Oxidative stress responses in transgenic tobacco containing altered levels of glutathione reductase activity

The importance of some glutathione metabolic pathways was examined in two highly dedifferentiated hepatomas, Yoshida AH-130 and Morris 3924 A hepatomas, and in normal liver in relation to their role against oxidative stress. The cytosol prepared from Yoshida hepatoma cells decreased the peroxidation rate in normal liver microsomes and mitochondria, but this antioxidant property was not displayed by Morris hepatoma. Glutathione peroxidase and glutathione-S-transferases activities were extremely low in both hepatomas; glutathione reductase activity values were about half the normal liver values. The large decrease in glutathione peroxidase and glutathione-S-transferases suggests that in these two tumors only small amounts of GSH can be used in reduction or conjugation reactions, such as the reduction of hydrogen peroxide and lipid hydroperoxides or the conjugation of GSH with the end products of lipoperoxidation, aldehydes or ketones. The hypothesis of a more efficient GSSG reduction in hepatomas, due to the low glutathione peroxidase/glutathione reductase activity ratio, is also discussed. The described changes in glutathione related enzymes do not seem to have any correlation with the protective effect against the lipoperoxidative processes displayed by some tumors since these enzymatic activities were similar in both hepatomas whereas only Yoshida hepatoma showed antioxidant properties.

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Latent Oxidative Stress Responses of Ozone-Fumigated Cucumber Plants Are Enhanced by Simultaneous Cold Exposures

Zeitschrift für Naturforschung C ◽

10.1515/znc-1996-5-612 ◽

1996 ◽

Vol 51 (5-6) ◽

pp. 355-362

Author(s):

Peter Streb ◽

Hermann Schaub ◽

Jürgen Feierabend

Keyword(s):

Oxidative Stress ◽

Glutathione Reductase ◽

Stress Responses ◽

Additional Stress ◽

Cucumis Sativus L ◽

Naturally Occurring ◽

Car Exhaust ◽

Long Time ◽

Defence Responses ◽

Oxidative Stress Responses

Abstract Cucumber plants (Cucumis sativus L.) were grown under controlled conditions and fumigated with either O3, diluted automobile exhaust or a combination of both. The ratio of variable to maximum chlorophyll fluorescence (Fv/Fm) was estimated as a measure of PSII activity Activities of the enzymes catalase, glutathione reductase and guaiacol-dependent peroxidase and contents of the antioxidants ascorbate and glutathione were assayed as potential indicators of oxidative stress. The behavior of catalase and of PSII are of particular diagnostic interest because they require continuous repair in light. Exposures of up to 13 days to moderate concentrations of the pollutant gases alone did not induce striking changes in any of the activities that were assayed. A lso when the plants were subjected to an additional stress treatment by exposing them to 4 short cold treatments (2h each at 0 - 4 °C in light on days 12-15 after sowing) which induced marked declines of the Fv/Fm ratio, the chlorophyll content and the catalase activity, these cold-induced symptoms of photodamage were not significantly enhanced by the fumigation treatments. However, increases of the activities of glutathione reductase and peroxidase observed during a period of recovery following the cold-exposures were markedly higher in O3-fumigated plants, as compared to plants grown in filtered air or fumigated with car exhaust alone. The results emphasize that effects of moderate pollutant exposures may be latent or delayed over long time periods and that defence responses can be enhanced when plants are exposed to additional, naturally occurring stress situations.

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Induction of Glutathione Synthesis and Glutathione Reductase Activity by Abiotic Stresses in Maize and Wheat

The Scientific World JOURNAL ◽

10.1100/tsw.2002.812 ◽

2002 ◽

Vol 2 ◽

pp. 1699-1705 ◽

Cited By ~ 20

Author(s):

Gábor Kocsy ◽

Gabriella Szalai ◽

Gabor Gáliba

Keyword(s):

Osmotic Stress ◽

Glutathione Reductase ◽

Temperature Stress ◽

Stress Responses ◽

Abiotic Stresses ◽

Reductase Activity ◽

Cold Treatment ◽

Wheat Variety ◽

High Temperature Stress ◽

Glutathione Reductase Activity

The effect of different abiotic stresses (extreme temperatures and osmotic stress) on the synthesis of glutathione and hydroxymethylglutathione, on the ratio of the reduced to oxidised forms of these thiols (GSH/GSSG, hmGSH/hmGSSG), and on the glutathione reductase (GR) activity was studied in maize and wheat genotypes having different sensitivity to low temperature stress. Cold treatment induced a greater increase in total glutathione (TG) content and in GR activity in tolerant genotypes of both species than in sensitive ones. The GSH/GSSG and hmGSH/hmGSSG ratios were increased by this treatment only in the frost-tolerant wheat variety. High-temperature stress increased the TG content and the GSH/GSSG ratio only in the chilling-sensitive maize genotype, but GR activity was greater after this treatment in both maize genotypes. Osmotic stress resulted in a great increase in the TG content in wheat and the GR activity in maize. The amount of total hydroxymethylglutathione increased following all stress treatments. These results indicate the involvement of these antioxidants in the stress responses of wheat and maize.

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Glutathione reductase activity following re-aeration of hypoxically pretreated wheat roots

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

10.1017/s0269727000014408 ◽

1994 ◽

Vol 102 ◽

pp. 413-417

Author(s):

G. Albrecht ◽

E.-M. Wiedenroth

Keyword(s):

Oxidative Stress ◽

Glutathione Reductase ◽

Reduced Glutathione ◽

Reductase Activity ◽

Thiobarbituric Acid ◽

Wheat Roots ◽

Reactive Material ◽

Glutathione Reductase Activity ◽

High Level ◽

Root Tissues

SynopsisDuring the first 2 h of oxygen re-exposure, the GSH level was almost constant, while the GSSG increased about 10-fold. This results in a decline of the GSH/GSSG ratio, which reflects oxidative stress induced by re-aeration following hypoxic pretreatment. Further evidence for this is an increase in lipid peroxidation measured as thiobarbituric acid-reactive material (TBA-rm) and the affected content of sulfydryl-groups in the root tissues.In spite of the high level of reduced glutathione in the roots under hypoxia-inducing conditions, they contained a retarded glutathione reductase (GR) activity compared with aerobically grown roots. Re-aeration up to 2 h resulted in a further decrease in GR activity. Only at the end of the 16-h period of re-aeration the enzyme activity was able to recover, by overshooting slightly those values of the continuously aerated controls. This was accompanied by a restoring a high GSH/GSSG ratio and an enhanced level of GSH.

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Dynamics of glutathione reductase activity in rat liver tissues during cryodestruction of the right atrium

E3S Web of Conferences ◽

10.1051/e3sconf/202127302014 ◽

2021 ◽

Vol 273 ◽

pp. 02014

Author(s):

Olga Pavlova ◽

Olga Gulenko ◽

Konstantin Krupin ◽

Pavel Boriskin ◽

Victor Leonov

Keyword(s):

Oxidative Stress ◽

Glutathione Reductase ◽

Rat Liver ◽

Right Atrium ◽

Liver Tissue ◽

Reductase Activity ◽

The Body ◽

Glutathione Reductase Activity ◽

The Right ◽

Liver Tissues

The metabolic processes of the human body are based on multiple redox reactions and oxidative stress occurs when homeostasis is imbalanced. Antioxidant system of the body is represented by such enzymes as catalase, glutathione reductase, superoxidismutase and glutathione peroxidase. Objective: to study the dynamics of glutathione reductase activity in rat liver tissues after cryodestruction of right atrial myocardium to initiate oxidative stress. Materials and methods: 420 male rats were used. The rats were divided into two groups - intact and experimental, 210 animals in each. To initiate oxidative stress, the experimental group rats underwent cryodestruction of the right atrium. The activity of glutathione reductase in the liver tissue was determined by accumulation of oxidized glutathione before the experiment, as well as on 1, 3, 5, 7 and 14 days of the experiment. Conclusions: oxidative stress arising after cryodestruction of the right atrium up to the 7th day of the experiment provokes a decrease in the glutathione reductase activity in the rat liver tissue, but the start of reparative processes helps to restore the disturbed redox equilibrium in the body and normalize the enzyme level.

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Repressive effect of Rhus coriaria L. fruit extracts on microglial cells-mediated inflammatory and oxidative stress responses

Journal of Ethnopharmacology ◽

10.1016/j.jep.2020.113748 ◽

2021 ◽

Vol 269 ◽

pp. 113748

Author(s):

Mohamad Khalil ◽

Ali Bazzi ◽

Dana Zeineddine ◽

Wissam Jomaa ◽

Ahmad Daher ◽

...

Keyword(s):

Oxidative Stress ◽

Stress Responses ◽

Microglial Cells ◽

Fruit Extracts ◽

Repressive Effect ◽

Rhus Coriaria ◽

Oxidative Stress Responses ◽

And Oxidative Stress

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Dynamic aqueous transformations of lithium cobalt oxide nanoparticle induce distinct oxidative stress responses of B. subtilis

Environmental Science Nano ◽

10.1039/d0en01151g ◽

2021 ◽

Author(s):

Metti K. Gari ◽

Paul Lemke ◽

Kelly H. Lu ◽

Elizabeth D. Laudadio ◽

Austin H. Henke ◽

...

Keyword(s):

Oxidative Stress ◽

Cobalt Oxide ◽

Stress Responses ◽

Lithium Ion ◽

Model Organisms ◽

Lithium Cobalt Oxide ◽

Oxygen Species ◽

Oxide Nanoparticle ◽

Oxidative Stress Responses ◽

Lithium Cobalt

Lithium cobalt oxide (LiCoO2), an example of nanoscale transition metal oxide and a widely commercialized cathode material in lithium ion batteries, has been shown to induce oxidative stress and generate intracellular reactive oxygen species (ROS) in model organisms.

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The Arabidopsis mediator complex subunit 8 regulates oxidative stress responses

The Plant Cell ◽

10.1093/plcell/koab079 ◽

2021 ◽

Cited By ~ 1

Author(s):

Huaming He ◽

Jordi Denecker ◽

Katrien Van Der Kelen ◽

Patrick Willems ◽

Robin Pottie ◽

...

Keyword(s):

Oxidative Stress ◽

Gene Expression ◽

Salicylic Acid ◽

Jasmonic Acid ◽

Stress Responses ◽

Negative Regulator ◽

Mediator Complex ◽

Defense Gene Expression ◽

A Genome ◽

Oxidative Stress Responses

Abstract Signaling events triggered by hydrogen peroxide (H2O2) regulate plant growth and defense by orchestrating a genome-wide transcriptional reprogramming. However, the specific mechanisms that govern H2O2-dependent gene expression are still poorly understood. Here, we identify the Arabidopsis Mediator complex subunit MED8 as a regulator of H2O2 responses. The introduction of the med8 mutation in a constitutive oxidative stress genetic background (catalase-deficient, cat2) was associated with enhanced activation of the salicylic acid pathway and accelerated cell death. Interestingly, med8 seedlings were more tolerant to oxidative stress generated by the herbicide methyl viologen (MV) and exhibited transcriptional hyperactivation of defense signaling, in particular salicylic acid- and jasmonic acid-related pathways. The med8-triggered tolerance to MV was manipulated by the introduction of secondary mutations in salicylic acid and jasmonic acid pathways. In addition, analysis of the Mediator interactome revealed interactions with components involved in mRNA processing and microRNA biogenesis, hence expanding the role of Mediator beyond transcription. Notably, MED8 interacted with the transcriptional regulator NEGATIVE ON TATA-LESS, NOT2, to control the expression of H2O2-inducible genes and stress responses. Our work establishes MED8 as a component regulating oxidative stress responses and demonstrates that it acts as a negative regulator of H2O2-driven activation of defense gene expression.

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