Alu antisense RNA ameliorates methylglyoxal-induced human lens epithelial cell apoptosis by enhancing antioxidant defense

AIM:To determine whether an antisense RNA corresponding to the human Alu transposable element(Aluas RNA)can protect human lens epithelial cells(HLECs)from methylglyoxal-induced apoptosis.METHODS:Cell counting kit-8(CCK-8)and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assays were used to assess HLEC viability.HLEC viability/death was detected using a Calcein-AM/PI double staining kit;the annexin V-FITC method was used to detect HLEC apoptosis.The cytosolic reactive oxygen species(ROS)levels in HLECs were determined using a reactive species assay kit.The levels of malondialdehyde(MDA)and the antioxidant activities of total-superoxide dismutase(T-SOD)and glutathione peroxidase(GSH-Px)were assessed in HLECs using their respective kits.RT-q PCR and Western blotting were used to measure m RNA and protein expression levels of the genes.RESULTS:Aluas RNA rescued methylglyoxal-induced apoptosis in HLECs and ameliorated both the methylglyoxalinduced decrease in Bcl-2 m RNA and the methylglyoxalinduced increase in Bax m RNA.In addition,Aluas RNA inhibited the methylglyoxal-induced increase in Alu sense RNA expression.Aluas RNA inhibited the production of ROS induced by methylglyoxal,restored T-SOD and GSHPx activity,and moderated the increase in MDA content after treatment with methylglyoxal.Aluas RNA significantly restored the methylglyoxal-induced down-regulation of Nrf2 gene and antioxidant defense genes,including glutathione peroxidase,heme oxygenase 1,γ-glutamylcysteine synthetase and quinone oxidoreductase 1.Aluas RNA ameliorated methylglyoxal-induced increases of the m RNA and protein expression of Keap1 that is the negative regulator of Nrf2.CONCLUSION:Aluas RNA reduces apoptosis induced by methylglyoxal by enhancing antioxidant defense.

Silicon and Nitric Oxide-Mediated Regulation of Growth Attributes, Metabolites and Antioxidant Defense System of Radish (Raphanus sativus L.) under Arsenic Stress

Arsenic(As)contaminated food chains have emerged as a serious public concern for humans and animals and are known to affect the cultivation of edible crops throughout the world.Therefore,the present study was designed to investigate the individual as well as the combined effects of exogenous silicon(Si)and sodium nitroprusside(SNP),a nitric oxide(NO)donor,on plant growth,metabolites,and antioxidant defense systems of radish(Raphanus sativus L.)plants under three different concentrations of As stress,i.e.,0.3,0.5,and 0.7 mM in a pot experiment.The results showed that As stress reduced the growth parameters of radish plants by increasing the level of oxidative stress markers,i.e.,malondialdehyde and hydrogen peroxide.However,foliar application of Si(2 mM)and pretreatment with SNP(100μM)alone as well as in combination with Si improved the plant growth parameters,i.e.,root length,fresh and dry weight of plants under As stress.Furthermore,As stress also reduced protein,and metabolites contents(flavonoids,phenolic and anthocyanin).Activities of antioxidative enzymes such as catalase(CAT),ascorbate peroxidase(APX),guaiacol peroxidase(POD),and polyphenol oxidase(PPO),as well as the content of non-enzymatic antioxidants(glutathione and ascorbic acid)decreased under As stress.In most of the parameters in radish,As III concentration showed maximum reduction,as compared to As I and II concentrations.However,the individual and combined application of Si and NO significantly alleviated the As-mediated oxidative stress in radish plants by increasing the protein,and metabolites content.Enhancement in the activities of CAT,APX,POD and PPO enzymes were recorded.Contents of glutathione and ascorbic acid were also enhanced in response to co-application of Si and NO under As stress.Results obtained were more pronounced when Si and NO were applied in combination under As stress,as compared to their individual application.In short,the current study highlights that Si and NO synergistically regulate plant growth through lowering the As-mediated oxidative stress by upregulating the metabolites content,activity of antioxidative enzymes and non-enzymatic antioxidants in radish plants.

Changes in Growth,Photosynthetic Pigments,Cell Viability,Lipid Peroxidation and Antioxidant Defense System in Two Varieties of Chickpea(Cicer arietinum L.)Subjected to Salinity Stress

Salinity is one of the most severe abiotic stresses for crop production.The present study investigates the salinityinduced modulation in growth indicators,morphology and movement of stomata,photosynthetic pigments,activity of carbonic anhydrase as well as nitrate reductase,and antioxidant systems in two varieties of chickpea(Pusa-BG5023,and Pusa-BGD72).On 20^(th) day of sowing,plants were treated with varying levels of NaCl(0,50,100,150 and 200 mM)followed by sampling on 45 days of sowing.Recorded observations on both the varieties reveal that salt stress leads to a significant decline in growth,dry biomass,leaf area,photosynthetic pigments,protein content,stomatal behavior,cell viability,activity of nitrate reductase and carbonic anhydrase with the rise in the concentration of salt.However,quantitatively these changes were less in Pusa-BG5023 as compared to Pusa-BGD72.Furthermore,salinity-induced oxidative stress enhanced malondialdehyde content,superoxide radicals,foliar proline content,and the enzymatic activities of superoxide dismutase,catalase,and peroxidase.The variety Pusa-BGD72 was found more sensitive than Pusa-BG5023 to salt stress.Out of different graded concentrations(50,100,150 and 200 mM)of sodium chloride,50 mM was least toxic,and 200 mM was most damaging.The differential behavior of these two varieties measured in terms of stomatal behavior,cell viability,photosynthetic pigments,and antioxidant defense system can be used as prospective indicators for selection of chickpea plants for salt tolerance and sensitivity.

Response of antioxidant defense system in copepod Calanus sinicus Brodsky exposed to CO_2-acidified seawater

Marine zooplankton responds sensitively to elevated seawater CO_2 concentration. However, the underlying physiological mechanisms have not been studied well. We therefore investigated the effects of elevated CO_2concentration(0.08%, 0.20%, 0.50% and 1.00%) on antioxidant defense components, as well as two detoxification enzymes of Calanus sinicus(copepod). The results showed that glutathione peroxidase(GPx) activity exposed to CO_2-acidified seawater was significantly stimulated while other antioxidant components, including glutathione-Stransferase(GST) activity, superoxide dismutase(SOD) activity decreased significantly with reduced glutathione(GSH) level and GSH/oxidized glutathione(GSSG) value. CO_2-acidified seawater exhibited stimulatory effects on adenosine triphosphatase(ATPase) activity and acetylcholinesterase(Ach E) activity was inhibited. Moreover, the results of principal component analysis indicated that 75.93% of the overall variance was explained by the first two principal components. The elevated CO_2 concentration may affect the metabolism and survivals of copepods through impacts these enzymes activities. Further studies are needed to focus on the synergistic effects of elevated CO_2 concentration and other environmental factors on copepods.

Antioxidant defense mechanisms and fatty acid catabolism in Red-billed Leiothrix(Leiothrix lutea)exposed to high temperatures

Extreme hot weather is occurring more frequently due to global warming,posing a significant threat to species survival.Birds in particular are more likely to overheat in hot weather because they have a higher body temperature.This study used a heat stress model to investigate the antioxidant defense mechanisms and changes in fatty acid catabolism in Red-billed Leiothrix(Leiothrix lutea)to gain an understanding of how birds adapt to high temperatures.The birds were divided into five groups:a control group(30℃for 0 days),1 D group(40℃for 1 day),3 D group(40℃for 3 days),14 D group(40℃for 14 days)and recovery group(40℃for 14 days,then 30℃for 14 days).Our results indicated that when Red-billed Leiothrix are subjected to heat stress,malondialdehyde(MDA)content in the liver significantly increased,as did the enzyme activities of catalase(CAT),glutathione-SH-peroxidase(GSH-PX)and total antioxidant capacity(T-AOC)in the liver.Furthermore,there was a significant increase in heat shock protein 70(HSP70)expression in the liver,while avian uncoupling protein(avUCP)expression in muscle was significantly reduced.Additionally,there was a significant reduction in fatty acid catabolism enzyme activity such as 3-hydroxyacyl-CoAdehydrogenase(HOAD)activity in the heart,and carnitine palmitoyl transferase 1(CPT-1)and citrate synthase(CS)activity in the heart and liver.Furthermore,fatty acid translocase(FAT/CD36)in the heart,heart-type fatty acid binding protein(H-FABP)and fatty acid binding protein(FABP-pm)in the liver and heart were also significantly decreased.These changes reverted after treatment,but not to the same level as the control group.Our results indicated that when Red-billed Leiothrix are exposed to heat stress their internal antioxidant defense system is activated to counteract the damage caused by high temperatures.However,even with high antioxidant levels,prolonged high temperature exposure still caused some degree of oxidative damage possibly requiring a longer recovery time.Additionally,Red-billed Leiothrix may be able to resist heat stress by reducing fatty acid transport and catabolism.

Cadmium-induced oxidative damage and antioxidant defense mechanisms in Glycine max L.

Objective:To analyze the effect of Cadmium(Cd)on the metabolism of reduced glutathione(GSH)in roots and leaves of Glycine max L.Methods:A capillary electrophoresis methodology was optimized to determinate simultaneously GSH and reduced and oxidized GSH in a precise and accurate way.The functional role of the genes involved in GSH cellular metabolism(γ-glutamylcysteine synthetase),GSH synthetase and glutathione reductase(GR)was evaluated.Finally,the activities of antioxidant enzymes as GR and superoxide dismutases were determinate.Results:The studies ofγ-glutamylcysteine synthetase and GSH synthetase gene expression showed an increase and GR showed a decrease in Cd-treated plants.GR and superoxide dismutases activities increased at 24 h and 6 h respectively in roots under Cd exposure.GSH content was higher and showed a significant increase in roots and leaves at 6 h and 24 h of treatment.Conclusions:The results of the present study showed a better understanding in signaling pathway by alterations in antioxidant mechanisms by Cd in soybean seedlings.

Grain Yield,Biomass Accumulation,and Leaf Photosynthetic Characteristics of Rice under Combined Salinity-Drought Stress

Simultaneous stresses of salinity and drought often coincide during rice-growing seasons in saline lands,primarily due to insufficient water resources and inadequate irrigation facilities.Consequently,combined salinity-drought stress poses a major threat to rice production.In this study,two salinity levels(NS,non-salinity;HS,high salinity)along with three drought treatments(CC,control condition;DJ,drought stress imposed at jointing;DH,drought stress imposed at heading)were performed to investigate their combined influences on leaf photosynthetic characteristics,biomass accumulation,and rice yield formation.Salinity,drought,and their combination led to a shortened growth period from heading to maturity,resulting in a reduced overall growth duration.Grain yield was reduced under both salinity and drought stress,with a more substantial reduction under the combined salinity-drought stress.The combined stress imposed at heading caused greater yield losses in rice compared with the stress imposed at jointing.Additionally,the combined salinity-drought stress induced greater decreases in shoot biomass accumulation from heading to maturity,as well as in shoot biomass and nonstructural carbohydrate(NSC)content in the stem at heading and maturity.However,it increased the harvest index and NSC remobilization reserve.Salinity and drought reduced the leaf area index and SPAD value of flag leaves and weakened the leaf photosynthetic characteristics as indicated by lower photosynthetic rates,transpiration rates,and stomatal conductance.These reductions were more pronounced under the combined stress.Salinity,drought,and especially their combination,decreased the activities of ascorbate peroxidase,catalase,and superoxide dismutase,while increasing the contents of malondialdehyde,hydrogen peroxide,and superoxide radical.Our results indicated a more significant yield loss in rice when subjected to combined salinity-drought stress.The individual and combined stresses of salinity and drought diminished antioxidant enzyme activities,inhibited leaf photosynthetic functions,accelerated leaf senescence,and subsequently lowered assimilate accumulation and grain yield.

Context‑dependent antioxidant defense system(ADS)‑based stress memory in response to recurrent environmental challenges in congeneric invasive species

Marine ecosystems are facing escalating environmental fluctuations owing to climate change and human activities,imposing pressures on marine species.To withstand recurring environmental challenges,marine organisms,especially benthic species lacking behavioral choices to select optimal habitats,have to utilize well-established strategies such as the antioxidant defense system(ADS)to ensure their survival.Therefore,understanding of the mechanisms governing the ADS-based response is essential for gaining insights into adaptive strategies for managing environmental challenges.Here we conducted a com-parative analysis of the physiological and transcriptional responses based on the ADS during two rounds of'hypersalinity-recovery'challenges in two model congeneric invasive ascidians,Ciona robusta and C.savignyi.Our results demonstrated that C.savignyi exhibited higher tolerance and resistance to salinity stresses at the physiological level,while C.robusta demonstrated heightened responses at the transcriptional level.We observed distinct transcriptional responses,particularly in the utilization of two superoxide dismutase(SOD)isoforms.Both Ciona species developed physiological stress memory with elevated total SOD(T-SOD)and glutathione(GSH)responses,while only C.robusta demonstrated transcriptional stress memory.The regulatory distinctions within the Nrf2-Keap1 signalling pathway likely explain the formation disparity of transcriptional stress memory between both Ciona species.These findings support the'context-dependent stress memory hypothesis',emphasizing the emergence of species-specific stress memory at diverse regulatory levels in response to recurrent environmental challenges.Our results enhance our understanding of the mechanisms of environmental challenge manage-ment in marine species,particularly those related to the ADS.

Mycorrhiza improves cold tolerance of Satsuma orange by inducing antioxidant enzyme gene expression

A potted experiment was carried out to study the effect of an arbuscular mycorrhizal fungus(Diversispora versiformis)and arbuscular mycorrhizal like fungus(Piriformospora indica)on antioxidant enzyme defense system of Satsuma orange(Citrus sinensis cv.Oita 4)grafted on Poncirus trifoliata under favourable temperature(25°C)and cold temperature(0°C)for 12 h.Such short-term treatment of cold temperature did not cause any significant change in root fungal colonization and spore density in soil.Under cold stress,D.versiformis inoculation did not change the activity of superoxide dismutase(SOD),catalase(CAT),and peroxidase(POD)in leaves and roots,whereas P.indica inoculation significantly increased the activity of CAT in roots and POD in leaves only.In addition,inoculation of two mycorrhizal fungi under cold stress significantly increased the relative expression levels of PtPOD and PtF-SOD in leaves,P.indica up-regulated the expression levels of PtCu/Zn-SOD in leaves,and D.versiformis also induced the expression levels of PtMn-SOD and PtCAT1 in leaves.In addition,inoculated Oita 4 trees maintained significantly lower hydrogen peroxide levels and malondialdehyde contents in leaves and roots under cold temperature,suggesting lower oxidative damage.Therefore,we concluded that arbuscular mycorrhizal fungi(especially P.indica)mainly induced the expression of antioxidant enzyme genes,depending on the fungal species,and thus mitigated oxidative damage for higher cold resistance in inoculated plants.

Organic Amendments Improve Plant Morpho-Physiology and Antioxidant Metabolism in Mitigating Drought Stress in Bread Wheat(Triticum aestivum L.)

Due to the unpredictable climate change,drought stress is being considered as one of the major threats to crop production.Wheat(Triticum aestivum L.cv.BARI Gom-26)being a dry season crop frequently faces scarcity of water and results in a lower yield.Therefore,this experiment aims to explore the role of different organic amendments(OAs)in mitigating drought stress-induced damage.The pot experiment consisted of different organic amendments viz.compost,vermicompost and poultry manure@0.09 kg m^(−2)soil,biochar@2.5%w/w soil and chitosan@1%w/w soil which was imposed on the plants grown under both well-watered and drought conditions.Results showed that drought stress reduced plant height(15%),SPAD value(16%),relative water content(13%),number of spikelet spike^(−1)(17%),number of grains spike^(−1)(12%),and 100-grain weight(18%).Organic amendments act as a protectant and reduce drought stress-induced damages by enhancing the morpho-physiological and yield attributes.Vermicompost enhanced SPAD value by 18%,number of spikelets spike^(−1)by 20%,number of grains spike^(−1)by 17%,whereas poultry manure increased plant height by 16%under drought condition compared to control plant.Unlike other OAs applied,vermicompost was proved to be capable of reducing the higher lipid peroxidation and proline content raised by drought condition.Drought stress-induced increment of catalase,ascorbate peroxidase and glutathione reductase activities were also efficiently modulated by the organic amendment application.The present study concluded that OAs play significant roles in alleviating drought stressinduced damages by improving the morpho-physiological attributes and among the different types of OAs used vermicompost performed better which in addition ceased the production of reactive oxygen species.

DROUGHT-INDUCED UNKNOWN PROTEIN 1 positively modulates drought tolerance in cultivated alfalfa(Medicago sativa L.)

Alfalfa is the most widely cultivated perennial legume forage crop worldwide.Drought is one of the major environmental factors influencing alfalfa productivity.However,the molecular mechanisms underlying alfalfa responses to drought stress are still largely unknown.This study identified a drought-inducible gene of unknown function,designated as Medicago sativa DROUGHT-INDUCED UNKNOWN PROTEIN 1(MsDIUP1).MsDIUP1 was localized to the nucleus,chloroplast,and plasma membranes.Overexpression of MsDIUP1 in Arabidopsis resulted in increased tolerance to drought,with higher seed germination,root length,fresh weight,and survival rate than in wild-type(WT)plants.Consistently,analysis of MsDIUP1 over-expression(OE)alfalfa plants revealed that MsDIUP1 also increased tolerance to drought stress,accompanied by physiological changes including reduced malondialdehyde(MDA)content and increased osmoprotectants accumulation(free proline and soluble sugar),relative to the WT.In contrast,disruption of MsDIUP1 expression by RNA interference(RNAi)in alfalfa resulted in a droughthypersensitive phenotype,with a lower chlorophyll content,higher MDA content,and less osmoprotectants accumulation than that of the WT.Transcript profiling of alfalfa WT,OE,and RNAi plants during drought stress showed differential responses for genes involved in stress signaling,antioxidant defense,and osmotic adjustment.Taken together,these results reveal a positive role for MsDIUP1 in regulating drought tolerance.

Salicylic Acid Application Mitigates Oxidative Damage and Improves the Growth Performance of Barley under Drought Stress

Drought is a severe environmental constraint,causing a significant reduction in crop productivity across the world.Salicylic acid(SA)is an important plant growth regulator that helps plants cope with the adverse effects induced by various abiotic stresses.The current study investigated the potential effects of SA on drought tolerance efficacy in two barley(Hordeum vulgare)genotypes,namely BARI barley 5 and BARI barley 7.Ten-day-old barley seedlings were exposed to drought stress by maintaining 7.5%soil moisture content in the absence or presence of 0.5,1.0 and 1.5 mM SA.Drought exposure led to severe damage to both genotypes,as indicated by phenotypic aberrations and reduction of dry biomass.On the other hand,the application of SA to drought-stressed plants protected both barley genotypes from the adverse effects of drought,which was reflected in the improvement of phenotypes and biomass production.SA supplementation improved relative water content and proline levels in drought-stressed barley genotypes,indicating the osmotic adjustment functions of SA under water-deficit conditions.Drought stress induced the accumulation of reactive oxygen species(ROS),such as hydrogen peroxide(H2O2)and superoxide(O_(2)•^(−)),and the lipid peroxidation product malondialdehyde(MDA)in the leaves of barley plants.Exogenous supply of SA reduced oxidative damage by restricting the accumulation of ROS through the stimulation of the activities of key antioxidant enzymes,including superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),ascorbate peroxidase(APX)and glutathione peroxidase(GPX).Among the three-applied concentrations of SA,0.5 mM SA exhibited better mitigating effects against drought stress considering the phenotypic performance and biochemical data.Furthermore,BARI barley 5 showed better performance under drought stress than BARI barley 7 in the presence of SA application.Collectively,our results suggest that SA played a crucial role in improving water status and antioxidant defense strategy to protect barley plants from the deleterious effects of water deficiency.

A Review on Selenium Function under Oxidative Stress in Plants Focusing on ROS Production and

One of the main reasons of the annual reduction in plant production all around the world is the occurrence of abiotic stresses as a result of an unpredicted changes in environmental conditions.Abiotic stresses basically trigger numerous pathways related to oxygen free radicals’generation resulting in a higher rate of reactive oxygen species(ROS)production.Accordingly,higher rate of oxygen free radicals than its steady state causes to oxidize various types of molecules and compartments within the plants’cells and tissues.Oxidative stress is the result of high amount free radicals of oxygen interfering with different functions leading to undergo significant changes from molecular to phenotypic levels.In response to oxidative stress,plants deploy different enzymatic and non-enzy-matic antioxidant mechanisms to detoxify extra free radicals and get back to a normal state.Applying some spe-cific treatments have shown to significantly affect the antioxidant capacity and efficiency of the stressed cells and compartments.One of such reportedly effective treatments is the utilization of selenium(Se)element in stressed plants.Over the past years some different experiments evaluated the probable effect or efficiency of Se regarding its impact on plant under oxidative stress.Accordingly,based on the recent studies,Se has a significant role in plant responses to abiotic stresses probably due to its ability to improve the plants’tolerance to oxidative stress.The significant influences of Se,and its related components such as nano-selenium,in plants under oxidative stress rooting from abiotic stresses,along with the newfinding pertaining to its metabolism and translocation mechanisms inside the plant cells under oxidative stress condition are clearly explained in this review.However,there are still lack of a comprehensive explanation related to the precise mechanism of Se in plants under oxida-tive stress.

Higher levels of the lipophilic antioxidants coenzyme Q_(10) and vitamin E in long-lived termite queens than in short-lived workers

Termite queens and kings live longer than nonreproductive workers.Several molecular mechanisms contributing to their long lifespan have been investigated;however,the underlying biochemical explanation remains unclear.Coenzyme Q(CoQ),a component of the mitochondrial electron transport chain,plays an essential role in the lipophilic antioxidant defense system.Its beneficial effects on health and longevity have been well studied in several organisms.Herein,we demonstrated that long-lived termite queens have significantly higher levels of the lipophilic antioxidant CoQ_(10) than workers.Liquid chromatography analysis revealed that the levels of the reduced form of CoQ_(10) were 4 fold higher in the queen's body than in the worker's body.In addition,queens showed 7 fold higher levels of vitamin E,which plays a role in antilipid peroxidation along with CoQ,than workers.Furthermore,the oral administration of CoQ_(10) to termites increased the CoQ_(10) redox state in the body and their survival rate under oxidative stress.These findings suggest that CoQ_(10) acts as an efficient lipophilic antioxidant along with vitamin E in long-lived termite queens.This study provides essential biochemical and evolutionary insights into the relationship between CoQ_(10) concentrations and termite lifespan extension.

Impact of ocean acidification on physiology and microbiota in hepatopancreas of Pacific oyster Crassostrea gigas

The hepatopancreas is an important tissue involved in various biological metabolism for mollusks,but its responses to ocean acidifi cation(OA)have not been well evaluated.In this study,the oysters were cultured in simulated conditions by continuously bubbling with ambient air(pH=8.10)or air-CO_(2)(pH=7.50)for up to two months,and the variations on the antioxidant capacity,digestive ability,and microbiota composition in hepatopancreas of Crassostrea gigas were analyzed.The results show that although superoxide dismutase and glutathione responded quickly to OA stress,the antioxidant capacity of the hepatopancreas was inhibited,as revealed by the decrease of the total antioxidant capacity,which led to an upward trend of the malondialdehyde,demonstrating that the oxidative damages were accumulated under the OA process.The determination of the digestive ability manifested as the decrease of pepsin activity and the recovery of lipase and amylase activity after long-term acidifi cation,which may be helpful to improve the adaptability of oysters.In addition,analysis on 16S rDNA amplicon revealed that the total species abundance and diversity of the hepatopancreas microbiota experienced a dynamic change,but fi nally it decreased greatly after long-term acidifi cation.The structure of the hepatopancreas microbiota was changed drastically with the change of the dominant species from aerobic to the anaerobic and facultative anaerobic bacteria,and the abnormal proliferation of some species,such as genus of Mycoplasma and order Clostridiales,which may aggravate the adverse eff ects of OA on the physiological functions of the hepatopancreas.As a result,our fi ndings enrich our understanding of the accumulated oxidative damage and adaptive digestive ability in oyster hepatopancreas caused by OA.For the fi rst time,the changes of the hepatopancreas microbiota under long-term acidifi cation conditions are described,proving a good reference for the study of the response and adaptation mechanisms of bivalve mollusks in a wide range of oceans OA.

Impact of nanomaterials on plants:What other implications do they have?

The use of nanomaterials has spread and has been applied in different industries,including agriculture.Here,the possibilities presented by NMs are very varied,from the biostimulation of favorable responses,or the control of pests and diseases,to the monitoring of characteristics of interest with the use of nanosensors.Particularly the biostimulation of agricultural crops with the use of nanomaterials is very relevant,since from this process stress tolerance,higher content of biocompounds,etc.,can be induced.Although the positive impacts on crops are clear,there is not enough information to determine the long-term impacts,both on ecosystems and on human health.

Oxidative stress indicators in human and bottlenose dolphin leukocytes in response to a pro-inflammatory challenge

Marine mammals undergo cycles of tissue ischemia and reperfusion during the dive response.Reperfusion injury can result in oxidative tissue damage and the activation of a pro-inflammatory immune response.The risk of oxidative damage is reduced by antioxidants.Our hypothesis is that the reported higher antioxidant defenses within marine mammal tissues provide additional protection in situations that produce oxidative stress,like inflammation,in comparison to terrestrial mammal tissues.Leukocytes were isolated from the whole blood of Pacific bottlenose dolphins(Tursiops truncatus gilli)and humans(Homo sapiens)and were exposed to lipopolysaccharides(LPS,10μg/mL)in vitro to simulate a pro-inflammatory challenge.Oxidative stress indicators,including superoxide radical(O_(2)^(•−))production,activities of superoxide dismutase(SOD),catalase(CAT),glutathione peroxidase(GPx),glutathione reductase(GR),and glutathione S-transferase(GST),as well as oxidative protein damage,were quantified by spectrophotometry.Following 48 h under experimental conditions,bottlenose dolphin leukocytes produced 1.9 times more O_(2)^(•−)but displayed 2.0 times lower protein carbonyl concentrations compared to human leukocytes.Following 48 h under experimental conditions,bottlenose dolphin leukocytes displayed 7.9,2.0,11.1,and 3.3 times more activities of CAT,GPx,GR,and GST,respectively,compared to human leukocytes.These results suggest that,under cell culture conditions,the antioxidant defenses in bottlenose dolphin leukocytes provide additional protection against pro-inflammatory challenges in comparison to human leukocytes,likely as an adaptive advantage.

Spirulina platensis extract improves the production and defenses of the common bean grown in a heavy metals-contaminated saline soil

Plants have to cope with several abiotic stresses,including salinity and heavymetals(HMs).Under these stresses,several extracts have been used as effective natural biostimulants,however,the use of Spirulina platensis(SP)extract(SPE)remains elusive.The effects of SPE were evaluated as soil addition(SA)and/or foliar spraying(FS)on antioxidant defenses and HMs content of common bean grown in saline soil contaminated with HMs.Individual(40 or 80 mg SPE/hill added as SA or 20 or 40 mg SPE/plant added as FS)or integrative(SA+FS)applications of SPE showed significant improvements in the following order:SA-80+FS-40>SA-80+FS-20>SA-40+FS-40>SA-40+FS-20>SA-80>SA-40>FS-40>FS-20>control.Therefore,the integrative SA+FS with 40 mg SP/plant was the most effective treatment in increasing plant growth and production,overcoming stress effects and minimizing contamination of the edible part.It significantly increased plant growth(74%–185%)and yield(107%–227%)by enhancing net photosynthetic rate(78.5%),stomatal conductance(104%),transpiration rate(124%),and contents of carotenoids(60.0%),chlorophylls(49%–51%),and NPK(271%–366%).These results were concurrent with the marked reductions in malondialdehyde(61.6%),hydrogen peroxide(42.2%),nickel(91%–94%),lead(80%–9%),and cadmium(74%–91%)contents due to the improved contents of glutathione(87.1%),ascorbate(37.0%),andα-tocopherol(77.2%),and the activities of catalase(18.1%),ascorbate peroxidase(18.3%),superoxide dismutase(192%),and glutathione reductase(52.2%)as reinforcing mechanisms.Therefore,this most effective treatment is recommended to mitigate the stress effects of salinity and HMs on common bean production while minimizing HMs in the edible part.

Ferroptosis in acute leukemia

Ferroptosis is an iron-dependent cell death pathway that is different from apoptosis,pyroptosis,and necrosis.The main characteristics of ferroptosis are the Fenton reaction mediated by intracellular free divalent iron ions,lipid peroxidation of cell membrane lipids,and inhibition of the anti-lipid peroxidation activity of intracellular glutathione peroxidase 4(GPX4).Recent studies have shown that ferroptosis can be involved in the pathological processes of many disorders,such as ischemia-reperfusion injury,nervous system diseases,and blood diseases.However,the specific mechanisms by which ferroptosis participates in the occurrence and development of acute leukemia still need to be more fully and deeply studied.This article reviews the characteristics of ferroptosis and the regulatory mechanisms promoting or inhibiting ferroptosis.More importantly,it further discusses the role of ferroptosis in acute leukemia and predicts a change in treatment strategy brought about by increased knowledge of the role of ferroptosis in acute leukemia.

The radioresistant and survival mechanisms of Deinococcus radiodurans

Deinococcus radiodurans (D. radiodurans) is distinguished by the most radioresistant organism ever known, and can tolerate extreme environments such as ionizing radiation, ultraviolet radiation, oxidation, and desiccation. D. radiodurans is an important model for studying DNA damage/repair and redox regulation upon high dose ionizing radiation. How D. radiodurans response and repair ROS-induced oxidative damage remains a subject of ongoing investigation. This review provides an overview of the radioresistance characteristics of D. radiodurans. Among them, the DNA damage repair pathway and high-efficiency antioxidant defense system are summarized in detail. Furthermore, a novel model that protects the cell against the ionizing radiation is proposed. This review also discusses the potential application , future challenges and directions in advancing towards D. radiodurans studies.