Response Of Antioxidant System Research Articles

Iron deficiency and toxicity trigger divergent metabolic responses and adaptive plasticity in Ulmus pumila: Insights from integrated transcriptomic and metabolomic analyses.

Iron homeostasis is critical for plant growth; however, the mechanisms underlying responses to iron deficiency and toxicity remain poorly understood. We investigated the adaptive strategies of Ulmus pumila, focusing on leaf physiological, transcriptomic, and metabolomic responses to iron stresses. Both iron deficiency and toxicity impaired chlorophyll biosynthesis, PS II efficiency, and chloroplast ultrastructure, resulting in reduced photosynthetic capacity and etiolation/wilting phenotypes. Iron deficiency reduced antioxidant enzyme activity and ROS levels, while iron toxicity activated the antioxidant enzyme system in response to the ROS burst. Integrated transcriptomic and metabolomic analyses provided insights into the underlying mechanism of these divergent responses: iron deficiency promoted primary metabolic adjustments, particularly the upregulation of genes (e.g., MDH, ACO, and IDH) and metabolites (e.g., malic acid, citric acid, and fumaric acid) associated with the TCA cycle to meet energy demands. Conversely, iron toxicity triggered a metabolic shift from primary to secondary metabolism, upregulating the genes (e.g., CHS, CHI, and F3H) and metabolites (e.g., laricitrin, trifolin, and rutin) involved in flavonoids biosynthesis to mitigate oxidative stress. Overall, U. pumila employs distinct adaptive mechanisms to balance survival and growth under iron stress: prioritizing energy metabolism and iron uptake to meet energy demands and improve iron uptake efficiency under deficiency, and enhancing the secondary metabolism to mitigate oxidative damage under toxicity. These findings enhance understanding of plant nutrient homeostasis and stress adaptation, providing insights into mitigating the impacts of soil degradation on agriculture and forestry.

Oxidative stress and filtration responses in Atlantic ribbed mussels (Geukensia demissa) exposed to radium-226.

Bivalves have been extensively utilized as sentinel biomonitoring species, organisms used to predict the extent and severity of environmental contamination. However, significant knowledge gaps remain regarding the operationalization and application of indicator species for radioactive contaminants in the marine environment. Dose-dependent organism responses with validated and practical measurement protocols need to be identified for use within biomonitoring frameworks. Our study explored tissue-specific oxidative stress and filtration responses in Geukensia demissa (Atlantic ribbed mussel) following static renewal exposure to a range of aqueous radium-226 (226Ra) concentrations and exposure durations. We investigated a two-tier antioxidant response system, with radical scavenging activity as the primary response and glutathione S-transferase and lipid peroxidation activities as secondary, downstream responses. A first-stage response of 226Ra exposure was observed, indicated by increased radical scavenging activity in the mantle tissues of mussels exposed to the highest treatment concentration (200 nCi/L = 200 ng/L, 73%) compared with the tissues of control and lower concentration (1, 10, and 100 nCi/L = 1, 10, and 100 ng/L) mussels (18%-44%). However, there was no clear impact for the second-stage responses. A reduction in filtration, quantified via algal removal, was also observed for mussels exposed to the highest 226Ra treatment concentration. This work represents the first investigation on the effects of a marine bivalve exposed to aqueous 226Ra. The responses of bivalves to radiological marine pollution, and the potential for cascading impacts to populations and ecosystems, is still relatively unknown but has important implications for ecological and human well-being.

ОТВЕТ АНТИОКСИДАНТНОЙ СИСТЕМЫ РАСТЕНИЙ ТРЕХ СОРТОВ ФАСОЛИ (PHASEOLUS VULGARIS L.) НА ОБРАБОТКУ СЕМЯН ГРАДИЕНТОМ КОНЦЕНТРАЦИЙ 6 БЕНЗИЛАМИНОПУРИНА КАК МОДЕЛЬ ВЛИЯНИЯ ЦИТОКИНИН-ПРОДУЦИРУЮЩИХ БАКТЕРИЙ НА РОСТ РАСТЕНИЙ

For successful application of bacterial preparations, it is important to determine the stimulating and inhibiting doses of the exogenous phytohormone affecting the growth of the host plant. Bean seeds were treated with different doses of 6-benzylaminopurine (BAP) 0.00001–10 mg/l. For the Ufimskaya variety, the stimulating doses were 0.01–0.1 mg/l, for the Elza variety – only 0.001 mg/l BAP, for the Zolotistaya variety – 0.001 and 0.1 mg/l BAP. In this case, the Ufimskaya and Zolotistaya varieties increased the development of adventitious roots, while the Elza variety increased the total root length. Individual varietal reactions of the antioxidant system in response to seed treatment with cytokinin were determined. The identified characteristics of the varieties highlight the importance of understanding the complex balance between phytohormone signaling and antioxidant defense mechanisms in plant-microbe interactions and necessitate the use of precision doses of growth regulators and cytokinin-producing bacteria to specific varieties to stimulate growth.

Toxic effects of acute and chronic atorvastatin exposure on antioxidant systems, autophagy processes, energy metabolism and life history in Daphnia magna

Atorvastatin (ATV) is a representative for hypolipidemic pharmaceuticals and is widely detectable in aquatic environments around the world. However, there are limited studies on the potential effects of ATV on aquatic non-target organisms, especially on aquatic invertebrates. In the present study, the model organism, Daphnia magna was used to investigate the responses of antioxidant system, autophagy process and energy metabolism under the acute exposure of ATV (24 h–96 h), and the changes of physiological parameters of D. magna in response to chronic ATV exposure (21 d) was addressed as well. The results showed that ATV caused oxidative stress in D. magna and elevated activities of antioxidant enzymes (SOD, GST, GPx, and TrxR) at 48 h. However, the progressively increasing oxidative pressure eventually suppressed antioxidant capacities and triggered the transcriptional autophagy process in organism under the regulation of Sestrin as well as its regulated genes (P62, LC3, ATG1, and ATG4B). ATV also altered the expression of DNA methylation related genes. Unlike the clinical response, we found acute ATV exposure led to lipid accumulation in D. magna, affecting energy metabolism. Chronic exposure of higher concentration of ATV (50, 500 μg L−1) adversely affected growth and reproduction parameters of D. magna, caused delayed molting, reduced body length, and decreased number and delayed time of neonates production. Lethal effects were observed in the 5000 μg L−1 of ATV. The present study investigated the toxic effects and mechanisms of acute and chronic ATV exposure on D. magna to provide a scientific basis for evaluating the potential ecological risks of statins on aquatic invertebrates.

Response of protein DJ-1 to oxidative stress in porcine longissimus thoracis and semimembranous muscles: Expression, oxidation, and protein interactions during postmortem aging

Reactive oxygen species (ROS) have been recognized to have a significant impact on meat quality, while the role of the antioxidant system in response to ROS in postmortem muscle remain unclear. Protein DJ-1 serves as a sensor of oxidative stress and has an antioxidant function in biological systems. Hence, this study aimed to investigate the expression, oxidation, and interaction of protein DJ-1 in porcine longissimus thoracis (LT) and semimembranous (SM) muscles, as well as its correlation with meat quality, to gain a better understanding of meat quality formation during postmortem aging. The findings indicated significant variations in pH, L*, a*, purge loss, cooking loss, and Warner-Bratzler shear force (WBSF) between the muscle groups (P < 0.05). The levels of reactive oxygen species (ROS), protein DJ-1, and oxidized DJ-1 (oxDJ-1) in SM muscle were higher than those in LT muscle throughout the 3 d of postmortem aging (P < 0.05). Moreover, protein DJ-1 and oxDJ-1 were significantly associated with water holding capacity and a* value of pork (P < 0.05). Through co-immunoprecipitation and mass spectrometry, a total of 23 DJ-1 interacting proteins were identified, mainly participating in glycolysis, energy metabolism, muscle contraction, resistance to oxidative stress, as well as amino acids biosynthesis and metabolism. These results suggest that DJ-1 may exert a regulatory influence on the development of pork quality during postmortem aging.

Analysis of the stereoselective fate and toxicity of penflufen in the water-sediment system for risk reduction

Chiral succinate dehydrogenase inhibitor (SDHI) fungicides are widely used in agricultural production, but there is insufficient research on their environmental risk in water–sediment ecosystems. Here, the stereoselective fate and toxic effects of the chiral SDHI fungicide, penflufen, in the water–sediment system were investigated. The results showed that S-penflufen is more persistent in water, sediment, and zebrafish. Additionally, the sorption coefficient (Koc) in sediment and uptake rate constant (Ku) in zebrafish of S-penflufen were higher than those of R-penflufen. The acute toxicity of S-penflufen to zebrafish, Daphnia magna and Chironomus kiiensis were 32-, 6.1-, and 8.9-fold higher than those of R-penflufen. The AlphaFold2 and molecular docking results showed that S-penflufen had stronger binding capability with SDH in the three water–sediment organisms than R-penflufen. Therefore, S-penflufen induced stronger sub-chronic toxic effects on zebrafish than R-penflufen, even at 0.05 mg/L. The results of multi-omics analysis showed that S-penflufen affected the tricarboxylic acid cycle in zebrafish and induced antioxidant, detoxification, and immune system responses, ultimately affecting zebrafish metabolic processes and cellular function. The overall results indicate that S-penflufen has a higher risk in water–sediment systems. Moreover, combining multi-omics and AlphaFold2 techniques facilitates the elucidation of the molecular mechanism of the stereoselective toxic effects of chiral pesticides.

Hydrogen peroxide mediates melatonin-induced chilling tolerance in cucumber seedlings.

MT mitigates chilling damage by enhancing antioxidant system and photosystem activities, and cold-responsive genes expression in cucumbers. H2O2 may act as a downstream signaling molecule in the MT-induced chilling tolerance. Melatonin (MT) and hydrogen peroxide (H2O2) are important endogenous signaling molecules that play multifaceted roles in plant responses to abiotic stress. However, the interactive mechanism by which MT and H2O2 regulate chilling tolerance remains unclear. Here we found that MT exhibited a positive regulatory effect on the chilling tolerance of cucumbers, with an optimum concentration of 100µM. MT markedly enhanced RBOH1 mRNA expression, activity and endogenous H2O2 accumulation in cucumber seedlings. However, 1.0mM H2O2 had no significant effect on mRNA levels of TDC and ASMT, the key genes for MT synthesis, and endogenous MT content. Both MT and H2O2 significantly decreased malondialdehyde (MDA), electrolyte leakage (EL) and chilling injury index (CI) by activating the antioxidant system, thereby alleviating chilling damage in cucumber seedlings. MT and H2O2 improved photosynthetic carbon assimilation, which was primarily attributed to an increase in activity, mRNA expression, and protein levels of RuBPCase and RCA. Meanwhile, MT and H2O2 induced the photoprotection for both PSII and PSI by enhancing the QA's electron transport capacity and elevating protein levels of the photosystems. Moreover, MT and H2O2 significantly upregulated the expression of cold response genes. MT-induced chilling tolerance was attenuated by N', N'-dimethylthiourea (DMTU), a H2O2 specific scavenger. Whereas, the MT synthesis inhibitor (p-chlorophenylalanine, p-CPA) did not influence H2O2-induced chilling tolerance. The positive regulation of MT on the antioxidant system, photosynthesis and cold response gene levels were significantly attenuated in RBOH1-RNAi plants compared with WT plants. These findings suggest that H2O2 may functions as a downstream signaling molecule in MT-induced chilling tolerance in cucumber plants.

Functional characterization of peroxiredoxin 5 from yellowtail clownfish (Amphiprion clarkii): Immunological expression assessment, antioxidant activities, heavy metal detoxification, and nitrosative stress mitigation

Peroxiredoxin 5 (Prdx5) is the last recognized member of Prdx family. It is a unique, atypical, 2-Cys antioxidant enzyme, protecting cells from death caused by reactive oxygen species (ROS). In this study, the Prdx5 ortholog of Amphiprion clarkii (AcPrdx5) was identified and characterized to explore its specific structural features and functional properties. The open reading frame of AcPrdx5 is 573 bp long and encodes 190 amino acids containing a mitochondrial targeting sequence, thioredoxin domain, and two conserved cysteine residues responsible for antioxidant function. The predicted molecular weight and theoretical isoelectric point of AcPrdx5 are 20.3 kDa and 9.01, respectively. AcPrdx5 sequences were found to be highly conserved across the other orthologs from various organisms and it distinctively clustered within the fish Prdx5 subclade of the phylogenetic tree. The expression of AcPrdx5 was ubiquitously detected among twelve tested tissues, with the highest level in the brain. Furthermore, the mRNA levels of AcPrdx5 in the blood and head-kidney tissues were significantly (p < 0.05) upregulated following polyinosinic-polycytidylic acid (Poly I:C), lipopolysaccharide (LPS), and Vibrio harveyi immune challenge. A concentration-dependent antioxidant potential of recombinant AcPrdx5 was observed in insulin disulfide bond reduction, heavy metal detoxification, free radical and hydrogen peroxide (H2O2) scavenging assays. Additionally, AcPrdx5 overexpression in fathead minnow (FHM) cells upregulated the antioxidant-associated gene (Rrm1, MAPK, SOD2, and PRDX1) expression after H2O2 treatment, and promoted cell viability upon arsenic (As) exposure. In macrophages, AcPrdx5 overexpression effectively suppressed substantial nitric oxide production under lipopolysaccharide treatment. Collectively, our results suggest that AcPrdx5 may play roles in both antioxidant defense system and innate immune response against pathogenic invasions in A. clarkii.

The combination of nanoparticles and endophytes boosts Thyme (Thymus vulgaris L.) resistance to drought stress by elevating levels of phenolic compounds, flavonoids, and essential oils

BackgroundAs climate change and water scarcity increasingly threaten agricultural productivity, enhancing plant resilience to drought has attracted great attention. This study explored the potential of combining Fe2O3 nanoparticles (FeNPs), endophytic bacteria (EB), and endophytic fungi (EF) to boost drought tolerance in Thymus vulgaris. The research aimed to assess how these combined treatments affect the plant’s physiological responses and chemical composition under drought stress.ResultsA factorial experiment was designed using completely randomized design (CRD) method, incorporating four irrigation levels [100%, 75%, 50%, and 25% field capacity (FC)], four FeNPs concentrations (0, 0.5, 1, and 1.5 mg L−1), and three endophyte types (control, bacteria, and fungi). After extracting, purifying, identifying, and screening EB and EF from nine Lamiaceae species, the endophytes Azospirillum lipoferum and Aspergillus oryzae isolated from Salvia mirzayanii exhibited the highest drought resistance. The highest amounts of TFM (45.45 g) and TDM (21.56 g) were obtained using the combination of EB and FeNPs at 1 mg L−1 under irrigation with 100% FC. At 25% FC, EB treatment increased the activities of polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) by 62.12% and 18.23% compared to the control, respectively. In addition, under optimal humidity conditions, FeNP concentrations were higher than 0.5 mg L−1 leading to a decrease in PPO activity. At 25% FC, the highest content of total phenols was observed with a 37.5% increase under EB treatment using 1 mg L−1 of FeNPs, while the highest content of total flavonoids showed a 62.72% increase under EF treatment with 0.5 mg/L of FeNPs. The highest level of p-coumaric acid was obtained under EF (34.27% compared to control). At 25% FC, EB and FeNPs (1 mg L−1) increased the level of caffeic acid in thyme plants by 24.70% and 10.08%, respectively. In addition, inoculation with EB increased (11.9%) the content of ferulic acid in plants and the application of FeNPs as a foliar spray decreased the level of ferulic acid in thyme plants. The highest essential oil percentage at 25% FC was observed after inoculation with EF and FeNPs (0.5 mg L−1), resulting in significant increases of 14.7% and 82.12%, respectively, compared to the control. A decrease in irrigation level led to an increase in the percentage of essential oil in thyme plants while decreasing dominant essential oil compounds, thymol, and carvacrol. The levels of thymol and carvacrol in the essential oil were not affected by the interaction effects of drought stress, endophytes, and FeNPs. EF and FeNPs (1.5 mg L−1), respectively, caused significant increases of 17.44% and 29.87% compared to the control in the amount of thymol and significant increases of 13.75% and 31.01% in the amount of carvacrol. All FeNPs concentrations decreased the concentrations of ferulic acid, FeNPs (1.5 mg L−1) and PPO; these particles act as abiotic stressors at sub-toxic levels and become phytotoxic at higher concentrations.ConclusionsIt seems that combining endophytes with FeNPs showed promise in enhancing drought tolerance in T. vulgaris. These treatments have significantly contributed to the production of enzymatic antioxidants, flavonoids, and phenolic compounds, leading to a reduction in the amounts of oxidants. At the same time, they have improved both the quality and quantity of essential oils. This highlights the importance of establishing an effective antioxidant system in response to environmental stresses.Graphical

The Impact of Perfluorooctanoic Acid (PFOA) on the Mussel Mytilus galloprovincialis: A Multi-Biomarker Evaluation

Perfluorooctanoic acid (PFOA) has been widely studied due to its environmental persistence and bioaccumulation potential, raising concerns about its effects on aquatic life. This research evaluates the impact of PFOA on the antioxidant defenses and stress response systems of the mussel Mytilus galloprovincialis. Mussels were exposed to three concentrations of PFOA (1, 10, and 100 µg·L−1) over 28 days. Several biomarkers, including glutathione S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), lipid peroxidation (LPO), total antioxidant capacity (TAC), vitellogenin (VTG), ubiquitin (UBI), and caspase-3 (CASP) were analyzed. The results suggest stress responses, particularly in animals exposed to higher concentrations, as shown by GST and SOD activities which increased according to PFOA concentrations. Additionally, oxidative stress markers such as MDA and CAT showed variable responses depending on the exposure concentration tested. This study underscores the need for further investigation into the effects of PFOA on mollusks but also the need to unveil gender-specific responses in aquatic organisms exposed to this contaminant. The concentrations of PFOA used in our research are lower than those examined in previous studies, providing crucial insights into the impacts of even minimal exposure levels. It highlights the potential of M. galloprovincialis as a bioindicator in environmental monitoring programs, providing crucial insights for environmental management and policymaking regarding regulating and monitoring PFOA in marine settings. Consequently, in a country where seafood consumption is the second largest in Europe, implementing environmental policies and regulatory measures to manage and monitor PFOA levels in marine environments is crucial.

Inoculation with multifunctional Bacillus sp. NEAU-DCB1-2 mitigates chromium toxicity in pakchoi (Brassica rapa ssp. chinensis) through a multi-level mechanism

Soil chromium (Cr) accumulation is escalating, severely hindering plant growth and development. Plant growth-promoting bacteria (PGPB) have shown potential in enhancing plant tolerance to heavy metals. However, the role and mechanisms of Cr(VI)-reducing PGPB strains in improving the growth of pakchoi under Cr toxicity remain unclear. This study aimed to isolate a Cr(VI)-reducing PGPB strain from Cr-contaminated soil, evaluate its effect on pakchoi growth under Cr(VI) stress, and investigate the mechanisms involved. Our findings showed that Bacillus sp. NEAU-DCB1–2 effectively reduce Cr(VI) to Cr(III) and produced indole-3-acetic acid and siderophores. Under Cr(VI) stress, inoculation with NEAU-DC1–2 significantly promoted seed germination and early growth of pakchoi. In pot experiments, NEAU-DCB1–2 significantly increased biomass accumulation, plant height, and root length of Cr(VI)-treated pakchoi seedlings, while reducing the Cr(VI) content in root, shoot and soil. Moreover, NEAU-DCB1–2 greatly increased catalase, superoxide dismutase, peroxidase, and ascorbate peroxidase activities in seedlings under Cr(VI) stress, thereby reducing malondialdehyde content. Transcriptome analysis indicated substantial alterations in gene expression patterns after inoculation with NEAU-DCB1–2 under Cr(VI) stress. Further analyses revealed that NEAU-DCB1–2 mainly affected the responses of antioxidant system, metal chelation and transport, together with auxin, abscisic acid, and jasmonic acid signaling to Cr(VI) stress. Conclusively, the Cr(VI)-reducing PGPB strain NEAU-DCB1–2 significantly enhances the growth and Cr tolerance of pakchoi through multiple mechanisms, offering a valuable microbial resource for mitigating the adverse effects of heavy metal contamination in agricultural soils on the yield and safety of vegetable crops.

The influence of inactivated entomopathogenic bacterium Bacillus thuringiensis on the immune responses of the Colorado potato beetle.

Invasion of microorganisms into the gut of insects triggers a cascade of immune reactions accompanied by increased synthesis of effectors (such as antimicrobial peptides, cytokines, and amino acids), leading to changes in the physiological state of the host. We hypothesized that even an inactivated bacterium can induce an immune response in an insect. The aim of this study was to compare the roles of reactive oxygen species (ROS) formation and of the response of detoxification and antioxidant systems in a Colorado potato beetle (CPB) larval model in the first hours after invasion by either an inactivated or live bacterium. The influence of per os inoculation with inactivated entomopathogenic bacterium Bacillus thuringiensis var. tenebrionis (Bt) on the survival and physiological and biochemical parameters of CPB larvae was assessed as changes in the total hemocyte count (THC), activity of phenoloxidases (POs), glutathione-S-transferases (GSTs), nonspecific esterases (ESTs), catalase, peroxidases, superoxide dismutases (SODs) and formation of reactive oxygen species (ROS). A series of changes occurred within the hemolymph and the midgut of CPBs inoculated with inactivated Bt at 12 h after inoculation. These physiological and biochemical alterations serve to mediate generalized resistance to pathogens. The changes were associated with an increase in the THC and a 1.4-2.2-fold enhancement of detoxification enzymatic activities (such as GST and EST) as well as increased levels of antioxidants (especially peroxidases) in hemolymph in comparison to the control group. Suppressed EST activity and reduced ROS formation were simultaneously detectable in the larval midgut. Inoculation of beetle larvae with active Bt cells yielded similar results (elevated THC and suppressed PO activity). A fundamental difference in the immune activation processes between larvae that ingested the inactivated bacterium and larvae that had consumed the active bacterium was that the inactivated bacterium did not influence ROS formation in the hemolymph but did reduce their formation in the midgut. At 24 h postinfection with active Bt, ROS levels went up in both the hemolymph and the midgut. This was accompanied by a significant 5.7-fold enhancement of SOD activity and a 5.3-fold suppression of peroxidase activity. The observed alterations may be due to within-gut toxicity caused by early-stage bacteriosis. The imbalance in the antioxidant system and the accumulation of products toxic to the "putative" pathogen can activate detoxification mechanisms, including those of an enzymatic nature (EST and GST). The activation of detoxification processes and of innate immune responses is probably due to the recognition of the "putative" pathogen by gut epithelial cells and is similar in many respects to the immune response at early stages of bacteriosis.

Dynamic responses of germination characteristics and antioxidant systems to alfalfa (Medicago sativa) seed aging based on transcriptome

Seed aging poses a significant challenge to agronomic production and germplasm conservation. Reactive oxygen species (ROS) are highly involved in the aging process. However, dynamic response of germination characteristics and antioxidant system to seed aging are not yet very clear. This study explored the potential physiological mechanisms responsible for the reduced and rapid loss of seed vigor in alfalfa, and identified key genes regulating seed vigor. The germination percentage exhibited a decreased trend with the prolongation of aging duration. From 16 to 32 days of aging, the antioxidant enzyme activities of SOD, POD, CAT, DHAR and MDHAR declined significantly, which lead to the disruption of ROS balance and a significant increase in ROS levels, exacerbating seed aging. Based on transcriptome, 29 differentially expressed genes (DEGs) including SOD1, APX-2 and GST-7 within the ROS scavenging system showed a significantly down-regulated expression trend at aging of 16 and 24 days, indicating the abnormal function of antioxidant metabolism. Furthermore, some related genes including ATPF1B, ATPeF0C-3, NDUFS1, NDUFS3 and ND2 in the mitochondrial ETC exhibited a downturn following seed aging, which would result in the losing of seed vigor. This study has uncovered a significant array of potential target genes within the seed antioxidant system and mitochondrial ETC. These discoveries offer a wider lens for delving into the molecular regulatory mechanisms of seed aging. Further research is crucial to comprehensively elucidate the precise pathways through which these pivotal genes regulate seed vigor.

Evaluation of oxidative stress, biochemical parameters and in silico markers in different pea accessions in response to drought stress.

ARG6 and ARG10 pea accessions exhibited better tolerance to drought by keeping drought-associated attributes stable and higher, that is, stable chlorophyll content, high antioxidant activity, and the presence of polymorphic bands with stress-responsive EST-SSR markers. Each year, a significant portion of crops is lost due to various abiotic stresses, and even pea (Pisum sativum) crop growth and yield are severely affected by the challenges posed by drought stress. Drought is a critical factor that limits crop growth and development, and its impact is exacerbated by changes in the magnitude of climatic conditions. Drought induces oxidative stress in plants, leading to the accumulation of high concentrations of reactive oxygen species that damage cell structures and vital functioning of cells. The primary objective was to identify stress-tolerant plants by evaluating different morphological and biochemical attributes, such as biomass, chlorophyll content, relative water content, ascorbate peroxidase (APX), superoxide dismutase (SOD), and DPPH scavenging activity, as well as protein, proline, and phenolic content. Our study revealed that pea accessions (ARG6 and ARG10) were more resilient to drought stress as their chlorophyll, relative water, protein, and proline contents increased under drought conditions. Antioxidant enzymes, such as SOD, APX, and DPPH activities, also increased under drought stress in ARG10 and ARG6, suggesting that these accessions could bolster the antioxidant defense system in response to drought stress. Based on putative (cellular, biological, and metabolic) functions, ten EST-SSR primers were selected for the amplification study. Three EST-SSR primers, AUMP06_110, AUMP18_300, and AUMP31_250, were used for ARG6 and ARG10. Based on the correlation between the presence or absence of specific EST-SSR alleles, various physiological and morphological traits, and DPPH scavenging activity, both ARG10 and ARG6 demonstrated resistance to drought stress.

Naringenin and caffeic acid increase ethanol production in yeast cells by reducing very high gravity fermentation-related oxidative stress.

Very high gravity (VHG) fermentation is an industrial-scale process utilizing a sugar concentration above 250g/L to attain a significant ethanol concentration, with the advantages of decreased labor, production costs, water usage, bacterial contamination, and energy consumption. Saccharomyces cerevisiae is one of the most extensively employed organisms in ethanol fermentation through VHG technology. Conversely, high glucose exposure leads to numerous stress factors that negatively impact the ethanol production efficiency of this organism. Here, the impact of various phytochemicals added to the VHG medium on viability, glucose consumption, ethanol production efficiency, total antioxidant-oxidant status (TAS and TOS), and the response of the enzymatic antioxidant system of yeast were investigated. 2.0 mM naringenin and caffeic acid increased ethanol production by 2.453 ± 0.198 and 1.261 ± 0.138-fold, respectively. The glucose consumption rate exhibited a direct relationship with ethanol production in the naringenin-supplemented group. The highest TAS was determined as 0.734 ± 0.044 mmol Trolox Eq./L in the same group. Furthermore, both phytochemical compounds exhibited robust positive correlations with TAS (rnaringenin = 0.9986; rcaffeic acid = 0.9553) and TOS levels (rnaringenin = -0.9824; rcaffeic acid = -0.9791). While naringenin caused statistically significant increases in glutathione reductase (GR) and thioredoxin reductase (TrxR) activities, caffeic acid significantly increased TrxR and superoxide dismutase (SOD). Both phytochemicals seem to impact the ethanol production ability by regulating the redox status of the cells. We believe that the incorporation of particularly cost-effective antioxidants into the fermentation medium may serve as an alternative way to enhance the efficiency of bioethanol production using VHG technology.

Seed priming with graphene oxide improves salinity tolerance and increases productivity of peanut through modulating multiple physiological processes

Graphene oxide (GO), beyond its specialized industrial applications, is rapidly gaining prominence as a nanomaterial for modern agriculture. However, its specific effects on seed priming for salinity tolerance and yield formation in crops remain elusive. Under both pot-grown and field-grown conditions, this study combined physiological indices with transcriptomics and metabolomics to investigate how GO affects seed germination, seedling salinity tolerance, and peanut pod yield. Peanut seeds were firstly treated with 400 mg L⁻¹ GO (termed GO priming). At seed germination stage, GO-primed seeds exhibited higher germination rate and percentage of seeds with radicals breaking through the testa. Meanwhile, omics analyses revealed significant enrichment in pathways associated with carbon and nitrogen metabolisms in GO-primed seeds. At seedling stage, GO priming contributed to strengthening plant growth, enhancing photosynthesis, maintaining the integrity of plasma membrane, and promoting the nutrient accumulation in peanut seedlings under 200 mM NaCl stress. Moreover, GO priming increased the activities of antioxidant enzymes, along with reduced the accumulation of reactive oxygen species (ROS) in response to salinity stress. Furthermore, the differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) of peanut seedlings under GO priming were mainly related to photosynthesis, phytohormones, antioxidant system, and carbon and nitrogen metabolisms in response to soil salinity. At maturity, GO priming showed an average increase in peanut pod yield by 12.91% compared with non-primed control. Collectively, our findings demonstrated that GO plays distinguish roles in enhancing seed germination, mitigating salinity stress, and boosting pod yield in peanut plants via modulating multiple physiological processes.

Responses of survival, antioxidant system and intestinal microbiota of native snail Bellamya purificata to the invasive snail Pomacea canaliculata

Pomacea canaliculata is one of the most successful invader in worldwide, adversely affecting native ecosystem through direct predation or indirect competition, while the mechanism of indirect effects on native species remain poorly understood. To clarify the effects of P. canaliculata on the native near-niche species, Bellamya purificata, a widespread freshwater gastropod in China, was selected as the research subject. The changes of mortality, histology, antioxidant system as well as the intestinal flora diversity of B. purificata were explored in present study. The results showed that the median lethal dose of P. canaliculata culture solution for B. purificata was 23.76 ind/L and a concentration-dependent damage of both the gonad and hepatopancreas were observed, the gonadal villi were dissolved and the hepatopancreas cells were broken at 20 ind/L. Furthermore, different concentrations of P. canaliculata culture solution leading to the antioxidant damage on the enzyme or non-enzyme systems of B. purificata at various degrees. Additionally, a decrease in the diversity of the intestinal flora was observed, accompanied by an increase in the abundance of pathogenic bacteria such as Pseudomonas and Aeromonas after the exposure of the culture solution of P. canaliculata. Last, after being recovered in freshwater for 24 h, the antioxidant damage of B. purificata and the disturbance of intestinal flora diversity were still not recovered especially in the high concentration group. The indirect competitive mechanism of P. canaliculata culture solution on B. purificata were explored from the aspects of tissue, biochemical level and intestinal flora, which enriched the research of P. canaliculata invasion on native snails in China, and provided new insights for the study of the invasion strategy of P. canaliculata.

Investigation of biochemical and antioxidant system responses of sugarcane CP48-103 under drought stress induced by polyethylene glycol

Investigation of biochemical and antioxidant system responses of sugarcane CP48-103 under drought stress induced by polyethylene glycol

Responses of oscar (Astronotus ocellatus) to different temperatures and its interaction with early mild stress

Non-optimum temperature results in stress in fish through different biological and physiological processes. This study investigated how early mild stress (EMS) and temperature can influence growth, hematology, blood biochemistry, immunological response, antioxidant system, liver enzymes, and stress response of juvenile oscar (Astronotus ocellatus; 8.02 ± 0.81 g) before and after acute confinement stress (AC stress). Eight experimental treatments were 17D (farmed at 17 °C), 22D (farmed at 22 °C), 27D (farmed at 27 °C), 32D (farmed at 32 °C), 17DES (farmed at 17 °C and EMS), 22DES (farmed at 22 °C and EMS), 27DES (farmed at 27 °C and EMS), and 32DES (farmed at 32 °C and EMS). At the end of the experiment (nine weeks), there was no significant difference in survival rate, feed conversion ratio, body composition, and survival rate after the AC stress (ten weeks). The growth rates in the 17 and 32 °C groups were lower than others, showing the negative effect of temperature being too high or too low. After nine weeks, fish farmed at 32 °C had the highest hematological parameters (hematocrit, hemoglobin, red blood cells, and blood performance) and liver enzymes (lactate dehydrogenase, alanine transaminase, and aspartate transaminase). This group also has the lowest lysozyme, alternative complement pathway (ACH50), immunoglobulin, complement C3, complement C4, superoxide dismutase, and glutathione peroxidase. The EMS did not positively or negatively affect fish physiology in this study. In conclusion, the optimum temperature for oscar to achieve the best growth performance, immune response, and health status is 22–27 °C.

Effects of Dietary Melatonin on Antioxidant Capacity, Immune Defense, and Intestinal Microbiota in Red Swamp Crayfish (Procambarus clarkii).

The aim of this study was to investigate the effects of melatonin (MT) feed supplementation on the antioxidant capacity, immune defense, and intestinal flora in Procambarus clarkii (P. clarkii). Six groups of P. clarkii were fed test feeds containing different levels of MT: 0mg/kg (control), 22.5, 41.2, 82.7, 165.1, and 329.2mg/kg for a duration of 2months. The specific growth rate, hepatosomatic index, and condition factor were recorded highest in the test group of shrimp fed an MT concentration of 165.1mg/kg. Compared to the control group, the rate of apoptosis was lower in hepatopancreas cells of P. clarkii supplemented with high concentrations of MT. Analyses of antioxidant capacity and immune-response-related enzymes in the hepatopancreas indicated that dietary supplementation of MT significantly augmented both the antioxidant system and immune responses. Dietary MT supplementation significantly increased the expression levels of antioxidant-immunity-related genes and decreased the expression levels of genes linked to apoptosis. Dietary MT was associated with an elevation in the abundance of the Firmicutes and a reduction in the abundance of the Proteobacteria in the intestines; besides, resulting in an increase in the abundance of beneficial bacteria, such as Lactobacilli. The broken-line model indicated that the suitable MT concentration was 154.09-157.09mg/kg. MT supplementation enhanced the growth performance of P. clarkii, exerting a positive influence on the intestinal microbiota, and bolstered both immune response and disease resistance. Thus, this study offered novel perspectives regarding the application of dietary MT supplementation within the aquaculture field.