Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30044 (antioxidant enzyme)
 8,037 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to investigate the existence of genetic variability in antioxidant enzyme defenses in sunflower, twelve inbred lines, six cytoplasmic male-sterile and six restorer lines, commonly used in breeding programs have been compared with respect to (a) their levels of constitutive superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11), glutathione reductase (GR, EC 1.6.4.2) and guaiacol-dependent peroxidase (GPX, EC 1.11.1.7), and (b) their isoenzyme polymorphism in SOD, CAT, and GPX activities. Constitutive levels of antioxidant enzymes in the 2nd leaf pair of 15-20-day-old sunflower plants showed significant differences between lines. The ranges of variation in enzyme activities of the different lines were equivalent to 34.3% (CAT), 38.2% (SOD), 59.5% (APX), 60.0% (GR), and 62.9% (GPX) of the respective maximal values. Isoenzyme profiles of CAT, GPX and SOD revealed the existence in sunflower of at least three, six and four isoforms of these enzymes, respectively. Further characterization of SOD isoenzymes revealed that no isoenzyme corresponded to a Mn-SOD, the faster moving isoform being a Cu/Zn-SOD and the remainder three Fe-SODs. Among the twelve inbred sunflower lines studied there were ample qualitative, and sometimes quantitative too, differences in isoenzyme dotation of CAT, GPX and Fe-SOD.
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PMID:Sunflower (Helianthus annuus) variability in antioxidant enzyme defenses. 1069 64

The aim of this study was to determine whether increases in stromal superoxide dismutase (SOD; EC 1.15.1.1), ascorbate peroxidase (APX; EC 1.11.1.11) and glutathione reductase (GR; EC 1.6.4.2) via transformation could reduce photosystem (PS) II photoinhibition at low temperature for cotton (Gossypium hirsutum L.) plants and to determine by what mechanism this protection may be realized. During 3-h exposures of lincomycin-treated leaf discs to 10 degrees C and a photon flux density of 500 &mgr;mol m-2 s-1, all transgenic plants exhibited significantly greater PSII activity and O2 evolution than did wild-type plants. Also, the rate constant of PSII photoinactivation was significantly lower for all transgenic plants than for wild-type plants. No significant differences existed between genotypes in non-photochemical quenching of chlorophyll a fluorescence and the regulated component of the thermal dissipation of excitation energy. The relationship between changes in variable to maximum chlorophyll fluorescence (Fv/Fm) and the time-dependent averaged excessive light exposure was similar for all genotypes. This observation excluded the possibility that differences in PSII photodamage were due to improvements in the direct protection of PSII from active oxygen by antioxidant enzyme overproduction. Similar decreases in Fv/Fm during the stress treatment for all genotypes when leaves were pre-treated with 3-(3',4'-dichlorophenyl)-1,1-dimethylurea (DCMU) suggested that the effect of overproduction involved events downstream of PSII in the electron transfer pathway. Since all transgenic plants exhibited a significantly higher photochemical quenching of chlorophyll fluorescence during the chilling treatment, we concluded that, under the conditions used in this study, the enhancement of the protection of PSII from photodamage by increasing the stromal antioxidant enzyme activity in cotton leaves was due to the maintenance of a higher rate of electron transport and, consequently, a lower reduction state of QA.
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PMID:Enhanced photochemical light utilization and decreased chilling-induced photoinhibition of photosystem II in cotton overexpressing genes encoding chloroplast-targeted antioxidant enzymes. 1206 Feb 76

ALA is a key precursor in the biosynthesis of porphyrins such as chlorophyll and heme, and was found to induce temporary elevations in the photosynthesis rate, APX, and CAT; furthermore, treatment with ALA at a low concentration might be correlated to the increase of NaCl tolerance of spinach plants. The photosynthetic rate and the levels of active oxygen-scavenging system in the 3rd leaf of spinach (Spinacia oleracea) plants grown by foliar treatment with 0, 0.18, 0.60 and 1.80 mmol/L 5-aminolevulinic acid under 50 and 100 mmol/L NaCl were analyzed. Plants treated with 0.60 and 1.80 mmol/L ALA showed significant increases in the photosynthetic rate at 50 and 100 mmol/L NaCl, while that of 0.18 mmol/L ALA did not show any changes at 50 mmol/L NaCl and a gradual decrease at 100 mmol/L NaCl. In contrast, the rate with 0 mmol/L ALA showed reduction at both concentrations of NaCl. The increase of hydrogen peroxide content by treatment with 0.60 and 1.80 mmol/L ALA were more controlled than that of 0 mmol/L ALA under both NaCl conditions. These ALA-treated spinach leaves also exhibited a lower oxidized/reduced ascorbate acid ratio and a higher reduced/oxidized glutathione ratio than the 0 mmol/L-treated spinach leaves when grown at both NaCl conditions. With regard to the antioxidant enzyme activities in the leaves, ascorbate peroxidase, catalase, and glutathione reductase activities were enhanced remarkably, most notably at day 3, by treatment with 0.60 and 1.80 mmol/L ALA under both NaCl conditions in comparison to that of 0 and 0.18 mmol/L ALA. These data indicate that the protection against oxidative damage by higher levels of antioxidants and enzyme activities, and by a more active ascorbate-glutathione cycle related to the increase of the photosynthesis rate, could be involved in the increased salt tolerance observed in spinach by treatment with 0.60 to 1.80 mmol/L ALA with NaCl.
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PMID:Role of 5-aminolevulinic acid (ALA) on active oxygen-scavenging system in NaCl-treated spinach (Spinacia oleracea). 1459 10

To analyse nodular antioxidant enzyme expression in response to salt stress, Phaseolus vulgaris genotype BAT477 was inoculated with reference strain CIAT899, and treated with 50 mM NaCl. Plant growth, nodulation and nitrogen fixing activity were analysed. Results showed that: (1) all parameters, particularly in nodules, were affected by salt treatments, and (2) confirmed preferential growth allocation to roots. The ARA was significantly decreased by salt treatments. Protein dosage confirmed that nodules were more affected by salt treatment than were roots. We analysed superoxide dismutase, catalase, ascorbate peroxidase and peroxidase in nodules, roots and a free rhizobial strain. Our results indicated that SOD and CAT nodular isozymes had bacterial and root origins. The SOD expressed the same CuZn, Fe and Mn SOD isoforms in nodules and roots, whereas in free rhizobia we found only one Fe and Mn SOD. APX and POX nodule and root profiles had only root origins, as no rhizobial band was detected. Under salt stress, plant growth, nitrogen fixation and activities of antioxidant defense enzymes in nodules were affected. Thus, these enzymes appear to preserve symbiosis from stress turned out that NaCl salinity lead to a differential regulation of distinct SOD and POX isoenzyme. So their levels in nodules appeared to be consistent with a symbiotic nitrogen fixing efficiency hypothesis, and they seem to function as the molecular mechanisms underlying the nodule response to salinity.
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PMID:Changes in ascorbate peroxidase, catalase, guaiacol peroxidase and superoxide dismutase activities in common bean (Phaseolus vulgaris) nodules under salt stress. 1614 19

Ultraviolet-B (UV-B) radiation has a negative impact on plant cells, and leads to the generation of reactive oxygen species (ROS). Heme oxygenase (HO, EC 1.14.99.3) plays a protective role against oxidative stress in mammals, but little is known about this issue in plants. Here, we report for the first time the response of HO in leaves of soybean (Glycine max L.) plants subjected to UV-B radiation. Under 7.5 and 15 kJ m(-2 )UV-B doses, HO, catalase (CAT, EC 1.11.1.6) and ascorbate peroxidase (APX, EC 1.11.1.11) activities were increased and the production of thiobarbituric acid reactive substances (TBARS) regain control values after 4 h of plant recuperation. Treatment with 30 kJ m(-2) UV-B provoked a decrease in these antioxidant enzyme activities. Immunoblot analysis showed a 4.3 and 3.7-fold increase in HO-1 protein expression after irradiation with 7.5 and 15 kJ m(-2), respectively. HO-1 transcript levels were enhanced (up to 77%) at these doses, as assessed by semi-quantitative RT-PCR. These data demonstrated that increased HO activity was associated with augmented protein expression and transcript levels. Plants pre-treated with the antioxidant ascorbic acid did not show the UV-B-induced up-regulation of HO-1 mRNA, but hydrogen peroxide treatment could mimic this reaction. Our results indicate that HO is up-regulated in a dose-depending manner as a mechanism of cell protection against oxidative damage and that such response occurred as a consequence of HO-1 mRNA enhancement involving ROS.
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PMID:Heme oxygenase up-regulation in ultraviolet-B irradiated soybean plants involves reactive oxygen species. 1670 57

Effects of high concentration manganese on active oxygen production and antioxidant enzymes in cucumber leaves under natural irradiation and 1/2 natural irradiation were studied. High concentration manganese increased the H2O2 content and O2*- producing rate of cucumber leaves (Fig.1A, B) and caused lipid peroxidation (Fig.1C). Compare to natural irradiation, 1/2 natural irradiation significantly decreased active oxygen production and lipid peroxidation (Fig.1). CAT activities in cytosols and chloroplasts were inhibited by high concentration manganese (Fig.2B), and other antioxidant enzyme activities were enhanced by high concentration manganese (Fig.2A, C-F). Especially activities of APX, DHAR and GR in chloroplasts were greatly stimulated by high concentration manganese under natural irradiation compared to 1/2 irradiation, which may play important roles in scavenging active oxygen species. Antioxidant enzymes in mitochondria showed higher activities under high concentration manganese under natural irradiation, but the differences were not significant under 1/2 natural irradiation (Fig.2A, C-F).
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PMID:[Effects of high concentration manganese on active oxygen production and antioxidant enzyme activities in cucumber leaves under different irradiations]. 1677 1

Changes in photosynthetic and antioxidant activities in maize (Zea mays L.) leaves of cultivars 3223 and 31G98 exposed to excess copper (Cu) were investigated. Cu treatment reduced the shoot and root length of both cultivars. No significant difference of Cu accumulation in the roots of both cultivars was observed while the cultivar 3223 accumulated significantly higher Cu in leaves than 31G98. The observed decreases in effective quantum efficiency of PSII, ETR and qP indicate an over excitation of photochemical system in 3223 compared to 31G98. The leaf chlorophyll and carotenoid contents of both cultivars decreased with increasing Cu concentration. A far higher production of anthocyanins in 31G98 has been observed than that of 3223. At 1.5 mM Cu concentration, all antioxidant enzyme activities increased in leaves of the cultivar 31G98 while there were no significant changes in SOD and GR activities in 3223 compared to the control except increased APX and POD activities. The lower Cu accumulation in leaves and higher antioxidant enzyme activities in 31G98 suggested an enhanced tolerance capacity of this cultivar to protect the plant from oxidative damage.
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PMID:Changes in photochemical and antioxidant enzyme activities in maize (Zea mays L.) leaves exposed to excess copper. 1710 27

In this paper, Hydrilla verticillata was cultured in the hoagland solution containing 5 mg L(-1) Cd2+ and different concentration ascorbic acid (AsA) to investigate the protective action of AsA to aquatic plant suffered from heavy metal's stress. The O2 generation rate, H2O2 content, antioxidants (AsA and GSH) contents, and antioxidant enzymes (SOD, POD, CAT and APX) activities were analyzed. The results showed that compared with single Cd2+ treatment, AsA addition lessened the reactive oxygen species (O2-* and H2O2) generation rates, endogenous AsA content, and antioxidant enzyme activities. It was concluded that exogenous AsA could relieve the Cd2+ poison to H. verticillata, and its optimum concentration was 60 mg x L(-1).
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PMID:[Protective effects of exogenous ascorbic acid on antioxidant system in Hydrilla verticillata under Cd2+]. 1714 97

The effect of drought on the chickpea variety ILC 3279 was investigated at the vegetative stage. After 20 days from sowing, the plants subjected to drought stress for 3, 5 and 7 days imposed by withholding water were permitted to recover by rewatering for 2 days after 3, 5 and 7 days of drought. Shoot elongation, leaf production, fresh and dry biomass reduced while MDA and proline accumulation increased with extended duration of stress. The plants stressed for 3 days exhibited a rapid drop in their relative and absolute water contents. The quantum efficiency of PSII open centres in the dark-adapted and light-saturated state, excitation energy trapping of PSII and electron transport rate decreased significantly from the 5th day to the end of the drought treatments. Plants drought-stressed for 7 days brought about a marked increase in non-photochemical energy dissipation and a marked decline in photochemical quenching. After rewatering all chlorophyll a fluorescence characteristics except for F(M) completely recovered and reached the control values. Under 5 and 7 days of drought, the anthocyanin content increased gradually while the total chlorophyll content of leaves declined compared to the controls. The total carotenoid content remained unchanged during the experiments. The antioxidant enzyme response to drought treatments was quite variable. The total SOD activity upregulated with increasing duration of stress. On the other hand, the total APX activity was significantly higher only on the 7th day while the total POD activity increased from the 5th day. Differences in the total GR activity of treated groups were not statistically significant compared to their controls throughout the treatments. The present results indicate that the chickpea variety ILC 3279 withstands severe drought with its upregulated protective mechanisms at the vegetative stage.
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PMID:PSII photochemistry and antioxidant responses of a chickpea variety exposed to drought. 1881 Oct 6

The present paper investigated the short-term colonization by plants of a highly degraded soil in field conditions. The objectives were to identify, through phytosociological analysis, the plant species able to grow on such polluted areas and to characterize pollutant effects at different biological levels through analyses of plant oxidative status, plant growth or community indexes of richness and biodiversity. Our results showed that among the plants present in the uncontaminated surrounding area, only few species were able to colonize the polluted soil. These species were typical of the first years of grassland successions. Ecological indexes proved that the polluted soil vegetation presented a lower degree of species richness and biodiversity than the control area. These discrepancies were partly explained by pollutant phytotoxicity. Indeed, for several species including Erigeron canadensis and Oenothera biennis, we observed toxic effects of the polluted soil on plant height and biomass. Moreover, at the cellular level, changes in antioxidant enzyme activities (SOD, CAT, APX, GPX and GRD) and lipid peroxidation level (MDA) were observed. Such biochemical changes seemed to play an important role on plant sensitivity/tolerance to pollutants and thus to render them more or less competitive for colonization of such disturbed areas.
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PMID:Ecological recovery of vegetation on a coke-factory soil: role of plant antioxidant enzymes and possible implications in site restoration. 1897 11


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