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141.
142.
Cd、Cu和Pb复合污染对蚯蚓抗氧化酶活性的影响 总被引:3,自引:0,他引:3
采用蚯蚓毒性试验和均匀组合设计(Cd:0~15 mg·kg-1,Cu:0~175 mg·kg-1,Pb:0~600 mg·kg-1)方法,以赤子爱胜蚓(Eisenia foetida)为试验蚓种,研究了土壤中重金属Cd、Cu、Pb复合污染对蚯蚓体内超氧化物歧化酶(SOD)、谷胱甘肽硫转移酶(GST)和酸性磷酸酶(AP)活性的影响,为重金属污染土壤的生物学诊断和风险评价提供科学依据.结果表明,Cd、Cu、Pb复合胁迫对蚯蚓SOD、GST和AP活性产生显著的诱导效应,酶活性与重金属含量及其持续时间密切相关:蚯蚓SOD活性在暴露前8 d因受重金属胁迫比第0 d增加了7.4%~240.5%,之后因胁迫过强被抑制,比第8 d下降了19.4%~69.7%.GST活性则在暴露前16 d持续增加了104.3%~217.3%,之后受抑制比第16 d下降了1.2%~40.3%.AP活性随时间呈"促进-抑制-促进-抑制"变化,在第8 d受胁迫比第0 d下降了9.2%~37.8%,至第16 d产生适应比第8 d增加了37.2%~117.2%,但最终因胁迫过强比第16 d下降了24.3%~34.0%.回归分析表明,Pb和Cd-Cu-Pb对SOD活性的产生影响最为显著,Cd和Cu则显著影响了GST和AP活性. 相似文献
143.
依据超氧化物歧化酶(SOD) 和过氧化氢酶(Cat) 的保守性氨基酸序列,设计简并引物,自D.radiodurans 基因组DNA扩增并克隆了SOD和Cat 基因片段.SOD 和Cat 基因片段分别长453 bp 和673 bp,各编码151和224 个氨基酸,氨基酸序列与不同生物来源的SOD或Cat 具有高度同源性 相似文献
144.
145.
BDE-47对4种海洋微藻抗氧化酶活性的影响 总被引:2,自引:1,他引:2
运用实验生态学和生物化学的方法,研究了不同质量浓度的2,2',4,4'-四溴联苯醚(BDE-47)对海水小球藻Chlorellaautotropica,牟氏角毛藻Chaetoceros muelleri,中肋骨条藻Skeletonema costatum和赤潮异弯藻Heterosigam akashiwo的抗氧化酶活性的影响.结果表明:在实验设定质量浓度范围内(0.1~2.5 μg·L~(-1)),4种微藻的超氧化物歧化酶(SOD)和过氧化氢酶(CAT)均能出现一定的应激活性,以减少BDE-47胁迫对藻细胞自身的危害,但是酶活增加的幅度却有很大不同.与赤潮异弯藻和中肋骨条藻相比,海水小球藻和牟氏角毛藻的SOD和CAT对BDE-47具有较高的敏感性.4种海洋微藻的SOD和CAT对BDE-47的敏感性顺序依次为:海水小球藻>牟氏角毛藻>中肋骨条藻>赤潮异弯藻.因此,海水小球藻的SOD和CAT可以作为指示海洋环境中BDE-47污染水平的生物标志物. 相似文献
146.
高浓度铬对凤眼莲的伤害及膜脂过氧化作用的影响 总被引:11,自引:0,他引:11
为了初步探讨在高浓度重金属胁迫下凤眼莲(Eichhornia crassipes)的生理变化,通过急性实验法从活性氧伤害角度探讨铬伤害凤眼莲的机理.结果表明,在高浓度(50ppm)铬污染下,凤眼莲叶片中SOD和CAT活性以及叶绿索α的含量明显下降,组织电解质外渗率和MDA含量明显升高,与对照值之间的差异达显著水平(P<0.05);叶片中H_2O_2含量无明显变化. 相似文献
147.
Brassinosteroid alleviates phenanthrene and pyrene phytotoxicity by increasing detoxification activity and photosynthesis in tomato 总被引:4,自引:0,他引:4
The present study was carried out to investigate the effects of exogenously applied 24-epibrassinolide (BR) on growth, gas exchange, chlorophyll fluorescence characteristics, lipid peroxidation and antioxidant systems of tomato seedlings grown under different levels (0, 10, 30, 100 and 300 μM) of phenanthrene (PHE) and pyrene (PYR) in hydroponics. A concentration-dependent decrease in growth, photosynthetic pigment contents, net photosynthetic rate (Pn), stomatal conductance (Gs), maximal quantum yield of PSII (Fv/Fm), effective quantum yield of PSII (ΦPSII), photochemical quenching coefficient (qP) has been observed following PHE and PYR exposure. By contrast, non-photochemical quenching coefficient (NPQ) was increased. PHE was found to induce higher stress than PYR. However, foliar or root application of BR (50 nM and 5 nM, respectively) alleviated all those depressions with a sharp improvement in the activity of photosynthetic machinery. The activities of guaicol peroxidase (GPOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) as well as content of malondialdehyde (MDA) were increased in a dose-dependent manner under PHE or PYR treatments. Compared with control the highest increments of GPOD, CAT, APX, GR and MDA by PHE/PYR alone treatments were observed following 300 μM concentration, which were 67%, 87%, 53%, 95% and 74% by PHE and 42%, 53%, 30%, 86% and 62% by PYR, respectively. In addition, both reduced glutathione (GSH) and oxidized glutathione (GSSG) were induced by PHE or PYR. Interestingly, BR application in either form further increased enzymatic and non enzymatic antioxidants in tomato roots treated with PHE or PYR. Our results suggest that BR has an anti-stress effect on tomato seedlings contaminated with PHE or PYR and this effect is mainly attributed by increased detoxification activity. 相似文献
148.
Potassium bromate (KBrO3) is a widely used food additive, a water disinfection by-product and a known nephrotoxic agent. The effect of KBrO3 on rat blood, especially on the anti-oxidant defense system, was studied in this work. Animals were given a single oral dose of KBrO3 (100 mg/kg body weight) and sacrificed 12, 24, 48, 96 and 168 h after this treatment. Blood was collected from the animals and separated into plasma and erythrocytes. KBrO3 administration resulted in increased lipid peroxidation, protein oxidation, hydrogen peroxide levels and decreased the reduced glutathione content indicating the induction of oxidative stress in blood. Methemoglobin levels and methemoglobin reductase activity were significantly increased while the total anti-oxidant power was greatly reduced upon KBrO3 treatment. Nitric oxide levels were enhanced while vitamin C concentration decreased in KBrO3 treated animals. The activities of major anti-oxidant enzymes were also altered upon KBrO3 treatment. The maximum changes in all these parameters were 48 h after the administration of KBrO3 and then recovery took place. These results show for the first time that KBrO3 induces oxidative stress in blood and impairs the anti-oxidant defense system. Thus impairment in the anti-oxidant power and alterations in the activities of major anti-oxidant enzymes may play an important role in mediating the toxic effects of KBrO3 in the rat blood. The study of such biochemical events in blood will help elucidate the molecular mechanism of action of KBrO3 and also for devising methods to overcome its toxic effects. 相似文献
149.
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous genotoxic environmental pollutants and potentially pose a health risk to humans. In most if not all cases, PAHs in the environment can be oxidized into their corresponding PAH-diones. This process is considered a detoxification pathway with regard to tumorigenicity. Nevertheless, photo-induced toxicological activity of PAH-diones has not been systematically investigated. In this study, we show that 27 potential environmental PAH-diones induced lipid peroxidation, in a dose (light) response manner, when irradiated with UVA at 7 and 21 J cm−2. Photoirradiation in the presence of sodium azide, deuterated methanol, or superoxide dismutase revealed that lipid peroxidation is mediated by reactive oxygen species. Electron spin resonance (ESR) spin trapping studies supported this observation. These results suggest that UVA photoirradiation of PAH-diones generates reactive oxygen species and induces lipid peroxidation. 相似文献