the excitonic effect in photoelectrochemical processes and provides insights into photocathode design for light-assisted Li-O2 batteries. This article is protected by copyright. All rights reserved.

Tailored Polymeric Carbon Nitride Coupled with Bi2O3 for Constructing Z‐Scheme Heterojunction with Enhanced Photocatalytic Activity

AbstractThe great demand for visible‐light‐induced catalysts with high photocatalytic performance has stimulated extensive interest in constructing g‐C3N4‐based Z‐Scheme heterojunctions. In this research work, the g‐C3N4/Bi2O3 Z‐Scheme heterojunction by precipitation‐hydrothermal method was constructed, and characterized by various techniques. The g‐C3N4/Bi2O3‐1 composite exhibited a transient photocurrent response approximately 7 and 5 times higher than that of bare g‐C3N4 and Bi2O3, respectively, and showed higher visible photocatalytic activity with 99.8 % degradation of methylene blue (MB) within 75 min. Meanwhile, the pH effect on the photocatalytic degradation of MB was investigated. Radicals trapping experiments showed that •OH free radical played a predominant role for the degradation of MB, EPR analysis confirmed the presence of superoxide radicals, which combined with the band structure of the composites, confirmed the Z‐Scheme of the heterojunction. A possible mechanism for photocatalytic degradation of MB dyes in g‐C3N4/Bi2O3‐1 composites was also proposed. This study provided a new avenue for the development of novel g‐C3N4‐based Z‐Scheme heterojunction materials with prospective applications in the fields of energy and environment.

Swertiamarin relieves radiation-induced intestinal injury by limiting DNA damage.

Radiotherapy is the conventional treatment for pelvic abdominal tumors. However, it can cause some damage to the small intestine and colorectal, which are very sensitive to radiation. Radiation-induced intestinal injury (RIII) affects the prognosis of radiotherapy, causing sequelae of loss of function and long-term damage to patients' quality of life. Swertiamarin is a glycoside that has been reported to prevent a variety of diseases including but not limited to diabetes, hypertension, atherosclerosis, arthritis, malaria, and abdominal ulcers. However, its therapeutic effect and mechanism of action on RIII have not been established. We investigated whether swertiamarin has a protective effect against RIII. In this article, we use irradiator to create cellular and mouse models of radiation damage. Preventive administration of swertiamarin could reduce ROS and superoxide anion levels to mitigate the cellular damage caused by radiation. Swertiamarin also attenuated RIII in mice, as evidenced by longer survival, less weight loss and more complete intestinal barrier. We also found an increase in the relative abundance of primary bile acids in irradiated mice, which was reduced by both FXR agonists and swertiamarin, and a reduction in downstream interferon and inflammatory factors via the cGAS-STING pathway to reduce radiation-induced damage.

Structure Elucidation of a Novel Polysaccharide Isolated from Euonymus fortunei and Establishing Its Antioxidant and Anticancer Properties

Euonymusfortunei polysaccharides (EFPs) have not been extensively investigated yet in terms of their extraction and biological activity. The orthogonal experimental design was employed in this study to evaluate the optimum yield of EFPs. A maximum yield of 2.63 ± 0.23% was attained using material-liquid ratios of 60 mL/g, extraction temperature of 80°C, ultrasonic power of 144 W, and extraction time of 75 mins. The polysaccharide content reached 53.47 ± 0.31% when deproteinized thrice. An analysis of monosaccharide composition revealed that these polysaccharides consist of Gal, Glc, Man, Fuc, and Rha with a molar ratio of 7.14 ∶ 23.99 ∶ 6.29 ∶ 6.55 ∶ 1.00, respectively, in EFPs. Subsequently, the in vitro scavenging capacities of 2,2-diphenylpicrylhydrazyl (DPPH) and ·OH and superoxide anion radicals, along with the reducing power of EFPs, were studied. Results revealed that EFPs have higher antioxidant activity, particularly ·OH scavenging, as well as reducing power, as compared to Astragalus polysaccharides (ASPs) and Lycium barbarum polysaccharides (LBPs). The Cell Counting Kit-8 (CCK-8) method was used to evaluate the effects of different concentrations of polysaccharides on SKOV3 cell proliferation, and the results revealed their inhibition at concentrations in the range of 200–800 μg/mL. In addition, findings from flow cytometry further confirmed that EFPs blocked the cell cycle at G0/G1 and S phases and induced SKOV3 cell apoptosis. In a word, EFPs could be exploited and used further based on the experimental results from this study.

Transcriptome and metabolome analyses reveal the regulatory role of MdPYL9 in drought resistance in apple

BackgroundThe mechanisms by which the apple MdPYL9 gene mediates the response to drought stress remain unclear. Here, transcriptome and metabolome analyses of apple plants under drought were used to investigate the mechanisms by which MdPYL9 regulates the response to drought stress in apple. MdPYL9-overexpressed transgenic and non-transgenic apple histoculture seedlings were rooted, transplanted, and subjected to drought treatments to clarify the mechanisms underlying the responses of apples to drought stress through phenotypic observations, physiological and biochemical index measurements, and transcriptomic and metabolomic analyses.ResultsUnder drought stress treatment, transgenic plants were less affected by drought stress than non-transgenic plants. Decreases in the net photosynthetic rate, stomatal conductance, and transpiration rate of transgenic apple plants were less pronounced in transgenic plants than in non-transgenic plants, and increases in the intercellular CO2 concentration were less pronounced in transgenic plants than in non-transgenic plants. The relative electrical conductivity and content of malondialdehyde, superoxide anion, and hydrogen peroxide were significantly lower in transgenic plants than in non-transgenic plants, and the chlorophyll content and activities of antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) were significantly higher in transgenic plants than in non-transgenic plants. The number of differentially expressed genes (DEGs) involved in the response to drought stress was lower in transgenic plants than in non-transgenic plants, and the most significant and highly annotated DEGs in the transgenic plants were involved in the flavonoid biosynthesis pathway, and the most significant and highly annotated DEGs in control plants were involved in the phytohormone signal transduction pathway. The number of differentially accumulated metabolites involved in the response to drought stress was lower in transgenic plants than in non-transgenic plants, and up-regulated metabolites were significantly enriched in apigenin-7-O-glucoside in transgenic plants and in abscisic acid in non-transgenic plants. In the flavonoid biosynthetic pathway, the expression of genes encoding chalcone synthase (CHS) and chalcone isomerase (CHI) was more significantly down-regulated in non-transgenic plants than in transgenic plants, and the expression of the gene encoding 4-coumarate-CoA ligase (4CL) was more significantly up-regulated in transgenic plants than in non-transgenic plants, which resulted in the significant up-regulation of apigenin-7-O-glucoside in transgenic plants.ConclusionsThe above results indicated that the over-expression of MdPYL9 increased the drought resistance of plants under drought stress by attenuating the down-regulation of the expression of genes encoding CHS and CHI and enhancing the up-regulated expression of the gene encoding 4CL, which enhanced the content of apigenin-7-O-glucoside.

Exogenous Application of Melatonin on the Preservation of Physicochemical and Enzymatic Qualities of Pepper Fruit from Chilling Injury

This study investigates the impact of melatonin (MT) treatment at varying concentrations (0, 25, 50, 75, 100 µmol L−1) on the post-harvest quality and shelf life of long green pepper fruits stored under low temperature for 28 days. Every 4 days, pepper fruits were examined for the chilling injury (CI) index, weight loss (WL), respiration rates, firmness, electrolyte leakage (EL), reactive oxygen species (ROS), malondialdehyde (MDA) levels, non-enzymatic antioxidant (NEA) content, antioxidant (AO) enzyme activity (superoxide dismutase (SOD), catalase (CAT), and peroxidases (PODs)), and cellular degrading enzymes (polygalacturonase (PG), pectin methylesterase (PME), phospholipase D (PLD), and lipoxygenase (LOX)). MT-treated samples exhibited delayed and reduced CI stress compared to controls, with higher exogenous MT concentrations (>50 µmol L−1) offering significant (p < 0.05) CI reductions. During storage, WL was notably mitigated by MT treatment in the tested samples compared to control samples. This study also demonstrated that MT-treated pepper fruits effectively decelerated respiration rates and consequently preserved pepper firmness. A higher concentration of MT-treated pepper fruits demonstrated a significantly (p < 0.05) lowered level of ROS and MDA while maintaining membrane stability, as evidenced by reduced EL. MT treatment with increasing concentration increased the levels of glutathione (GSH), glutathione disulfide (GSSG), ascorbic acid (AsA), dehydroascorbate (DHA), and total phenolic content (TPC) in the pepper fruits compared to control and thus significantly (p < 0.05) suppressed the ROS production (superoxide anion (O2•−) and hydrogen peroxide (H2O2) radicals) in the pepper fruits. Furthermore, AO enzymes such as SOD, CAT, and POD were also high in the pepper fruits that were treated with higher concentrations of MT (>50 µmol L−1). Additionally, the activities of cellular degrading enzymes (PG, PME, PLD, and LOX), which are linked to senescence and stress-induced physiological disorders, were also effectively regulated by MT-treated (>75 µmol L−1) pepper fruits. Overall, the application of MT at higher concentrations (>75 µmol L−1) demonstrated substantial benefits in preserving the quality and extending the shelf life of pepper fruits during cold storage.

A Bulk Oxygen Vacancy Dominating WO3−x Photocatalyst for Carbamazepine Degradation

Creating oxygen vacancy in tungsten trioxide (WO3) has been considered as an effective strategy to improve the photocatalytic performance for degrading organic pollutants. In this study, oxygen vacancies were introduced into WO3 by thermal treatment under Ar atmosphere and their proportion was changed by setting different treatment times. WO3−x samples show better photoelectric properties and photocatalytic degradation performance for carbamazepine (CBZ) than an oxygen-vacancy-free sample, and WO3−x with the optimal proportion of oxygen vacancies is obtained by thermal treatment for 3 h in 550 °C. Furthermore, it discovers that the surface oxygen vacancies on WO3−x would be recovered when it is exposed to air, resulting in a bulk oxygen vacancy dominating WO3−x (bulk-WO3−x). The bulk-WO3−x exhibited much higher degradation efficiency for CBZ than WO3−x with both surface and bulk oxygen vacancies. The mechanism study shows bulk-WO3−x mainly degrades the CBZ by producing OH radicals and superoxide radicals, while oxygen-vacancy-free sample mainly oxidizes the CBZ by the photoexcited hole, which requires the CBZ to be adsorbed on the surface for degradation. The radical generated by bulk-WO3−x exhibits stronger oxidizing capacity by migrating to the solution for CBZ degradation. In summary, the influence of oxygen vacancy on photocatalytic degradation performance depends on both the proportion and location distribution and could lie in the optimization of the photodegradation mechanism. The results of this study could potentially broaden our understanding of the role of oxygen vacancies and provide optimal directions and methods for oxygen vacancy regulation for photocatalysts.

Ultrasound Irradiation-Induced Superoxide Anion Radical Mediates the Reduction of Tetravalent Platinum Prodrug for Anti-tumor Therapy

Ultrasound Irradiation-Induced Superoxide Anion Radical Mediates the Reduction of Tetravalent Platinum Prodrug for Anti-tumor Therapy