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1.
棉蚜抗氧化乐果品系及敏感品系羧酸酯酶性质的比较   总被引:11,自引:5,他引:6  
在室内用氧化乐果逐代筛选的棉蚜抗性品系,相对于敏感品系的抗性倍数是17。用α-乙酸萘酯(α-NA)、α-丁酸萘酯(α-NB)、α-磷酸萘酯(α-NP)和β-磷酸萘酯(β-NP)作底物比较研究了氧化乐果抗性和敏感品系棉蚜Aphis gossypii羧酸酯酶的比活力、米氏常数(Km)和最大反应速度Vmax)等有关的动力学常数。以α-NA和α-NB作底物时,抗性品系棉蚜的比活力显著低于敏感品系的;以α-NP和β-NP作底物时,两个品系棉蚜的比活力、Km和Vmax没有明显差异。用α-NA、β-NA作底物染色做酯酶同工酶电泳,抗性品系棉蚜的酯酶同工酶染色比敏感品系棉蚜的浅。  相似文献   

2.
耳状网褶菌的化学成分   总被引:5,自引:2,他引:3  
从野生真菌耳状网褶菌(Paxillus pamuoides Fr.)子实体中分得4个化合物,经光谱和化学方法分别鉴定为(2S,3S,4R,2′R)-2-(2′-羟基二十四碳酰氨基)十八碳-1,3,4-三醇(1)、5α,8α-表二氧-(22E,24R)-麦角甾-6,22-二烯-3β-醇[5α,8α-epidioxy-(22E,24R)-ergosta-6,22-dien-3β-o1,2]、(22E,24R)-麦角甾-4,6,8(14),22-四烯-3-酮[(22E,24R)-ergosta-4,6,8(14),22-tetraen-3-one,3]和对羟基苯甲酸乙酯(ethyl 4-hydroxybenzoate,4)。其中化合物4作为天然产物属首次报道。化合物1-4为本科真菌中首次分得。  相似文献   

3.
抗性品系棉蚜乙酰胆碱酯酶和羧酸酯酶的变异   总被引:14,自引:4,他引:10  
李飞  韩召军  唐波 《昆虫学报》2003,46(5):578-583
用浸叶法测定了采自我国不同地区(泰安、莱阳、南京、北京和安阳)的棉蚜品系Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ对久效磷、甲胺磷、抗蚜威和灭多威等杀虫剂的抗性水平,各棉蚜品系对杀虫剂的抗性依次为Ⅴ>Ⅳ>Ⅲ,Ⅱ>Ⅰ。进一步研究表明,Ⅴ和Ⅳ品系棉蚜乙酰胆碱酯酶对杀虫剂的敏感性显著下降,Ⅱ品系次之,Ⅲ和Ⅰ品系接近于敏感品系。Ⅴ和Ⅳ品系乙酰胆碱酯酶的Km值显著下降,表明酶发生了质的变化。不同棉蚜抗性品系的酯酶(全酯酶和羧酸酯酶)活性均显著升高,其中Ⅲ品系的酯酶活力为Ⅱ品系的2倍。Ⅴ品系羧酸酯酶Km值达2460.4 μmol/L,而Ⅳ品系仅为84.4 μmol/L,该两个品系羧酸酯酶发生了质的变化。研究结果表明,不同抗性程度的棉蚜品系均存在代谢抗性和靶标抗性。低抗水平的棉蚜品系,以代谢抗性为主,靶标抗性为辅;中抗水平的棉蚜品系,抑或由于解毒代谢酶的活性显著增强,也可能由于靶标的敏感性显著下降;而高抗水平的棉蚜品系,依赖于代谢抗性和靶标抗性的联合作用。  相似文献   

4.
棉蚜抗氧化乐果品系的羧酸酯酶基因突变   总被引:12,自引:5,他引:7  
郭惠琳  高希武 《昆虫学报》2005,48(2):194-202
用氧化乐果对室内敏感品系棉蚜Aphis gossypii (Glover)进行抗性选育,经24代筛选,抗性指数达到124.7倍。以α-乙酸萘酯(α-NA)为底物,比较了氧化乐果敏感和抗性品系棉蚜羧酸酯酶的比活力,发现抗性品系羧酸酯酶比活力明显小于敏感品系。对这两个品系的羧酸酯酶基因进行了克隆,通过对抗性和敏感品系羧酸酯酶基因核苷酸序列及推导的氨基酸序列比较,发现抗性品系有4个氨基酸残基发生了替代 (His104→Arg, Ala128→Val, Thr333→Asp, Lys484→Arg)。对其蛋白质三维结构分析推测只有His104→Arg的替代是位于其活性中心。棉蚜氧化乐果敏感和抗性品系羧酸酯酶基因cDNA全长的GenBank登录号分别为AY485216和AY485214。  相似文献   

5.
棉蚜抗吡虫啉品系和敏感品系主要解毒酶活性比较   总被引:9,自引:0,他引:9  
通过生物测定和生物化学方法比较了棉蚜 Aphis gossypii 对吡虫啉抗性(约为7倍)和敏感品系几种主要解毒酶的活性。结果表明:氧化胡椒基丁醚对两个品系均无明显增效作用。抗性品系中羧酸酯酶和谷胱甘肽S-转移酶的比活力均明显高于敏感品系,抗性品系中羧酸酯酶的Km值也显著高于敏感品系,说明抗性品系羧酸酯酶与底物的亲和力明显高于敏感品系。上述结果证明羧酸酯酶和谷胱甘肽S-转移酶活力增强在棉蚜对吡虫啉的抗性中起重要作用。  相似文献   

6.
樱草杜鹃中的黄酮类化合物   总被引:5,自引:0,他引:5  
从樱草杜鹃(Rhododendron primulaeflorum)地上部分的乙醇提取物中分离得到10个黄酮类化合物,经理化性质及波谱分析,鉴定为杜鹃素(1)、4’,5,7-三羟基-8-甲基黄烷酮(2)、二氢山柰酚(3)、异鼠李素(4)、槲皮素(5)、陆地棉苷(6)、瑞诺苷(7)、(2R,3R)-花旗松素-3—O-α-L-吡喃阿拉伯糖苷(8)、(2R,3S)-花旗松素-3—O-α-L-吡喃阿拉伯糖苷(9)、(2S,3R)-花旗松素-3-O-α-L-吡喃阿拉伯糖苷(10)。所有化合物均为首次从该植物中分得。  相似文献   

7.
为了研究抗性和敏感棉蚜Aphis gossypii品系对菊酯类药剂代谢的差异, 本实验合成了溴氰菊酯和高效氯氰菊酯报告荧光底物, 应用这两种底物水解后生成具有荧光化合物的特性,测定了不同品系棉蚜羧酸酯酶的代谢活性。结果表明: 氧化乐果棉蚜抗性和敏感品系羧酸酯酶对溴氰菊酯报告荧光底物的代谢活性分别为10.0和3.4 pmol/min·mg; 对高效氯氰菊酯报告荧光底物的代谢活性分别为4.0和2.4 pmol/min·mg, 抗性品系羧酸酯酶对溴氰菊酯和高效氯氰菊酯报告荧光底物的代谢活性分别为敏感品系的2.9和1.7倍; 溴氰菊酯棉蚜抗性和敏感品系羧酸酯酶对溴氰菊酯报告荧光底物的代谢活性分别为7.6和6.2 pmol/min·mg; 对高效氯氰菊酯报告荧光底物的代谢活性分别为9.3和5.2 pmol/min·mg, 抗性品系羧酸酯酶对溴氰菊酯和高效氯氰菊酯报告荧光底物的代谢活性分别为敏感品系的1.2和1.8倍。这种衍生的报告荧光底物能够用来检测抗性棉蚜羧酸酯酶的水解活性, 表明羧酸酯酶可能参与棉蚜对溴氰菊酯和氧化乐果抗性的形成。  相似文献   

8.
儿茶酚胺类药物对草鱼生长激素分泌的影响   总被引:3,自引:1,他引:2  
本文研究了儿茶酚胺类药物对草鱼生长激素水平的影响。腹腔注射儿茶酚胺合成抑制剂α-甲基-对-酪氨酸(α-MPT,5μg/gb·w和50μg/gb·w)显著降低草鱼鱼种血清生长激素水平,腹腔注射儿茶酚胺能神经毒素6-羟多巴胺(6-HODA,5μg/gb·w和50μg/gb·w)也显著降低草鱼鱼种血清生长激素水平。阿卟吗啡(APO,7.1mg/Kgb·w和12.5mg/Kgb·w)通过背大动脉插管注入草  相似文献   

9.
转Bt基因抗虫棉对棉蚜的杀虫剂敏感性及解毒酶系的影响   总被引:6,自引:0,他引:6  
采用浸叶法,以亲本常规棉作对照,室内测定了吡虫啉和辛硫磷对在转Bt基因棉上取食不同世代棉蚜Aphis gossypii Glover的毒力,并用酶标仪测定了转Bt基因棉对棉蚜酯酶、羧酸酯酶和乙酰胆碱酯酶活力的影响。结果表明,棉蚜对吡虫啉和辛硫磷的敏感性并未受Bt棉的影响,2种杀虫剂对分别取食Bt棉1代和多代(60代以上)的棉蚜与取食亲本常规棉棉蚜的LC50值之间均无显著差异。在抗虫棉GK12上取食1代和21代的棉蚜,其酯酶、羧酸酯酶和乙酰胆碱酯酶的活力与取食亲本常规棉的棉蚜之间差异不显著。可见,转Bt基因棉对棉蚜的杀虫剂敏感性和解毒酶活力无显著影响。  相似文献   

10.
用澳氰菊酯、久效磷、灭多威及硫丹对敏感棉蚜以浸渍法连续选择16代或12代后,棉蚜对上述1种药剂的敏感度分别降低了300.0、6.0、5.0、及5.0倍。对4个抗性品系和敏感品系棉蚜的实验种群生命表分析表明:澳氰菊酯抗性品系棉蚜的存活率呈“S”形曲线下降,其内禀增长率为0.2985;久效磷抗性品系及敏感品系棉蚜的存活率呈二次曲线下降趋势,其内禀增长率分别为0.2979和0.2973;灭多戚及硫丹抗性品系棉蚜的存括率呈指数曲线下降趋势,其内禀增长率分别为0.2602和0.2533。  相似文献   

11.
Extensive use of insecticides on cotton has prompted resistance development in the cotton aphid, Aphis gossypii (Glover) in China. A deltamethrin‐selected population of cotton aphids from Xinjiang Uygur Autonomous Region, China with 228.59‐fold higher resistance to deltamethrin was used to examine how carboxylesterase conferred resistance to this pyrethroid insecticide. The carboxylesterase activity in the deltamethrin‐resistant strain was 3.67‐, 2.02‐ and 1.16‐fold of the susceptible strain when using α‐naphthyl acetate (α‐NA), β‐naphthyl acetate (β‐NA) and α‐naphthyl butyrate (α‐NB) as substrates, respectively. Carboxylesterase cDNA was cloned and sequenced from both deltamethrin‐resistant and susceptible strains. The cDNA contained 1581 bp open reading frames (ORFs) coding a 526 amino acid protein. Only one amino acid substitution (Val87‐Ala) was observed between deltamethrin‐resistant and susceptible strains but it is not genetically linked to resistance by the catalytic triad and signature motif analysis. The real‐time polymerase chain reaction analysis indicated that the resistant strain had a 6.61‐fold higher level of carboxylesterase mRNA than the susceptible strain. The results revealed that up‐regulation of the carboxylesterase gene, not modified gene structure, may be responsible for the development of resistance in cotton aphids to deltamethrin.  相似文献   

12.
13.
Resistance to omethoate was suppressible by the hydrolytic enzyme inhibitor SSS-tributyl phosphorotrithioate in a laboratory-selected resistant cotton aphid, Aphis gossypii Glover, strain, suggesting the involvement of hydrolytic enzymes in the detoxification process. The kinetic properties of carboxylesterases from both resistant and susceptible cotton aphids were characterized by four acyl ester substrates: alpha-naphthyl acetate (alpha-NA), alpha-naphthyl butyrate (alpha-NB), alpha-naphthyl phosphate (alpha-NP), and beta-naphthyl phosphate (beta-NP). No significant differences of carboxylesterase activity were found between resistant and susceptible strains by using either alpha-NP or beta-NP as substrates. In contrast, the susceptible A. gossypii exhibited significantly higher activity compared with resistant aphids with either alpha-NA or alpha-NB as substrates. To understand the molecular basis of this esterase-mediated resistance, carboxylesterase genes from both strains were cloned. Two genes share 99.4% identity at the nucleic acid level and 99.2% identity at the amino acid level. The full length of the cDNA opening reading frame is 1581 bp, encoding 526 amino acids. Four amino acid substitutions, Thr210 --> Met210, Asn294 --> Lys294, Gly408 --> Asp408, and Ser441 --> Phe441, were identified in the resistant strain. Probing of Southern blots with the 0.5 kb esterase fragment showed the same banding patterns and intensities with genomic DNA extracts from both resistant and susceptible A. gossypii. Furthermore, the MspI and HpaII fragments are the same in both strains, indicating there is no methylation of sequences detected by the probe. The combined results suggest that the structural gene substitution is likely the molecular basis of the organophosphate resistance in this laboratory-selected cotton aphid strain.  相似文献   

14.
INSECTICIDE RESISTANCE OF COTTON APHID IN NORTH CHINA   总被引:2,自引:0,他引:2  
Abstract  The cotton aphid ( Aphis gossypii Glover) is one of the most important pests infesting cotton in the cotton areas of North China. Since 1953 organophosphorus insecticides such as parathion and systox have been used to control the aphids for keeping up good yield of cotton. After several years. the concentration and the amount of spray were increasing in the field. In the early 1980's highly effective pyrethroid insecticides such as decis and sumicidin were largely imported into China. When first used 2. 5% decis emulsion was diluted in the ratio from 1:10000 to 1: 12000. However in 1985 the resistance of cotton aphid to pyrethroids increased by 171 times in general, 3230 times in some cotton fields. Thus it has prompted us to investigate the mechanism of resistance to insecticides and to search for the strategy to control the resistant aphids.
Experiments showed that the use of synergists including SV1 (O, O-diethyl, O-phenyl phos-phorothionate) and PB has given evidence indicating mixed function oxidases (MFO). α-NA esterases and α-NA carboxylesterase are involved in the formation of resistance. The results also showed that the sensitivity of AChE to paraoxon in resistant aphids was lower than that in susceptible aphids.
Experiments showed that SV1 was particularly synergistic to organophosphorus or pyrethroid insecticides and had played an excellent role in overcoming the resistance of cotton aphids to insecticides.  相似文献   

15.
二化螟对杀螟硫磷产生抗性的机理   总被引:6,自引:0,他引:6  
韩启发  庄佩君 《昆虫学报》1995,38(3):266-271
本文就二化螟Ckilo suppressalis Walker对杀螟硫磷抗性发生的机理进行了较为全面的研究。活体增效作用研究表明,脱叶磷(DEF)和氧化胡椒基丁醚(PBO)对抗性种群可分别增效1.3和34.8倍。这表明了多功能氧化酶(MFO)活性增强,而似乎与水解酶的活性无关。对寓体解毒酶的进一步研究表明,抗性和敏感种群的非特异性酯酶活力无明显差异,但羧酸酮酶(CarE,加入10-4mol/L的毒扁豆碱)和MFO的活力在抗性种群中有所增高。R种群幼虫CarE活力分别是s的2.42和2.92倍(以a-和β-乙酸萘酯为底物);R种群幼虫MFO的O-脱甲基作用的活力为s幼虫的1.43倍(以对硝基茴香醚为底物);R幼虫乙酰胆碱酯酶(AChE)对乙酰胆碱的活力是s的1.3倍,两者相差不大。但从米氏常数Km)和最大反应速度(Vmax)看,R幼虫是s幼虫的1.9和1.6倍;以对氧磷为抑制剂的R幼虫150是s幼虫的2倍。这些表明了R和s的AChE是不同的。研究结果还表明,二化螟对杀螟硫磷抗性的机理至少包括:(1)CarE活性的增高;(2)MFO的O-脱甲基活力的增高和(3)AChE敏感性的降低等。  相似文献   

16.
菜蚜茧蜂对甲胺磷和灭多威的抗性机制   总被引:5,自引:1,他引:4  
吴刚  江树人 《昆虫学报》2003,46(3):292-298
采用试管药膜法测定了菜蚜茧蜂 Diaeretiella rapae 对甲胺磷和灭多威的抗性及增效剂的增效作用,并测定了菜蚜茧蜂和菜缢管蚜 Lipaphis erysimi 乙酰胆碱酯酶动力学参数、解毒酶活性及增效剂对菜蚜茧蜂酶活性的体内抑制作用。福州地区菜蚜茧蜂已对甲胺磷和灭多威产生5.6和9.1倍的抗性,胡椒基丁醚、磷酸三苯酯和马来酸二乙酯对两种杀虫剂的抗性品系均有显著增效作用,胡椒基丁醚的作用最为显著。胡椒基丁醚对抗性菜蚜茧蜂杀虫剂敏感性的增效作用远高于对敏感菜蚜茧蜂的影响。3种增效剂对菜蚜茧蜂乙酰胆碱酯酶均无抑制作用;磷酸三苯酯和胡椒基丁醚对羧酸酯酶,马来酸二乙酯对谷胱甘肽S转移酶有显著抑制作用。抗性和敏感菜蚜茧蜂乙酰胆碱酯酶的米氏常数Km)、最大反应速度(Vmax)、羧酸酯酶及谷胱甘肽S转移酶活性值相近,但敏感菜蚜茧蜂乙酰胆碱酯酶的双分子速度常数(KI)值远高于抗性的。此外,对菜蚜茧蜂和菜缢管蚜乙酰胆碱酯酶、羧酸酯酶和谷胱甘肽S转移酶进行了比较研究。结果表明菜蚜茧蜂对甲胺磷和灭多威的低水平抗性与乙酰胆碱酯酶的不敏感性及解毒酶的解毒代谢有关。  相似文献   

17.
二斑叶螨对七种杀螨剂的抗药性测定及其机理研究   总被引:3,自引:0,他引:3  
室内测定了相对敏感种群(S)和抗性种群(R)对常用7种杀螨剂的敏感性,并测定了羧酸酯酶、谷胱甘肽S-转移酶和乙酰胆碱酯酶3种酶的比活力。结果表明:二斑叶螨Tetranychus urticae Koch R种群已对甲氰菊酯和哒螨灵产生了抗性,抗性倍数分别为5.45和105.47。其中,甲氰菊酯对雌成螨的毒力最低(>3000mg/L),已远远超过田间推荐剂量,不宜继续使用。酶活测定结果表明:谷胱甘肽S-转移酶解毒活性的提高是二斑叶螨对甲氰菊酯产生抗性的原因之一;二斑叶螨对哒螨灵抗性的增强可能与羧酸酯酶有关。  相似文献   

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