The Apoplastic and Symplastic Antioxidant System in Onion: Response to Long-Term Salt Stress

The response of apoplastic antioxidant systems in root and leaf tissues from two onion genotypes (‘Texas 502’, salt-sensitive and ‘Granex 429’, salt-resistant) in response to salinity was studied. Electrolyte leakage data indicated the membrane integrity impairing by the effect of salts, especially in ‘Texas 502’. We detected superoxide dismutase (SOD) and peroxidase (POX) activity in the root and leaf apoplastic fractions from onion plants. Salinity increased SOD activity in the root symplast of ‘Texas 502’ and in ‘Granex 429’ leaves. In contrast, salinity reduced SOD activity in the leaf and root apoplastic fractions from ‘Texas 502’. In ‘Granex 429’, salt-stress increased leaf apoplastic POX activity and symplastic catalase (CAT) activity of both organs, but a decline in root apoplastic POX from ‘Texas 502’ took place. Salt-stress increased monodehydroascorbate reductase (MDHAR) in root and leaf symplast and in root glutathione reductase GR, mainly in ‘Granex 429’, but only in this genotype, leaf dehydroascorbate reductase (DHAR) activity increased. In contrast, a decline in leaf GR was produced only in ‘Texas 502’. Salinity increased leaf ASC levels, and no accumulation of dehydroascorbate (DHA) was observed in roots in both cases. These responses increased the redox state of ascorbate, especially in roots. In contrast, salinity declined reduced glutathione (GSH), but oxidised glutathione (GSSG) was accumulated in leaves, decreasing the redox state of glutathione. Salinity slightly increased root GSH concentration in the salt-tolerant genotype and was unchanged in the salt-sensitive genotype, but no accumulation of GSSG was produced, favoring the rise and/or maintenance of the redox state of the glutathione. These results suggest that the lower sensitivity to salt in ‘Granex 429’ could be related to a better performance of the antioxidant machinery under salinity conditions.

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Long-Term Administration of Abacavir and Etravirine Impairs Semen Quality and Alters Redox System and Bone Metabolism in Growing Male Wistar Rats

Oxidative Medicine and Cellular Longevity ◽

10.1155/2021/5596090 ◽

2021 ◽

Vol 2021 ◽

pp. 1-32

Author(s):

Agnieszka Matuszewska ◽

Beata Nowak ◽

Wojciech Niżański ◽

Maria Eberhardt ◽

Kinga Domrazek ◽

...

Keyword(s):

Wistar Rats ◽

Redox State ◽

Volume Fraction ◽

Male Rats ◽

Bending Test ◽

Saline Control ◽

Term Therapy ◽

Sod Activity ◽

Male Wistar Rats

Highly active antiretroviral therapy (HAART) is used in HIV-infected patients. Alongside the prolongation of patients’ life, adverse side effects associated with long-term therapy are becoming an increasing problem. Therefore, optimizing of HAART is extremely important. The study is aimed at evaluating the toxicity of abacavir and etravirine in monotherapy on the reproductive system, liver, kidneys, and bones in young, sexually mature, male rats. Thirty-six 8-week-old male Wistar rats randomized into three 12-animal groups received either normal saline (control), abacavir 60 mg/kg (AB group), or etravirine 40 mg/kg (ET group) once daily for 16 weeks. Semen morphology, oxide–redox state parameters (MDA, SOD, catalase, GPx, glutathione, GSH/GSSG ratio) in tissue homogenates (testes, liver, kidneys), and serum samples were studied. In bones, microcomputed tomography and a four-point bending test were performed. Total sperm count, sperm concentration, motility, and sperm morphology did not differ significantly in AB or ET groups compared to the control. In the flow cytometry of semen, an increased percentage of cells with denatured DNA was noticed for both tested drugs. However, no significant changes of oxide–redox state in testicular homogenates were found, except of increased SOD activity in the AB-receiving group. Additionally, ET significantly altered catalase and GPx in the liver and SOD activity in kidneys. Abacavir decreased catalase in the liver and GSH levels in kidneys. AB caused significant changes to bone microarchitecture (bone volume fraction, trabecular number, connectivity density, total porosity) and increased Young’s modulus. Etravirine had a greater impact on macrometric parameters of bones (tibial index, mid-tibial diameter, femur length). After 4 weeks in the ET group, a lower 1,25-dihydroxyvitamin D3 serum concentration was found. The results showed that abacavir and etravirine disturb oxidative stress. An increase in the percentage of sperms with chromatin damage suggests decreased fertility in rats receiving the studied drugs. Both drugs affected bone formation in growing rats. Additionally, etravirine disturbed vitamin D metabolism.

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Biochar and Chitosan Regulate Antioxidant Defense and Methylglyoxal Detoxification Systems and Enhance Salt Tolerance in Jute (Corchorus olitorius L.)

Antioxidants ◽

10.3390/antiox10122017 ◽

2021 ◽

Vol 10 (12) ◽

pp. 2017

Author(s):

Mirza Hasanuzzaman ◽

Md. Rakib Hossain Raihan ◽

Ebtihal Khojah ◽

Bassem N. Samra ◽

Masayuki Fujita ◽

...

Keyword(s):

Salt Stress ◽

Biomass Accumulation ◽

Protective Role ◽

Monodehydroascorbate Reductase ◽

Antioxidant Systems ◽

Corchorus Olitorius ◽

Glutathione S Transferase ◽

Detoxification Systems ◽

Catalase Peroxidase

We investigated the role of biochar and chitosan in mitigating salt stress in jute (Corchorus olitorius L. cv. O-9897) by exposing twenty-day-old seedlings to three doses of salt (50, 100, and 150 mM NaCl). Biochar was pre-mixed with the soil at 2.0 g kg−1 soil, and chitosan-100 was applied through irrigation at 100 mg L−1. Exposure to salt stress notably increased lipid peroxidation, hydrogen peroxide content, superoxide radical levels, electrolyte leakage, lipoxygenase activity, and methylglyoxal content, indicating oxidative damage in the jute plants. Consequently, the salt-stressed plants showed reduced growth, biomass accumulation, and disrupted water balance. A profound increase in proline content was observed in response to salt stress. Biochar and chitosan supplementation significantly mitigated the deleterious effects of salt stress in jute by stimulating both non-enzymatic (e.g., ascorbate and glutathione) and enzymatic (e.g., ascorbate peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase, glutathione reductase superoxide dismutase, catalase, peroxidase, glutathione S-transferase, glutathione peroxidase) antioxidant systems and enhancing glyoxalase enzyme activities (glyoxalase I and glyoxalase II) to ameliorate reactive oxygen species damage and methylglyoxal toxicity, respectively. Biochar and chitosan supplementation increased oxidative stress tolerance and improved the growth and physiology of salt-affected jute plants, while also significantly reducing Na+ accumulation and ionic toxicity and decreasing the Na+/K+ ratio. These findings support a protective role of biochar and chitosan against salt-induced damage in jute plants.

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Effects of salt stress on physiological and biochemical responses of three maize genotypes at the early seedling stage

Acta agriculturae Slovenica ◽

10.14720/aas.2021.117.1.1964 ◽

2021 ◽

Vol 117 (1) ◽

pp. 1

Author(s):

Ali DOĞRU

Keyword(s):

Salt Stress ◽

Crop Productivity ◽

Antioxidant Systems ◽

Enzymatic Antioxidants ◽

Sod Activity ◽

Oxidative Markers ◽

Maize Genotypes ◽

Stress Changes ◽

Relative Water ◽

Glutathione Cycle

Salt stress is one of the major global problems for crop productivity in the arid and semi-arid regions of the world. In this study, variations in some physiological parameters, water relations, and antioxidant systems under salinity (300 mM NaCl) among three maize (Zea mays L.) genotypes (‘P3167’, ‘32K61’, and ‘Bora’) were investigated. Our result indicated that shoot growth is more sensitive to salinity as compared to root growth. Salt stress led to physiological drought in all maize genotypes as indicated by the significant decrease in relative water content and increase in water deficit index. Salt stress increased SOD activity in all genotypes showing an efficient formation and detoxification of superoxide radical. The constant level of oxidative markers (MDA and H2O2) and the increased level of the reduced ascorbate and phenolic may indicate that non-enzymatic antioxidants are responsible for the elimination of oxidative stress. Changes in ascorbate peroxidase and glutathione reductase activities under salinity demonstrated a functional failure in the ascorbate-glutathione cycle, especially in ‘P3167’ and ‘32K61’. Based on the presented results we may conclude that the genotype ‘Bora’ is tolerant to salinity while ‘P3167’ and ‘32K61’ are sensitive.

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Regulation of enzymatic and non-enzymatic antioxidants contributes to salt tolerance in hitherto unknown upland farmer rice varieties.

Current Botany ◽

10.25081/cb.2020.v11.6019 ◽

2020 ◽

pp. 18-27

Author(s):

Lins Simon ◽

Yusuf Akkara

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Stability Index ◽

Monodehydroascorbate Reductase ◽

Enzymatic Antioxidants ◽

Salt Tolerant ◽

Sod Activity ◽

Rice Varieties ◽

Pronounced Increase ◽

Nacl Concentration

Salt tolerance potential of the three upland farmer varieties, koduvelliyan, mullankayama and marathondi was evaluated by comparing with the released salt-tolerant pokkali variety, vytilla-2. The salt tolerance exhibited by the upland varieties was identical with the salt tolerant variety. The superoxide (O2-) content in the upland varieties was lower; however, the hydrogen peroxide (H2O2) content increased with the salt concentration. The lesser malondialdehyde (MDA) content in the koduvelliyan variety was equivalent to the vytilla-2 and slight increase was observed in mullankayama and marathondi. The ascorbate (AsA) content in the upland varieties was comparable to vytilla-2 and upon exposure to increased concentration of NaCl, the AsA level reduced in all the treatments. Reduced glutathione (GSH) content was uniform in all the varieties up to a concentration of 100mM NaCl, however, in 125-150mM NaCl, mullankayama showed a pronounced increase in GSH content. Under salt stress, due to the formation of O2-, the oxidation of GSH was higher, maintaining a stable GSH/GSSG ratio. Superoxide dismutase (SOD) and catalase (CAT) activity of the upland varieties was higher than vytilla-2 up to 100mM NaCl, however, in 125-150mM NaCl the SOD activity increased slightly and the CAT activity decreased. Ascorbate peroxidase (APX) activity increased in upland varieties up to 125mM NaCl, and in 150mM NaCl, maintained a steady level in all the varieties. Glutathione reductase (GR) activity increased proportionate with NaCl concentration; with highest activity in all the upland varieties. Monodehydroascorbate reductase (MDHAR) activity was uniform in all the varieties up to 100mM NaCl, however, in 125 and 150mM NaCl, vytilla-2 showed higher MDHAR activity. Dehydroascorbate reductase (DHAR) activity was lesser in upland varieties under salt stress compared to vytilla-2. The GSH/GSSG ratio decreased in marathondi and koduvelliyan varieties with the increase in NaCl concentration, however, in mullankayama and vytilla-2, the GSH/GSSG ratio was higher. The membrane stability index of all the varieties was uniform in all the concentrations of NaCl used, except marathondi. The Na+ content in all the varieties increased in relation to NaCl concentration and the K+ efflux was higher suggesting a higher Na+/K+ ratio, with increased NaCl concentration.

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Enzymatic defence against post-anoxic injury in higher plants

Proceedings of the Royal Society of Edinburgh Section B Biological Sciences ◽

10.1017/s0269727000014378 ◽

1994 ◽

Vol 102 ◽

pp. 381-390 ◽

Cited By ~ 3

Author(s):

B. Wollenweber-Ratzer ◽

R. M. M. Crawford

Keyword(s):

Ascorbic Acid ◽

Oxygen Radicals ◽

Higher Plants ◽

Reduced Glutathione ◽

Dehydroascorbic Acid ◽

Oxygen Deprivation ◽

Dehydroascorbate Reductase ◽

Monodehydroascorbate Reductase ◽

Anoxic Injury

SynopsisPlants tolerant of long-term flooding and oxygen deprivation in their perennating organs such as rhizomes and tubers are able to avoid the deleterious effects of anoxia and minimise the dangers of re-entry to air by reactions with antioxidants such as ascorbic acid and glutathione. In processes of detoxification of oxygen radicals, ascorbic acid is oxidised to dehydroascorbic acid and reduced glutathione to oxidised glutathione. Through the action of enzymes such as monodehydroascorbate reductase (MR) and dehydroascorbate reductase (DHAR), glutathione and ascorbic acid may be regenerated to maintain sufficient levels of antioxidants within the tissue in order to quench oxygen radicals.

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Cold stress in soybean (Glycine max L.) roots: Exogenous gallic acid promotes water status and increases antioxidant activities

Botanica Serbica ◽

10.2298/botserb1901059o ◽

2019 ◽

Vol 43 (1) ◽

pp. 59-71 ◽

Cited By ~ 1

Author(s):

Ceyda Ozfidan-Konakci ◽

Evren Yildiztugay ◽

Aysegul Yildiztugay ◽

Mustafa Kucukoduk

Keyword(s):

Lipid Peroxidation ◽

Glycine Max ◽

Cold Stress ◽

Gallic Acid ◽

Antioxidant Activities ◽

Water Status ◽

Monodehydroascorbate Reductase ◽

Antioxidant Systems ◽

Sod Activity ◽

Soybean Roots

Gallic acid (GLA; 3,4,5- trihydroxybenzoic acid) is a strong antioxidant in plants. In order to clarify the effects of GLA as a pro-oxidant or an antioxidant on cells under stress conditions, soybean (Glycine max) was grown under normal conditions or in the presence of cold stress (5 and 10?C) in the absence or presence of gallic acid (GLA; 1 and 2 mM) for 72 h. The soybean roots exposed to stress exhibited a significant decline in growth (RGR), water content (RWC), osmotic potential (??) and proline content (Pro). However, GLA treatment under stress significantly improved these parameters and alleviated the stress-generated damage. Stress decreased superoxide dismutase (SOD) activity, but GLA effectively mitigated the adverse effects on enzyme activity. After stress treatment, only catalase (CAT) was induced in soybean roots, although it was not sufficient to prevent toxic hydrogen peroxide (H2O2) accumulation. Thus, the levels of lipid peroxidation (TBARS content) markedly increased. However, GLA contributed to detoxification of H2O2 and lipid peroxidation by enhancing activities of CAT and peroxidase (POX). In addition to these enzymes, SOD activity was able to scavenge superoxide anion radicals, as evidenced by decline in TBARS content. However, monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), total ascorbate (tAsA) and glutathione (GSH) showed a decline of content in roots treated with GLA (both concentrations) plus stress. Our results suggest a protective role of GLA, which may strengthen plant tolerance by ensuring efficient water use and enhancing antioxidant systems. In soybean roots, GLA successfully alleviated the toxicity of cold stress by modulating the activities of SOD, CAT and POX rather than enzymes of the ascorbate-glutathione cycle.

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Indicators of the antioxidant system in the long-term period after acute mercury nitrate poisoning in the experiment

Токсикологический вестник ◽

10.36946/0869-7922-2020-2-35-40 ◽

2020 ◽

pp. 36-41

Author(s):

E. G. Batotsyrenova ◽

O. A. Vakunenkova ◽

E. A. Zolotoverkhaya ◽

V. A. Kashuro ◽

T. A. Kostrova ◽

...

Keyword(s):

Antioxidant System ◽

Antioxidant Defense ◽

Reduced Glutathione ◽

Antioxidant Defense System ◽

Mercury Content ◽

The State ◽

Cytotoxic Effects ◽

Entire Study ◽

Mercury Nitrate

The article presents experimental data on the state of the antioxidant system in red blood cells of white outbred rats 1 and 3 months after acute mercury nitrate poisoning with a semilethal dose. It has been established that this form of intoxication is accompanied by pronounced changes in the state of the antioxidant defense system in erythrocytes of poisoned animals (a decrease in the concentration of reduced glutathione, a decrease in the activity of superoxide dismutase and glutathione peroxidase, and an increase in the concentration of lipid peroxidation products).It has been shown that the mercury content in the blood of experimental animals remains elevated during the entire study period.The results obtained indicate the importance of impaired functioning of the antioxidant system in the implementation of long-term consequences of acute mercury poisoning. The reasons for the occurrence of these biochemical shifts and their role in the development of the long-term cytotoxic effects of mercury nitrate are discussed.

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Biogeochemical Controls on the Redox Evolution of Earth’s Oceans and Atmosphere

Elements ◽

10.2138/gselements.16.3.191 ◽

2020 ◽

Vol 16 (3) ◽

pp. 191-196 ◽

Cited By ~ 4

Author(s):

Christopher T. Reinhard ◽

Noah J. Planavsky

Keyword(s):

Redox State ◽

Modeling Tools ◽

Evolutionary Trajectory ◽

Geochemical Tracers ◽

Atmosphere System ◽

Ocean Atmosphere ◽

Dramatic Shift ◽

Redox Evolution

The redox state of Earth’s atmosphere has undergone a dramatic shift over geologic time from reducing to strongly oxidizing, and this shift has been coupled with changes in ocean redox structure and the size and activity of Earth’s biosphere. Delineating this evolutionary trajectory remains a major problem in Earth system science. Significant insights have emerged through the application of redox-sensitive geochemical systems. Existing and emerging biogeochemical modeling tools are pushing the limits of the quantitative constraints on ocean–atmosphere redox that can be extracted from geochemical tracers. This work is honing our understanding of the central role of Earth’s biosphere in shaping the long-term redox evolution of the ocean–atmosphere system.

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Assessment of Morpho-Physiological, Biochemical and Antioxidant Responses of Tomato Landraces to Salinity Stress

Plants ◽

10.3390/plants10040696 ◽

2021 ◽

Vol 10 (4) ◽

pp. 696

Author(s):

Reem H. Alzahib ◽

Hussein M. Migdadi ◽

Abdullah A. Al Ghamdi ◽

Mona S. Alwahibi ◽

Abdullah A. Ibrahim ◽

...

Keyword(s):

Salt Stress ◽

Salinity Stress ◽

Dry Weight ◽

Proline Content ◽

Enzymatic Antioxidants ◽

Sod Activity ◽

Carotene Content ◽

Antioxidants Activity ◽

Solanum Lycopersicum L ◽

Salinity Levels

Understanding salt tolerance in tomato (Solanum lycopersicum L.) landraces will facilitate their use in genetic improvement. The study assessed the morpho-physiological variability of Hail tomato landraces in response to different salinity levels at seedling stages and recommended a tomato salt-tolerant landrace for future breeding programs. Three tomato landraces, Hail 548, Hail 747, and Hail 1072 were tested under three salinity levels: 75, 150, and 300 mM NaCl. Salinity stress reduced shoots’ fresh and dry weight by 71% and 72%, and roots were 86.5% and 78.6%, respectively. There was 22% reduced chlorophyll content, carotene content by 18.6%, and anthocyanin by 41.1%. Proline content increased for stressed treatments. The 300 mM NaCl treatment recorded the most proline content increases (67.37 mg/g fresh weight), with a percent increase in proline reaching 61.67% in Hail 747. Superoxide dismutase (SOD) activity decreased by 65% in Hail 548, while it relatively increased in Hail 747 and Hail 1072 treated with 300 mM NaCl. Catalase (CAT) activity was enhanced by salt stress in Hail 548 and recorded 7.6%, increasing at 75 and 5.1% at 300 mM NaCl. It revealed a reduction in malondialdehyde (MDA) at the 300 mM NaCl concentration in both Hail 548 and Hail 1072 landraces. Increasing salt concentrations showed a reduction in transpiration rate of 70.55%, 7.13% in stomatal conductance, and 72.34% in photosynthetic rate. K+/Na+ ratios decreased from 56% for 75 mM NaCl to 85% for 300 mM NaCl treatments in all genotypes. The response to salt stress in landraces involved some modifications in morphology, physiology, and metabolism. The landrace Hail 548 may have better protection against salt stress and observed protection against reactive oxygen species (ROS) by increasing enzymatic “antioxidants” activity under salt stress.

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Induction of cell wall phenolic monomers as part of direct defense response in maize to pink stem borer (Sesamia inferens Walker) and non-insect interactions

Scientific Reports ◽

10.1038/s41598-021-93727-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

P. Lakshmi Soujanya ◽

J. C. Sekhar ◽

C. V. Ratnavathi ◽

Chikkappa G. Karjagi ◽

E. Shobha ◽

...

Keyword(s):

Induced Defense ◽

Stem Borer ◽

Defense Responses ◽

Short Term ◽

Mechanical Wounding ◽

Leaf Tissues ◽

Short And Long Term ◽

Insect Interactions ◽

Induced Defense Responses

AbstractPink stem borer (PSB) causes considerable yield losses to maize. Plant–insect interactions have significant implications for sustainable pest management. The present study demonstrated that PSB feeding, mechanical wounding, a combination of mechanical wounding and PSB regurgitation and exogenous application of methyl jasmonate have induced phenolic compound mediated defense responses both at short term (within 2 days of treatment) and long term (in 15 days of treatment) in leaf and stalk tissues of maize. The quantification of two major defense related phenolic compounds namely p-Coumaric acid (p-CA) and ferulic acid (FA) was carried out through ultra-fast liquid chromatography (UFLC) at 2 and 15 days after imposing the above treatments. The p-CA content induced in leaf tissues of maize genotypes were intrinsically higher when challenged by PSB attack at V3 and V6 stages in short- and long-term responses. Higher p-CA content was observed in stalk tissues upon wounding and regurgitation in short- and long-term responses at V3 and V6 stages. Significant accumulation of FA content was also observed in leaf tissues in response to PSB feeding at V3 stage in long-term response while at V6 stage it was observed both in short- and long-term responses. In stalk tissues, methyl jasmonate induced higher FA content in short-term response at V3 stage. However, at V6 stage PSB feeding induced FA accumulation in the short-term while, wounding and regurgitation treatment-induced defense responses in the long-term. In general, the resistant (DMRE 63, CM 500) and moderately resistant genotypes (WNZ ExoticPool) accumulated significantly higher contents of p-CA and FA content than susceptible ones (CM 202, BML 6) in most of the cases. The study indicates that phenolic mediated defense responses in maize are induced by PSB attack followed by wounding and regurgitation compared to the other induced treatments. Furthermore, the study confirmed that induced defense responses vary with plant genotype, stage of crop growth, plant tissue and short and long-term responses. The results of the study suggested that the Phenolic acids i.e. p-CA and FA may contribute to maize resistance mechanisms in the maize-PSB interaction system.

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