Antioxidant Scavenging Enzymes Research Articles

Transcriptome analysis of waterlogging-induced adventitious root and control taproot of Mentha arvensis.

The present study reports differentially expressed transcripts in the waterlogging-induced adventitious root (AR) of Mentha arvensis; the identified transcripts will help to understand AR development and improve waterlogging stress response. Waterlogging notably hampers plant growth in areas facing waterlogged soil conditions. In our previous findings, Mentha arvensis was shown to adapt better in waterlogging conditions by initiating the early onset of adventitious root development. In the present study, we compared the transcriptome analysis of adventitious root induced after the waterlogging treatment with the control taproot. The biochemical parameters of total carbohydrate, total protein content, nitric oxide (NO) scavenging activity and antioxidant enzymes, such as catalase activity (CAT) and superoxide dismutase (SOD) activity, were enhanced in the adventitious root compared with control taproot. Analysis of differentially expressed genes (DEGs) in adventitious root compared with the control taproot were grouped into four functional categories, i.e., carbohydrate metabolism, antioxidant activity, hormonal regulation, and transcription factors that could be majorly involved in the development of adventitious roots. Differential expression of the upregulated and uniquely expressing thirty-five transcripts in adventitious roots was validated using qRT-PCR. This study has generated the resource of differentially and uniquely expressing transcripts in the waterlogging-induced adventitious roots. Further functional characterization of these transcripts will be helpful to understand the development of adventitious roots, leading to the resistance towards waterlogging stress in Mentha arvensis.

Shelf life quality retention and decay inhibition of winter jujube (Zizyphus jujuba Mill. cv. Dalidongzao) using 1-methylcyclopropene

Winter jujube is susceptible to cold stress during cold storage, resulting in quality deterioration. Shelf life of winter jujube after cold storage has not been investigated. This study investigated the effects of 1.0 μL L−1 1-methylcyclopropene (1-MCP) fumigation treatment for 24 h on the quality characteristics of jujube fruits (Zizyphus jujuba Mill. cv. Dalidongzao) during cold storage. The jujubes from the early experimental stage (0 d) were stored at room temperature (20 ± 1 °C) to estimate the shelf life. The remaining jujubes were transferred to cold storage at 0 ± 1 °C and were removed during the middle (40 d) and the later (60 d) stages of the experiment. The decay rate, firmness, color, titratable acidity, total phenolics and flavonoids, antioxidant activity, and antioxidant enzyme activity of winter jujube were measured every 3 days until the end of shelf life. The results indicated that the application of 1-MCP treatment extended the time for jujube to exceed a decay rate of more than 10 % by three days after 40 and 60 days of cold storage. 1-MCP treatment effectively retard the decrease of total phenolic and flavonoid content in jujube, and maintain high free radical scavenging ability and antioxidant enzyme activity throughout shelf life storage.

Harnessing the potential of endophytes: Sustainable solutions for enhancing forage crop resilience and soil fertility

Environmental changes pose significant challenges to sustainable agriculture, adversely affecting crop production and soil fertility. Factors such as drought, salinity, pathogens, and soil type exert their influence on the behavior of fodder crops by altering their morphological, biochemical, and molecular mechanisms, ultimately leading to reduced yields and productivity. Consequently, there is a pressing need to develop mitigation strategies aimed at enhancing the tolerance of forage crops to both biotic and abiotic stresses, addressing a critical challenge in sustaining their growth.
 In recent times, the use of biofertilizers has emerged as an environmentally friendly alternative to chemical fertilizers, holding promise for sustainable horticultural, agricultural, and forestry production systems. Notably, endophytic microorganisms play a pivotal role in promoting plant growth through direct or indirect mechanisms. Additionally, endophytic bacteria actively regulate gene expression responsible for the production of antioxidant enzymes, various phytohormones, siderophores, and ROS scavenging enzymes, all of which contribute to supporting the growth of host plants even in extreme environments. Consequently, there is a growing focus on understanding and validating the mechanisms through which beneficial plant endophytes interact to combat both biotic and abiotic stresses.
 This review emphasizes the potential of endophytes as biofertilizers, biocontrol agents, and contributors to the mitigation of abiotic and biotic stresses, all of which play crucial roles in maintaining the development of forage crops and soil fertility.

Positive Interaction of Selenium Nanoparticles and Olive Solid Waste on Vanadium-Stressed Soybean Plant

The purpose of the current study was to determine the possible improvement in soybean plants’ tolerance against vanadium-induced stress in response to the application of olive solid waste (OSW) and selenium nanoparticles (Se-NPs), by assessing metabolites and plant defense systems. Drawing upon this aim, a pot experiment was performed where the soybean plants were grown with a fertilization treatment (including, control, OSW, Se-NPs, and Se-NPs + OSW) under vanadium stress (including non-stress and 350 mg sodium orthovanadate per kg of soil). Enhancement of hydrogen peroxide (H2O2) and malondialdehyde (MDA) accumulation in vanadium-stressed plants confirmed the oxidative damage in unfertilized plants. Results indicated the positive effects of the combined treatment (Se-NPs + OSW) in improving the plant stress tolerance by causing a balance in the produced ROS and detoxified ROS in the plant. It was mainly stimulated through the improvement of the photosynthetic parameters, anthocyanin metabolism pathway, phenylpropanoid pathway, non-enzymatic antioxidant metabolites (tocopherols, malondialdehyde, polyphenols, and flavonoids), antioxidant enzymes, and biochemical components involved in the ASC/GSH cycle (ascorbate, ascorbate peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase, glutathione, glutathione reductase, and glutathione peroxidase), and antioxidant direct scavenging enzymes (peroxidase, catalase, and superoxide dismutase), which finally resulted in higher plant biomass. In conclusion, the simultaneous application of OSW and Se-NPs treatments provided a reliable protection for soybean plants in vanadium-contaminated soils through the activation of antioxidant and non-antioxidant defense mechanisms.

Impact of carbendazim on cellular growth, defence system and plant growth promoting traits of Priestia megaterium ANCB-12 isolated from sugarcane rhizosphere.

Agrochemicals are consistently used in agricultural practices to protect plants from pathogens and ensure high crop production. However, their overconsumption and irregular use cause adverse impacts on soil flora and non-target beneficial microorganisms, ultimately causing a hazard to the ecosystem. Taking this into account, the present study was conducted to determine the high dosage of fungicide (carbendazim: CBZM) effects on the rhizobacteria survival, plant growth promoting trait and reactive oxygen species (ROS) scavenging antioxidant enzyme system. Thus, a multifarious plant growth promoting rhizobacteria (PGPR) isolate, ANCB-12, was obtained from the sugarcane rhizosphere through an enrichment technique. The taxonomic position of the isolated rhizobacteria was confirmed through 16S rRNA gene sequencing analysis as Priestia megaterium ANCB-12 (accession no. ON878101). Results showed that increasing concentrations of fungicide showed adverse effects on rhizobacterial cell growth and survival. In addition, cell visualization under a confocal laser scanning microscope (CLSM) revealed more oxidative stress damage in the form of ROS generation and cell membrane permeability. Furthermore, the increasing dose of CBZM gradually decreased the plant growth promoting activities of the rhizobacteria ANCB-12. For example, CBZM at a maximum 3,000 μg/ml concentration decreases the indole acetic acid (IAA) production by 91.6%, ACC deaminase by 92.3%, and siderophore production by 94.1%, respectively. Similarly, higher dose of fungicide enhanced the ROS toxicity by significantly (p < 0.05) modulating the stress-related antioxidant enzymatic biomarkers in P. megaterium ANCB-12. At a maximum 3,000 μg/ml CBZM concentration, the activity of superoxide dismutase (SOD) declined by 82.3%, catalase (CAT) by 61.4%, glutathione peroxidase (GPX) by 76.1%, and glutathione reductase (GR) by 84.8%, respectively. The results of this study showed that higher doses of the fungicide carbendazim are toxic to the cells of plant-beneficial rhizobacteria. This suggests that a recommended dose of fungicide should be made to lessen its harmful effects.

Controlled Atmosphere Improves the Quality, Antioxidant Activity and Phenolic Content of Yellow Peach during the Shelf Life

Controlled atmosphere (CA) has been demonstrated to maintain the shelf-life quality of fruits, but its effect on the antioxidant activities and phenolic content of yellow peach is not comprehensive. This study analyzed the role of CA on the quality of shelf period, phenolic content and antioxidant activity of "Jinxiu" yellow peach. Yellow peach was left under specific aeration conditions (3.5-4% CO2, 2-3% O2, 92-95.5% N2, 1 ± 0.5 °C) and the control (1 ± 0.5 °C) for 21 d, to observe changes in physiological parameters of the fruit during 10 d of the shelf life (25 ± 1 °C). The result showed that CA reduced the weight loss rate (WLR), decay rate (DR), and browning index (BI) of yellow peaches. Furthermore, the CA held a high level of total flavonoid content (TFC), total phenol content (TPC) and phenolic content in the fruit. Antioxidant analysis showed that polyphenol oxidase (PPO) enzyme activity was lower and free radical scavenging capacity (DPPH, ABTS, and FRAP) and antioxidant enzyme activities (POD and PAL) were higher in the CA group. Combining the results of significance analysis, correlation analysis, principal component analysis (PCA) and hierarchical cluster analysis (HCA) clearly identified the differences between the CA group and the control group. The results showed that the CA could maintain higher phenolic content and reduce the oxidation of yellow peach fruit and enhance fruit quality by affecting the antioxidant activities of yellow peach.

Spectral light distribution affects photosynthesis, leaf reflective indices, antioxidant activity and growth of Vanilla planifolia

Vanilla planifolia is an obligate sciophyte (shade plant) with crassulacean acid metabolism (CAM) photosynthesis. Plants were grown for 12 months under black, blue, green, or red photoselective shade netting (PSN) to alter the spectral light distribution impacting the plants. Light wavelengths were measured in each treatment and plants were assessed for photosynthetic characteristics, leaf chlorophyll index (LCI), maximum quantum yield of photosystem II, leaf reflectance indices, leaf area, growth, antioxidant enzymes, lipid peroxidation, reactive oxygen species (ROS), and osmolyte content. Plants grown under red PSN had a higher quantity of red and far-red light and had greater nocturnal net CO2 assimilation (NocA), leaf area and leaf dry weight than plants in the other treatments. Plants grown under blue PSN had a higher quantity of blue light, resulting in a higher LCI and maximum quantum yield than plants in the other treatments. Plants grown under the red and blue PSN had increased leaf spectral reflectance indices compared to plants in the other treatments, which resulted in the highest levels of antioxidant scavenging enzymes, ascorbic acid (AsA), proline, and glycine betaine, and the lowest levels of H2O2. These findings demonstrate that increasing light in the red and far-red or blue portions of the spectrum by using PSN alters the photosynthetic and/or antioxidant responses of V. planifolia and increasing red and far-red light by using red PSN can also accelerate plant growth, possibly due to higher photosynthesis.

Polyamines effectively mitigate senescence in persistent leaves of Berginia ciliata - a novel model system.

Plant leaves provide a unique insight into the changes that occur in organs, tissues and cells as they approach senescence. As part of the parental outlay, plants instigate leaf senescence to reallocate resources from older tissues to new organs towards the termination of the growing season. The aim of crop breeding initiatives is to optimize senescence for specific species. Considering hormonal regulation and their crosstalk during leaf senescence through integration of developmental signals, this work examines the efficacy of polyamines (PAs) in modulating several biochemical and physiological aspects with an ultimate aim to delay leaf senescence in leaf discs of Berginia ciliata (Haw.) sternb. Leaf discs were treated with putrescine (Put), spermidine (Spd) and spermine (Spm) at 20μM, 20μM and 15μM concentration, respectively. A set of leaf discs kept in distilled water served as the control. Leaf discs treated with PAs were green and fresh by about 4 days compared to the control, thus exhibited delayed senescence. This delayed leaf senescence corroborated with the maintenance of high activity of reactive oxygen species (ROS) scavenging antioxidant enzymes viz , superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and higher content of chlorophylls. A marked increase was also observed in membrane stability and soluble proteins in leaf discs treated with PAs. Exogenous PAs reduced oxidative stress in the leaf discs, as revealed by lower malondialdehyde (MDA) level, which is manifested as reduced lipid peroxidation (LPO). Improved membrane stability was proportional to lower LPO, as measured by the membrane stability index (MSI).

Unravelling homeostasis effects of phosphorus and zinc nutrition by leaf photochemistry and metabolic adjustment in cotton plants

Phosphorus (P) and zinc (Zn) uptake and its physiological use in plants are interconnected and are tightly controlled. However, there is still conflicting information about the interactions of these two nutrients, thus a better understanding of nutritional homeostasis is needed. The objective of this work was to evaluate responses of photosynthesis parameters, P-Zn nutritional homeostasis and antioxidant metabolism to variation in the P × Zn supply of cotton (Gossypium hirsutum L.). Plants were grown in pots and watered with nutrient solution containing combinations of P and Zn supply. An excess of either P or Zn limited plant growth, reduced photosynthesis-related parameters, and antioxidant scavenging enzymes. Phosphorus uptake favoured photochemical dissipation of energy decreasing oxidative stress, notably on Zn-well-nourished plants. On the other hand, excessive P uptake reduces Zn-shoot concentration and decreasing carbonic anhydrase activity. Adequate Zn supply facilitated adaptation responses to P deficiency, upregulating acid phosphatase activity, whereas Zn and P excess were alleviated by increasing P and Zn supply, respectively. Collectively, the results showed that inter ionic effects of P and Zn uptake affected light use and CO2 assimilation rate on photosynthesis, activation of antioxidant metabolism, acid phosphatase and carbonic anhydrase activities, and plant growth-related responses to different extents.

ThNAC12 from Tamarix hispida directly regulates ThPIP2;5 to enhance salt tolerance by modulating reactive oxygen species

NAC (NAM, ATAF1/2 and CUC2) transcription factors play critical roles in plant development and abiotic stress responses, and aquaporins have diverse functions in environmental stress responses. In this study, we described the salt-induced transcriptional responses of ThNAC12 and ThPIP2;5 in Tamarix hispida, and their regulatory mechanisms in response to salt stress. Using yeast one-hybrid (Y1H), chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays, we identified that ThNAC12 directly binds to the NAC recognition sequence (NACRS) of the ThPIP2;5 promoter and then activates the ThPIP2;5 expression. Subcellular localization and transcriptional activation assays demonstrated that ThNAC12 was a nuclear protein with a C-terminal transactivation domain. Compared with the corresponding control plants, transgenic plants overexpressing ThNAC12 exhibited enhanced salt tolerance and displayed increased reactive oxygen species (ROS) scavenging capability and antioxidant enzyme activity levels under salt stress. All results suggested that overexpression of ThNAC12 in plants enhanced salt tolerance through modulation of ROS scavenging via direct regulation of ThPIP2;5 expression in T. hispida.

Dietary supplementation with natural astaxanthin from Haematococcus pluvialis improves antioxidant enzyme activity, free radical scavenging ability, and gene expression of antioxidant enzymes in laying hens

The objective of this study was to evaluate the effects of natural astaxanthin (ASTA) from Haematococcus pluvialis on production performance, egg quality, antioxidant enzyme activity, free radical scavenging ability, and gene expression of antioxidant enzymes in laying hens. Nongda No. 3 laying hens (n = 450) were randomly allocated to 1 of 5 dietary treatments. Each treatment had 6 replicates of 15 hens each. All birds were assigned to a corn-soybean meal-based diet containing 0, 20, 40, 80, or 160 mg/kg ASTA for 4 wk. With increasing dietary ASTA, no significant effects were observed on egg weight, feed consumption, feed efficiency, laying rate, Haugh unit, or eggshell strength. Yolk color darkened linearly with increasing dose of ASTA (P < 0.05). Glutathione peroxidase activity was improved in the kidney with dietary ASTA at levels of 40 mg/kg. Total superoxide dismutase (SOD) was significantly increased in the liver, kidney, and plasma with dietary ASTA supplementation at 40 mg/kg. With increasing dietary ASTA, the scavenging abilities of hydroxyl radicals and superoxide anions were linearly increased (P < 0.05), and the malondialdehyde content decreased linearly (P < 0.05). Compared with the control group, mRNA expression of Cu-Zn SOD (SOD1), Mn SOD (SOD2), and nuclear factor E2-related factor 2 (NRF2) in the liver and kidney was significantly increased in the 40 mg/kg ASTA group (P < 0.05). The level of GPX4 mRNA in the liver and kidney was significantly increased with ASTA supplementation at 40 and 80 mg/kg (P < 0.05). The results demonstrate that dietary ASTA improves free radical scavenging ability and antioxidant enzyme activity, which may be related in part to the upregulated mRNA expression of genes encoding antioxidant enzymes and NRF2.

The ThSOS3 Gene Improves the Salt Tolerance of Transgenic Tamarix hispida and Arabidopsis thaliana.

The salt overly sensitive (SOS) signal transduction pathway is one of the most highly studied salt tolerance pathways in plants. However, the molecular mechanism of the salt stress response in Tamarix hispida has remained largely unclear. In this study, five SOS genes (ThSOS1–ThSOS5) from T. hispida were cloned and characterized. The expression levels of most ThSOS genes significantly changed after NaCl, PEG6000, and abscisic acid (ABA) treatment in at least one organ. Notably, the expression of ThSOS3 was significantly downregulated after 6 h under salt stress. To further analyze ThSOS3 function, ThSOS3 overexpression and RNAi-mediated silencing were performed using a transient transformation system. Compared with controls, ThSOS3-overexpressing transgenic T. hispida plants exhibited greater reactive oxygen species (ROS)-scavenging capability and antioxidant enzyme activity, lower malondialdehyde (MDA) and H2O2 levels, and lower electrolyte leakage rates under salt stress. Similar results were obtained for physiological parameters in transgenic Arabidopsis, including H2O2 and MDA accumulation, superoxide dismutase (SOD) and peroxidase (POD) activity, and electrolyte leakage. In addition, transgenic Arabidopsis plants overexpressing ThSOS3 displayed increased root growth and fresh weight gain under salt stress. Together, these data suggest that overexpression of ThSOS3 confers salt stress tolerance on plants by enhancing antioxidant enzyme activity, improving ROS-scavenging capability, and decreasing the MDA content and lipid peroxidation of cell membranes. These results suggest that ThSOS3 might play an important physiological role in salt tolerance in transgenic T. hispida plants. This study provides a foundation for further elucidation of salt tolerance mechanisms involving ThSOSs in T. hispida.

Evaluation of Free Radical Scavenging Activities Against Multiple Heavy Metals Stress in Avicennia marina (Forsk.) and Rhizophora mucronata Lamk

The tolerance mechanism of mangrove species (Avicennia marina (Forsk.) and Rhizophora mucronataLamk) was studied by inducing multiple heavy metal stress in roots and leaves of the plants. Mangrove seedlings weretreated with different concentrations of heavy metal solution (Cr, Cd, Pb and Hg) for a period of 2 months. Scavengingantioxidant enzymes like Polyphenol Oxidase (PPO), Glutathione-S-transferase (GSTs) and Guaiacol Peroxidase(POD) were analyzed in both species after appropriate intervals of 15 days. Results revealed that activities of theseantioxidative enzymes were altered due to multiple heavy metals exposure in both mangrove species, whereas leavesexhibited the higher values as compared to the roots. In the leaves of both mangrove plants GSTs exhibited anincreased trend throughout the investigated period whereas, PPO activity initially showed an increasing trend, butgradually decreased with the passage of time in response to heavy metal stress. Furthermore, an increased level ofantioxidants was also observed in A. marina than R. mucronata which proves that the former is a strong candidate forheavy metals phyto-remediation with its viable survival strategies.

Exogenous glutathione revealed protection to bacterial spot disease: Modulation of photosystem II and H2O2 scavenging antioxidant enzyme system in Capsicum annum L

In a greenhouse, parallel two experiments were carried out for the estimation of the impact of exogenous GSH (reduced glutathione) on photosynthetic properties, the efficiency of the photosystem II, and the H2O2-scavenging mechanism in chilli (Capsicum annum L.) seedlings. On the bases of pathogenicity, resistant and susceptible verities were selected. The application of GSH increased the chlorophyll fluorescence parameters such as photochemical quantity yield (YII). It declined the excitation pressure (1-qP) of photosystem and production of non-regulated energy dissipation [Y (NO)] in Xanthomonas campestris treated chilli leaves. In the addition of GSH, accumulation of reactive oxygen species was down and maintained the activity of ROS-scavenging enzymes (enzymatic antioxidants) in resistant and susceptible plants. Consequently, GSH supplementation relieves inhibition of production of bacterial toxin and photosynthesis primarily by overwhelming stomatal limitations, enhancing the performance of photosystem, and modulating the antioxidant protection mechanism to defend chloroplasts from oxidation. The Present study confirmed that seed priming with GSH in chilli plants to relieve biotic stress.

Mitigation of salt-stress effects by moringa leaf extract or salicylic acid through motivating antioxidant machinery in damask rose

Despite the fact that damask rose (Rosa damascena Mill. var. trigintipetala Dieck) is an economically important aromatic plant, its growth and development has been severely suppressed by salt stress. Reports show that moringa leaf extract (MLE) or salicylic acid (SA) are involved in salt-stress tolerance. Nevertheless, scarce information is available about MLE or SA impacts on aromatic plants, especially damask rose under salinity. This investigation was, therefore, conducted to investigate the effects of MLE and (or) SA on salt-stress mitigation in damask rose. Rose plants were treated with 200 mmol·L−1 sodium chloride, and foliar applied with MLE at 1:30 (v:v) and (or) 0.2 mmol·L−1 SA. Foliar spraying with MLE and (or) SA enhanced the growth attributes, chlorophyll content, relative water content, proline content, and membrane stability index under salinity. Less accumulation of malondialdehyde and H2O2 was also observed when MLE and (or) SA were applied. Furthermore, MLE and (or) SA applications considerably increased the radical scavenging activity, total phenols, and antioxidant enzyme activity (catalase and superoxide dismutase) under stress. The mitigative effect of MLE or SA was more pronounced when they were applied in combination. Collectively, MLE and (or) SA had efficient antioxidant defense system that scavenged reactive oxygen species, and thus afforded considerable protection against salt-induced oxidative damage.

Timing-dependent effects of salicylic acid treatment on phytohormonal changes, ROS regulation, and antioxidant defense in salinized barley (Hordeum vulgare L.)

Cross-talk between exogenous salicylic acid (SA) and endogenous phytohormone pathways affects the antioxidant defense system and its response to salt stress. The study presented here investigated the effects of SA treatment before and during salt stress on the levels of endogenous plant growth regulators in three barley cultivars with different salinity tolerances: Hordeum vulgare L. cvs. Akhisar (sensitive), Erginel (moderate), and Kalaycı (tolerant). The cultivars’ relative leaf water contents, growth parameters, proline contents, chlorophyll a/b ratios, and lipid peroxidation levels were measured, along with the activities of enzymes involved in detoxifying reactive oxygen species (ROS) including superoxide-dismutase, peroxidase, catalase, ascorbate-peroxidase, and glutathione-reductase. In addition, levels of several endogenous phytohormones (indole-3-acetic-acid, cytokinins, abscisic acid, jasmonic acid, and ethylene) were measured. Barley is known to be more salt tolerant than related plant species. Accordingly, none of the studied cultivars exhibited changes in membrane lipid peroxidation under salt stress. However, they responded differently to salt-stress with respect to their accumulation of phytohormones and antioxidant enzyme activity. The strongest and weakest increases in ABA and proline accumulation were observed in Kalaycı and Akhisar, respectively, suggesting that salt-stress was more effectively managed in Kalaycı. The effects of exogenous SA treatment depended on both the timing of the treatment and the cultivar to which it was applied. In general, however, where SA helped mitigate salt stress, it appeared to do so by increasing ROS scavenging capacity and antioxidant enzyme activity. SA treatment also induced changes in phytohormone levels, presumably as a consequence of SA-phytohormone salt-stress cross-talk.

Reactive oxygen species scavenging mechanisms associated with polyethylene glycol mediated osmotic stress tolerance in Chinese potato

Influence of polyethylene glycol (PEG) mediated osmotic stress on reactive oxygen species (ROS) scavenging machinery of Chinese potato (Solenostemon rotundifolius (Poir.) J. K. Morton) was investigated. Five genotypes of Chinese potato were raised in Murashige and Skoog (MS) basal medium containing 6–benzylaminopurine (BAP, 1 mg L–1) along with various concentrations of PEG–6000 mediated stress conditions (0, –0.2 and –0.5 MPa) and evaluated for osmotic stress tolerance in vitro. The medium containing PEG–6000 had a detrimental effect on plantlet growth and development while compared with the control. Accumulation of H2O2 was lower in Sreedhara and Subala and higher in Nidhi under PEG stress, which was evident by in situ detection in leaves. Lipid peroxidation product such as malondialdehyde (MDA) content was increased due to PEG stress which was more in susceptible genotype than that in tolerant ones. An enhanced ROS–scavenging antioxidant enzyme was observed under stress with respect to the control. The enzymes of ascorbate–glutathione cycle showed an important role in scavenging ROS. The imposition of PEG stress also increased the non–enzymatic antioxidants viz., the ascorbate and reduced glutathione content which was prominent in tolerant genotypes in comparison to susceptible. The present study indicated that, Sreedhara and Subala showed more tolerance to osmotic stress with better ROS scavenging machineries which would be the lines of interest for augmenting future breeding strategies in this climate resilient minor tuber crop.

Silicon dioxide nanoparticles alleviate the threats of broomrape infection in tomato by inducing cell wall fortification and modulating ROS homeostasis

An infographic diagram that summarizes the influence of SiNP-seed priming upon tomato plants underOrobancheinfection conditions. GRW: growth, PHO: photosynthesis, NEAO: non-enzymatic antioxidants, ASE: antioxidant-scavenging enzymes.

Anti-proliferative effect of ZnO NPs against the growth of Ehrlich Solid carcinoma

Background: Zinc oxide nanoparticle (ZnO NPs) has been widely used in biomedical applications and cancer therapy and has been reported to induce a selective cytotoxic effect on cancer cell proliferation. Methods: Female Swiss Albino mice were inoculated subcutaneously with Ehrlich ascites carcinoma (EAC) cells. ZnO NPs or MTX were injected intraperitoneally. Tumor growth inhibition rate (TIR %), increase in life span (ILS%), zinc concentration, lipid peroxidation marker (MDA), glutathione (GSH) contents, and the activity of the antioxidant scavenger enzymes SOD and catalase CAT was examined. Also, DNA fragmentation and histopathological studies of all groups were carried out. Results: Treatment of tumor-bearing mice with ZnO NPs significantly increased (MST), (TIR %), (ILS %) and reduced tumor weight, compared to tumor-bearing controls. Additionally, Zn concentration and DNA fragmentation were significantly increased in tumor tissues. ZnO nanoparticles were also found to induce oxidative stress, evidenced by the generation of reactive oxygen species and depletion of the antioxidants in tumor tissues, with no changes in the liver. Our data demonstrate that ZnO NPs exert distinct effects via the killing of cancer cells. Conclusion: The study findings demonstrated that the ZnO NPs can induce selective cytotoxicity through reactive oxygen spe­cies generation and oxidative stress.

State of antioxidant systems and phenolic compounds’ production in Hypericum perforatum L. hairy roots

Hypericum perforatum hairy root clones (HR A–HR O) transformed with Agrobacterium rhizogenes A4 were evaluated for growth characteristics, phenolic compounds production, antioxidant/radical scavenging activity, antioxidant enzymes, and oxidative stress markers. The screening of growth characteristics revealed that HR clones were characterized with higher biomass accumulation, root elongation, and lateral branching in comparison to non-transformed roots. Significant increase of phenolics production in HR clones was related to phenylalanine ammonia lyase activity indicating an up-regulation of phenylpropanoid/flavonoid metabolism. Positive correlation of phenolics, flavonoids, and tannins with antioxidant assays indicated that these secondary metabolites significantly contributed to the antioxidant/radical scavenging properties of HR cultures. Regarding the enzymatic antioxidant state, an enhancement of superoxide dismutase activity in HR lines coincided with decrease in O 2 •− production rate, while ascorbate peroxidase and catalase greatly contributed to the reduction of H2O2 levels. The substantial accumulation of malondialdehyde in HR clones indicated an efficiency of antioxidant enzymes to reduce O 2 •− and H2O2 at levels that are not deleterious for membrane lipids. These results confirmed the involvement of an efficient antioxidant defense system in the response adjustment of H. perforatum HR cultures to transformation process. Two superior clones denoted as HR B and HR F were selected as fast-growing and high biomass yielding lines with up-regulated phenolic compounds’ production, antioxidant, and radical scavenging activity. Altogether, the best performing H. perforatum HR clones could be proposed as a prospective biotechnological system for scale-up production of antioxidant phenolic compounds.