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hCG treatment raises H<Subscript>2</Subscript>O<Subscript>2</Subscript> levels and induces germ cell apoptosis in rat testis 总被引:1,自引:0,他引:1
Gautam DK Misro MM Chaki SP Chandra M Sehgal N 《Apoptosis : an international journal on programmed cell death》2007,12(7):1173-1182
The clinical significance of exogenous hCG treatment is to stimulate steroidogenesis and spermatogenesis in the testis. However,
the pathogenesis of detrimental effects on the testis arising out of chronic hCG treatment is yet to be clearly ascertained.
In the present study we have shown that hCG treatment (100 IU/day) to rats for 30 days raises testicular oxidative stress
leading to germ cell apoptosis and impairment of spermatogenesis. The treatment raises testicular H2O2 levels along with increase in lipid peroxidation and concomitant decrease in the enzymatic antioxidant activities like superoxide
dismutase, catalase and glutathione-s-transferase. The rise in the number of apoptotic germ cells was associated with up regulation
of Fas protein expression and caspase-3 activity in the testis. However, serum testosterone which was elevated by 15 days
of hCG treatment declined to pretreatment levels by 30 days. No significant alteration in serum gonadotropins was observed.
The above findings indicate that the pathogenesis of deleterious effects following chronic hCG treatment is due to increase
in testicular oxidative stress with high H2O2 availability leading to apoptosis among germ cells. 相似文献
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The effects of Ca(NO3)2 stress on biomass production, oxidative damage, antioxidant enzymes activities and polyamine contents in roots of grafted
and non-grafted tomato plants were investigated. Results showed that when exposed to 80 mM Ca(NO3)2 stress, the biomass production reduction in non-grafted plants was more significant than that of grafted plants. Under Ca(NO3)2 stress, superoxide anion radical (O2•−) producing rate, hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents of non-grafted plants roots were significantly higher than those of grafted plants, however,
nitrate (NO3
−), ammonium (NH4
+) and proline contents, superoxide dismutase (SOD, EC1.15.1.1), peroxidase (POD, EC1.11.1.7), catalase (CAT, EC1.11.1.6) and
arginine decarboxylase (ADC, EC 4.1.1.19) activities of grafted plants roots were significantly higher than those of non-grafted
plants. Regardless of stress, free, conjugated and bound polyamine contents in roots of grafted plants were significantly
higher than those of non-grafted plants. The possible roles of antioxidant enzymes, prolines and polyamines in adaptive mechanism
of tomato roots to Ca(NO3)2 stress were discussed.
Gu-Wen Zhang and Zheng-Lu Liu contributed equally to this work. 相似文献
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The chickpea genotype, CSG-8962 was raised in screenhouse to study salinity induced changes in ethylene evolution, antioxidative defence system and membrane integrity in relation to changes in plant water and mineral content. At vegetative stage (60 d after sowing), the plants were exposed to single saline irrigation (0, 2.5, 5.0 and 10.0 dS m–1). Sampling was done 3 d after saline treatments. The other sets of treated plants were re-irrigated with water and sampled after further 3 d. The w of leaf and s of leaf and roots decreased from –0.47 to –0.61 MPa, –0.67 to –1.23 MPa and from –0.57 to –0.95 MPa, respectively, with increasing salinity. Similarly, RWC of leaf and roots reduced from 87.5 to 72.3 % and 96.7 to 84.35 %, respectively. The decline in s of roots was mainly due to accumulation of proline and total soluble sugar. With salinity, increase in ethylene evolution, 1-aminocyclopropane-1-carboxylic acid (ACC) content and ACC oxidase activity was reported. Similarly, marked increase in H2O2 content (20 – 182 %) and lipid peroxidation (43 – 170 %) was observed. The defense mechanism activated in roots was confirmed by the increased activities of superoxide dismutase (SOD), peroxidase (POX), ascorbate peroxidase (APX), glutathione transferase (GTase), glutathione reductase (GR) and catalase (CAT) but ascorbic acid (AA) content was decreased. About 3-fold increase in Na+/K+ ratio and 2.5 fold increase in Cl– content was observed. Upon desalinization, a partial recovery was observed in most of the parameters studied. 相似文献
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Chao Su Liu Liu Haipei Liu Brett J. Ferguson Yanmin Zou Yankun Zhao Tao Wang Youning Wang Xia Li 《Journal of Plant Biology》2016,59(3):260-270
The accumulation and redistribution of the plant hormone auxin plays a crucial role in root development and patterning. Plants can alter their root system architecture (RSA) to adapt to different biotic and abiotic stresses. In addition, reactive oxygen species (ROS), such as H2O2, are known to increase in plants undergoing stress. Here, we present evidence that H2O2 can regulate auxin accumulation and redistribution through modulating polar auxin transport, leading to changes in RSA. Plants exposed to different concentrations of H2O2 formed a highly branched root system with abundant lateral roots and a shorter primary root. Monitoring of the auxin responsive DR5::GUS indicated that auxin accumulation decreased in lateral root primordia (LRP) and emerging lateral root tips. In addition, polar auxin transport, including both basipetal and acropetal transport modulated by AUX1 and PIN protein carriers, was involved in the process. Taken together, our results suggest that H2O2 could regulate plastic RSA by perturbing polar auxin transport as a means of modulating the accumulation and distribution of auxin. 相似文献
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The effect of Al stress on H2O2 production of rice (Oryza sativa L.) seedlings and difference in responses of antioxidant enzymes between Al-tolerant variety (Azucena) and Al-sensitive rice
one (IR 64) were investigated. Aluminum-induced H2O2 production and malondialdehyde (MDA) content were more pronounced for IR 64 than for Azucena. In the presence of 2 mM Al,
addition of 10 mM imidazole (inhibitor of NADPH oxidase) and 1 mM azide (inhibitor of peroxidase) significantly decreased
H2O2 production by 16% and 43% for Azucena, and 21% and 68% for IR 64, respectively. Under Al treatment, the Al-tolerant variety
Azucena had significantly higher activities of catalase, ascorbate peroxidase, dehydroascorbate reducase, glutathione peroxidase
and glutathione reductase, and higher concentrations of reduced glutathione than the Al-sensitive one IR 64. Treatment with
buthionine sulfoximine, a specific inhibitor of GSH synthesis, significantly increased H2O2 production in both varieties in the presence and absence of Al. In contrast, the treatment with GSH significantly decreased
the production of H2O2 induced by Al stress. Results suggest that GSH may play an important role in scavenging H2O2 caused by Al stress. 相似文献
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Barley seedlings were pre-treated with 1 and 5 μM H2O2 for 2 d and then supplied with water or 150 mM NaCl for 4 and 7 d. Exogenous H2O2 alone had no effect on the proline, malondialdehyde (MDA) and H2O2 contents, decreased catalase (CAT) activity and had no effect on peroxidase (POX) activity. Three new superoxide dismutase
(SOD) isoenzymes appeared in the leaves as a result of 1 μM H2O2 treatment. NaCl enhanced CAT and POX activity. SOD activity and isoenzyme patterns were changed due to H2O2 pre-treatment, NaCl stress and leaf ageing. In pre-treated seedlings the rate of 14CO2 fixation was higher and MDA, H2O2 and proline contents were lower in comparison to the seedlings subjected directly to NaCl stress. Cl− content in the leaves 4 and 7 d after NaCl supply increased considerably, but less in pre-treated plants. It was suggested
that H2O2 metabolism is involved as a signal in the processes of barley salt tolerance. 相似文献
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The effect of foliar pretreatment by hydrogen peroxide (H2O2) at low concentrations of 0, 5, 10, and 15 mM on the chilling tolerance of two Zoysia cultivars, manilagrass (Zoysia matrella) and mascarenegrass (Zoysia tenuifolia), was studied. The optimal concentration for H2O2 pretreatment was 10 mM, as demonstrated by the lowest malondialdehyde (MDA) content and electrolyte leakage (EL) levels and
higher protein content under chilling stress (7°C/2°C, day/night). Prior to initiation of chilling, exogenous 10 mM H2O2 significantly increased catalase (CAT), ascorbate peroxidase (APX), glutathione-dependent peroxidases (GPX), and glutathione-S-transferase (GST) activities in manilagrass, and guaiacol peroxidase (POD), APX, and glutathione reductase (GR) activities
in mascarenegrass, suggesting that H2O2 may act as a signaling molecule, inducing protective metabolic responses against further oxidative damage due to chilling.
Under further stress, optimal pretreatments alleviated the increase of H2O2 level and the decrease of turfgrass quality, and improved CAT, POD, APX, GR, and GPX activities, with especially significant
enhancement of APX and GPX activities from the initiation to end of chilling. These antioxidative enzymes were likely the
important factors for acquisition of tolerance to chilling stress in the two Zoysia cultivars. Our results showed that pretreatment with H2O2 at appropriate concentration may improve the tolerance of warm-season Zoysia grasses to chilling stress, and that manilagrass had better tolerance to chilling, as evaluated by lower MDA and EL, and
better turfgrass quality, regardless of the pretreatment applied. 相似文献
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It was shown that tobacco leaf treatment with 100 mM H2O2 increased their content of endogenous H2O2 and activities of catalase and hydrolases (acid phosphatase, proteases, and RNase) and also caused various changes in the cell structure. In this case, programmed cell death (PCD) occurred in some cells, which was observed as chromatin condensation, cytoplasm collapse, etc. In the meantime, many cells displayed organelle activation rather than PCD. It is suggested that cells that undergo H2O2-dependent PCD release signaling molecules inducing protective mechanisms against oxidative stress in neighboring cells not exhibiting PCD. 相似文献
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S. Saeidi-Sar R. A. Khavari-Nejad H. Fahimi M. Ghorbanli A. Majd 《Russian Journal of Plant Physiology》2007,54(1):74-79
The effects of nickel in combination with ascorbic acid (AsA) and gibberellin on 7-day-old soybean seedlings were examined.
Exposure to 0.25 mM NiCl2 × 6H2O for 5 days resulted in toxicity symptoms, such as formation of reddish-brown mottled spots on the leaf blade. Addition of
0.05 mM GA3 or 1 mM AsA reduced toxic effects of nickel. After their simultaneous application, these symptoms did not appear. Ni decreased
dry weights of roots and shoots and reduced chlorophyll content in leaves. An enhanced level of lipoxygenase activity and
malondialdehyde, and changes in the activities of the antioxidant enzymes, catalase, guaiacol peroxidase and ascorbate peroxidase,
in both roots and leaves indicated that Ni caused an oxidative stress in soybean plants. The Ni-stressed seedlings exposed
to AsA or GA3, especially to GA3 plus AsA, exhibited an improved growth as compared to Ni-treated plants. GA3 decreased Ni uptake by roots, while ascorbic acid considerably reduced root-to-shoot translocation of Ni. Interaction of
AsA plus GA3 prevented the decrease in chlorophyll content and lipid peroxidation as well as increased the activities of the antioxidant
enzymes. These results suggest that GA3 plus AsA treatment counteracts the negative effects of Ni on soybean seedlings.
Published in Russian in Fiziologiya Rastenii, 2007, Vol. 54, No. 1, pp. 85–91.
The text was submitted by the authors in English. 相似文献
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The aim of the present studies was to compare H2O2 and ascorbate contents as well as peroxidase (PO) and catalase (CAT) activities in leaves of less susceptible cultivar Perkoz
and more susceptible Corindo after B. cinerea infection.
Increase in H2O2 contents in both Perkoz and Corindo cytosol was observed, however, it appeared earlier in the less susceptible cultivar.
The increase in PO activity in the cytosol fraction was observed 48 hours after infection in both cultivars but it was greater
in the less susceptible Perkoz. No significant differences between the tested cultivars were observed in ascorbate peroxidase
(APX) activity and in reduced and oxidated ascorbate contents. PO activity was thoroughly analyzed in the apoplast fraction.
It was measured with syringaldazine (S), tetramethylbenzidine (TMB) and ferulic acid (FA)—substrates characteristic of isoenzymes
involved in lignification and stiffening of a cell wall. Increase in PO activity with these substrates was observed earlier
in cultivar Perkoz than in cultivar Corindo. Similarly, increase in PO activity with NADH appeared significantly earlier in
cultivar Perkoz. Apoplastic PO was separated with DEAE Sepharose and two fractions binding and non-binding were obtained.
Binding PO fraction was significantly more active especially with S, TMB and NADH after B. cinerea infection. The increase in the enzyme activity was mostly observed in cultivar Perkoz. Binding PO was separated by electrophoresis
on acrylamide gel and revealed six enzymatic forms from which three were much more active after infection in cultivar Perkoz.
The obtained results suggest that cell wall strengthening mediated by apoplast PO is a key factor responsible for different
resistance of tomato cultivars Perkoz and Corindo to B. cinerea infection. 相似文献
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The development of nanotechnologies has increased the amount of manufactured metal oxide nanoparticles in the environment. In the view of nanoparticle dispersion to the environment, assessment of their toxicity becomes very crucial. Aluminum oxide (Al2O3) nanoparticles have wide range of use in industry as well as personal care products. The aim of this study was to evaluate the dose dependent effects of 13-nm-sized Al2O3 nanoparticles on wheat correlating with the appearance of enzymatic and non-enzymatic antioxidant defense response. Wheat roots were exposed to different concentrations of Al2O3 nanoparticles (5, 25 and 50 mg mL?1) for 96 h. The effects of Al2O3 nanoparticles were studied using different parameters such as H2O2 content, superoxide dismutase and catalase activity, lipid peroxidation, total proline, photosynthetic pigment and anthocyanin content. The results indicated that while Al2O3 nanoparticles caused a dose dependent increase in H2O2 content, superoxide dismutase activity, lipid peroxidation and proline contents, the catalase activity was decreased in compare the control. Moreover, total chlorophyll, chlorophyll a, carotenoids and anthocyanin contents reduced in the highest concentration 50 mg mL?1. In conclusion, Al2O3 nanoparticles caused oxidative stress in wheat after 96 h. 相似文献
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Sha Luo Tao Luo Peng Peng Yanping Li Xiaogang Li 《Plant Cell, Tissue and Organ Culture》2016,127(3):729-737
Reactive oxygen species (ROS) and calcium (Ca2+), two crucial intracellular signaling molecules, have been reported to play important roles in chlorophyll biosynthesis. In this study, we aimed to investigate whether disturbance of chlorophyll synthesis affects chloroplast ROS and Ca2+ homeostases. Chlorophyll biosynthesis was inhibited at the Mg branch by virus-induced gene silencing (VIGS) of CHLI gene encoding the Mg chelatase CHLI subunit in pea (Pisum sativum). Subsequently, ROS and intracellular free Ca2+ concentration ([Ca2+]i) in these chlorophyll-deficient pea plants were evaluated by histochemical and fluorescent staining assays. The results showed that the superoxide anion and hydrogen peroxide were predominantly generated in chloroplasts of the yellow leaves of pea VIGS-CHLI plants. The expression of genes encoding chloroplast antioxidant enzymes (CuZn-superoxide dismutase, ascorbate peroxidase, glutathione reductase, phospholipid glutathione peroxidase, peroxiredoxin and thioredoxins) were also decreased in the leaves of VIGS-CHLI plants compared with the control plants. Additionally, the [Ca2+]i were significantly reduced in the yellow leaves of VIGS-CHLI plants compared with the green leaves of VIGS-GFP control plants. The expression of genes encoding Ca2+ signaling related proteins (thylakoid Ca2+ transporter, calmodulins and calcineurin B-like protein) was down-regulated in yellow VIGS-CHLI leaves. These results indicate that inhibition of chlorophyll biosynthesis at the Mg branch by silencing CHLI affects chloroplast ROS homeostasis and Ca2+ signaling and down-regulates the expression of ROS scavenging genes and Ca2+ signaling related genes. 相似文献
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The changes in lipid peroxidation, antioxidative and lignifying enzyme activities were studied in leaves and stems of Cu-stressed
sunflower seedlings. In both organs, membrane lipid peroxidation was enhanced by copper treatment. Additionally, catalase
(EC 1.11.1.6) and superoxide dismutase (EC 1.15.1.1) activities were modulated: The activity of superoxide dismutase was enhanced
in both plant organs. Differently, catalase activity was not affected in leaves but significantly reduced in stems. Peroxidase
(EC 1.11.1.7) activities were also changed. Guaiacol peroxidase activity was increased in leaves and stems. In the same way,
electrophoretic analysis of the anionic isoperoxidases involved in lignification (syringaldazine peroxidase) revealed qualitative
and quantitative changes on the isoenzyme patterns. These modifications were accompanied by the increase of the NADH-oxidase
activity in ionically cell wall bound fraction. It appeared that the growth delay caused by copper excess could be related
to the activation of lignifying peroxidases. 相似文献
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Qing-Lin Liu Ke-Dong Xu Nan Ma Li Zeng Liang-Jun Zhao 《Molecular biology reports》2010,37(2):1137-1142
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Kun Yan Wei Chen Guoyou Zhang Sheng Xu Zhouli Liu Xingyuan He Lanlan Wang 《Acta Physiologiae Plantarum》2010,32(2):375-385
Using open top chambers, the effects of elevated O3 (80 nmol mol−1) and elevated CO2 (700 μmol mol−1), alone and in combination, were studied on young trees of Quercus mongolica. The results showed that elevated O3 increased malondialdehyde content and decreased photosynthetic rate after 45 days of exposure, and prolonged exposure (105 days)
induced significant increase in electrolyte leakage and reduction of chlorophyll content. All these changes were alleviated
by elevated CO2, indicating that oxidative stress on cell membrane and photosynthesis was ameliorated. After 45 days of exposure, elevated
O3 stimulated activities of superoxide dismutase (SOD, EC 1.15.1.1) and ascorbate peroxidase (APX, EC 1.11.1.11), but the stimulation
was dampened under elevated CO2 exposure. Furthermore, ascorbate (AsA) and total phenolics contents were not higher in the combined gas treatment than those
in elevated O3 treatment. It indicates that the protective effect of elevated CO2 against O3 stress was achieved hardly by enhancing ROS scavenging ability after 45 days of exposure. After 105 days of exposure, elevated
O3 significantly decreased activities of SOD, catalase (CAT, EC 1.11.1.6) and APX and AsA content. Elevated CO2 suppressed the O3-induced decrease, which could ameliorate the oxidative stress in some extent. In addition, elevated CO2 increased total phenolics content in the leaves both under ambient O3 and elevated O3 exposure, which might contribute to the protection against O3-induced oxidative stress as well. 相似文献
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Brassinosteroids (BRs) can effectively alleviate the oxidative stress caused by Ca(NO3)2 in cucumber seedlings. The root system is an essential organ in plants due to its roles in physical anchorage, water and nutrient uptake, and metabolite synthesis and storage. In this study, 24-epibrassinolide (EBL) was applied to the cucumber seedling roots under Ca(NO3)2 stress, and the resulting chemical and anatomical changes were characterized to investigate the roles of BRs in alleviating salinity stress. Ca(NO3)2 alone significantly induced changes in the components of cell wall, anatomical structure, and expression profiles of several lignin biosynthetic genes. Salt stress damaged several metabolic pathways, leading to cell wall reassemble. However, EBL promoted cell expansion and maintained optimum length of root system, alleviating the oxidative stress caused by Ca(NO3)2. The continuous transduction of EBL signal thickened the secondary cell wall of casparian band cells, thus resisting against ion toxicity and maintaining water transport. 相似文献
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Effects of exogenous salicylic acid (SA) on plant growth, contents of Na, K, Ca and Mg, activities of superoxide dismutase
(SOD), guaiacol peroxidase (GPX), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR)
and catalase (CAT), and contents of ascorbate and glutathione were investigated in tomato (Lycopersicon esculentum L.) plants treated with 100 mM NaCl. NaCl treatment significantly increased H2O2 content and lipid peroxidation indicated by accumulation of thiobarbituric acid reactive substances (TBARS). A foliar spray
of 1 mM SA significantly decreased lipid peroxidation caused by NaCl and improved the plant growth. This alleviation of NaCl
toxicity by SA was related to decreases in Na contents, increases in K and Mg contents in shoots and roots, and increases
in the activities of SOD, CAT, GPX and DHAR and the contents of ascorbate and glutathione. 相似文献