氰氟草酯、杀虫安亚致死剂量对金鱼Carrasius auratus和麦穗鱼Pseudorasbora parva肝脏酯酶及谷胱甘肽-S-转移酶活性的影响

研究了 10 %千金乳油 (有效成分 :氰氟草酯 )和 78%杀虫安可溶性粉剂对金鱼和麦穗鱼肝脏酯酶及谷胱甘肽-S-转移酶 (GST)活性的亚致死剂量效应。发现杀虫安 (0 .2 34mg· L-1)对两种鱼的 GST活性均具诱导作用 ,而氰氟草酯 (1,2 mg· L-1)仅诱导了麦穗鱼的 GST活性 ;当杀虫安与氰氟草酯混合处理时 ,对麦穗鱼 GST活性的诱导效应最为明显。在一定的浓度范围内 ,氰氟草酯 (1,2 mg· L-1)和杀虫安 (0 .117,0 .2 34mg· L-1)均可诱导金鱼肝脏酯酶活性 ;对麦穗鱼肝脏酯酶而言 ,杀虫安为诱导作用 ,氰氟草酯则抑制其活性。研究结果表明 :两种酶的活性直接或间接地受供试药剂的影响 ,两种试鱼对氰氟草酯和杀虫安的生物反应存在差异。     

转sck/cry1Ac基因稻谷对米蛾幼虫解毒酶系的影响

采用酶活力测定及酯酶同工酶电泳方法研究米蛾(Corcyra cephalonica)幼虫取食表达SCK/Cry1Ac毒蛋白的转基因稻谷后体内重要解毒酶活力的变化,明确其代谢毒蛋白的主要酶类。结果表明:取食转Bt基因稻谷米蛾幼虫体内的α-乙酸萘酯酶、碱性磷酸酯酶的活力在24～72h显著低于对照;酸性磷酸酯酶活力在12、48h和72h时也显著低于对照;而α-乙酸萘酯羧酸酯酶和乙酰胆碱酯酶的活力显著高于对照。谷胱甘肽-S-转移酶的活性除饲喂24h的处理外,其他处理与对照无显著差异。此外处理72h后米蛾幼虫体内酯酶同工酶谱有4条酯酶酶带,4种酯酶Est1、Est2、Est3、Est4的活性均受到不同程度的抑制,酯酶Est4的抑制效果最明显。这些解毒酶和酯酶同工酶直接参与Bt毒蛋白的代谢作用。     

大麦品种对BYMV的抗性与过氧化物酶、酯酶的关系研究

4个不同生育期的叶片过氧化物酶活力测定呈两峰两谷现象。感病品种早期叶片过氧化物酶活力大于抗病品种,感病严重度与酶活力呈正相关。三叶期叶片同工酶电泳表明,抗病品种过氧化物酶在快带区比感病品种多1条酶带,酯酶同工酶在慢带区多1条酶带,这些酶带可作为抗性品种的特异性生化指标。分蘗期叶片过氧化物酶中有1条酶带与抗性有关。拔节期叶片有3条酯酶同工酶带、根材料中有2条分别与感病性有关。本文初步探讨了同工酶与抗病性的关系。     

苹果轮纹病菌抗戊唑醇突变体UV-TS1-10的生理生化特性

利用苹果轮纹病菌敏感菌株TS1和抗戊唑醇突变体UV-TS1-10进行了苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)活力、可溶性蛋白含量及酯酶同工酶图谱等生理生化特性的测定。经不同浓度药剂处理0~24h,抗性突变体UV-TS1-10体内PAL活性一直高于敏感菌株TS1,两者都呈现先上升后下降的趋势,并在1.5h达到最高值;抗药突变体UV-TS1-10体内POD活力也高于TS1,一直处于上升趋势,24h达到最高值时两菌株活力差异最大;UV-TS1-10体内可溶性蛋白含量为TS1的1.3倍,同一菌株在不同浓度戊唑醇处理后可溶性蛋白含量差异不大,稳定性好;抗药突变体UV-TS1-10比敏感菌株TS1的酯酶同工酶图谱少了一条Rf=0.33的谱带,多了Rf=0.14的特征性谱带,表明抗戊唑醇突变体UV-TS1-10其生理生化特性发生了较大变化。本文以研究敏、抗菌株间生理生化特性的差异为基础,探讨苹果轮纹病菌对戊唑醇可能的抗性机制,为科学地指导生产用药提供理论依据。     

稻纹枯菌酯酶同工酶、可溶性蛋白及致病力的研究初报

 对稻纹枯菌25个菌株分别进行了致病力测定、酯酶同工酶和可溶性蛋白分析.结果表明:不同菌株存在明显的致病力分化,而酯酶同工酶图谱却有较强的一致性,它们的主酶带基本相同,但在副酶带上反映出一定的同工酶表型异质性,表现为带的数目及着色深浅的不同;可溶性蛋白图谱比酯酶同工酶图谱表现出更多的多样性,大多数致病力较强的菌株都有l~2条特征谱带,而且它们的谱带数目比弱毒力菌株的多出3~5条.     

虫酰肼对甜菜夜蛾六类酶活性的影响

用一个采自武汉地区的甜菜夜蛾田间种群(N)和一个相对敏感种群(CK),比较了甜菜夜蛾的表皮酚氧化酶(PPO)、乙酰胆碱酯酶(TCE)、谷胱甘肽-S转移酶(GST)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)酶活力差异。用含有0.14mg/kg(致死中量)虫酰肼的带毒饲料处理CK种群的甜菜夜蛾,处理后24、48h和72h测定酶活力,结果与CK种群相比,PPO酶活力分别降低79.12%、10.54%和56.23%;SOD酶活力分别上升71.59%、63.16%和79.55%;GST酶活力在处理后24h酶活力上升41.43%。N种群与CK种群比,PPO酶活力降低38.47%;GST酶活力升高34.20%。采用PAGE凝胶电泳方法比较了CK、N和用虫酰肼分别汰选CK种群4代和6代的甜菜夜蛾种群酯酶同工酶谱差异。结果表明,CK共有15条酯酶同工酶带,N和汰选种群均只有10条带。研究结果初步表明甜菜夜蛾对虫酰肼的抗药性可能与PPO、GST、SOD、EI酶活力变化有关,与CAT关系不大,与TCE无关。     

稻瘟菌不同小种间可溶性蛋白及酯酶同工酶的多态性

采用聚丙烯酰胺凝胶泳对来自太湖稻区的１０个水稻稻瘟病菌株和２个禾本科杂草瘟菌的可溶性蛋白及酯酶同工酶进行了分析比较。结果表明：供试菌株菌体可溶性蛋白可呈现１６～２５条电泳谱带，其中在Ｒｆ值为０．２３，０．３３，０．４４的３条谱带为１２２个菌株所共有，没有发现生理小种特异性谱带。对１２个菌株α－酯酶同工酶的分析表明，在所有菌株同工酶谱带中可分辩出具有不同迁移率的１２条谱带，据此可将菌株分为８个不同的同工酶谱带类型。同时表明，α－酯酶同工酶在太湖稻区稻瘟病菌中存在丰富的多态性，但其谱带类型与病菌生理小种无相关性。     

澳洲大蠊二种同工酶谱及胆碱酯酶活性的研究

本文采用聚丙烯酰胺凝胶盘状电泳研究澳洲大蠊三个发育阶段酯酶同工酶，过氧化物酶同工酶谱的变化，并分别测定了发育三阶段和成虫头、胸、腹、脚胆碱脂酶活性。结果发现过化物酶同工酶与酯酶同工酶酶谱各有特征，从卵到二龄幼虫发育过程中表现最大活性的同工酶的酶带位置各不相同，胆碱酯酶活性在卵、一龄、二龄幼虫中以一龄幼虫活性最高，成虫中以头部活性最高，腹部活性最小。     

燕麦DNA导入普通小麦后代的同工酶酶谱分析

以健壮燕麦（Avera sativa L.)为供体，宁春4号小麦为受体，采用花粉管通道法进行外源DNA导入。对供体、受体及其D5代的变异株系进行酯酶同工酶和过氧化物酶同工酶分析表明：变异后代与亲本的谱带有明显差异，无论是在酯酶同工酶中还是在过氧化物酶同工酶中，均出现了供体特有的谱带；在过氧化物酶同工酶中既出现了供、受体均不具有的新的杂交酶带，有的还显现了偏父或偏母以及完全互补型的酶带；酶的活性也发生了很大变化。认为可以用同工酶分析作为鉴定外源DNA导入的生化指标之一。     

澳洲大蠊二种同工酶谱及胆碱酯酶活性的研究

本文采用聚丙烯酰胺凝胶盘状电泳研究澳洲大蠊（ＰｅｒｉｐｌａｎｅｔａａｕｓｔｒａｌａｓｉａｅＦａｂ．）三个发育阶段酯酶同工酶、过氧化物酶同工酶谱的变化，并分别测定了发育三阶段和成虫头、胸、腹、脚胆碱酯酶活性。结果发现过氧化物酶同工酶与酯酶同工酶酶谱各有特征。从卵到二龄幼虫发育过程中表现最大活性的同工酶的酶带位置各不相同。胆碱酯酶（ＣＨＥ）活性在卵、一龄、二龄幼虫中以一龄幼虫活性最高，成虫中以头部活性最高、腹部活性最小     

麦穗鱼脑乙酰胆碱酯酶(AChE)的纯化及其比较性研究

用PEG2000双水相萃取、DEAE-Sephadex A-50和Sephadex G-200方法分离纯化麦穗鱼Pseudorasbora parva脑中的乙酰胆碱酯酶(AChE),然后比较分析纯酶液与粗酶液中鱼脑AChE 的动力学特性和抗抑制性,以便更直接地了解底物与酶以及毒剂与酶的反应关系。研究结果表明,经过一系列步骤的纯化,最后所得的AChE是纯度较高的酶液;通过对AChE的动力学研究发现,纯化后的麦穗鱼脑AChE与底物之间的亲和力和其在粗酶状态时没有显著的差别,而且纯化后的鱼脑AChE对底物抑制作用更敏感;抗抑制性研究发现,纯化后的麦穗鱼脑AChE对经溴水氧化的马拉硫磷(malathion)和三唑磷(triazophos)的敏感性显著高于粗酶状态的AChE,酶更易受抑制。     

锐劲特与马拉硫磷混用对麦穗鱼的影响研究

锐劲特fipronil(化学名(±)-5-氨基-1-(2,6-二氯-α,α,α-三氟-ρ-甲苯基-)-4-三氟甲基-亚硫酰基吡唑-3-碳化腈),是一广谱的新型杀虫剂,其作用靶标是γ-氨基丁酸调节的神经轴突氯离子通道。进入我国市场后能有效防治蔬菜、水稻害虫[1～3],具有较好的推广潜力。有关该农药对家蚕、鱼、天敌的毒性已有研究[1～5]。但该药与其他农药的相互作用,尚未见报道。本文研究了该农药与马拉硫磷混合使用时,对麦穗鱼的影响。1　材料与方法1.1　实验用鱼麦穗鱼(Pseudorasboraparva),体重0.39-1.09g,体长4.1-5.8cm,购自杭州花鸟市场,试验前在实验室驯养一…     

Measurement of the bioconcentration factors of pesticides by freshwater fish and their correlation with physicochemical properties or acute toxicities

The bioconcentration factors (BCF) for 15 pesticides by a freshwater fish (topmouth gudgeon) were measured under continuous flow conditions in water containing 5 to 20 μg litre^?1 of each pesticide at the equilibrium condition. A significant correlation was found between the BCF by the fish and the water solubility of the pesticide or its partition coefficient (PC) between octan-1-01 and water. Moreover, a significant correlation was also found between the BCF by topmouth gudgeon and the acute toxicities to carp, rainbow trout and water flea. It would therefore appear that the bioconcentration potential of a pesticide by a fish may be predicted from knowledge of its solubility or PC, and that the acute toxicity of a pesticide to a fish may be predicted from knowledge of the BCF.     

麦穗鱼脑AChE间接非竞争ELISA定量分析法的建立

用PEG2000双水相萃取、 DEAE-Sephadex A-50和Sephadex G-200方法分离纯化麦穗鱼Pseudorasbora parva脑中的乙酰胆碱酯酶(AChE), 并制备了兔抗麦穗鱼脑AChE抗血清。用兔抗麦穗鱼脑AChE抗体连接抗原, 建立了定量分析麦穗鱼脑AChE的间接非竞争酶联免疫吸附法(Indirect and non-competitive ELISA), 此法操作简便、灵敏度高, 适用于定量检测。该方法的建立有利于AChE在环境科学和农药学研究领域的进一步研究和应用。     

溴氰菊酯对麦穗鱼谷胱甘肽S-转移酶(GSTs)的影响

研究了溴氰菊酯不同浓度、不同处理时间对麦穗鱼体内谷胱甘肽S-转移酶(GSTs)活性的影响,同时测定了麦穗鱼不同组织中谷胱甘肽S-转移酶对低浓度溴氰菊酯处理的反应特点。结果表明,处理48 h后,高浓度(0.009 mg/L)组对肝中GSTs活性的抑制率达到43.7％,对鳃中GSTs活性的抑制率达54.3％;而低浓度组(0.001 mg/L)对鳃中GSTs活性有一定的诱导作用。亚致死剂量的溴氰菊酯(3.0×10-4mg/L)处理96 h后,对卵巢的诱导活性最高,其GSTs活性是对照的2.43倍,但对肝、鳃、肾、肠的诱导作用均较低。溴氰菊酯对麦穗鱼不同组织GSTs活性诱导的时间效应和强度不同。     

Impacts of hypersaline water on the biotransformation and toxicity of fenthion on rainbow trout (Oncorhynchus mykiss), striped bass (Morone saxatilis X Morone chrysops) and tilapia (Oreochromis mossambicus)

Hypersaline water derived from agricultural practices primarily in arid landscapes can impact fisheries in streams receiving run-off from fields. Previous studies have indicated significant elevation in the toxicity of thio-ether pesticides by hypersaline water in certain species of euryhaline fish due to enhanced formation of sulfoxide metabolites which may be more toxic than the parent compounds. The objectives of this study were to evaluate the effects of salinity on the toxicity of the thio-ether organophosphate pesticide, fenthion in three species of euryhaline fish: rainbow trout (Oncorhynchus mykiss), striped bass (Morone saxatilis X Morone chrysops), tilapia (Oreochromis mossambicus) and determine whether a relationship was observed between toxicity and enantioselective sulfoxidation. Stereochemical formation and total sulfoxide formation did not mirror acute toxicity in the three species exposed in fresh or hypersaline conditions. Mortality of striped bass and rainbow trout due to fenthion exposure was enhanced by hypersaline treatments and a trend towards increased toxicity was observed in tilapia. In liver microsomes of rainbow trout, inhibition of cytochrome P450 (CYP) caused a respective 7- and 3-fold increase in sulfoxide formation in liver microsomes fresh and saltwater fish, and a significant increase in the formation of the (+)R-sulfoxide. CYP inhibition also caused a significant elevation of the (+)R-sulfoxide in freshwater striped bass, but not in hypersaline-treated bass. The results indicated contribution by CYP in the sulfoxidation of fenthion as well as the formation of other metabolites in all three species. In summary, hypersaline conditions impacted fenthion toxicity under conditions that appeared to be independent of fenthion sulfoxide formation indicating a much more complex mechanism of action for compounds with phosphorothioate and thio-ether structural features potentially involving multiple oxidative pathways.     

Penetration of malathion into locusts

Topically applied dilute solutions of malathion in kerosene extract ‘bottoms’ are more toxic and rapid in action than concentrated ones. Dilute solutions spread farther, penetrate more rapidly and consequently their rate of activation into the more toxic malaoxon is higher. With a single dose of 2·5% malathion the rate of penetration and activation varies according to the loci of topical application, presumably reflecting differences in sclerotisation of the cuticle. There are also inherent differences in the susceptibility of various body regions associated perhaps with the differential vulnerability of some vital internal organ (e.g. the central nervous system). Very rapid hydrolytic degradation of malathion occurs through its conversion into malaoxon; locusts survive the lethal action of malathion by way of such degradation only where activation into malaoxon takes place in areas away from the sensitive head region, or where the rate of activation is slow, or where the circulatory system delays its arrival at such sensitive sites. The higher rate of activation observable in immature adults of Schistocerca gregaria compared with mature adults is, however, counterbalanced by a higher rate of hydrolysis in the former.     

Oxidative cleavage of a carboxyester bond as a mechanism of resistance to malaoxon in houseflies

The synergistic effect of triphenyl phosphate (a carboxyesterase inhibitor), sesamex (inhibitor of microsomal oxidation) and O,O-diethyl O-phenyl phosphorothioate on the toxicity of malathion and malaoxon for one susceptible and two resistant strains of housefly was studies. It was found that in the resistant strain G (characterized by high carboxyesterase activity) both malathion and malaoxon were synergized by triphenyl phosphate, but only malaoxon (and not malathion) by sesamex. The other resistant strain E 1, moderately tolerant for malathion but highly resistant to malaoxon, differed from strain G in that triphenyl phosphate had no effect; its response to sesamex was similar to that of strain G. The third synergist, O,O-diethyl O-phenyl phosphorothioate, combined the properties of triphenyl phosphate and sesamex. It was found to be the best of the three compounds used.Biochemical in vitro studies showed that both resistant strains could degrade malaoxon oxidatively at a rate at least 10 × higher than that of the susceptible strain. This oxidation could be inhibited by very low concentrations of the thiono analogue; a malaoxon to malathion ratio of 10:1 gave an inhibition of about 70% at a malaoxon concentration of 5 × 10^?6M. The product of this oxidation is malaoxon β-monocarboxylic acid. This metabolite was also found 1 hr after application of malaoxon in vivo.The results mentioned in this paper indicate that houseflies may become resistant to malaoxon by an increased rate of oxidative carboxyester bond cleavage.     

芸苔链格孢菌种内和链格孢菌种间的酯酶同工酶比较

 对链格孢菌(Alternaria)不同种和芸苔链格孢菌(Alternaria brassicae)不同菌系的10个菌株的酯酶同工酶进行聚丙烯酰胺凝胶电泳(IF-PAGE)和TL紫外扫描分析。试验发现,链格孢菌种间酯酶同工酶的扫描结果差异比种内菌株间要大;对来自不同地区,不同品种的芸苔链格孢菌的酯酶同工酶扫描结果表明,白帮菌系和青帮菌系间的差异大于各菌系内菌株的差异,说明白菜青帮菌系内和白帮菌系内各菌株间各自的同源性较近。可见,IF-PAGE技术可用来鉴定病原菌的致病小种和菌系,也可用来研究病原菌的致病遗传机理。