Superoxide dismutases of chestnut leaves, Castanea sativa: Characterization and study of their involvement in natural leaf senescence

Superoxide dismutases (SOD; EC 1.15.1.1) in chestnut ( Castanea sativa Mill., cv. 431) leaves were characterized by native polyacrylamide gel electrophoresis. The three molecular forms of SOD were distinguished from each other by their different sensitivity to cyanide and H₂O₂ Three CuZn-containing SODs were detected (CuZn-SOD I, II. and III), and all the isozymes had a molecular mass of 33 kDa. CuZn-SOD III was the most abundant isozyme. whereas CuZn-SOD II was present in a minor amount. In leaves showing typical symptoms of senescence increases of 2.5-. 7- and 4-fold in the specific activities of CuZn-SODs I, II, and III. respectively, were found. In addition, the pattern of the three isozymes was modified by the age of leaves, a rise in the CuZn-SOD II and a decrease in the CuZn-SOD 1 percentages being found in senescent leaves compared to green leaves. As to other activated oxygen-related enzymes, an increase in the superoxide-generating xanthine oxidase activity and a decline in both catalase and peroxidase activities during natural senescence of chestnut leaves were observed. Results obtained suggest that in natural senescence of chestnut leaves activated oxygen species are involved, and an overproduction of hydrogen peroxide and superoxide radicals probably takes place.     

Lhca polypeptides are maintained during dark-induced senescence of leaves

Thylakoid polypeptides samples from fresh and dark-incubated (0–6 days) leaves were tested for changes in relative abundancies of Lhca polypeptides using a set of polyclonal and monoclonal antibodies in conjunction with immunoblot technique and integrating densitometry. All Lhca polypeptides were found to be more stable within 6 days of dark incubation than bulk chlorophyll itself. On chlorophyll basis the relative abundance of Lhca 1–4 increased after 6 days of dark incubation to 154, 177, 144 and 121 %, respectively, of the values found in fresh leaves.     

Erythrocyte Oxidant/Antioxidant Status in Essential Hyperhidrosis

Essential Hyperhidrosis is a disorder of excessive, bilateral, and relatively symmetric sweating occurring in the axillae, palms, soles, or craniofacial region without obvious etiology. Nitric oxide may play a physiological part in the production and/or excretion of sweat in skin eccrine glands. Tempol, a SOD mimetic, increases the half-life of NO and results in vasodilatation, hypotension, and reflex activation of sympathetic nervous system. Reactive oxygen species (ROS) may directly activate both central and peripheral sympathetic nervous system activity. We assessed the levels of malondialdehyde (MDA), the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) of red blood cells in patients with essential hyperhidrosis (n = 31) compared to age-and sex-matched healthy controls (n = 28). Erythrocyte activities of SOD and level of MDA were detected significantly higher (p = 0.020, p = 0.004 and respectively) and activities of CAT and GSH-Px were significantly lower (p = 0.0001, p = 0.0001 respectively) in patients than controls. Our results support the hypothesis that oxidative damage resulting from increased ROS production along with insufficient capacity of antioxidant mechanisms may be involved in pathogenesis of EH.     

Singlet Oxygen and Other Reactive Oxygen Species are Involved in Regulation of Release of Iron-Binding Chelators from Scenedesmus cells

Freshly-added iron only slightly affected the growth of iron-sufficient cells of the green alga Scenedesmus incrassatulus Bohl, strain R-83, but induced accumulation of malondialdehyde (MDA) in cells and excretion of MDA in the medium. These effects were stronger in response to Fe²⁺ as compared to Fe³⁺, but Fe³⁺ induced the release of more iron-binding chelators from these cells than Fe²⁺. Fe³⁺ added either in dark or in light induced release of equal concentrations of iron-complexing agents, part of which formed strong chelates with iron in the medium. Exogenously added hydrogen peroxide inhibited iron-induced release of chelators but the effect was removed by addition of the hydroxyl radical scavenger dimethylsulfoxide (DMSO). Malondialdehyde also inhibited the release of chelators. Release of chelators was induced in the absence of iron salts by photoexcited chlorophyll (Chl). The Chl-induced release was efficiently inhibited by singlet oxygen scavengers such as dimethylfuran, -carotene, sodium azide and vitamin B₆, and stimulated in D₂O or DMSO. Exogenously added catalase inhibited the release more than added superoxide dismutase. The Fe³-induced release of chelators was also inhibited by scavengers of singlet oxygen, but was not affected by sodium azide and by ethanol. Hence both H₂O₂ and singlet oxygen were involved in induction of chelator release in the absence of iron in light. The induction of chelator release by iron in dark involved H₂O₂, but not singlet oxygen.     

Alleviation of NaCl Stress by Pretreatment with Phytohormones in Vigna radiata

Efficiency of pretreatment as foliar spray of indole-3-acetic acid, gibberellic acid and kinetin, each ranging from 0.1 to 10.0 μM concentration, in restoring the metabolic alterations imposed by NaCl salinity was investigated in Vigna radiata (L.) Wilczek. Glycolate oxidase, superoxide dismutase, catalase and peroxidase activities increased under stress in leaves and roots also. Malondialdehyde content and total peroxide content also increased under stress. All the three hormones used were able to overcome to variable extents the adverse effects of stress imposed by NaCl to these parameters. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effect of drought on biomass, protein content, lipid peroxidation and antioxidant enzymes in two sesame cultivars

The effects of drought on growth, protein content, lipid peroxidation, superoxide dismutase (SOD), peroxidase (POX), catalase (CAT) and polyphenol oxidase (PPO) were studied in leaves and roots of Sesamum indicum L. cvs. Darab 14 and Yekta. Four weeks after sowing, plants were grown under soil moisture corresponding to 100, 75, 50 and 25 % field capacity for next four weeks. Fresh and dry masses, and total protein content in leaves and roots decreased obviously under drought. However, several new proteins appeared and content of some proteins was affected. Measurement of malondialdehyde content in leaves and roots showed that lipid peroxidation was lower in Yekta than in Darab 14. Severe stress increased SOD, POX, CAT and PPO activities in leaves and roots, especially in Yekta. According to the present study Yekta is more resistant to drought than Darab 14.     

Antioxidative responses in Galleria mellonella larvae infected with the entomopathogenic nematode Heterorhabditis sp. beicherriana

The effects of a new species Heterorhabditis sp. beicherriana on the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and malondialdehyde (MDA) content of the host were studied. Last-instar larvae of Galleria mellonella were used as host insects and were experimentally infected with H. beicherriana at 0, 20, 40, 80 infective juveniles (IJs) per insect. At 0, 8, 16, 24, 32 and 40 h after infection, activities of SOD, POD, CAT and MDA content were determined in extracts from infected and control insects. We found that H. beicherriana infection resulted in gradually increased activities of SOD, POD and CAT the first day and decreased activities of these enzymes thereafter. However, MDA content in the insects of both control and IJ-inoculated groups stayed at a similar level at 24 h post-infection, but a significant decrease of MDA content in inoculated groups was recorded after 32 h of the infection, which is 8 hours later than the activities of SOD, POD and CAT were significantly increased. Our results suggest that H. beicherriana infection increases the level of oxidative stress and antioxidative responses in the larval G. mellonella, and it seems that oxidative damage contributes to cell death in this host.     

Oxidant/antioxidant parameters and their relationship with medical treatment in multiple myeloma

Multiple myeloma (MM) is a neoplastic disorder characterized by monoclonal multiplying of plasma cells. Although radiation, environmental factors, viruses and other factors have been suggested as potential causes of the disease, the aetiopathogenesis of MM is still obscure. This clinical study was designed to investigate the role of reactive oxygen species (ROS) in the aetiopathogenesis of the disease and the possible relationships between treatment and ROS production. For this purpose, erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities as well as plasma nitric oxide (NO) and malondialdehyde (MDA) levels were measured in 14 MM patients newly diagnosed at stage III. The relationship between the above-mentioned parameters and vincristine-adriamycin-dexamethasone (VAD) therapy were also investigated in the same patients. All the enzyme activities and the parameters of oxidative stress were found to be significantly reduced after VAD therapy. These findings suggest that ROS may be involved in the aetiopathogenesis of MM. Further investigations with a larger cohort of MM patients are needed to provide definitive data about the role of ROS in MM and the alternative therapeutic approaches to MM.     

Short-term effect of elevated CO2 concentration and high irradiance on the antioxidant enzymes in bean plants

The effect of short-term exposure to elevated CO₂ concentration and high irradiance on the activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol peroxidases (GPX) and catalase (CAT), and on the extent of the lipid peroxidation was studied in bean (Phaseolus vulgaris L.) plants. Plants were exposed for 4 d (8 h a day) to irradiance of 100 (LI) or 1000 (HI) μmol m⁻² s⁻¹ at ambient (CA, 350 μmol mol⁻¹) or elevated (CE, 1300 μmol mol⁻¹) CO₂ concentration. Four-day exposure to CE increased the leaf dry mass in HI plants and RuBPC activity and chlorophyll content in LI plants. Total soluble protein content, leaf dry matter and RuBPC activity were higher in HI than in LI plants, although the HI and CE increased the contents of malonyldialdehyde and H₂O₂. Under CA, exposure to HI increased the activity of APX and decreased the total SOD activity. Under CE, HI treatment also activated APX and led to reduction of both, SOD and GPX, enzymes activities. CE considerably reduced the CAT activity at both irradiances, possibly due to suppressed rate of photorespiration under CE conditions.     

H2O2 metabolism during senescence of rice leaves: changes in enzyme activities in light and darkness

The possible role of H₂O₂ metabolism on light-regulated senescence of detached rice leaves was investigated. Light retards senescence but at the same time accumulates more H₂O₂. Light treatment resulted in an increase in malondialdehyde level in detached rice leaves but no membrane leakage was observed in light-treated detached leaves. It seems that there was no direct relationship between lipid peroxidation and deterioration in membrane integrity. The results obtained suggest that retardation of senescence by light is closely related to high activities of superoxide dismutase and ascorbate peroxidase.     

Detection of ischemia-reperfusion cardiac injury by cardiac muscle chemiluminescence

Various methods have been used in the past to assess the implication of oxygen free radicals (OFR) in ischemia-reperfusion-induced cardiac injury. Luminol-enhanced tert-butyl-initiated chemiluminescence in cardiac tissue reflects oxidative stress and is a very sensitive method. It was used to elucidate the role of OFR in cardiac injury due to ischemia and reperfusion. Studies were conducted on perfused isolated rabbit hearts in three groups (n = 8 in each): I, control; II, submitted to global ischemia for 30 min; III, submitted to ischemia for 30 min followed by reperfusion for 60 min. The heart tissue was then assayed for chemiluminescence (CL); content of malondialdehyde (MDA), an indicator of OFR-induced cardiac injury; and activity of tissue levels of antioxidants [superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px)].The control values for left and right ventricular CL and malondialdehyde were 81.1 ± 15.4 (S.E.) and 182.4 ± 50.3 (S.E.), mv-min-mg protein^–1; and 0.024 ± 0.006 (S.E.) and 0.324 ± 0.005 (S.E.) nmoles-mg protein^–1 respectively. Ischemia produced an increase in the cardiac CL (3.3 to 4.4 fold) and MDA content (2 to 2.6 fold). Reperfusion following ischemia also produced similar changes in CL and MDA content. The control values for activity of left ventricular SOD, catalase, and GSH-Px were 45.77 ± 1.73 (S.E.) U-mg protein^–1 5.35 ± 0.51 (S.E.) K-10^–3-sec^–1-mg protein^–1, and 77.50 ± 7.70 (S.E.) nmoles NADPH-min^–1-mg protein^–1 respectively. Activities of SOD and catalase decreased during ischemia but were similar to control values in ischemic-reperfused hearts. The GSH-Px activity of left ventricle was unaffected by ischemia, and ischemia-reperfusion. GSH-Px activity of the right ventricle increased with ischemia, and ischemic-reperfusion.These results indicate that cardiac tissue chemiluminescence would be a useful and sensitive tool for the detection of oxygen free radical-induced cardiac injury.     

Responses of Camellia sinensis to Drought and Rehydration

The effects of drought and rehydration on tea seedlings were significant. After five days of drought imposition the contents of chlorophylls, carotenoids, ascorbate and glutathione, and activities of guaiacol peroxidase and glutathione reductase decreased. Simultaneously, contents of proline, H₂O₂ and superoxide anion, lipid peroxidation and activities of catalase and superoxide dismutase increased. These parameters recovered to different degrees during subsequent rehydration.     

Natural and dark-induced nodule senescence in chickpea: nodule functioning and H2O2 scavenging enzymes

An investigation was carried out on chickpea (Cicer arietinum L.) cv. C-235 inoculated withRhizobium sp.Cicer strain cv 4 Az^r. Nodule functioning was monitored at 15 d intervals starting from 45 days after sowing (DAS) and inoculation in order to study nodule development and senescence under natural and stress conditions (dark treatments of 18 and 66 h). Maximum rate of N₂-fixation was observed between 50 - 60 DAS. After this acetylene reducing activity (ARA) fell and it was negligible 75 DAS. This decline in ARA with ageing of plants and nodules was accompanied by a decline in leghemoglobin content and greening of the nodules. When 60 % of the nodule tissue had turned green 75 DAS, a sharp increase in nodule peroxidase activity (3.7 fold) was observed whereas the catalase activity was reduced by 50 % in comparison with the control. The glutathione-reductase and ascorbate-peroxidase activity followed a trend parallel to that in N₂-fixation, but the variation was much smaller. The changes in the total soluble carbohydrates, cytosolic proteins and nitrogen content per se were not expressive. Dark treatments induced premature senescence of the nodules as was evident from the marked decrease in ARA. However, the decline in leghemoglobin content was relatively small as compared to ARA. The changes in cytosolic proteins, total soluble carbohydrates, peroxidase activity, catalase activity, glutathione reductase activity and ascorbate peroxidase activity of nodules under dark-induced nodule senescence were almost parallel to those observed under natural senescence.     

Heat shock responses of bean plants: involvement of free radicals, antioxidants and free radical/active oxygen scavenging systems

In non-acclimated bean plants heat shock induced oxidative damage (increase of free radical concentration and drop of bound thiols, indicating aggregation of proteins) which was regulated by the enhanced activities of peroxidase and superoxide dismutase, as well as by the accumulation of polyphenols and especially of polyamines. In the plants acclimated to high temperature no oxidative damage occurred following heat shock. This revised version was published online in July 2006 with corrections to the Cover Date.     

Responses of antioxidative enzymes to elevated CO2 in leaves of beech (Fagus sylvatica L.) seedlings grown under a range of nutrient regimes

To study whether responses of antioxidative enzymes to enhanced atmospheric CO₂ concentrations are affected by plant nutrition, the activities of superoxide dismutase, catalase and peroxidase were investigated in leaves of 3-year-old beech trees grown with low (0.1 × optimum), intermediate (0.5 × optimum) and high (2 × optimum) nutrient supply rates in open-top chambers at either ambient (～ 355 μmol mol^?1) or elevated (700 μmol mol^?1) CO₂ concentrations. These treatments resulted in foliar C/N ratios of about 20 in the presence of high and > 30 in the presence of low nutrient supply rates. Pigment and malon-dialdehyde contents were determined to assess plant stress levels. Low nutrient supply rates caused pigment loss, whereas elevated CO₂ had no effect on pigmentation. Guaiacol peroxidase activities did not respond to either CO₂ or nutrient treatment. Catalase activity decreased with decreasing nutrient supply rate and also in response to elevated CO₂. Superoxidase dismutase activity was affected by both nutrient supply and CO₂ concentration. In leaves from trees grown with the high-nutrient treatment, superoxide dismutase activity was low irrespective of CO₂ concentration. In chlorotic leaves, superoxide dismutase activity was increased, suggesting an enhanced need for detoxification of reactive oxygen species. Leaves from plants grown under elevated CO₂ with medium nutrient supply rates showed decreased malondialdehyde contents and superoxide dismutase activities. This suggests that the intrinsic oxidative stress of leaves was decreased under these conditions. These results imply that intrinsic oxidative stress is modulated by the balance between N and C assimilation.     

Peroxide metabolism in the cestodes Hymenolepis diminuta and Moniezia expansa

The enzymes of hydrogen peroxide metabolism have been investigated in the cestodes H. diminuta and M. expansa. Neither catalase, lipoxygenase, glutathione peroxidase, NADH peroxidase nor NADPH peroxidase could be detected in homogenates of either species. However, both H. diminuta and M. expansa possessed a peroxidase which had a high affinity for reduced cytochrome c. The peroxidase was characterized by substrate and inhibitor studies and cell fractionation showed the enzyme to be located in the mitochondrial membrane fraction. The peroxidase could act as a substitute for catalase, by destroying metabolic hydrogen peroxide. Appreciable superoxide dismutase activity was found in M. expansa and H. diminuta and it is possible that this enzyme is the source of helminth hydrogen peroxide.     

Plant growth regulator interactions results enhancement of antioxidant enzymes in Catharanthus roseus

Abstract

The present investigation was carried out with the objectives to understand the effect of paclobutrazol, gibberellic acid and Pseudomonas fluorescens on the enzymatic antioxidants like Ascorbate peroxidase (APX, EC: 1.11.1.11), Superoxide dismutase (SOD, EC: 1.15.1.1), Catalase (CAT, EC: 1.11.1.6), Peroxidase (POX, EC 1.11.1.7) and polyphenol oxidase (PPO, Ec 1.10.3.1) activities of Catharanthus roseus plants under field conditions. 10 mg l^?1 paclobutrazol, 5 µM gibberellic acid and 1 mg P. fluorescens concentrations were used for the treatments, and control plants were irrigated with well water. The treatments were given 38, 53, 68 and 83 days after planting (DAP) by soil drenching. The plants were taken randomly 45, 60, 75 and 90 DAP and separated into root, stem, leaves and flowers and used for estimating the antioxidant enzymes. The results showed that these plant growth regulators have significant effects on antioxidant enzymes of C. roseus.     

Homeostasis of polyamines and antioxidant systems in roots and leaves of <Emphasis Type="Italic">Plantago major</Emphasis> under salt stress

Functioning of the antioxidant system in roots and leaves of Plantago major L. in water culture at the stage of 5–6 genuine leaves of the plants subjected to NaCl (100 mM) action for 96 h was investigated. This plant exhibited a pronounced organ specificity of antioxidant defense system functioning. The roots were characterized by high constitutive activities of superoxide dismutase and three forms of peroxidase, and a lower catalase activity. Constitutive level of polyamines in roots was higher than in leaves. In both leaves and roots during first 24 h, the polyamine content declined but spermidine remained to be a predominant polyamine. The analysis of differential expression of the genes encoding enzymes of polyamine biosynthesis demonstrated certain differences in these plant organs. The changes in expression of genes MET1, SPMS1, and SPMS2 were observed in roots, whereas in leaves expression of MET1, SAMDC1, SPDS1, and SPMS1 was altered. These changes are possibly one of the mechanisms responsible for the regulation of polyamine endogenous level under salinity. In contrast to leaves, in roots, the oxidative degradation of spermidine by polyamine oxidase can take part in the regulation of endogenous spermidine level. Taken together, these findings allowed us to conclude that, unlike leaves, the roots of P. major under salinity conditions possessed a higher activity of the antioxidant system protecting plants from injurious action of oxidative stress, thereby providing survival of this plant species under stress conditions. Published in Russian in Fiziologiya Rastenii, 2009, Vol. 56, No. 3, pp. 359–368. This text was submitted by the authors in English.