[Objective] The research aimed to study the correlations between catalase(CAT) and ascorbate peroxidase(ASP) and the growth and development of rice roots under cadmium stress.[Method] Taking rice variety Zhonghua ...[Objective] The research aimed to study the correlations between catalase(CAT) and ascorbate peroxidase(ASP) and the growth and development of rice roots under cadmium stress.[Method] Taking rice variety Zhonghua No.11 as materials,the changes of rice seedlings under the treatment conditions of Cd,Cd+CAT inhibitor,Cd+APX inhibitor were studied.[Result] Under Cd stress,inhibition of CAT activity caused the significant inhibition on the growth of aerial parts,decreased the number of adventitious roots and lateral roots,but it can significant promote the elongation growth of adventitious roots and lateral roots.Moreover,the length of the first lateral root from root tip on the primary roots and adventitious roots was also increased than control.When APX activity was inhibited,the growth changes of rice were similar with that treated by CAT inhibitor.[Conclusion] CAT and APX may play important roles in the regulation of rice root system growth in both non-stress and Cd-stressed rice展开更多
[Objective] This study aimed to investigate the effect of potyamine priming on physiological and biochemical variations of Lolium perenne embryos and seed germination. [Method] With annual Lolium perenne (Diamond T a...[Objective] This study aimed to investigate the effect of potyamine priming on physiological and biochemical variations of Lolium perenne embryos and seed germination. [Method] With annual Lolium perenne (Diamond T and Grazing-8000) as experimental materials, after priming with 0.5 mmol/L putrescine (Put), spermidine (Spd) and spermine (Spm) for 24 h and chilling imbibition at 5 ℃ for 12, 24, 36 and 48 h, the effect of Put, Spd and Spm priming on chilling tolerance and germination ability of annual Lolium perenne seeds during imbibition was investigated. [Result] Put, Spd and Spm priming improved the activities of peroxidase (POD), catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX) and content of soluble protein content under low temperature stress, significantly in-creased the germination rate, and shortened the average germination duration. After chilling imbibition for 48 h, compared with the control, the average germination rate of annual Lolium perenne seeds was improved by 15.5% and 12.0% after Put, Spd and Spm priming, and the average germination duration was shortened by 1.21 and 1.14 d. During seed imbibition, the chilling tolerance of Grazing-8000 was stronger than that of Diamond T. Overall, Put, Spd and Spm treatment could increase the chilling tolerance of annual Lolium perenne seeds during imbibition, and improve the germination ability of seeds under low temperature stress. [Conclusion] Results of this study provided theoretical basis for the application of seed priming technology in the production of annual ryegrass.展开更多
[Objective] This study was conducted to investigate the regulation of heat shock factor AtHsfA1a on ascorbate peroxidase under heat stress in Arabidopsis thaliana. [Method] After heat stress treatment on transgenetic ...[Objective] This study was conducted to investigate the regulation of heat shock factor AtHsfA1a on ascorbate peroxidase under heat stress in Arabidopsis thaliana. [Method] After heat stress treatment on transgenetic A. thaliana with silenced endogenetic AtHsfA1a gene and wild A. thaliana plants as materials, the change in activity of APX enzyme was analyzed by spectrophotometry, the expression level of APX gene was investigated by real-time fluorescent quantitative PCR, and the binding condition of AtHsfAla with the promoter region of APX gene was analyzed by chromatin immunoprecipitation assay. [Result] The activity and mRNA level of APX in plants with silenced endogenetic AtHsfAla gene were higher than those in wild plants. Fragments of the promoter region of APX gene were not screened from the plants with silenced endogenetic AtHsfA1a gene, but found in wild plants. [Conclusion] This study provides a theoretical basis for the understanding of the important role of AtHsfAla in resistance to stress in plant, and is of great significance to the revealing of mechanism of resistance to stress in plant.展开更多
Ascorbate peroxidases (APX), localized in the cytosol, peroxisome, mitochondria, and chloroplasts of plant cells, catalyze the reduction of H2O2 to water by using ascorbic acid as the specific electron donor. To det...Ascorbate peroxidases (APX), localized in the cytosol, peroxisome, mitochondria, and chloroplasts of plant cells, catalyze the reduction of H2O2 to water by using ascorbic acid as the specific electron donor. To determine the role of peroxisomal type ascorbate peroxidase (pAPX), an antioxidant enzyme, in protection against salt-induced oxidative stress, transgenic Arabidopsis thaliana plant carrying a pAPX gene (HvAPX1) from barley (Hordeum vulgate L.) was analyzed. The transgenic line pAPX3 was found to be more tolerant to salt stress than the wild type. Irrespective of salt stress, there were no significant differences in Na^+, K^+, Ca^2+, and Mg^2+ contents and the ratio of K^+ to Na^+ between pAPX3 and the wild type. Clearly, the salt tolerance in pAPX3 was not due to the maintenance and reestablishment of cellular ion homeostasis. However, the degree of H2O2 and lipid peroxidation (measured as the levels of malondialdehyde) accumulation under salt stress was higher in the wild type than in pAPX3. The mechanism of salt tolerance in transgenic pAPX3 can thus be explained by reduction of oxidative stress injury. Under all conditions tested, activities of superoxide, glutathione reductase, and catalase were not significantly different between pAPX3 and the wild type. In contrast, the activity of APX was significantly higher in the transgenic plant than in wild type under salt stress. These results suggested that in higher plants, HvAPX1 played an important role in salt tolerance and was a candidate gene for developing salttolerant crop plants.展开更多
Macroalgae in a littoral zone are inevitably exposed to UV-B irradiance. We analyzed the effects of UV-B on isoenzyme patterns and activities of superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and ...Macroalgae in a littoral zone are inevitably exposed to UV-B irradiance. We analyzed the effects of UV-B on isoenzyme patterns and activities of superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and ascorbate peroxidase (APX) of red algae Grateloupia filicina (Lamour.) C. Agardh. The activities of SOD, CAT, and APX changed in response to UV-B in a time- and dose-dependent manner. POX activity increased significantly under all three UV-B treatments. The enzymatic assay showed three distinct bands of SODI (Mn-SOD), SODII (Fe-SOD), and SODIII (CuZn-SOD) under a low (Luv) and medium (Muv) dose of UV-B irradiation, while SODI and SODIII activities decreased significantly when exposed to a high dose of UV-B irradiation (Huv). The activity of POX isoenzymes increased significantly after exposure to UV-B, which is consistent with the total activity. In addition, a clear decrease in activity of CATIV was detected in response to all the three doses of UV treatments. Some bands ofAPX isoenzyme were also clearly influenced by UV-B irradiation. Correspondingly, the daily growth rate declined under all the three exposure doses, and was especially significant under Muv and Huv treatments. These data suggest that, although the protection mechanisms of antioxidant defense system are partly inducible by UV-B to prevent the damage, G.filicina has incomplete tolerance to higher UV-B irradiation stress.展开更多
The antioxidative capacity of astaxanthin and enzyme activity of reactive oxygen eliminating enzymes such as superoxide dismutase (SOD),peroxidase (POD),catalase (CAT) and ascorbate peroxidase (APX) were studied in th...The antioxidative capacity of astaxanthin and enzyme activity of reactive oxygen eliminating enzymes such as superoxide dismutase (SOD),peroxidase (POD),catalase (CAT) and ascorbate peroxidase (APX) were studied in three cell types of Haematococcus pluvialis exposed to high concentrations of a superoxide anion radical (O2ˉ).The results show that defensive enzymes and astaxanthin-related mechanisms were both active in H.pluvialis during exposure to reactive oxygen species (ROS) such as Oˉ2.Astaxanthin reacted with ROS much faster than did the protective enzymes,and had the strongest antioxidative capacity to protect against lipid peroxidation.The defensive mechanisms varied significantly between the three cell types and were related to the level of astaxanthin that had accumulated in those cells.Astaxanthin-enriched red cells had the strongest antioxidative capacity,followed by brown cells,and astaxanthin-deficient green cells.Although there was no significant increase in expression of protective enzymes,the malondialdehyde (MDA) content in red cells was sustained at a low level because of the antioxidative effect of astaxanthin,which quenched Oˉ2 before the protective enzymes could act.In green cells,astaxanthin is very low or absent;therefore,scavenging of ROS is inevitably reliant on antioxidative enzymes.Accordingly,in green cells,these enzymes play the leading role in scavenging ROS,and the expression of these enzymes is rapidly increased to reduce excessive ROS.However,because ROS were constantly increased in this study,the enhance enzyme activity in the green cells was not able to repair the ROS damage,leading to elevated MDA content.Of the four defensive enzymes measured in astaxanthin-deficient green cells,SOD eliminates Oˉ2,POD eliminates H2O2,which is a by-product of SOD activity,and APX and CAT are then initiated to scavenge excessive ROS.展开更多
The response of enzyme and non-enzymatic antioxidants of Mn hyperaccumuator, Polygonum hydropiper (P. hydropiper), to Mn stress was studied using hydroponics culture experiments to explore the mechanism of Mn tolera...The response of enzyme and non-enzymatic antioxidants of Mn hyperaccumuator, Polygonum hydropiper (P. hydropiper), to Mn stress was studied using hydroponics culture experiments to explore the mechanism of Mn tolerance in this species. Results showed that both chlorophyll and carotenoid contents significantly (p〈0.05) decreased with increasing Mn treatment levels (0, 0.5, 1, 2, 4, and 8 mg/L) in hydroponics. The concentrations of malondialdehyde (MDA) and hydrogen peroxide (H202) in the root and shoot of P hydropiper were accumulated under Mn stress. Meanwhile, the anti-oxidative functions of several important enzymes, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD) in plants were stimulated by Mn spike in leaves and roots, especially at low Mn stress; while sulfhydryl group (--SH) and glutathion (GSH) were likely involved in Mn detoxification ofP. hydropiper under high Mn stress.展开更多
The present investigation was carried out to investigate the effect of heat stress and revival on some antioxidative enzymes and metabolites in leaves of the wheat (Triticum aestivum L.) seedlings of heat susceptib...The present investigation was carried out to investigate the effect of heat stress and revival on some antioxidative enzymes and metabolites in leaves of the wheat (Triticum aestivum L.) seedlings of heat susceptible (cv. WH 147 and HS 277) and heat tolerant (cv. WH 1021 and HW 2045) cultivars. Seven days old seedlings grown at 25 ℃ were exposed to 40 ℃ for 6 h and these seedlings were again brought to 25 ℃. The observations were recorded in the leaves of control, stressed and revived seedlings on 2nd and 4th day of revival. For the selection ofthermo-tolerant cultivars, screening of the thirty-six cultivars was done based on wilting of primary leaf and values of chlorophyll fluorescence. The MDA (malondialdehyde) and H2O2 concentration in leaves of wheat seedlings increased at the high temperature. There was enhancement in the activities of antioxidative enzymes, viz. CAT (catalase), POX (peroxidase), GR (glutathione reductase) and APX (ascorbate peroxidase) in leaves of the tolerant and susceptible cultivars under heat stress, however, higher percent increase was observed in tolerant cultivars. Heat stress increased the SOD (superoxide dismutase) activity in tolerant cultivars but activity declined in susceptible cultivars. On revival, the activities of the CAT, POX and GR declined in comparison to stressed seedlings but remained higher as compared to control. Ascorbate peroxidase activity remained higher on 2nd day and 4th day of revival in all the cultivars.展开更多
Reactive oxygen species (ROS) scavengers, including ascorbate peroxidase, superoxide dismutase, catalase and peroxidase, are the most commonly used biomarkers in assessing an organisms' response to many biotic and ...Reactive oxygen species (ROS) scavengers, including ascorbate peroxidase, superoxide dismutase, catalase and peroxidase, are the most commonly used biomarkers in assessing an organisms' response to many biotic and abiotic stresses. In this study, we cloned an 866 bp GST(phi) gene in Lemna minor and investigated its characteristics, expression and enzymatic activities under 75 lamol/L cadmium concentrations in comparison with other ROS scavengers. GST(phi) gene expression patterns were similar to those of other scavengers of ROS. This suggests that GST(phi) might be involved in responding to heavy metal (cadmium) stress and that its expression level could be used as a bio-indicator in monitoring cadmium pollution.展开更多
Flooding/submergence of rice fields is a severe problem in South and South-East Asia, affecting more than 20 million hectares of rice every year. Submergence creates hypoxic or anoxic condition causing poor germinatio...Flooding/submergence of rice fields is a severe problem in South and South-East Asia, affecting more than 20 million hectares of rice every year. Submergence creates hypoxic or anoxic condition causing poor germination, seedling establishment,and enormous yield loss. Standing water in the field from weeks to months also leads to significant yield losses when large part of aerial tissues is under water. For flash flooding, a rice variety FR1A3 with tolerant gene(SUB1A) was identified. SNORKEL1 and SNORKEL2 have been identified for their ability to survive deep-water flooding by rapid elongation. Submergence stress has also been reported to adversely affect cell division and damage cellular and organelle membranes. Research on antioxidative enzymes response and genes that confer tolerance to prolonged flooding is in progress. Here we review the different anoxia responsive genes and the potential involvement of antioxidative enzymes, such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase, which occur in cells of rice plant exposed to submergence stress.展开更多
Myeloperoxidase antineutrophil cytoplasmic antibody(MPO-ANCA)associated vasculitis is an autoimmune disease usually with severe multiple dysfunction syndrome,especially prominent acute renal failure.A 65-year-old woma...Myeloperoxidase antineutrophil cytoplasmic antibody(MPO-ANCA)associated vasculitis is an autoimmune disease usually with severe multiple dysfunction syndrome,especially prominent acute renal failure.A 65-year-old woman was admitted with progressive dyspnoea for six months and fever,sputum with blood,pain of the lower extremities and intermittent claudication for two days,indicating multiple organ involvement(respiratory system,blood vessels).The renal involvement was relatively mild,presenting with microscopic haematuria.The chest computed tomography demonstrated multiple pulmonary embolisms.Ultrasound and computed tomography angiography for the lower extremity vessels showed venous and arterial thrombosis.Exclusion of other diseases that can cause multiple organ damage and thrombosis,the positive perinuclear ANCA and MPO-ANCA strongly support the diagnosis of MPO-ANAC-associated vasculitis.The patient’s physical condition has been greatly improved by treatment with corticosteroids and anticoagulation.展开更多
Cyanobacterial blooms are ubiquitous in fresh and brackish eutrophic waters in India. The cyanotoxins produced by many bloom forming cyanobacteria severely affect the health of animals, fishes, birds and human beings....Cyanobacterial blooms are ubiquitous in fresh and brackish eutrophic waters in India. The cyanotoxins produced by many bloom forming cyanobacteria severely affect the health of animals, fishes, birds and human beings. Different physical and chemical factors contribute towards bloom formation. Ten bloom forming cyanobacteria were isolated from natural blooms of northern India. The strains were purified and enriched in the laboratory. The aim of this study was to understand the influence of iron on growth, pigmentation and antioxidative activity of enzymes-catalase and ascorbate peroxidase of bloom forming cyanobacteria. Results show that different strains of bloom forming cyanobacteria attain optimum growth at varied concentration of iron. The cyanobacterial strains like Synechocystis aquatalis, Merismopedia glauca, Anabaena variabilis and Anabaena iyengarii exhibit maximum growth at low iron concentration (2 pM) while some species require higher concentration of iron for their optimum growth namely, Arthrospira platensis show optimum growth at 10uM, and Nostocpaludosum shows maximum growth at 100uM concentration of iron. It was also noticed that chlorophyll and phycobiliprotein content also varies with change in iron concentration. The activity of antioxidative enzymescatalase and ascorbate peroxidase was noticed in all ten cyanobacterial strains. In the light of the findings, it seems that Arthrospira platensis possess maximum catalase and ascorbate peroxidase activity. Increment in concentration beyond optimum value leads to deterioration in the growth, pigment content and enzymatic activity of the cyanobacterial strains. Knowledge about the factors influencing growth of bloom forming cyanobacteria will help to work out ways for eradication of hazardous cyanobacterial blooms.展开更多
Salinity is the most damaging factor towards crop production. The aim of this study was to investigate the possible role of thiourea in salinity tolerance. These experiments were carried out on two maize hybrids (DK6...Salinity is the most damaging factor towards crop production. The aim of this study was to investigate the possible role of thiourea in salinity tolerance. These experiments were carried out on two maize hybrids (DK6789 and 33M15) using the optimized thiourea level (400 μM) in autumn and spring seasons, and the growth and physiological attributes were observed. Salt stress caused a substantial suppression of growth, and damaging effects were observed, as reduction in shoot and root length, their fresh and dry weights, decreased root number and shoot/root ratio, increased accumulation of H202, malondialdehyde (MDA) in root and shoot tissues, and enhancement in activities of some key antioxidant enzymes (catalase, peroxidase and superoxide dismutase) with altered ascorbate peroxidase level in leaves of both maize hybrids. Medium supplemented thiourea was found to be very effective in improving growth may be due to decreased H202, MDA and further enhanced the activities of antioxidants with higher accumulation of ascorbate peroxidase under control and saline conditions. Salinity tolerance induced by thiourea was superior in the spring than in autumn grown maize. From the changes in the growth and physiological attributes of maize, it can be concluded that thiourea application has a great potential to alleviate the deteriorating effects of salt stress on maize and is recommended for improving growth in marginally to moderately saline soils.展开更多
Female-specific serum protein(FSSP)is normally present in the sera of female fish,but it is notfound in males.However,estradiol benzoate(EB)was found to induce the appearance of FSSP inmale fish and immature female fi...Female-specific serum protein(FSSP)is normally present in the sera of female fish,but it is notfound in males.However,estradiol benzoate(EB)was found to induce the appearance of FSSP inmale fish and immature female fish.Massive doses of FSSP caused a rapid increase in FSSP.Ultrastructural examination of the liver indicated an extensive proliferation of the rough endoplasmicreticulum and a decrease in glycogen and lipid droplets after EB injection.A preparative PAGE for isolating highly purified FSSP from the serum of EB-treated fish,Carassiusauratus cuvieri(Temminck & Schlegel),is described.Purified FSSP obtained from EB-induced O-crucian fish has a molecular weight of 466,000±4,000(n=10),while that in mature female serumis 480,000±40,000(n=2).FSSP appears to be a dimer,with the size of the possible monomerbeing 240,000±8,000(n=6).SDS-PAGE on gradient gels indicated that sera from males given multiple(12)injections of EBcontain a main band with a molecular weight of 147,000±6,000(n=6).However,the same serumsamples provided three bands of protein on the PAGE gels.Antiserum was raised against the electrophoretically purified FSSP.The resulting antibody formeda single,continuous precipitation line with sera from EB-treated males and vitellogenic females,butnot with that from normal males.lmmunocytochemistry(PAP method)was used to locate FSSP in the liver and ovary of maturefemales and the liver of EB-treated males.Strongly positive particles were found clustered in groupsaround liver cell nuclei under light microscopy,and the yolk granules in the oocytes were also filledwith positive particles.展开更多
Objective: To probe into the mechanism of moxibustion preconditioning in preventive brain-protecting effect. Methods: The global brain ischemia rat model was developed by blocking 4 arteries. Seventy-eight Wistar male...Objective: To probe into the mechanism of moxibustion preconditioning in preventive brain-protecting effect. Methods: The global brain ischemia rat model was developed by blocking 4 arteries. Seventy-eight Wistar male rats were randomly divided into 5 groups: a normal control group, a sham-operation group, a brain ischemia group, a brain ischemia preconditioning group, a moxibustion pretreating group. The brains in the 5 groups were taken at 24 h, 48 h, and 72 h after operation respectively. Superoxide dismulase (SOD) activity was determined with xanthine oxidase method and malondialdehyde (MDA) content with thiobarbituric acid method. Results: After the operation, in the moxibustion preconditioning group, SOD activity significantly increased, especially 24 h after moxibustion preconditioning; and MDA content decreased, with a very significant difference as compared with that of the cerebral ischemia group (P<0.01). Conclusion: Moxibustion preconditioning protects the ischemic and anoxic brain tissue by increasing the activity of endogenous antioxidase.展开更多
Single phytotoxicity of two representative phthalate esters(PAEs),di-n-butyl phthalate(DnBP)and bis(2-ethylhexyl)phthalate(DEHP),was tested in mung bean(Vigna radiata)seedlings germinated for 72 h in soils spiked with...Single phytotoxicity of two representative phthalate esters(PAEs),di-n-butyl phthalate(DnBP)and bis(2-ethylhexyl)phthalate(DEHP),was tested in mung bean(Vigna radiata)seedlings germinated for 72 h in soils spiked with varying concentrations(0-500 mg kg^(-1)soil)of DnBP or DEHP.PAEs added at up to 500 mg kg^(-1)soil exerted no significant effect on germination but both pollutants significantly inhibited root elongation(P<0.01),DEHP inhibited shoot elongation(P<0.01)and DnBP depressed biomass on a fresh weight basis(P<0.05).Seedling shoot and root malondialdehyde(MDA)contents tended to be stimulated by DnBP but inhibited by DEHP.However,increases in superoxide dismutase,peroxidase,ascorbate peroxidase and polyphenol oxidase activities,as well as glutathione(GSH)content,were induced at higher concentrations(e.g.,20 mg kg^(-1))of both compounds.Accumulation of proline in both roots and shoots and the storage compounds,such as free amino acids and total soluble sugars,in whole plant was induced under the stress exerted by both PAEs.The general responses of mung bean seedlings indicated higher toxicity of DnBP than DEHP on primary growth,during which root elongation was a more responsive index.MDA and GSH were more sensitive parameters in the roots than in the shoots and they might be recommended as physiologically sensitive parameters to assess the toxicity of PAE compounds in soils in future long-term studies.展开更多
Salinity stress is a major factor limiting the growth of turfgrass irrigated with recycled wastewater. The change in lipid peroxidation in terms of malondialdehyde (MDA) content and the activities of superoxide dism...Salinity stress is a major factor limiting the growth of turfgrass irrigated with recycled wastewater. The change in lipid peroxidation in terms of malondialdehyde (MDA) content and the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxide (APX) and glutathione reductase (GR) in the shoots and roots of Kentucky bluegrass and tall rescue were investigated under salinity stress. Plants were subjected to 0, 50, 100, 150 and 200 mmol L-1 NaCl for 40 d. The MDA content under salinity stress was lower in tall fescue than in Kentucky bluegrass in both shoots and roots. Activities of SOD in the shoots of both species increased with salinity stress. The activities of CAT and APX decreased in Kentucky bluegrass, but no significant difference in the activities of CAT and APX was observed in tall rescue. The activities of SOD, CAT and APX in the shoots of tall fescue were higher than those in Kentucky bluegrass. In the roots of Kentucky bluegrass, SOD and GR activities increased and CAT and APX activities decreased in comparison with the control. In the roots of tall fescue, salinity increased the activities of SOD, CAT, and APX. These results suggested that tall fescue exhibited a more effective protection mechanism and mitigated oxidative stress and lipid peroxidation by maintaining higher SOD, CAT and APX activities than Kentucky bluegrass.展开更多
An 888-bp ful-length ascorbate peroxidase (APX) complementary DNA (cDNA) gene was cloned from Anthurium andraeanum, and designated as AnAPX. It contains a 110-bp 5′-noncoding region, a 28-bp 3′-noncoding region,...An 888-bp ful-length ascorbate peroxidase (APX) complementary DNA (cDNA) gene was cloned from Anthurium andraeanum, and designated as AnAPX. It contains a 110-bp 5′-noncoding region, a 28-bp 3′-noncoding region, and a 750-bp open reading frame (ORF). This protein is hydrophilic with an aliphatic index of 81.64 and its structure consisting ofα-helixes,β-turns, and random coils. The AnAPX protein showed 93%, 87%, 87%, 87%, and 86% similarities to the APX homologs from Zantedeschia aethiopica, Vitis pseudoreticulata, Gossypium hirsutum, Elaeis guineensis, and Zea mays, respectively. AnAPX gene transcript was measured non-significantly in roots, stems, leaves, spathes, and spadices by real-time polymerase chain reaction (RT-PCR) analysis. Interestingly, this gene expression was remarkably up-regulated in response to a cold stress under 6 °C, implying that AnAPX might play an important role in A. andraeanum tolerance to cold stress. To confirm this function we overexpressed AnAPX in tobacco plants by transformation with an AnAPX expression construct driven by CaMV 35S promoter. The transformed tobacco seedlings under 4 °C showed less electrolyte leakage (EL) and malondialdehyde (MDA) content than the control. The content of MDA was correlated with chilling tolerance in these transgenic plants. These results show that AnAPX can prevent the chilling challenged plant from cellmembrane damage and ultimately enhance the plant cold tolerance.展开更多
基金Supported by National Natural Science Foundation of China(30671126)~~
文摘[Objective] The research aimed to study the correlations between catalase(CAT) and ascorbate peroxidase(ASP) and the growth and development of rice roots under cadmium stress.[Method] Taking rice variety Zhonghua No.11 as materials,the changes of rice seedlings under the treatment conditions of Cd,Cd+CAT inhibitor,Cd+APX inhibitor were studied.[Result] Under Cd stress,inhibition of CAT activity caused the significant inhibition on the growth of aerial parts,decreased the number of adventitious roots and lateral roots,but it can significant promote the elongation growth of adventitious roots and lateral roots.Moreover,the length of the first lateral root from root tip on the primary roots and adventitious roots was also increased than control.When APX activity was inhibited,the growth changes of rice were similar with that treated by CAT inhibitor.[Conclusion] CAT and APX may play important roles in the regulation of rice root system growth in both non-stress and Cd-stressed rice
基金Supported by Agricultural Research Project of Guizhou Province([2010]No.3045)~~
文摘[Objective] This study aimed to investigate the effect of potyamine priming on physiological and biochemical variations of Lolium perenne embryos and seed germination. [Method] With annual Lolium perenne (Diamond T and Grazing-8000) as experimental materials, after priming with 0.5 mmol/L putrescine (Put), spermidine (Spd) and spermine (Spm) for 24 h and chilling imbibition at 5 ℃ for 12, 24, 36 and 48 h, the effect of Put, Spd and Spm priming on chilling tolerance and germination ability of annual Lolium perenne seeds during imbibition was investigated. [Result] Put, Spd and Spm priming improved the activities of peroxidase (POD), catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX) and content of soluble protein content under low temperature stress, significantly in-creased the germination rate, and shortened the average germination duration. After chilling imbibition for 48 h, compared with the control, the average germination rate of annual Lolium perenne seeds was improved by 15.5% and 12.0% after Put, Spd and Spm priming, and the average germination duration was shortened by 1.21 and 1.14 d. During seed imbibition, the chilling tolerance of Grazing-8000 was stronger than that of Diamond T. Overall, Put, Spd and Spm treatment could increase the chilling tolerance of annual Lolium perenne seeds during imbibition, and improve the germination ability of seeds under low temperature stress. [Conclusion] Results of this study provided theoretical basis for the application of seed priming technology in the production of annual ryegrass.
文摘[Objective] This study was conducted to investigate the regulation of heat shock factor AtHsfA1a on ascorbate peroxidase under heat stress in Arabidopsis thaliana. [Method] After heat stress treatment on transgenetic A. thaliana with silenced endogenetic AtHsfA1a gene and wild A. thaliana plants as materials, the change in activity of APX enzyme was analyzed by spectrophotometry, the expression level of APX gene was investigated by real-time fluorescent quantitative PCR, and the binding condition of AtHsfAla with the promoter region of APX gene was analyzed by chromatin immunoprecipitation assay. [Result] The activity and mRNA level of APX in plants with silenced endogenetic AtHsfAla gene were higher than those in wild plants. Fragments of the promoter region of APX gene were not screened from the plants with silenced endogenetic AtHsfA1a gene, but found in wild plants. [Conclusion] This study provides a theoretical basis for the understanding of the important role of AtHsfAla in resistance to stress in plant, and is of great significance to the revealing of mechanism of resistance to stress in plant.
基金a grant of CAS (Chinese Academy of Sciences) Research Program on Soil Biosystems and Agro-Product Safety (No.CXTD-Z2005-4)the Knowledge Innovation Project of CAS (No.KZCX3-SW-439).
文摘Ascorbate peroxidases (APX), localized in the cytosol, peroxisome, mitochondria, and chloroplasts of plant cells, catalyze the reduction of H2O2 to water by using ascorbic acid as the specific electron donor. To determine the role of peroxisomal type ascorbate peroxidase (pAPX), an antioxidant enzyme, in protection against salt-induced oxidative stress, transgenic Arabidopsis thaliana plant carrying a pAPX gene (HvAPX1) from barley (Hordeum vulgate L.) was analyzed. The transgenic line pAPX3 was found to be more tolerant to salt stress than the wild type. Irrespective of salt stress, there were no significant differences in Na^+, K^+, Ca^2+, and Mg^2+ contents and the ratio of K^+ to Na^+ between pAPX3 and the wild type. Clearly, the salt tolerance in pAPX3 was not due to the maintenance and reestablishment of cellular ion homeostasis. However, the degree of H2O2 and lipid peroxidation (measured as the levels of malondialdehyde) accumulation under salt stress was higher in the wild type than in pAPX3. The mechanism of salt tolerance in transgenic pAPX3 can thus be explained by reduction of oxidative stress injury. Under all conditions tested, activities of superoxide, glutathione reductase, and catalase were not significantly different between pAPX3 and the wild type. In contrast, the activity of APX was significantly higher in the transgenic plant than in wild type under salt stress. These results suggested that in higher plants, HvAPX1 played an important role in salt tolerance and was a candidate gene for developing salttolerant crop plants.
基金Supported by the National Natural Science Foundation of China(No.31300326)the Natural Science Foundation of Shandong Province(Nos.ZR2010DQ007,ZR2011CM006)
文摘Macroalgae in a littoral zone are inevitably exposed to UV-B irradiance. We analyzed the effects of UV-B on isoenzyme patterns and activities of superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and ascorbate peroxidase (APX) of red algae Grateloupia filicina (Lamour.) C. Agardh. The activities of SOD, CAT, and APX changed in response to UV-B in a time- and dose-dependent manner. POX activity increased significantly under all three UV-B treatments. The enzymatic assay showed three distinct bands of SODI (Mn-SOD), SODII (Fe-SOD), and SODIII (CuZn-SOD) under a low (Luv) and medium (Muv) dose of UV-B irradiation, while SODI and SODIII activities decreased significantly when exposed to a high dose of UV-B irradiation (Huv). The activity of POX isoenzymes increased significantly after exposure to UV-B, which is consistent with the total activity. In addition, a clear decrease in activity of CATIV was detected in response to all the three doses of UV treatments. Some bands ofAPX isoenzyme were also clearly influenced by UV-B irradiation. Correspondingly, the daily growth rate declined under all the three exposure doses, and was especially significant under Muv and Huv treatments. These data suggest that, although the protection mechanisms of antioxidant defense system are partly inducible by UV-B to prevent the damage, G.filicina has incomplete tolerance to higher UV-B irradiation stress.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (No. 2008AA09Z403)the Special Project for Marine Public Welfare Industry (No.200705010)the National Natural Science Foundation of China (No. 30771638)
文摘The antioxidative capacity of astaxanthin and enzyme activity of reactive oxygen eliminating enzymes such as superoxide dismutase (SOD),peroxidase (POD),catalase (CAT) and ascorbate peroxidase (APX) were studied in three cell types of Haematococcus pluvialis exposed to high concentrations of a superoxide anion radical (O2ˉ).The results show that defensive enzymes and astaxanthin-related mechanisms were both active in H.pluvialis during exposure to reactive oxygen species (ROS) such as Oˉ2.Astaxanthin reacted with ROS much faster than did the protective enzymes,and had the strongest antioxidative capacity to protect against lipid peroxidation.The defensive mechanisms varied significantly between the three cell types and were related to the level of astaxanthin that had accumulated in those cells.Astaxanthin-enriched red cells had the strongest antioxidative capacity,followed by brown cells,and astaxanthin-deficient green cells.Although there was no significant increase in expression of protective enzymes,the malondialdehyde (MDA) content in red cells was sustained at a low level because of the antioxidative effect of astaxanthin,which quenched Oˉ2 before the protective enzymes could act.In green cells,astaxanthin is very low or absent;therefore,scavenging of ROS is inevitably reliant on antioxidative enzymes.Accordingly,in green cells,these enzymes play the leading role in scavenging ROS,and the expression of these enzymes is rapidly increased to reduce excessive ROS.However,because ROS were constantly increased in this study,the enhance enzyme activity in the green cells was not able to repair the ROS damage,leading to elevated MDA content.Of the four defensive enzymes measured in astaxanthin-deficient green cells,SOD eliminates Oˉ2,POD eliminates H2O2,which is a by-product of SOD activity,and APX and CAT are then initiated to scavenge excessive ROS.
基金Project(41161057)supported by the National Natural Science Foundation of ChinaProject(Guikezhuan 14122008-2)supported by Guangxi Provincial Science and Technology Development,China+2 种基金Project(2014GXNSFAA118303)supported by the Natural Science Foundation of Guangxi Province,ChinaProjects(YRHJ15K002,YRHJ15Z026)supported by Key Laboratory of Karst Ecology and Environment Change of Guangxi Normal University,ChinaProject(2016JJ6135)supported by the Natural Science Foundation of Hunan Province,China
文摘The response of enzyme and non-enzymatic antioxidants of Mn hyperaccumuator, Polygonum hydropiper (P. hydropiper), to Mn stress was studied using hydroponics culture experiments to explore the mechanism of Mn tolerance in this species. Results showed that both chlorophyll and carotenoid contents significantly (p〈0.05) decreased with increasing Mn treatment levels (0, 0.5, 1, 2, 4, and 8 mg/L) in hydroponics. The concentrations of malondialdehyde (MDA) and hydrogen peroxide (H202) in the root and shoot of P hydropiper were accumulated under Mn stress. Meanwhile, the anti-oxidative functions of several important enzymes, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD) in plants were stimulated by Mn spike in leaves and roots, especially at low Mn stress; while sulfhydryl group (--SH) and glutathion (GSH) were likely involved in Mn detoxification ofP. hydropiper under high Mn stress.
文摘The present investigation was carried out to investigate the effect of heat stress and revival on some antioxidative enzymes and metabolites in leaves of the wheat (Triticum aestivum L.) seedlings of heat susceptible (cv. WH 147 and HS 277) and heat tolerant (cv. WH 1021 and HW 2045) cultivars. Seven days old seedlings grown at 25 ℃ were exposed to 40 ℃ for 6 h and these seedlings were again brought to 25 ℃. The observations were recorded in the leaves of control, stressed and revived seedlings on 2nd and 4th day of revival. For the selection ofthermo-tolerant cultivars, screening of the thirty-six cultivars was done based on wilting of primary leaf and values of chlorophyll fluorescence. The MDA (malondialdehyde) and H2O2 concentration in leaves of wheat seedlings increased at the high temperature. There was enhancement in the activities of antioxidative enzymes, viz. CAT (catalase), POX (peroxidase), GR (glutathione reductase) and APX (ascorbate peroxidase) in leaves of the tolerant and susceptible cultivars under heat stress, however, higher percent increase was observed in tolerant cultivars. Heat stress increased the SOD (superoxide dismutase) activity in tolerant cultivars but activity declined in susceptible cultivars. On revival, the activities of the CAT, POX and GR declined in comparison to stressed seedlings but remained higher as compared to control. Ascorbate peroxidase activity remained higher on 2nd day and 4th day of revival in all the cultivars.
基金Supported by the National Natural Science Foundation of China(No.31370296)the Shandong Provincial Natural Science Foundation of China(Nos.Y2007D34,ZR2011CM044)the Key Technologies R&D Program of Shandong Province of China(No.2010GNC10937)
文摘Reactive oxygen species (ROS) scavengers, including ascorbate peroxidase, superoxide dismutase, catalase and peroxidase, are the most commonly used biomarkers in assessing an organisms' response to many biotic and abiotic stresses. In this study, we cloned an 866 bp GST(phi) gene in Lemna minor and investigated its characteristics, expression and enzymatic activities under 75 lamol/L cadmium concentrations in comparison with other ROS scavengers. GST(phi) gene expression patterns were similar to those of other scavengers of ROS. This suggests that GST(phi) might be involved in responding to heavy metal (cadmium) stress and that its expression level could be used as a bio-indicator in monitoring cadmium pollution.
文摘Flooding/submergence of rice fields is a severe problem in South and South-East Asia, affecting more than 20 million hectares of rice every year. Submergence creates hypoxic or anoxic condition causing poor germination, seedling establishment,and enormous yield loss. Standing water in the field from weeks to months also leads to significant yield losses when large part of aerial tissues is under water. For flash flooding, a rice variety FR1A3 with tolerant gene(SUB1A) was identified. SNORKEL1 and SNORKEL2 have been identified for their ability to survive deep-water flooding by rapid elongation. Submergence stress has also been reported to adversely affect cell division and damage cellular and organelle membranes. Research on antioxidative enzymes response and genes that confer tolerance to prolonged flooding is in progress. Here we review the different anoxia responsive genes and the potential involvement of antioxidative enzymes, such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase, which occur in cells of rice plant exposed to submergence stress.
文摘Myeloperoxidase antineutrophil cytoplasmic antibody(MPO-ANCA)associated vasculitis is an autoimmune disease usually with severe multiple dysfunction syndrome,especially prominent acute renal failure.A 65-year-old woman was admitted with progressive dyspnoea for six months and fever,sputum with blood,pain of the lower extremities and intermittent claudication for two days,indicating multiple organ involvement(respiratory system,blood vessels).The renal involvement was relatively mild,presenting with microscopic haematuria.The chest computed tomography demonstrated multiple pulmonary embolisms.Ultrasound and computed tomography angiography for the lower extremity vessels showed venous and arterial thrombosis.Exclusion of other diseases that can cause multiple organ damage and thrombosis,the positive perinuclear ANCA and MPO-ANCA strongly support the diagnosis of MPO-ANAC-associated vasculitis.The patient’s physical condition has been greatly improved by treatment with corticosteroids and anticoagulation.
文摘Cyanobacterial blooms are ubiquitous in fresh and brackish eutrophic waters in India. The cyanotoxins produced by many bloom forming cyanobacteria severely affect the health of animals, fishes, birds and human beings. Different physical and chemical factors contribute towards bloom formation. Ten bloom forming cyanobacteria were isolated from natural blooms of northern India. The strains were purified and enriched in the laboratory. The aim of this study was to understand the influence of iron on growth, pigmentation and antioxidative activity of enzymes-catalase and ascorbate peroxidase of bloom forming cyanobacteria. Results show that different strains of bloom forming cyanobacteria attain optimum growth at varied concentration of iron. The cyanobacterial strains like Synechocystis aquatalis, Merismopedia glauca, Anabaena variabilis and Anabaena iyengarii exhibit maximum growth at low iron concentration (2 pM) while some species require higher concentration of iron for their optimum growth namely, Arthrospira platensis show optimum growth at 10uM, and Nostocpaludosum shows maximum growth at 100uM concentration of iron. It was also noticed that chlorophyll and phycobiliprotein content also varies with change in iron concentration. The activity of antioxidative enzymescatalase and ascorbate peroxidase was noticed in all ten cyanobacterial strains. In the light of the findings, it seems that Arthrospira platensis possess maximum catalase and ascorbate peroxidase activity. Increment in concentration beyond optimum value leads to deterioration in the growth, pigment content and enzymatic activity of the cyanobacterial strains. Knowledge about the factors influencing growth of bloom forming cyanobacteria will help to work out ways for eradication of hazardous cyanobacterial blooms.
文摘Salinity is the most damaging factor towards crop production. The aim of this study was to investigate the possible role of thiourea in salinity tolerance. These experiments were carried out on two maize hybrids (DK6789 and 33M15) using the optimized thiourea level (400 μM) in autumn and spring seasons, and the growth and physiological attributes were observed. Salt stress caused a substantial suppression of growth, and damaging effects were observed, as reduction in shoot and root length, their fresh and dry weights, decreased root number and shoot/root ratio, increased accumulation of H202, malondialdehyde (MDA) in root and shoot tissues, and enhancement in activities of some key antioxidant enzymes (catalase, peroxidase and superoxide dismutase) with altered ascorbate peroxidase level in leaves of both maize hybrids. Medium supplemented thiourea was found to be very effective in improving growth may be due to decreased H202, MDA and further enhanced the activities of antioxidants with higher accumulation of ascorbate peroxidase under control and saline conditions. Salinity tolerance induced by thiourea was superior in the spring than in autumn grown maize. From the changes in the growth and physiological attributes of maize, it can be concluded that thiourea application has a great potential to alleviate the deteriorating effects of salt stress on maize and is recommended for improving growth in marginally to moderately saline soils.
文摘Female-specific serum protein(FSSP)is normally present in the sera of female fish,but it is notfound in males.However,estradiol benzoate(EB)was found to induce the appearance of FSSP inmale fish and immature female fish.Massive doses of FSSP caused a rapid increase in FSSP.Ultrastructural examination of the liver indicated an extensive proliferation of the rough endoplasmicreticulum and a decrease in glycogen and lipid droplets after EB injection.A preparative PAGE for isolating highly purified FSSP from the serum of EB-treated fish,Carassiusauratus cuvieri(Temminck & Schlegel),is described.Purified FSSP obtained from EB-induced O-crucian fish has a molecular weight of 466,000±4,000(n=10),while that in mature female serumis 480,000±40,000(n=2).FSSP appears to be a dimer,with the size of the possible monomerbeing 240,000±8,000(n=6).SDS-PAGE on gradient gels indicated that sera from males given multiple(12)injections of EBcontain a main band with a molecular weight of 147,000±6,000(n=6).However,the same serumsamples provided three bands of protein on the PAGE gels.Antiserum was raised against the electrophoretically purified FSSP.The resulting antibody formeda single,continuous precipitation line with sera from EB-treated males and vitellogenic females,butnot with that from normal males.lmmunocytochemistry(PAP method)was used to locate FSSP in the liver and ovary of maturefemales and the liver of EB-treated males.Strongly positive particles were found clustered in groupsaround liver cell nuclei under light microscopy,and the yolk granules in the oocytes were also filledwith positive particles.
文摘Objective: To probe into the mechanism of moxibustion preconditioning in preventive brain-protecting effect. Methods: The global brain ischemia rat model was developed by blocking 4 arteries. Seventy-eight Wistar male rats were randomly divided into 5 groups: a normal control group, a sham-operation group, a brain ischemia group, a brain ischemia preconditioning group, a moxibustion pretreating group. The brains in the 5 groups were taken at 24 h, 48 h, and 72 h after operation respectively. Superoxide dismulase (SOD) activity was determined with xanthine oxidase method and malondialdehyde (MDA) content with thiobarbituric acid method. Results: After the operation, in the moxibustion preconditioning group, SOD activity significantly increased, especially 24 h after moxibustion preconditioning; and MDA content decreased, with a very significant difference as compared with that of the cerebral ischemia group (P<0.01). Conclusion: Moxibustion preconditioning protects the ischemic and anoxic brain tissue by increasing the activity of endogenous antioxidase.
基金Supported by the National Environmental Protection Special Fund for Scientific Research on Public Causes of China(Nos.201109018and 2010467016)
文摘Single phytotoxicity of two representative phthalate esters(PAEs),di-n-butyl phthalate(DnBP)and bis(2-ethylhexyl)phthalate(DEHP),was tested in mung bean(Vigna radiata)seedlings germinated for 72 h in soils spiked with varying concentrations(0-500 mg kg^(-1)soil)of DnBP or DEHP.PAEs added at up to 500 mg kg^(-1)soil exerted no significant effect on germination but both pollutants significantly inhibited root elongation(P<0.01),DEHP inhibited shoot elongation(P<0.01)and DnBP depressed biomass on a fresh weight basis(P<0.05).Seedling shoot and root malondialdehyde(MDA)contents tended to be stimulated by DnBP but inhibited by DEHP.However,increases in superoxide dismutase,peroxidase,ascorbate peroxidase and polyphenol oxidase activities,as well as glutathione(GSH)content,were induced at higher concentrations(e.g.,20 mg kg^(-1))of both compounds.Accumulation of proline in both roots and shoots and the storage compounds,such as free amino acids and total soluble sugars,in whole plant was induced under the stress exerted by both PAEs.The general responses of mung bean seedlings indicated higher toxicity of DnBP than DEHP on primary growth,during which root elongation was a more responsive index.MDA and GSH were more sensitive parameters in the roots than in the shoots and they might be recommended as physiologically sensitive parameters to assess the toxicity of PAE compounds in soils in future long-term studies.
基金Supported by the Global Center of Excellence for Dryland Science from the Ministry of Education,Science,Culture,Sports and Technology of Japan
文摘Salinity stress is a major factor limiting the growth of turfgrass irrigated with recycled wastewater. The change in lipid peroxidation in terms of malondialdehyde (MDA) content and the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxide (APX) and glutathione reductase (GR) in the shoots and roots of Kentucky bluegrass and tall rescue were investigated under salinity stress. Plants were subjected to 0, 50, 100, 150 and 200 mmol L-1 NaCl for 40 d. The MDA content under salinity stress was lower in tall fescue than in Kentucky bluegrass in both shoots and roots. Activities of SOD in the shoots of both species increased with salinity stress. The activities of CAT and APX decreased in Kentucky bluegrass, but no significant difference in the activities of CAT and APX was observed in tall rescue. The activities of SOD, CAT and APX in the shoots of tall fescue were higher than those in Kentucky bluegrass. In the roots of Kentucky bluegrass, SOD and GR activities increased and CAT and APX activities decreased in comparison with the control. In the roots of tall fescue, salinity increased the activities of SOD, CAT, and APX. These results suggested that tall fescue exhibited a more effective protection mechanism and mitigated oxidative stress and lipid peroxidation by maintaining higher SOD, CAT and APX activities than Kentucky bluegrass.
基金supported by the Science and Technology Key Project ofZhejiang Province(No.2009C12095)the National NaturalScience Foundation of China(No.31200527)
文摘An 888-bp ful-length ascorbate peroxidase (APX) complementary DNA (cDNA) gene was cloned from Anthurium andraeanum, and designated as AnAPX. It contains a 110-bp 5′-noncoding region, a 28-bp 3′-noncoding region, and a 750-bp open reading frame (ORF). This protein is hydrophilic with an aliphatic index of 81.64 and its structure consisting ofα-helixes,β-turns, and random coils. The AnAPX protein showed 93%, 87%, 87%, 87%, and 86% similarities to the APX homologs from Zantedeschia aethiopica, Vitis pseudoreticulata, Gossypium hirsutum, Elaeis guineensis, and Zea mays, respectively. AnAPX gene transcript was measured non-significantly in roots, stems, leaves, spathes, and spadices by real-time polymerase chain reaction (RT-PCR) analysis. Interestingly, this gene expression was remarkably up-regulated in response to a cold stress under 6 °C, implying that AnAPX might play an important role in A. andraeanum tolerance to cold stress. To confirm this function we overexpressed AnAPX in tobacco plants by transformation with an AnAPX expression construct driven by CaMV 35S promoter. The transformed tobacco seedlings under 4 °C showed less electrolyte leakage (EL) and malondialdehyde (MDA) content than the control. The content of MDA was correlated with chilling tolerance in these transgenic plants. These results show that AnAPX can prevent the chilling challenged plant from cellmembrane damage and ultimately enhance the plant cold tolerance.