Induction of resistance to hydrogen peroxide and radiation inDeinococcus radiodurans

1995 ◽  
Vol 41 (2) ◽  
pp. 170-176 ◽  
Author(s):  
Ping Wang ◽  
Herb E. Schellhorn
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Defense Mechanism ◽  
Deinococcus Radiodurans ◽  
Inducible Defense ◽  
Dna Damaging Agents ◽  
Radiation Resistant ◽  
Γ Rays ◽  
Induction Of Resistance ◽  
Mutagenic Effects

Though bacteria of the radiation-resistant genus Deinococcus have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. To investigate antioxidant enzyme responses in Deinococcus spp., the catalase activity produced by these bacteria was measured and the sensitivity of these bacteria to hydrogen peroxide was tested. Deinococcus spp. had higher levels of catalase and were more resistant to hydrogen peroxide than Escherichia coli K12. The high levels of catalase produced by Deinococcus radiodurans were, in part, regulated by growth phase. Cultures of D. radiodurans, when pretreated with sublethal levels of hydrogen peroxide, became relatively resistant to the lethal effects of hydrogen peroxide and exhibited higher levels of catalase than untreated control cultures. These pretreated cells were also resistant to lethality mediated by ultraviolet light and γ-rays. These results suggest that Deinococcus spp. possess inducible defense mechanism(s) against the deleterious effects of oxidants and ionizing and ultraviolet radiation.Key words: catalase, oxidative stress, radiation resistance, Deinococcus spp.

scholarly journals Comparative Proteomics Analysis Reveals New Features of the Oxidative Stress Response in the Polyextremophilic Bacterium Deinococcus radiodurans

2020 ◽  
Vol 8 (3) ◽  
pp. 451 ◽  
Author(s):  
Lihua Gao ◽  
Zhengfu Zhou ◽  
Xiaonan Chen ◽  
Wei Zhang ◽  
Min Lin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Repair ◽  
Ribosomal Proteins ◽  
Deinococcus Radiodurans ◽  
Resistance Mechanisms ◽  
Comparative Proteomics ◽  
Label Free ◽  
Proteomics Analysis ◽  
Dna Damaging Agents ◽  
Oxidative Resistance

Deinococcus radiodurans is known for its extreme resistance to ionizing radiation, oxidative stress, and other DNA-damaging agents. The robustness of this bacterium primarily originates from its strong oxidative resistance mechanisms. Hundreds of genes have been demonstrated to contribute to oxidative resistance in D. radiodurans; however, the antioxidant mechanisms have not been fully characterized. In this study, comparative proteomics analysis of D. radiodurans grown under normal and oxidative stress conditions was conducted using label-free quantitative proteomics. The abundances of 852 of 1700 proteins were found to significantly differ between the two groups. These differential proteins are mainly associated with translation, DNA repair and recombination, response to stresses, transcription, and cell wall organization. Highly upregulated expression was observed for ribosomal proteins such as RplB, Rpsl, RpsR, DNA damage response proteins (DdrA, DdrB), DNA repair proteins (RecN, RecA), and transcriptional regulators (members of TetR, AsnC, and GntR families, DdrI). The functional analysis of proteins in response to oxidative stress is discussed in detail. This study reveals the global protein expression profile of D. radiodurans in response to oxidative stress and provides new insights into the regulatory mechanism of oxidative resistance in D. radiodurans.

scholarly journals Melatonin alleviates heat-induced damage of tomato seedlings by balancing redox homeostasis and modulating polyamine and nitric oxide biosynthesis

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Mohammad Shah Jahan ◽  
Sheng Shu ◽  
Yu Wang ◽  
Zheng Chen ◽  
Mingming He ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Nitric Oxide ◽  
Hydrogen Peroxide ◽  
Heat Stress ◽  
Heat Shock ◽  
Defense Mechanism ◽  
Enzymatic Antioxidants ◽  
Tomato Seedlings ◽  
Glutathione Cycle

Abstract Background Melatonin is a pleiotropic signaling molecule that plays multifarious roles in plants stress tolerance. The polyamine (PAs) metabolic pathway has been suggested to eliminate the effects of environmental stresses. However, the underlying mechanism of how melatonin and PAs function together under heat stress largely remains unknown. In this study, we investigated the potential role of melatonin in regulating PAs and nitric oxide (NO) biosynthesis, and counterbalancing oxidative damage induced by heat stress in tomato seedlings. Results Heat stress enhanced the overproduction of reactive oxygen species (ROS) and damaged inherent defense system, thus reduced plant growth. However, pretreatment with 100 μM melatonin (7 days) followed by exposure to heat stress (24 h) effectively reduced the oxidative stress by controlling the overaccumulation of superoxide (O2•−) and hydrogen peroxide (H2O2), lowering the lipid peroxidation content (as inferred based on malondialdehyde content) and less membrane injury index (MII). This was associated with increased the enzymatic and non-enzymatic antioxidants activities by regulating their related gene expression and modulating the ascorbate–glutathione cycle. The presence of melatonin induced respiratory burst oxidase (RBOH), heat shock transcription factors A2 (HsfA2), heat shock protein 90 (HSP90), and delta 1-pyrroline-5-carboxylate synthetase (P5CS) gene expression, which helped detoxify excess ROS via the hydrogen peroxide-mediated signaling pathway. In addition, heat stress boosted the endogenous levels of putrescine, spermidine and spermine, and increased the PAs contents, indicating higher metabolic gene expression. Moreover, melatonin-pretreated seedlings had further increased PAs levels and upregulated transcript abundance, which coincided with suppression of catabolic-related genes expression. Under heat stress, exogenous melatonin increased endogenous NO content along with nitrate reductase- and NO synthase-related activities, and expression of their related genes were also elevated. Conclusions Melatonin pretreatment positively increased the heat tolerance of tomato seedlings by improving their antioxidant defense mechanism, inducing ascorbate–glutathione cycle, and reprogramming the PAs metabolic and NO biosynthesis pathways. These attributes facilitated the scavenging of excess ROS and increased stability of the cellular membrane, which mitigated heat-induced oxidative stress.

scholarly journals Nectar defense and hydrogen peroxide in floral nectar of Cucurbita pepo

2015 ◽  
Vol 68 (2) ◽  
pp. 187-193 ◽  
Author(s):  
Daniele Nocentini ◽  
Massimo Guarnieri ◽  
Chiara Soligo
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Cucurbita Pepo ◽  
Defense Mechanism ◽  
Starch Accumulation ◽  
Floral Nectar ◽  
Male Flowers ◽  
Female Flowers

This study was carried out to investigate some similarities between the nectaries of <em>Nicotiana</em> sp. and <em>Cucurbita</em> pepo, such as starch accumulation in the nectary parenchyma, changes in nectary color during maturation, and the production of a large quantity of sucrose-dominant nectar. The concentration of hydrogen peroxide in <em>C. pepo</em> floral nectar was determined in order to verify the presence of a defense mechanism similar to that found in <em>Nicotiana</em> sp. which protects nectar from yeast and bacteria proliferation. We also tested the eventual accumulation of antioxidants in the nectary of <em>C. pepo</em> as a protection against oxidative stress caused by hydrogen peroxide. The level of hydrogen peroxide found in the floral nectar of <em>C. pepo</em> was much lower than that found in <em>Nicotiana</em> sp. and the male flowers of <em>Cucurbita</em> had a higher concentration than the female flowers. The low oxidative stress induced by this level of hydrogen peroxide caused the accumulation of a low amount of lutein inside the plastoglobules which were contained in amyloplasts. Plastids of the <em>C. pepo</em> nectary are specialized in the accumulation of starch rather than antioxidants.

scholarly journals YtkD and MutT Protect Vegetative Cells but Not Spores of Bacillus subtilis from Oxidative Stress

2006 ◽  
Vol 188 (6) ◽  
pp. 2285-2289 ◽  
Author(s):  
Francisco X. Castellanos-Juárez ◽  
Carlos Álvarez-Álvarez ◽  
Ronald E. Yasbin ◽  
Barbara Setlow ◽  
Peter Setlow ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Dna Damage ◽  
Bacillus Subtilis ◽  
Mutation Frequency ◽  
Spontaneous Mutation ◽  
Vegetative Cells ◽  
Oxidizing Agents ◽  
Mutagenic Effects ◽  
Spontaneous Mutation Frequency

ABSTRACT ytkD and mutT of Bacillus subtilis encode potential 8-oxo-dGTPases that can prevent the mutagenic effects of 8-oxo-dGTP. Loss of YtkD but not of MutT increased the spontaneous mutation frequency of growing cells. However, cells lacking both YtkD and MutT had a higher spontaneous mutation frequency than cells lacking YtkD. Loss of either YtkD or MutT sensitized growing cells to hydrogen peroxide (H2O2) and t-butylhydroperoxide (t-BHP), and the lack of both proteins sensitized growing cells to these agents even more. In contrast, B. subtilis spores lacking YtkD and MutT were not sensitized to H2O2, t-BHP, or heat. These results suggest (i) that YtkD and MutT play an antimutator role and protect growing cells of B. subtilis against oxidizing agents, and (ii) that neither YtkD nor MutT protects spores against potential DNA damage induced by oxidative stress or heat.

scholarly journals Unraveling Oxidative Stress Resistance: Molecular Properties Govern Proteome Vulnerability

2020 ◽  
Author(s):  
Roger L. Chang ◽  
Julian A. Stanley ◽  
Matthew C. Robinson ◽  
Joel W. Sher ◽  
Zhanwen Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Resistance ◽  
Deinococcus Radiodurans ◽  
Multiple Scales ◽  
Molecular Properties ◽  
Structural Systems ◽  
Γ Irradiation ◽  
Oxidative Stress Resistance ◽  
Radiation Resistant ◽  
Structural Systems Biology

Abstract:Oxidative stress alters cell viability, from microorganism irradiation sensitivity to human aging and neurodegeneration. Deleterious effects of protein carbonylation by reactive oxygen species (ROS) make understanding molecular properties determining ROS-susceptibility essential. The radiation-resistant bacterium Deinococcus radiodurans accumulates less carbonylation than sensitive organisms, making it a key model for deciphering properties governing oxidative stress resistance. We integrated shotgun redox proteomics, structural systems biology, and machine learning to resolve properties determining protein damage by γ-irradiation in Escherichia coli and D. radiodurans at multiple scales. Local accessibility, charge, and lysine enrichment accurately predict ROS-susceptibility. Lysine, methionine, and cysteine usage also contribute to ROS-resistance of the D. radiodurans proteome. Our model predicts proteome maintenance machinery and proteins protecting against ROS are more resistant in D. radiodurans. Our findings substantiate that protein-intrinsic protection impacts oxidative stress resistance, identifying causal molecular properties.One Sentence SummaryProteins differ in intrinsic susceptibility to oxidation, a mode of evolutionary adaptation for stress tolerance in bacteria.

scholarly journals Reduction of Fe(III), Cr(VI), U(VI), and Tc(VII) byDeinococcus radiodurans R1

2000 ◽  
Vol 66 (5) ◽  
pp. 2006-2011 ◽  
Author(s):  
J. K. Fredrickson ◽  
H. M. Kostandarithes ◽  
S. W. Li ◽  
A. E. Plymale ◽  
M. J. Daly
Keyword(s):  
Ionizing Radiation ◽  
Humic Acids ◽  
Deinococcus Radiodurans ◽  
Solid Phase ◽  
Nitrilotriacetic Acid ◽  
Strictly Aerobic ◽  
Electron Shuttle ◽  
Dna Damaging Agents ◽  
Potential Applications ◽  
Radiation Resistant

ABSTRACT Deinococcus radiodurans is an exceptionally radiation-resistant microorganism capable of surviving acute exposures to ionizing radiation doses of 15,000 Gy and previously described as having a strictly aerobic respiratory metabolism. Under strict anaerobic conditions, D. radiodurans R1 reduced Fe(III)-nitrilotriacetic acid coupled to the oxidation of lactate to CO2 and acetate but was unable to link this process to growth. D. radiodurans reduced the humic acid analog anthraquinone-2,6-disulfonate (AQDS) to its dihydroquinone form, AH2DS, which subsequently transferred electrons to the Fe(III) oxides hydrous ferric oxide and goethite via a previously described electron shuttle mechanism. D. radioduransreduced the solid-phase Fe(III) oxides in the presence of either 0.1 mM AQDS or leonardite humic acids (2 mg ml−1) but not in their absence. D. radiodurans also reduced U(VI) and Tc(VII) in the presence of AQDS. In contrast, Cr(VI) was directly reduced in anaerobic cultures with lactate although the rate of reduction was higher in the presence of AQDS. The results are the first evidence that D. radiodurans can reduce Fe(III) coupled to the oxidation of lactate or other organic compounds. Also, D. radiodurans, in combination with humic acids or synthetic electron shuttle agents, can reduce U and Tc and thus has potential applications for remediation of metal- and radionuclide-contaminated sites where ionizing radiation or other DNA-damaging agents may restrict the activity of more sensitive organisms.

Evaluation of the role of enzymatic and nonenzymatic antioxidant systems in the radiation resistance of Deinococcus

2010 ◽  
Vol 56 (3) ◽  
pp. 195-201 ◽  
Author(s):  
Ravindranath Shashidhar ◽  
Sanjukta A. Kumar ◽  
Hari S. Misra ◽  
Jayant R. Bandekar
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Stress Resistance ◽  
Radiation Resistance ◽  
Resistant Bacteria ◽  
Antioxidant Systems ◽  
Defense Systems ◽  
Antioxidant Metabolites ◽  
Radiation Resistant

Antioxidant enzymes and antioxidant metabolites appear to have different roles in the oxidative stress resistance responses of radiation-resistant bacteria belonging to the Deinococcus – Thermus group. Twelve distinct strains belonging to 7 Deinococcus species were characterized for their responses to hydrogen peroxide, ciprofloxacin, and ionizing radiation. The levels of catalase and peroxidase activities in these strains showed a positive correlation with resistance to hydrogen peroxide and ciprofloxacin. However, the levels of these enzymes and carotenoids did not appear to contribute significantly to radiation resistance. Our findings support the idea that enzymatic defense systems are not sufficient to account for the extreme radiation resistance of Deinococcus species. Consistent with previously published reports, the Deinococcus strains had high intracellular manganese/iron ratios. No significant correlation was found between intracellular manganese/iron ratios and radiation resistance within different Deinococcus species, suggesting that other components are involved in conferring radiation resistance.

scholarly journals Repair of Oxidized Bases in the Extremely Radiation-Resistant Bacterium Deinococcus radiodurans

1999 ◽  
Vol 181 (1) ◽  
pp. 262-269 ◽  
Author(s):  
Cécile Bauche ◽  
Jacques Laval
Keyword(s):  
Deinococcus Radiodurans ◽  
Excision Repair ◽  
Dna Glycosylase ◽  
Repair System ◽  
Thymine Glycol ◽  
Dna Damaging Agents ◽  
Repair Mechanisms ◽  
Radiation Resistant ◽  
Base Excision ◽  
Base Excision Repair System

ABSTRACT Deinococcus radiodurans is able to resist and survive extreme DNA damage induced by ionizing radiation and many other DNA-damaging agents. It is believed that it possesses highly efficient DNA repair mechanisms. To characterize the repair pathway of oxidized purines in this bacteria, we have purified, from crude extracts, proteins that recognize these oxidized bases. We report here thatD. radiodurans possesses two proteins excising the oxidized purines (formamidopyrimidine and 8-oxoguanine) by a DNA glycosylase–a purinic/apyrimidine lyase mechanism. Moreover, one of those proteins is endowed with a thymine glycol DNA glycosylase activity. One of these proteins could be the homolog of the Escherichia coli Fpg enzyme, which confirms the existence of a base excision repair system in this bacteria.

Effect of Turmeric and Ginger on Lipid Profile in Male Rats Exposed to Oxidative Stress

2019 ◽  
Vol 10 (01) ◽  
Author(s):  
Eman A. Al-Rekabi ◽  
Dheyaa K. Alomer ◽  
Rana Talib Al-Muswie ◽  
Khalid G. Al-Fartosi
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Drinking Water ◽  
Lipid Profile ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Male Rats ◽  
Control Group ◽  
Very Low Density Lipoprotein ◽  
Low Density

The present study aimed to investigate the effect of turmeric and ginger on lipid profile of male rats exposed to oxidative stress induced by hydrogen peroxide H2O2 at a concentration of 1% given with consumed drinking water to male rats. Methods: 200 mg/kg from turmeric and ginger were used, and the animals were treatment for 30 days. Results: the results showed a significant increase in cholesterol, triglycerides, low density lipoprotein (LDL), very low density lipoprotein (VLDL), whereas it explained a significant decrease in high density lipoprotein (HDL) of male rats exposed to oxidative stress when compared with control group. the results showed a significant decrease in cholesterol, triglycerides, (LDL), (VLDL), whereas it explained a significant increase in (HDL) of rats treated with turmeric and ginger at dose 200 mg/kg when compared with male rats exposed to oxidative stress.

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