共查询到15条相似文献，搜索用时 640 毫秒
1.
为更好地了解苏云金芽胞杆菌Bacillus thuringiensis毒素蛋白对二点委夜蛾Athetis lepigone的毒力以及作用机理,通过饲喂含有Cry1Ac、Cry1Ab、Cry2Ab和Vip3Aa四种不同Bt毒素蛋白饲料,测定Bt毒素蛋白对二点委夜蛾幼虫的毒力,并观察取食4种毒素蛋白后幼虫中肠组织的病理学变化。结果显示,二点委夜蛾幼虫取食毒素蛋白后72 h,Cry1Ab和Cry1Ac毒素蛋白对二点委夜蛾幼虫的杀虫活性较高,校正死亡率为84.7%和76.4%;Vip3Aa和Cry2Ab毒素蛋白的毒力较弱。二点委夜蛾幼虫取食4种Bt毒素蛋白后,中肠柱状细胞微绒毛脱落,杂乱地分散在肠腔内,杯状细胞变形和腔内微绒毛脱落,线粒体和内质网等变形破裂,细胞核的核膜消失、核质凝聚和形状发生变化,经Cry1Ab和Cry1Ac毒素蛋白处理后中肠细胞的病变症状和速度明显高于Cry2Ab和Vip3Aa毒素蛋白处理。表明Cry1Ab和Cry1Ac毒素蛋白对二点委夜蛾幼虫杀虫活性较高,显著高于Cry2Ab和Vip3Aa毒素蛋白,且对其中肠细胞的破坏作用也较强。 相似文献
2.
为了明确Cry1F杀虫蛋白对亚洲玉米螟和黏虫两种重要玉米害虫的作用机制,本文通过透射电镜观察了亚洲玉米螟和黏虫4龄幼虫取食含Cry1F蛋白人工饲料后的中肠组织病理变化,并与其取食含Cry1Ab蛋白人工饲料后的组织病理变化进行了比较。亚洲玉米螟和黏虫4龄幼虫取食Cry1F蛋白48 h后中肠杯状细胞发生了明显的病变,主要表现为：细胞微绒毛肿胀、脱落;细胞核变形,质膜和核膜界限不清晰;染色质发生固缩、贴近核膜;线粒体拉伸变形数量减少,严重的发生空泡化;内质网肿胀与断裂、数量减少,与取食含Cry1Ab蛋白人工饲料相比,玉米螟和黏虫中肠组织发生的病变程度相似。本研究可为Cry1F作为转基因玉米重要的杀虫蛋白在未来亚洲玉米螟和黏虫防治中更好地发挥作用提供理论依据。 相似文献
3.
Cry1Ca对斜纹夜蛾、甜菜夜蛾等多种鳞翅目害虫具有很高的杀虫活性，它在转多种Bt蛋白基因策略中，可用于扩大杀虫谱，并可用于当前Bt蛋白的抗性治理，是极具潜力蛋白之一。为明确Cry1Ca对斜纹夜蛾的作用机制，我们利用透射电镜观察了幼虫取食Cry1Ca后中肠组织的病理变化。结果表明斜纹夜蛾取食含Cry1Ca蛋白的饲料2 h后中肠组织开始表现明显的病理变化，且随取食时间的增加病变越来越严重。具体表现为：中肠细胞微绒毛肿胀、扭曲、断裂和脱落；细胞核拉长或畸形、核膜模糊、染色质不均匀或聚集；线粒体变形、空泡化和内脊模糊不清；内质网杂乱无章、肿胀变形和数量变少。研究结果可为更好地利用Cry1Ca防治斜纹夜蛾提供理论依据。 相似文献
4.
本文研究了苦瓜Momordica charantia叶片提取物对黄曲条跳甲Phyllotreta striolata成虫的拒食活性,结果表明,用4000μg/ml苦瓜叶片乙醇提取物对黄曲条跳甲成虫的取食有明显的抑制作用。用石油醚、乙酸乙酯、正丁醇和水依次对苦瓜叶片乙醇提取物进行萃取,在4种萃取物中,乙酸乙酯萃取物对黄曲条跳甲成虫的拒食作用最强。用2000μg/ml和4000μg/ml的苦瓜叶乙酸乙酯萃取物处理甘蓝叶片48h后,在选择性试验中对黄曲条跳甲成虫的拒食率分别为41.42%和66.27%;在非选择性试验中的拒食率分别为30.90%和59.62%。 相似文献
5.
黄曲条跳甲幼虫致病菌的鉴定及其对黄曲条跳甲的杀虫活性研究 总被引：6，自引：0，他引：6
从自然死亡黄曲条跳甲幼虫体中分离出1株对黄曲条跳甲幼虫和成虫有较高致病性菌株PS-1。通过病原菌的形态观察、Biolog系统鉴定以及16S rDNA序列测定分析,确定菌株PS-1隶属于肠杆菌科、沙雷氏菌属的粘质沙雷氏菌Serratia marcescens族群。用菌株PS-1浓度为3×104、3×106和3×108 cfu/mL的菌悬液浸泡鲜萝卜块饲喂黄曲条跳甲幼虫24 h,4 d后的校正死亡率分别为36.1%、63.9%和75.0%;2、3和4 d的LC50分别是7.98×106、4.27×106和8.02×105 cfu/mL。用浓度1×108 cfu/mL的菌悬液处理菜心叶片饲喂黄曲条跳甲成虫,12 d的校正死亡率为23.25%。用浓度1×105、1×107和1×109 cfu/mL的菌悬液浸渍黄曲条跳甲卵,其孵化率与对照无显著差异。结果表明,粘质沙雷氏菌PS-1菌株对黄曲条跳甲成虫和幼虫有较强的毒力,在黄曲条跳甲的生物防治方面具有一定的应用前景。 相似文献
6.
黄曲条跳甲Phyllotreta striolata是为害十字花科蔬菜的重要害虫,长期使用大量的化学农药,不仅增强了黄曲条跳甲的耐药性,也会导致蔬菜农药残留增加,危害人们的饮食健康。因此,利用绿色防控手段防治害虫成为近些年的研究热点。本文在室内测定了以植物源甘油酯为主要成分的植物油乳剂、绿僵菌以及二者混配液对黄曲条跳甲成虫的毒力并对油菌混配液的田间防控效果进行了评价。室内毒力测定结果表明,施用植物油乳剂50～800倍液时,黄曲条跳甲成虫第2 d的死亡率为37.93%～100%;施用绿僵菌1.25×107～2×108孢子/mL时,黄曲条跳甲成虫第5 d的死亡率为32.2%～93.22%;施用植物油乳剂和绿僵菌混配液时,黄曲条跳甲成虫第1 d的死亡率在95%以上,显著高于2种单剂,且混配液能够极显著缩短黄曲条跳甲致死中时。田间试验结果表明,以植物油乳剂100倍液和绿僵菌1×108孢子/mL混配处理第6 d时,黄曲条跳甲成虫的相对防效和虫口减退率均达60%以上,第8 d时,黄曲条跳甲成虫的相对防效和虫口减退率分别为89.80%和74.62%,显著高于同时间同浓度2种单剂。本研究结果表明植物源甘油酯乳剂和绿僵菌在防治黄曲条跳甲方面具有显著的协同增效作用,二者混合使用可以弥补各自的防治缺点并有效地防治黄曲条跳甲。为探究和利用生物源农药之间的协同增效作用防控害虫提供了实用案例。 相似文献
7.
鱼藤酮与氟虫腈混用增效对黄曲条跳甲的控制作用 总被引：2，自引：3，他引：2
黄曲条跳甲是蔬菜重要害虫，生产实践中亟需高效安全的防治药剂。采用浸渍法从有机磷、拟除虫菊酯、新型杂环、植物源类等共16种常用杀虫剂中筛选出对黄曲条跳甲成虫触杀活性较高的鱼藤酮和氟虫腈，两者以3：2混用时，处理后24h对黄曲条跳甲成虫的LC50为9．60μg／mL，共毒系数为230．14，增效作用明显。以此配方配制成6％鱼氟乳油，质量稳定合格，触杀活性强，作用迅速，以0．45μg/cm^2和0．75μg/cm^2剂量药膜法处理后48h校正死亡率分别为83．72％和98．70％；以50μg/mL处理试虫致死中时LT50为10．12min。鱼氟乳油处理显著增强对黄曲条跳甲成虫呼吸的抑制作用可能是其主要增效机制。6％鱼氟乳油450mL／hm^2处理后10天内，田间虫口减退率为72％～96％．防治效果为90％以上。 相似文献
8.
暗黑鳃金龟Holotrichia parallela是一种重要的农业害虫,其成虫和幼虫均能对多种作物造成严重危害。为筛选对暗黑鳃金龟成虫具有毒杀活性的Bt蛋白,本研究首先对暗黑鳃金龟成虫的生活习性进行观察,用浸泡蛋白的榆树叶饲喂成虫,建立了Bt蛋白对暗黑鳃金龟成虫的生物学活性测定方法;制备了6种Bt Cry8类杀虫晶体全长蛋白和胰蛋白酶消化蛋白,对暗黑鳃金龟成虫进行了杀虫活性测定。初筛结果发现Cry8Ga1原毒素和消化蛋白均对暗黑鳃金龟成虫具有较高毒杀活性,其在浓度1.0 mg/mL时对暗黑鳃金龟成虫的7 d校正死亡率分别为100%和55%。为更进一步确定Cry8Ga1蛋白的杀虫活性,进行了致死中浓度测定,7 d生测结果显示,Cry8Ga1原毒素的LC50为0.387 mg/mL （95%置信区间为0.108~0.746 mg/mL）,Cry8Ga1蛋白经胰蛋白酶消化后的LC50为0.702 mg/mL （95%置信区间为0.150~2.664 mg/mL）。取食Cry8Ga1原毒素蛋白及其消化蛋白后的暗黑鳃金龟成虫中肠细胞产生显著的病理学变化。本研究筛选到对暗黑鳃金龟成虫有毒杀作用的Bt蛋白,研究结果将为金龟子的生物防治开辟新的途径。 相似文献
9.
为探讨TAT PTD对苏云金杆菌鞘翅目特效基因CryAa是否具有协同作用,本试验在实现了融合基因TAT PTD-Cry3Aa大肠杆菌原核表达的基础上,以甘薯小象甲为生测对象测定了原核表达产物PTD-Cry3Aa与Cry3Aa的毒力。结果表明,用大肠杆菌表达的Cry3A和PTD-Cry3Aa包涵体初提物均对甘薯小象甲成虫和幼虫有杀虫活性,且表现出一定毒力增效作用,对成虫的增效倍数为2.01倍,对幼虫的增效作用更加明显,达到3.19倍。这一研究结果对于甘薯小象甲的生物防治研究以及转基因抗虫甘薯的研究具有重要的指导作用。 相似文献
10.
Cry2Ab杀虫蛋白对小地老虎幼虫致死效果及体内酶活性的影响 总被引：5，自引：2，他引：3
为治理小地老虎的危害,研究了Bt杀虫蛋白对小地老虎幼虫的控制作用.室内生物测定结果表明,Cry2Ab杀虫蛋白对小地老虎初孵幼虫的致死效果高于Cry1Ac杀虫蛋白.取食含有Cry2Ab杀虫蛋白人工饲料的小地老虎幼虫体内的中肠总蛋白酶和类胰凝乳蛋白酶活性高于对照,当人工饲料中Cry2Ab杀虫蛋白含量达到12μg/g时,小地老虎幼虫中肠氨肽酶活性显著升高;而取食含有Cry1Ac杀虫蛋白人工饲料的小地老虎幼虫中肠蛋白酶活性无显著变化.此外,小地老虎幼虫取食含有Cry2Ab杀虫蛋白的人工饲料后,体内谷胱甘肽-S-转移酶活性显著升高,而取食合有Cry1Ac杀虫蛋白的人工饲料后其变化不明显. 相似文献
11.
氨肽酶N(APN)是锌金属蛋白酶M1家族的成员,鳞翅目昆虫中肠刷状缘膜囊泡(brush border membrane vesicles,BBMV)细胞膜上的APN不仅在蛋白消化吸收过程中起着重要的作用,而且是Bt的重要受体蛋白.本研究通过PCR技术克隆得到7条棉铃虫APN基因全长序列,HaAPN1～7(Genbank... 相似文献
12.
Camila Ochoa-Campuzano Amparo C. Martínez-RamírezEstefanía Contreras Carolina RausellM. Dolores Real 《Pesticide biochemistry and physiology》2013
Bacillus thuringienesis (Bt) Cry toxins constitute the most extensively used environmentally safe biopesticide and their mode of action relies on the interaction of the toxins with membrane proteins in the midgut of susceptible insects that mediate toxicity and insect specificity. Therefore, identification of Bt Cry toxin interacting proteins in the midgut of target insects and understanding their role in toxicity is of great interest to exploit their insecticidal action. Using ligand blot, we demonstrated that Bt Cry3Aa toxin bound to a 30 kDa protein in Colorado potato beetle (CPB) larval midgut membrane, identified by sequence homology as prohibitin-1 protein. Prohibitins comprise a highly conserved family of proteins implicated in important cellular processes. We obtained the complete CPB prohibitin-1 DNA coding sequence of 828 pb, in silico translated into a 276-amino acid protein. The analysis at the amino acid level showed that the protein contains a prohibitin-homology domain (Band7_prohibitin, cd03401) conserved among prohibitin proteins. A striking feature of the CPB identified prohibitin-1 is the predicted presence of cadherin elements, potential binding sites for Cry toxins described in other Bt susceptible insects. We also showed that CPB prohibitin-1 protein partitioned into both, detergent soluble and insoluble membrane fractions, as well as a prohibitin-2 homologous protein, previously reported to form functional complexes with prohibitin-1 in other organisms. Prohibitin complexes act as membrane scaffolds ensuring the recruitment of membrane proteases to facilitate substrate processing. Accordingly, sequestration of prohibitin-1 by an anti-prohibitin-1 antibody impaired the Cry3Aa toxin inhibition of the proteolytic cleavage of a fluorogenic synthetic substrate of an ADAM-like metalloprotease previously reported to proteolize this toxin. In this work, we also demonstrated that prohibitin-1 RNAi silencing in CPB larvae produced deleterious effects and together with a LD50 Cry3Aa toxin treatment resulted in a highly efficient short term response since 100% larval mortality was achieved just 5 days after toxin challenge. Therefore, the combination of prohibitin RNAi and Cry toxin reveals as an effective strategy to improve crop protection. 相似文献
13.
Taisuke Kato Ryo Endo Kousuke Haginoya Tohru Hayakawa Ryoichi Sato 《Pesticide biochemistry and physiology》2006,84(1):1-9
We evaluated the ability of Cry1Aa9, Cry1Ab4, and Cry1Ac1 insecticidal toxins from Bacillus thuringiensis to destroy liposomes. Cry1A toxins are thought to form pores in midgut apical cell membranes (BBMV), thereby disrupting midgut cells. Liposomes containing fluorescent calcein were prepared using phosphatidylcholine (PC) and phosphatidylserine (PS) (PC/PS-Liposomes) or PC alone (PC-Liposomes). Cry1Ab (1.4 μM), but not Cry1Aa or Cry1Ac, disrupted PC/PS-Liposomes and PC-Liposomes. PC/PS-Liposomes containing cholesterol and oligosaccharylceramide from Plutella xylostella midgut were damaged even more extensively by Cry1Ab, but the inclusion of either lipid alone had no effect. The initial velocity of Cry1Ab-mediated liposome disruption increased 17-fold when liposomes were prepared with Triton X-100-soluble proteins from Bombyx mori BBMV and PC (PC/Proteo-Liposomes), and Cry1Aa and Cry1Ac also caused slight disruption. These data suggest that Cry1Ab achieves higher penetration into PC/PS-Liposomes, PC-Liposomes, and PC/Proteo-Liposomes compared with Cry1Aa or Cry1Ac and that Cry1Ab may interact with membrane proteins. 相似文献
14.
从二点委夜蛾幼虫体内首次分离到一种微孢子虫ED2013,用透射电镜观察了该微孢子虫感染二点委夜蛾幼虫后中肠的病理变化。结果发现寄主被感染后,中肠细胞微绒毛与杯状细胞的细胞质突起存在肿胀并掉落的情况;有些细胞核出现明显变形及膨大,或被挤压成长条状,细胞核内未发现微孢子虫侵入;部分线粒体略微肿胀变形,嵴的排列方向发生变化,随着感染时间延长而逐渐降解;细胞质中的粗面内质网上附着的核糖体脱落,后期感染严重阶段断裂成小段。染病后期的中肠细胞内充满微孢子虫,细胞质中的各细胞器均出现严重降解。根据研究结果并结合前人成果,认为该微孢子虫侵染二点委夜蛾的病理过程是从中肠细胞的病理变化开始并最终导致细胞破裂,逐渐扩大到寄主组织和器官,使其功能丧失,重者死亡。 相似文献
15.
Yulin Gao Juan Luis Jurat‐Fuentes Brenda Oppert Jeffrey A Fabrick Chenxi Liu Jianhua Gao Zhongren Lei 《Pest management science》2011,67(9):1076-1081
BACKGROUND: Biopesticides containing Cry insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) are effective against many lepidopteran pests, but there is a lack of Bt‐based pesticides for efficient control of important coleopteran pests. Based on the reported increase in Bt toxin oligomerization by a polypeptide from the Cry3Aa receptor cadherin in Tenebrio molitor (Coleoptera: Tenebrionidae), it was hypothesized that this cadherin peptide, rTmCad1p, would enhance Cry3Aa toxicity towards coleopteran larvae. To test this hypothesis, the relative toxicity of Cry3Aa, with or without rTmCad1p, against damaging chrysomelid vegetable pests of China was evaluated. RESULTS: Cry3Aa toxicity was evaluated in the spotted asparagus beetle (Crioceris quatuordecimpunctata), cabbage leaf beetle (Colaphellus bowringi) and daikon leaf beetle (Phaedon brassicae). To assess the effect of rTmCad1p on Cry3Aa toxicity, neonate larvae were fed Cry3Aa toxin alone or in combination with increasing amounts of rTmCad1p. The data demonstrated that Cry3Aa toxicity was significantly increased in all three vegetable pests, resulting in as much as a 15.3‐fold increase in larval mortality. CONCLUSION: The application of rTmCad1p to enhance Cry3Aa insecticidal activity has potential for use in increasing range and activity levels against coleopteran pests displaying low susceptibility to Bt‐based biopesticides. Copyright © 2011 Society of Chemical Industry 相似文献