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1.
羧酸酯酶介导的小菜蛾对氟虫腈的抗性   总被引:3,自引:0,他引:3  
【目的】羧酸酯酶(carboxylesterases, CarEs)是昆虫重要的解毒代谢酶之一,可以介导靶标昆虫对多种杀虫剂的代谢抗性。本研究检测了羧酸酯酶对小菜蛾Plutella xylostella 抗药性的介导功能,旨在阐明羧酸酯酶在小菜蛾代谢解毒中的生理生化和分子机理。【方法】采用点滴法测定氟虫腈对小菜蛾敏感种群和抗氟虫腈种群的毒力,以及羧酸酯酶抑制剂磷酸三苯酯(triphenyl phosphate, TPP)对氟虫腈的增效作用;以LC30和LC50浓度的氟虫腈处理抗性小菜蛾,测定药剂处理后CarEs酶活性的变化;利用qRT-PCR技术分析Pxae22和Pxae31两个基因在小菜蛾不同发育阶段、组织和种群的表达模式;利用dsRNA干扰Pxae22和Pxae31后观察基因的表达变化和小菜蛾3龄幼虫对药剂敏感性的变化。【结果】TPP可以削弱小菜蛾3龄幼虫对氟虫腈的抗性,增效倍数约为6倍;使用较低剂量(LC30和LC50)氟虫腈处理小菜蛾3龄幼虫后,处理组CarEs比活力明显高于对照,提示氟虫腈对小菜蛾CarEs活性具有诱导作用。对羧酸酯酶基因Pxae22和Pxae31在小菜蛾不同发育阶段、4龄幼虫不同组织和不同种群3龄幼虫中的表达模式分析发现,这两个基因在小菜蛾4龄幼虫中的表达量最高;在4龄幼虫中以中肠组织中的表达量较高,头、表皮、脂肪体中的表达量很低; 抗性种群中的表达量显著高于敏感种群。通过干扰 Pxae22和 Pxae31后的qRT-PCR验证,两个基因的表达量均显著降低,进一步的氟虫腈毒力测定发现,干扰P xae22和 Pxae31后的小菜蛾3龄幼虫对氟虫腈的敏感性分别增加了1.63倍和1.73倍。【结论】羧酸酯酶在小菜蛾对氟虫腈解毒代谢中具有重要作用;Pxae22和Pxae31是小菜蛾的两个抗性相关基因,其表达水平的变化直接影响小菜蛾对氟虫腈的敏感性。  相似文献   

2.
氯虫苯甲酰胺诱导甜菜夜蛾细胞色素P450基因上调表达   总被引:5,自引:0,他引:5  
【目的】明确氯虫苯甲酰胺对甜菜夜蛾Spodoptera exigua (Hübner)细胞色素P450基因的诱导表达作用。【方法】采用O-脱乙基香豆素法研究了低剂量氯虫苯甲酰胺处理对甜菜夜蛾幼虫中肠P450s酶活性的影响,应用Real-time PCR方法测定了其对P450基因(CYP9A9, CYP4G37,CYP4S11和CYP6B)和NADPH细胞色素P450还原酶基因(HQ852049)表达的影响。【结果】氯虫苯甲酰胺对甜菜夜蛾P450酶及相关基因的诱导作用均表现出时间效应和剂量效应,。甜菜夜蛾4龄幼虫取食0.02 mg/kg氯虫苯甲酰胺饲料至5龄, 在蜕皮后6-36 h内, 其P450s酶活性增加为对照组的1.90~2.92倍, 诱导效应高于0.01 mg/kg氯虫苯甲酰胺处理组(其P450s酶活性为对照组的1.11~1.62倍)。同时, 0.02 mg/kg氯虫苯甲酰胺处理组甜菜夜蛾中肠P450基因CYP9A9, CYP4G37和CYP6B mRNA的相对表达量分别上升为对照组的1.97~3.95, 2.46~4.29及1.53~4.48倍, NADPH细胞色素P450还原酶基因 HQ852049 的相对表达量亦增加为对照的1.85~4.08倍。【结论】结果提示,氯虫苯甲酰胺可能通过诱导3种P450基因及细胞色素P450还原酶基因 HQ852049 基因mRNA的上调表达而增强了甜菜夜蛾幼虫中肠P450s酶活性。  相似文献   

3.
谢苗  尤民生 《昆虫知识》2011,48(6):1728-1733
本文从解毒酶系的角度研究了小菜蛾Plutella xylostella(L.)对氟虫腈的短期生理生化响应。用氟虫腈LC50剂量处理小菜蛾3龄幼虫一定时间后,测定小菜蛾幼虫体内多功能氧化酶(MFO)、酯酶(EST)和谷胱甘肽S-转移酶(GST)活性的动态变化。研究结果表明:经氟虫腈处理后小菜蛾体内解毒酶的活性均显著高于未经处理的对照,并且随着处理时间的延长,解毒酶活性逐渐提高。这说明氟虫腈对小菜蛾敏感品系的解毒酶具有一定的诱导作用,反之,解毒酶加快了小菜蛾体内对氟虫腈的代谢,降低了小菜蛾对氟虫腈的敏感性。  相似文献   

4.
【目的】小菜蛾Plutella xylostella(L.)是全球十字花科植物上最重要的害虫。氰虫酰胺作为一种新型的邻甲酰胺基苯甲酰胺类杀虫剂有着独特的作用方式,而关于氰虫酰胺对小菜蛾的影响的报道几乎没有。【方法】本研究采用叶片药膜法研究室内条件下氰虫酰胺对小菜蛾生理生化的影响,饲喂小菜蛾含有氰虫酰胺药液(0, LC20和LC50)的甘蓝叶片48 h后,观察小菜蛾的生物学特性及其相关酶活性的变化。【结果】氰虫酰胺对小菜蛾3龄幼虫的LC20和LC50分别为0.03和0.08 mg/L。使用LC20和LC50浓度的氰虫酰胺处理小菜蛾3龄幼虫48 h后,对其影响表现为显著降低小菜蛾的蛹重、化蛹率和羽化率;明显延长4龄幼虫期和蛹期。采用这两个浓度氰虫酰胺处理小菜蛾48 h,其保护酶(CAT和POD)活性在处理24 h内持续升高并且高于对照组;随后,活性继续升高但是与对照组没有差异(CAT: P=0.58; POD: P=0.13)。而其解毒酶(CarE, GST和ODM)活性在处理12 h内与对照组没有差异(CarE: P=0.43; GST: P=0.54; ODM: P=0.25),但是随着取食时间的延长,其活性明显高于对照组。【结论】LC20和LC50浓度氰虫酰胺能够显著抑制小菜蛾的生长发育,对降低害虫虫口密度有一定的作用。同时这两个浓度氰虫酰胺还能够诱导小菜蛾体内解毒酶活性的升高,这将为田间合理施药,延缓害虫抗药性的产生提供理论依据。  相似文献   

5.
【目的】细胞色素P450单加氧酶(P450)和谷胱甘肽-S-转移酶(GST)是生物降解外源有毒物质的重要解毒酶家族,在昆虫适应杀虫剂选择的过程中发挥重要的作用。以往在致倦库蚊Culex pipiens quinquefasciatus对硫磷抗性研究中,发现了一个Epsilon GST基因(GSTe1)和一个P450 CYP9家族基因(CYP9J40)在抗性品系中高表达。研究它们在蚊虫中的时空表达模式对理解它们的生物学功能有重要意义。【方法】本研究利用实时定量PCR和原位杂交的方法探讨了这两个解毒酶基因在蚊虫中的时空表达。【结果】定量PCR显示GSTe1和CYP9J40在对硫磷抗性蚊虫中的转录水平分别是敏感蚊虫的4.2倍和1.9倍,它们在蚊虫整个生活周期的表达模式相似,均为幼虫期表达量相对较低,从蛹期开始表达量显著升高,到成虫期雌虫达到顶峰,而雄虫与幼虫期表达量相当。原位杂交结果表明这两个基因在肌肉、消化道和卵巢中都有表达,且CYP9J40的表达更广泛,在脑和胸部神经节也有明显表达。【结论】基因表达的发育阶段特异性和广泛的组织分布说明GSTe1和CYP9J40除了参与蚊虫对杀虫剂的抗性,还可能具有其它生理功能,如对雌虫发育有重要的影响。  相似文献   

6.
【目的】斜纹夜蛾Spodoptera litura(Fabricius)是一种重要农业害虫,因药物、外界环境等选择压力的不同,造成其生长发育有所差异。噻虫啉是第二代氯代烟碱类杀虫剂,对昆虫烟碱型乙酰胆碱受体有很强的激动作用。本实验旨在探讨噻虫啉对斜纹夜蛾的亚致死效应,为斜纹夜蛾的综合防治和噻虫啉的合理使用提供理论依据。【方法】采用饲料混毒法,测定噻虫啉对斜纹夜蛾3龄幼虫的毒力,确定其亚致死剂量LC25和LC50。通过离体酶活性测定,分析噻虫啉亚致死剂量对斜纹夜蛾体内羧酸酯酶、谷胱甘肽-S转移酶和多功能氧化酶3种代谢解毒酶活性的影响。记录各个年龄阶段的生长发育、繁殖力以及种群增长等数据,应用特征年龄-龄期及两性生命表方法分析LC25和LC50剂量处理和对照的斜纹夜蛾子代(F1)两性生命表参数的差异。【结果】以LC25和LC50剂量处理斜纹夜蛾3龄幼虫48 h,羧酸酯酶活性均受到明显诱导,分别升高了14.2%和45.1%;谷胱甘肽-S转移酶活性受到明显的抑制,分别降低了9.8%和37.1%;而多功能氧化酶活性均低于对照,其抑制作用与浓度成正比,但差异不显著。LC25和LC50剂量处理斜纹夜蛾幼虫后,子代(F1)的成虫前期分别比对照延长了3.05 d和4.80 d,雄成虫寿命分别缩短了2.06 d和3.31 d,雌成虫寿命分别缩短了0.13 d和0.92 d;其单雌产卵量均显著减少,分别降低了17.7%和33.3%;化蛹率分别降低了10.7%和11.4%;两个处理的内禀增长率(r)、周限增长率(λ)和净增殖率(R0)均显著小于对照,平均世代时间(T)均明显延长。【结论】羧酸酯酶可能为斜纹夜蛾对噻虫啉解毒代谢过程中的主要解毒酶,在其后续抗性形成中起主要作用;噻虫啉亚致死剂量对斜纹夜蛾的生长、发育、繁殖有显著的抑制作用。  相似文献   

7.
细胞色素P450单氧酶(cytochrome P450 monooxygenase,CYP)是昆虫体内重要的解毒酶。CYP6AS亚家族基因特异性的存在于膜翅目昆虫中,一些特异性的CYP6AS基因已经被证实参与到蜜蜂对某些外源物质和杀虫剂的解毒和代谢过程中。本研究主要探测了亚致死浓度噻虫嗪对意大利蜜蜂Apis mellifera ligustica CYP单氧酶活性及CYP6AS亚家族基因表达水平的影响。首先测定了噻虫嗪LC_(10)和LC_5经口处理4日龄意大利蜜蜂后48 h CYP酶活性,然后应用荧光定量PCR技术检测了6种CYP6AS基因(CYP6AS3,CYP6AS4,CYP6AS5,CYP6AS10,CYP6AS14和CYP6AS15)表达变化情况。结果表明,噻虫嗪LC_(10)和LC_5处理后,意大利蜜蜂CYP酶活性均极显著增加(P0.01)。噻虫嗪LC_(10)和LC_5处理对意大利蜜蜂CYP6AS4,CYP6AS10和CYP6AS15基因表达没有显著影响;LC_(10)和LC_5处理后CYP6AS3基因表达量显著增加(P0.05); LC_(10)处理能够显著诱导CYP6AS5基因上调表达(P0.05);而LC_(10)和LC_5处理极显著抑制CYP6AS14基因的表达(P0.01)。这为进一步探究蜜蜂对噻虫嗪的解毒机制提供了新的线索。  相似文献   

8.
【目的】基于烟粉虱Bemisia tabaci转录组数据,系统分析了烟粉虱解毒代谢酶基因在噻虫嗪抗性品系中的表达模式,探讨了这些基因在烟粉虱不同发育阶段差异表达的生物学意义。【方法】分别收集室内长期饲养的烟粉虱噻虫嗪抗性和敏感品系的卵、4龄若虫和刚羽化1 d的雌成虫,在烟粉虱转录组数据库中挑选8 394条解毒代谢相关基因设计探针,通过探针杂交,得到烟粉虱噻虫嗪抗性品系表达谱芯片,比较了这些基因在抗性烟粉虱3个不同发育阶段的表达情况。并随机挑选了9个基因,在抗感品系间3个不同发育阶段进行了荧光定量PCR验证。【结果】在抗性烟粉虱的卵和4龄若虫发育阶段,共有3 424个差异表达基因,其中489个是编码3类解毒代谢酶(羧酸酯酶、谷胱甘肽-S-转移酶和细胞色素P450多功能氧化酶)的基因;有14个基因在4龄若虫发育阶段过量表达,其中10个为P450基因,4个为GST家族基因。在抗性烟粉虱的4龄若虫和雌成虫发育阶段,总共有1 273个差异表达基因,193个为3类解毒代谢酶家族的基因,其中有9个P450家族基因在雌成虫期的表达量超过4龄若虫期的10倍。此外,表达谱芯片分析还筛选到了一些候选抗性基因。qRT-PCR验证显示在这些候选基因中,与敏感品系相比,9个基因在抗性烟粉虱的3个不同发育阶段表达上调,其中GST基因家族的p_06027和P450基因p_06013在抗性品系的卵和4龄若虫中过量表达;p_05885和p_07806和编码CYP6家族蛋白的p_00988在抗性品系的4龄若虫期的表达量上调;p_05916和p_00478在抗性品系卵和4龄若虫期表达量很低,而在成虫期过量表达;而p_00059和p_00428在抗性品系雌成虫发育阶段表达量显著上调,其中编码CYP4C1的p_00059的差异表达倍数在雌成虫期约为15.15倍。【结论】表达谱芯片分析结果提示,CYP6和CYP4C1基因的过量表达可能会是烟粉虱抗性产生的机制之一。解毒代谢酶基因在烟粉虱不同发育阶段的特异性表达,可能与其在抵御杀虫剂胁迫时体内能量的分布及有效利用率有关,也可能是害虫在环境选择压下的一种适应机制。  相似文献   

9.
【目的】研究有机磷杀虫剂毒死蜱对飞蝗体内细胞色素P450的影响。【方法】采用酶活力测定法和实时定量PCR技术分别研究了毒死蜱3种亚致死剂量(LD_(10)、LD_(30)和LD_(50))处理飞蝗3龄幼虫24 h后,体内细胞色素P450酶活性及CYP409A1和CYP408B1基因表达量的变化。【结果】不同亚致死剂量毒死蜱处理引起细胞色素P450活性显著性降低,分别为对照组的0.68、0.50和0.62倍。同时通过mRNA水平表达的差异比较显示,飞蝗的两个P450基因CYP409A1和CYP408B1的表达受到抑制,均出现表达量减少的现象。【结论】某些细胞色素P450基因表达受不同亚致死剂量毒死蜱的抑制而使酶的量被降低,从而造成飞蝗整体细胞色素P450酶活性的下降。  相似文献   

10.
【目的】明确甜菜夜蛾Spodoptera exigua(Hübner)不同龄期幼虫对甲氨基阿维菌素苯甲酸盐和毒死蜱的敏感性及其与羧酸酯酶、多功能氧化酶、谷胱甘肽S-转移酶和乙酰胆碱酯酶活性的相关性。【方法】采用室内生物测定方法检测甜菜夜蛾不同龄期幼虫对药剂的敏感性,并检测了不同龄期幼虫体内羧酸酯酶、多功能氧化酶、谷胱甘肽S-转移酶和乙酰胆碱酯酶的活力。【结果】在所测定的5个龄期中,随龄期增加,敏感性逐渐降低,其中1~5龄幼虫对甲氨基阿维菌素苯甲酸盐的LC50分别为0.1010、0.3561、0.7568、1.4325和8.4390 mg/L,对毒死蜱的LC50分别为27.4632、46.8495、87.5222、129.3217和1 356.6770 mg/L。单头幼虫的羧酸酯酶、多功能氧化酶、谷胱甘肽S-转移酶和乙酰胆碱酯酶活力随虫龄的增加而提高,与龄期间对药剂的敏感性呈负相关(由于外源化合物摄入量减少,5龄单头幼虫的多功能氧化酶活力略有降低)。【结论】甜菜夜蛾不同龄期幼虫对药剂的敏感性存在非常明显的差异,在田间防治中,应选择对杀虫剂敏感性较高的低龄幼虫作为最佳防治时期。  相似文献   

11.
Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.  相似文献   

12.
The cell has been represented as a charged liquid drop. Contrary to the DLVO-theory, the effect of the surface potential upon the value of the interfacial tension of the cell membrane has also been taken into consideration. The cell membrane has visco-elastic properties and its constituents may move against each other. Cell movement is caused by the appearance of a small number of the electrically charged constituents of the cell membrane on the leading edge of the cell. This produces a local decrease in the surface tension and the cell membrane expansion. At the moment of contact between two cells proton transfers occur between the strongly negatively charged microvilli of one cell and the body of the other, analogous to a condenser breakdown. This, through the effect on the surface tension, causes contact inhibition of movement. The distribution of the proton dissociable groups modifies the interaction between the cells (differentiation) and between the cell and the substratum (adhesion). Adsorption of the charged compounds at the surface of the cell membrane, decreasing the surface potential and increasing the surface tension, causes the phenomena of chemotaxis, phagocytosis and pinocytosis. Cell division, considered in the terms of the surface energy, requires an adequate supply of considerable quantities of energy inversely proportional to the surface potential value. In case of a reduction of the distance between the cells, their surface potential and the energetic barrier of the cell division processes increases, and causes contact inhibition of cell division. Due to their high charge, division of neoplastic cells is inhibited much later than division of normal cells, or is completely ininhibited due to geometric conditions. Fusion of the cell membrane in the intra-cellular and intercellular processes is a reverse process in relation to the cell division.  相似文献   

13.
Acute and chronic toxicity tests for malathion, diazinon, copper (Cu), mercury (Hg), lead (Pb), zinc (Zn), nickel (Ni), and iron (Fe) were conducted. Mortalities ofBarilius vagra andCyprinus carpio (common carp) were variable but LC50-96 hr were similar for pesticides. AdultB. vagra seem to be more sensitive to malathion than juvenile carp. Both juvenile carp and adultB. vagra were extremely sensitive to diazinon. Long-term exposure to pesticides modified morphology and behavior. The LC50-96 values for Cu, Hg, and Pb were 0.3, 0.16, and 0.44, respectively, for smaller fish and 1.0, 0.77, and 1.33, respectively, for larger fish. Replicate LC50 values for Zn, Ni, and Fe were somewhat variable, and for these metals, the size of the fish seemed to affect response because LC50 values increased as fish size increased. Cooper, Pb, Zn, and Fe residues following exposure to sublethal concentrations of these metals for 15 d were significantly greater in whole juvenile common carp than in controls.  相似文献   

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The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.  相似文献   

16.
The sieve-element plastids of 69 species of theCaryophyllales were investigated by transmission electron microscopy. All contained the specific subtype-P3 plastids characterized by a peripheral ring of protein filaments. The presence or absence of an additional central protein crystal and their shape being either polygonal or globular as well as the average sizes of the sieve-element plastids are useful features in the characterization of some families.—Barbeuia contains sieve-element plastids that confirm its placement within thePhytolaccaceae. Lyallia differs fromHectorella by including small starch grains in their sieve-element plastids, which otherwise by their globular crystals negate a closer connection to theCaryophyllaceae. The lack of a central protein crystal in its form-P3fs plastids placesMicrotea best within theChenopodiaceae. Sarcobatus, a so far uncontested member of theChenopodiaceae, contains form-P3cf plastids, i.e., including a central crystal not found elsewhere in this family.Telephium andCorrigiola, shifted back and forth betweenMolluginaceae andCaryophyllaceae, have form-P3cf(s) plastids with a polygonal crystal which favor their placement within theCaryophyllaceae.  相似文献   

17.
The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum samples (n=110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three reconstituted reference serum samples by comparison with other methods and by the standard addition procedure. The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision, and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest in the environment, the relatively delicate sample handling, and the high cost of the equipment.  相似文献   

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The translocation of the radionuclides of Co, Zn, Se, Rb, Y, Tc, and Re into red and green fruits, flesh, seeds, rind, calyxes, flower, leaves, and stems via the root of the tomato plant at two different growth stages was studied by a multitracer technique. The contents (%/g) of Co, Zn, Se, and Y in the roots were the highest among the organs, but only small amounts of them were translocated into the aerial parts after 5 d cultivation with a multitracer. In contrast, Rb, Tc, and Re showed rapid translocation into the stems and leaves from the root. In the plants cultivated for 95 d with a multitracer, Zn, Se, and Rb distributed in all of the organs, Co in the organs except for flowers, and Y, Tc, and Re in the limited organs. The translocation ratio of the elements for the edible part of the plants cultivated for 95 d decreased in the order of Rb>Zn>Co≈Se>Tc≈Y>Re. The transfer factor of the elements for tomato fruit was determined to be in the range of 10−5–10−2. The characteristic translocation behavior of the elements gives us fundamental information on the assessment of pollutant uptake by the tomato plant.  相似文献   

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