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81.
以矿区筛选抗性黑曲霉(Aspergillus niger TL-F2)为材料,研究不同浓度(50、100、150、200、250、300 mg·L-1)Cu(Ⅱ)对不同生长阶段黑曲霉谷胱甘肽系统(GSH/GPx)的影响。结果显示:随着Cu(Ⅱ)浓度增大,A.niger TL-F2生长量、可溶性蛋白含量呈降低趋势,丙二醛(MDA)含量则增加;谷胱甘肽系统中还原型谷胱甘肽(GSH)含量呈现上升趋势,而氧化型谷胱甘肽(GSSG)、谷胱甘肽过氧化物酶(GPx)和谷胱甘肽还原酶(GR)活力则呈现先增后降趋势;在金属浓度为150 mg·L-1时GSSG含量达到最大为365.68 μmol·L-1,GPx和GR活力分别在金属浓度为100 mg·L-1时达到峰值,GSH/GSSG比值也随Cu(Ⅱ)浓度和处理时间的增加呈下降趋势。结果表明:在Cu(Ⅱ)作用下A.niger TL-F2菌体内GSH/GPx系统产生氧化应激反应,通过调节GSH、GSSG、GPx和GR的增减来抵御过量活性氧(ROS)胁迫;GSH/GSSG比值也可直观地反映Cu(Ⅱ)对A.niger TL-F2毒性大小。 相似文献
82.
Response of Glutathione and Glutathione S-transferase in Rice Seedlings Exposed to Cadmium Stress 总被引:3,自引:0,他引:3
A hydroponic culture experiment was done to investigate the effect of Cd stress on glutathione content(GSH)and glutathione S-transferase(GST,EC 2.5.1.18)activity in rice seedlings.The rice growth was severely inhibited when Cd level in the solution was higher than 10 mg/L.In rice shoots,GSH content and GST activity increased with the increasing Cd level,while in roots,GST was obviously inhibited by Cd treatments.Compared with shoots,the rice roots had higher GSH content and GST activity,indicating the ability of Cd detoxification was much higher in roots than in shoots.There was a significant correlation between Cd level and GSH content or GST activity,suggesting that both parameters may be used as biomarkers of Cd stress in rice. 相似文献
83.
Premysl Mikula Jana Blahova Marcela Havelkova Martin Hulak 《Pesticide biochemistry and physiology》2009,93(1):13-89
The aim of the study was to evaluate the effect of subchronic exposure to the herbicide LASSO MTX (alachlor 42% W/V) on biometric parameters and important liver biomarkers in the common carp (Cyprinus carpio). One year old fish were exposed for 28 days to LASSO MTX added to the tank water at concentrations of 240 and 2400 μg L−1. The exposure did not affect fish biometric parameters. Glutathione-S-tranferase (GST) activity in liver (hepatopancreas) remained unchanged in exposed fish when compared to controls. However, significant induction of total cytochrome P 450 (CYP 450), ethoxyresorufin-O-deethylase (EROD) activity and elevated glutathione (GSH) in liver of exposed fish were detected. 相似文献
84.
Aflatoxin, the secondary metabolite of Aspergillus flavus and A. parasiticus, is the most toxic product in nature. In this study, N-acetylcysteine (NAC), ascorbate, and H2O2 were used to ascertain their effects on fungal metabolic response of A. flavus. The results demonstrated that NAC did not affect fungal growth, but inhibited the aflatoxin Bt production, with the concomitant sporulation reduction. NAC increased the ratio of reduced glutathione (GSH) and oxidized glutathione (GSSG), but decreased the activity of glutathione reductase (GR). Ascorbate had similar effect on fungal growth, sporulation, and GR activity, but GSH/GSSG and total glutathione (tGSH, including GSH and GSSG) were significantly increased. H2O2 at high concentration (5 mM) inhibited fungal growth, but the aflatoxin production was increased. At the same time, it reduced GR activity and enhanced tGSH. Though reductive agents had different effects on GSH metabolism, reductive conditions inhibited aflatoxin production and sporulation without any effect on fungal growth. The results in this report confirmed that the relationship between oxidative stress and aflatoxin production is theoretically important in controlling aflatoxin contamination. 相似文献
85.
D. Every 《Journal of Cereal Science》1999,30(3):245
White flour from wheat was shown to contain basic-ascorbate oxidase (AOX) enzymes (pI 7·6–9·6) and acidic-AOX enzymes (pI 5·1–6·6) in a ratio of 0·4:1, based on chromatography data. Immature wheat kernels (two weeks post-anthesis) contained about 12 times more AOX activity (units/g dry weight) than flour from mature grain, and the ratio of basic- to acidic-AOX was 5:1. Acidic-AOX was purified 90-fold from flour by hydrophobic interaction, gel filtration and anion exchange chromatography. Basic-AOX was purified 20 000-fold from immature wheat by hydrophobic interaction, anion exchange, cation exchange and gel filtration chromatography in a yield of 5%. The acid-AOX had a M of 140 k, was optimally active at pH 6·3 and 40 °C, and was stable in the pH range 5–9 and at 30 °C for 0·5 h at pH 6·2. The Km values were 0·26 m
for L-ascorbic acid and 0·93 m
for D-iso ascorbic acid. The basic-AOX had a M of 139 k and subunit M of 72 k. The enzyme was optimally active at pH 6·2 and 50 °C, and was stable in the pH range 5–9 and at 40 °C for 0·5 h at pH 6·2. The Km values were 0·30 m
for L-ascorbic acid and 0·53 m
for D-iso ascorbic acid. The absorption spectrum of basic-AOX had absorption maxima at 280 nm and 607 nm of similar magnitude to those measured in AOX fromCucurbita species (squash). This indicates that wheat AOX contains protein-bound copper similar to other plant AOX. 相似文献
86.
抗性和敏感小菜蛾谷胱甘肽-S-转移酶和谷胱甘肽的比较 总被引:2,自引:0,他引:2
研究了抗性和敏感小菜蛾谷胱甘肽 - S-转移酶 ( GSTs)在不同发育期的变化及有机磷类杀虫剂对虫体谷胱甘肽 ( GSH)质量摩尔浓度的影响 .结果表明 :抗性和敏感小菜蛾 GSTs比活力在各发育期中变化不大 ,但虫体 GSTs总活力随虫体生长发育而显著增加 ,在 4龄和蛹期达到最大值 .抗性小菜蛾 GSTs活力明显高于敏感小菜蛾 .甲胺磷和水胺硫磷对敏感小菜蛾幼虫 GSH影响不明显 ,但可导致抗性小菜蛾 GSH质量摩尔浓度的显著降低 .因此可以认为 ,GSTs活力增高和 GSH的结合作用应是小菜蛾对有机磷类杀虫剂抗性的重要机制 . 相似文献
87.
Oxidative Stress and Antioxidants in Wheat Genotypes: Possible Mechanism of Water Stress Tolerance 总被引:8,自引:0,他引:8
The role of plant antioxidant systems in water stress tolerance was studied in three contrasting wheat genotypes. Water stress imposed at different stages after anthesis resulted in an increase in lipid peroxidation and a decrease in membrane stability and chlorophyll and carotenoid contents. The antioxidant enzymes ascorbate peroxidase, glutathione reductase and non-specific peroxidase also increased significantly under water stress. Genotype PBW 175, which had highest ascorbate peroxidase, glutathione reductase and peroxidase activity, had the lowest lipid peroxidation (malondialdehyde content) and highest membrane stability and contents of chlorophyll and carotenoids under water stress, while the susceptible genotype WH 542 exhibited the lowest antioxidant enzyme activity, membrane stability and contents of chlorophyll and carotenoids and the highest lipid peroxidation. Genotype HD 2402 showed intermediate behaviour. It seems that drought tolerance of PBW 175, as represented by higher membrane stability and chlorophyll and carotenoid contents and lower lipid peroxidation, is related to its higher antioxidant enzyme activity. 相似文献
88.
An attempt was made to examine the possible connection between the various ratios of calcium/aluminum (Ca/Al) in the nutrient
solution of plant cultures and the active oxygen scavenging system of hinoki cypress (Chamaecyparis obtusa) seedlings. The hinoki cypress seedlings were transferred to nutrient solutions containing 5 mM AlCl3 together with various concentrations of Ca(NO3)2 in pots containing glass beads and Teflon tips. The activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase
(APX) and glutathione reductase (GR) in the needles were estimated at several stages during the 7-day treatment. The samples
treated with the lower Ca/Al solutions show the highest SOD activities. The activities of APX and GR, both of them involved
in the ascorbate-glutathione cycle, showed the same tendency with decrease to higher Ca/Al ratio. These results indicate that
rhizospheric Ca might compete with Al and ameliorate Al toxicity on and in the roots, the Al stress is not transformed to
the needles after a few days, and the ascorbate-glutathione cycle in the hinoki cypress needles might fluctuate and be suppressed
by the rhizospheric Al stress during the 7 days.
This work was supported in part by funding from the Japan Science & Technology Corporation, the CREST program 1996–2001, and
the Center for Forest Decline Studies. 相似文献
89.
不同来源硒对异育银鲫的生物学效应研究 总被引:1,自引:0,他引:1
以异育银鲫为试验动物,研究不同来源的硒(蛋氨酸硒和纳米硒)对其生长性能、肌肉生化组成和谷胱甘肽过氧化物酶活性的影响。试验分为3个处理,日粮中添加硒浓度分别为0 mg/kg(对照组)、0.5 mg/kg(蛋氨酸硒)和0.5 mg/kg(纳米硒),每个处理3个重复。结果显示,与对照组相比,蛋氨酸硒和纳米硒均可显著提高异育银鲫的末重、相对增重率以及谷胱甘肽过氧化物酶活性(P<0.05),但是蛋氨酸硒处理组和纳米硒处理组间差异不显著。纳米硒处理组肌肉中硒含量显著高于其他两组(P<0.05),蛋氨酸硒处理组肌肉中硒含量显著高于对照组(P<0.05)。研究表明,饵料中添加一定浓度的蛋氨酸硒和纳米硒具有一定的生物学效应。 相似文献
90.
为了探讨草莓中单脱氢抗坏血酸还原酶(Monodehydroascorbate reductase,MDHAR)和谷胱甘肽还原酶(Glutathione reductase,GR)基因的功能,采用同源克隆的方法从‘丰香’草莓中克隆得到cDNA全长序列,并采用实时定量PCR方法对其在不同组织和不同发育阶段果实中的表达模式进行分析。结果表明:草莓MDHAR基因cDNA(FaMDHAR,GenBank登录号:KP025946)全长1 305 bp,编码434个氨基酸,分子量约为47 kD,含有保守的FAD结合结构域,定位于细胞质中。GR基因cDNA(FaGR,GenBank登录号:JQ339738)开放阅读框全长1 491 bp,编码496个氨基酸,分子量为53 kD,定位于细胞质中。FaMDHAR在各组织中均有表达,在成熟果实中表达量最高,叶和花次之,根中最低;在果实发育过程中FaMDHAR在绿果期有相对较高的表达,随后急剧增加,到白熟期最高,之后下降并维持在相对稳定水平。FaGR在叶和花中表达较高,在成熟果实中较低;在果实发育过程中,表达量从小绿期呈现增加趋势,至转红果期达最高,随后逐渐下降,在成熟果实中较低。果实发育过程中酶活性变化呈现出与各自基因表达量相似的变化规律。经过4 ℃低温处理24 h后的草莓叶片中,FaMDHAR相对表达量较对照显著增加,而FaGR无显著变化。草莓中FaMDHAR和FaGR表达存在时空差异,并对低温逆境响应存在差异。 相似文献