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1.
嗜线虫致病杆菌北京变种Xenorhabdus var.pekingensis CB6菌株是本研究室自主分离的新菌株,其代谢物对棉铃虫具有很强的拒食和抑制生长活性.为了进一步明确代谢物中杀虫蛋白的生物活性,作者用饲料染毒法和叶碟法测定了杀虫蛋白对棉铃虫不同龄期幼虫取食和生长发育的影响.结果表明,杀虫蛋白对棉铃虫幼虫有很强的抑制生长作用,用64μg/g含杀虫蛋白饲料饲喂初孵、1、2和3龄幼虫5天的生长抑制率分别达95.37%、92.73%、87.15%和88.64%,并明显延长幼虫发育历期,影响幼虫的化蛹及蛹的羽化.杀虫蛋白对5龄棉铃虫幼虫拒食效果明显,幼虫饲喂经1.6mg/mL杀虫蛋白处理的叶片24h,选择性拒食率和非选择性拒食率分别为76.22%和85.42%.当蛋白浓度为0.32mg/mL时,24h选择性拒食和非选择性拒食率分别为68.39%和74.75%.  相似文献   

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研究了昆虫病原线虫共生细菌4个种和1组未定名种28个菌株发酵液对棉铃虫、菜青虫幼虫的致死、抑制生长和拒食作用。嗜线虫致病杆菌对棉铃虫幼虫具有较高的口服毒性,含20%(V/W)嗜线虫致病杆菌CBl2、CB6、CB5、CB28菌株发酵液的人工饲料饲喂棉铃虫初孵幼虫6天后,幼虫校正死亡率分别为97.7%、88.7%、88.4%和88.4%,饲喂棉铃虫3龄幼虫5天后,相对生长抑制率分别为96.4%、95.1%、95.6%和93.8%,上述菌株发酵原液涂抹白菜叶片饲喂5龄棉铃虫幼虫24h后相对拒食率分别为87.6%、83.6%、91.4%和89.8%;光杆状菌CBl、cBl52菌株、嗜线虫致病杆菌CB19菌株和波氏致病杆菌CB32菌株发酵原液涂抹白菜叶片饲喂菜青虫24h后,相对拒食率分别为82.7%、77.2%、75.8%和75.0%。  相似文献   

4.
草地贪夜蛾是一种世界性重大农业害虫,给玉米等多种主要粮食和经济作物造成严重危害。为实现对草地贪夜蛾的高效、绿色、持续防控,亟需筛选高毒力苏云金芽胞杆菌菌株资源。本研究以前期实验室储备的对斜纹夜蛾、小地老虎具有杀虫活性的363株野生菌株库为候选菌株,基于菌株杀虫基因差异及进化关系,去除冗余菌株后获得172株候选菌株。通过培养获取这些菌株胞晶混合物,进行杀虫蛋白定量后,测定杀虫活性,获得27株对草地贪夜蛾初孵幼虫具有较高杀虫活性的菌株,其中菌株B14-D2的杀虫活性最高,LC50为0.155 μg/g。克隆了该菌株中的cry1Ea3基因并在HD73-无晶体突变株中表达,Cry1Ea3蛋白对草地贪夜蛾初孵幼虫LC50为1.789 μg/g。本研究为新的Bt产品和杀虫基因的开发利用提供了丰富资源。  相似文献   

5.
为评估转cry1Ab/cry2Aj、cry1Ab/vip3DA玉米对棉铃虫Helicoverpa armigera(Hübner)、甜菜夜蛾Spodoptera exigua(Hübner)和斜纹夜蛾Prodenia litura(Fabricius)的抗虫性,在室内测定了3个转cry1Ab/cry2Aj玉米品系和1个转cry1Ab/vip3DA玉米品系对3种害虫幼虫存活和生长发育的影响,研究了该系列Bt玉米不同组织器官对害虫的杀虫活性和控制效果。结果显示,棉铃虫初孵幼虫取食各品系Bt玉米叶片96h后死亡率为87.50%~90.00%,取食花丝和雌穗的幼虫96h后几乎全部死亡;甜菜夜蛾初孵幼虫取食各品系Bt玉米叶片、花丝和雌穗168h后死亡率为22.50%~68.33%,幼虫的生长发育受到明显抑制,体重抑制率达85.00%~95.00%;斜纹夜蛾初孵幼虫取食各品系Bt玉米叶片、花丝和雌穗96 h后死亡率显著高于非转基因亲本对照,168h后幼虫死亡率达90.00%以上。研究表明,转cry1Ab/cry2Aj和cry1Ab/vip3DA玉米品系对棉铃虫和斜纹夜蛾的初孵幼虫表现出较好的抗性,可以作为转多基因抗虫玉米育种的备选材料。  相似文献   

6.
昆虫病毒重组增效蛋白的广谱增效活性   总被引:7,自引:1,他引:7  
室内生物测定表明 ,大肠杆菌表达的粉纹夜蛾颗粒体病毒重组增效蛋白P96可显著或极显著提高棉铃虫核型多角体病毒、苏云金杆菌和阿维菌素对棉铃虫幼虫的致死率 ,分别提高1 6 9.78%、73.90 %和 36 .0 4 % ;对苜蓿丫纹夜蛾核型多角体病毒感染甜菜夜蛾幼虫也有明显增效作用。Na2 CO3 溶解的P96对棉铃虫初孵幼虫有一定致死作用。  相似文献   

7.
嗜线虫致病杆菌北京变种Xenorhabdus nematophila var. pekingensis CB6菌株产生的蛋白XnAFP2对多种昆虫有拒食活性。生物信息学分析表明,XnAFP2包含DomainⅠ、DomainⅡ和DomainⅢ3个功能结构域。为确定其主效活性区域,分别对3个结构域进行了克隆、表达和生物活性测定。结果表明,3个蛋白片段对棉铃虫Helicoverpa armigera3龄幼虫的生长抑制率分别为17.4%、39.8%和20.2%,对玉米螟Ostrinia furnacalis3龄幼虫的生长抑制率分别为20.2%3、8.6%和21.7%,对小菜蛾Plutella xylostella3龄幼虫的非选择性拒食率分别为25.7%、44.1%和26.8%。研究结果表明,DomainⅡ是拒食蛋白XnAFP2的主效活性区域。  相似文献   

8.
采用桑叶浸渍法和饲料表面覆盖法测定发现,从土壤中分离的一株苏云金芽胞杆菌菌株GS8对家蚕Bombyx mori、甜菜夜蛾Spodoptera exigua和棉铃虫Helicoverpa armigera初孵幼虫均表现出较高的杀虫活性,经形态学和生理生化反应鉴定该菌株为东北亚种(Bacillus thuringiensis subsp.tohokuensis)。聚丙烯酰胺凝胶电泳(SDS-PAGE)分析结果表明,GS8菌株的杀虫蛋白晶体主要由分子质量为130、81和60 kDa的蛋白组成。聚合酶链反应-限制性片段长度多态性(PCR-RFLP)鉴定结果显示,GS8菌株含有 cry1Aa、cry1Ab、cry1Ib、cry2Ab和cry9Ba 等基因。  相似文献   

9.
杀虫荧光假单胞工程菌对棉铃虫的离体及活性生物测定   总被引:3,自引:0,他引:3  
利用转座子mini-Tn5将δ-毒素基因cryIA(c)整合到生防细菌荧光假单胞菌P303-1染色体上,构建成荧光假单胞工程菌,以棉铃虫二龄幼虫作供试昆虫的离体生测表明:在同一剂量水平上, PT45、PT51、PT61、PT71等工程菌株对棉铃虫幼虫的杀虫活性均高于野生菌株HD-73。浓度最高时PT45、PT51、PT61、PT71、HD-73处理棉铃虫的死亡率分别为86.7%、76.7%、80.0%、86.7%、70.0%,死亡率与浓度呈正相关,体重与浓度呈负相关,用上述工程菌接种棉花活体,喷雾处理3周后,用棉叶饲喂的棉铃虫死亡率分别达70.0%、60.0%、60.0%、66.7%、33.3%,用棉顶尖饲喂的棉铃虫死亡率分别达70.0%、63.3%、26.7%。73.3%、30.0%;用棉蕾饲喂的棉铃虫死亡率分别为63.3%、53.3%、50.0%、63.3%、26.7%。  相似文献   

10.
杀虫荧光假单胞工程菌对棉铃虫的离体及活体生物测定   总被引:1,自引:0,他引:1  
利用转座子mini Tn5将δ 毒素基因cryIA(c)整合到生防细菌荧光假单胞菌P30 3 1的染色体上 ,构建成荧光假单胞工程菌。以棉铃虫二龄幼虫作供试昆虫的离体生测表明 :在同一剂量水平上 ,PT4 5、PT51、PT6 1、PT71等工程菌株对棉铃虫幼虫的杀虫活性均高于野生菌株HD 73;浓度最高时PT4 5、PT51、PT6 1、PT71、HD 73处理棉铃虫的死亡率分别为 86 7%、76 7%、80 0 %、86 7%、70 0 % ,死亡率与浓度呈正相关 ,体重与浓度呈负相关。用上述工程菌接种棉花活体 ,喷雾处理 3周后 ,用棉叶饲喂的棉铃虫死亡率分别达 70 0 %、6 0 0 %、6 0 0 %、6 6 7%、33 3% ;用棉顶尖饲喂的棉铃虫死亡率分别达 70 0 %、6 3 3%、6 0 0 %、73 3%、30 0 % ;用棉蕾饲喂的棉铃虫死亡率分别为 6 3 3%、53 3%、50 0 %、6 3 3%、2 6 7%。  相似文献   

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寄生蜂毒液和卵巢蛋白在寄生过程中起着重要作用,蛋白成分和性质的研究日益深入。本文主要通过SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)试验,分析了腰带长体茧蜂毒液和卵巢蛋白的分子量组成。结果表明,腰带长体茧蜂毒液蛋白图谱显示约有7条蛋白带介于43~100kDa之间,含量较高的三条带为97kDa、64kDa、45kDa;卵巢蛋白图谱显示约有12条蛋白带,位于30~200kDa之间,含量较高的两条带为39kDa、43kDa。并对毒液和卵巢的生物学功能进行了探讨。  相似文献   

13.
 葡萄座腔菌(Botryosphaeria dothidea)是引起多种果树和林木枝干溃疡病和果实腐烂病的重要病原菌。为明确葡萄座腔菌的致病机理,采用SignalP、WoLF PSORT、TMHMM、GPI-SOM等软件,对葡萄座腔菌全基因组14 998条蛋白序列进行了分泌蛋白预测和功能分析。结果表明B.dothidea全基因组编码蛋白中有851条序列具有典型的分泌蛋白特征,占蛋白总数的5.67%,其长度主要分布在100~700个氨基酸范围内。信号肽的分析结果表明,以19个氨基酸为信号肽的分泌蛋白数目最多,非极性氨基酸丙氨酸(A)在信号肽中的使用频率最高,而有带电侧链的天冬氨酸(D)和谷氨酸(E)使用频率最低,信号肽-3和-1位置的氨基酸相对保守,其切割位点属于典型的A-X-A型。对分泌蛋白功能预测结果表明,578个分泌蛋白获得了功能注释,其功能主要涉及碳水化合物的运输、代谢过程,蛋白翻译后修饰和氨基酸代谢、运输过程。分泌蛋白中效应蛋白(effector)预测结果表明,B. dothidea分泌蛋白中共有119个潜在的效应蛋白,其中11个可被PHI数据库注释到,其与引起其他植物病原菌致病力变化的致病效应蛋白具有较高的相似性。碳水化合物活性酶类(CAZymes)的预测结果表明,B. dothidea分泌蛋白组中共有279个CAZymes,其中GHs家族最多。这些结果的获得为今后进一步筛选B. dothidea的效应蛋白,明确B. dothidea的致病机理,以及筛选寄主新的抗性基因提供了必要的基础。  相似文献   

14.
昆虫抗寒性的研究进展   总被引:4,自引:0,他引:4  
由于季节的变化,生活在温带和寒带的昆虫在生活史中都要面临冬季低温的制约。为繁衍后代,昆虫在长期的进化过程中,形成了一系列的适应对策和抗寒机制。本文综述了昆虫的越冬虫态、生态适应性、抗寒的生理生化及分子机理,包括过冷却点、体内含水量、冰核物质、抗寒性物质变化等抗寒机制,特别是对近年来引起关注的抗冻蛋白和热激蛋白的基因、结构、功能等的研究进展进行了综述,最后探讨了昆虫抗寒性研究与预测预报及害虫综合防治的关系。  相似文献   

15.
格氏线虫表皮蛋白和分泌蛋白都具有抑制昆虫免疫反应的能力,能够帮助侵染期线虫侵染寄主,但两者所含蛋白组分并不相同,从而导致蛋白活性也有所差异。本研究采用乙醇萃取和昆虫匀浆诱导,分别从侵染期的格氏线虫体表及分泌物中得到了表皮蛋白和分泌蛋白,并比较了这两者之间的异同。结果表明,无论是在昆虫体内还是体外,侵染期线虫表皮蛋白和分泌蛋白都具有抑制昆虫免疫反应的生物活性,并且分泌蛋白的活性更强。本研究为进一步研究线虫侵染与昆虫免疫间的相互关系和线虫抑制昆虫免疫反应的作用机理提供了科学佐证。  相似文献   

16.
Plant growth promoting rhizobacteria (PGPR) include bacteria that fix nitrogen (e.g., Rhizobiaceae, Herbaspirillum, Azoarcus), produce phytohormones (e.g., Azospirillum) and provide protection against fungal and/or bacterial pathogens (e.g., Pseudomonas, Bacillus, Streptomyces). Interactions between PGPR and plants can be divided into different steps which include initial attraction, attachment, proliferation and colonization e.g., of roots, stem, leaves and flowers. At the genetic level the expression of many bacterial genes are altered during these processes. In addition to the interaction with the plant, PGPR interact and compete with the endogenous microflora, consisting of other bacteria, fungi and/or mycorrhizal fungi. In the case of biocontrol bacterial strains, a direct interaction with the pathogen is often required to suppress the disease. Microscopic analyses of plant growth promoting rhizobacteria (PGPR) in their natural environment and in specific during their interaction(s) with the host plant(s) and/or their target organism(s) is essential for the elucidation of their functioning and the successful application of commercial inoculants. With the discovery and development of auto fluorescent proteins (AFPs) as markers and the development of highly sophisticated fluorescence microscopes such as confocal laser scanning microscopes, a new dimension has been created for studying PGPR in their natural environment. This paper will give a short overview on available tools, the application of AFPs in PGPR research and some future perspectives. Several recent reviews will give the reader an option for further reading (Bloemberg and Lugtenberg 2004; Chalfie and Kain 2005; Larrainzar et al. 2005; Rediers et al. 2005; Bloemberg and Camacho 2006).  相似文献   

17.
The aim of this study was to learn more about the accumulation of defense-related proteins in stem tissue from carnation cultivar Pallas inoculated with 2 near-isogenic races, the avirulent race 1 and the virulent race 8 of Fusarium oxysporum f.sp. dianthi. Stem tissue was used, from which the epidermis, cortex and medulla were peeled off from the vascular cylinder. It appeared that chitinase activity was constitutively expressed in the intercellular fluids (IFs) of untreated leaves, stems and roots of carnation. The total chitinase activity in the IFs of stem tissue increased with time after inoculation. This increase was similar after inoculation with the virulent, the avirulent race and water. At least four chitinase isoenzymes, three acidic and one basic isoform, were detected in the IFs of inoculated plants. In contrast, total 1,3--glucanase activity was not detected in the IFs of untreated leaves, stems and roots. Furthermore, the increases in 1,3--glucanase activity in IFs of stem tissue were markedly higher in the compatible and incompatible interactions than in the water control, indicating that this activity is specially induced by elicitors common to both races 1 and 8 of Fusarium oxysporum f.sp. dianthi. Using an antiserum against 1,3--glucanase P3 of tomato, 2 bands were detected on immunoblots in the IFs of stem tissue inoculated with races 1 and 8. No bands were visible after inoculation with water. Total peroxidase activity increased with time in all combinations. One basic and one acidic peroxidase isoform were present in these IFs. Peroxidase activity in a cell wall fraction prepared from stem tissue was clearly higher, and its increase faster, than the activity in the soluble stem fraction. These increases were similar in the virulent, the avirulent race and the water control. The growth of the fungus Trichoderma viride was inhibited by the IFs obtained from stem tissue inoculated with the virulent and the avirulent race of Fusarium oxysporum f.sp. dianthi. However, the growth of Fusarium oxysporum f.sp. dianthi itself was not affected by these IFs.  相似文献   

18.
The fungal infection of emmer grain (Triticum dicoccum) with Fusarium graminearum and Fusarium culmorum was investigated at the level of the proteome. High‐resolution two‐dimensional gel electrophoresis and mass spectrometry were used to identify proteins that were differentially expressed in response to fungal infection of emmer. Moreover, the effects of natural field conditions at two locations on the carbon and nitrogen contents and the mycotoxin concentration of emmer grains were evaluated. Inoculation of emmer with a mixture of the two Fusarium species led to infection of the ears, with deoxynivalenol concentrations up to 10 mg kg?1 in the grain. Carbon concentration and crude protein content were not significantly changed, but 10 distinct proteins changed in abundance. Stress‐related proteins, such as a serine protease inhibitor, a thaumatin‐like protein that reduced fungal growth and the starch hydrolysis β‐amylase increased upon infection, whereas the stress‐related proteins peroxidase, peroxiredoxin, a starch‐synthesis protein (a glycosyltransferase) and a fungal cell wall degrading protein (a chitinase) decreased. Furthermore, levels of three storage proteins in emmer grains were affected by Fusarium infection: α‐gliadin decreased and two globulins increased upon infection.  相似文献   

19.
Fusarium oxysporum (Fo) is an important soil-borne fungus that cause huge economic losses worldwide. Fungal-specific Common in Fungal Extracellular Membrane (CFEM) proteins are known to be involved in some important physiological processes associated with pathogenicity. To date, few Fo CFEM proteins have been characterized. The recent publication of several genomes of Fo has allowed us to conduct a genome-wide comparison analysis of CFEM proteins in Fo. In this study, we identified CFEM proteins for 12 different Fo formae speciales(f. sp) and obtained an average of 16 CFEM proteins for each Fo. The Fo CFEM proteins were classified into three groups (groups 1–3) according to structural features. Importantly, we identified a new conserved motif containing about 50 amino acids (DR motif) in group 1 members. CFEM proteins containing DR motif (CFEM_DR proteins) are remarkably conserved among Fo, and their number is greater in Fo compared with other fungi. We found the expansion of CFEM_DR proteins in Fo can be attributed to the segmental duplications in the genomes. Expression analysis revealed that CFEM_DR genes had a higher expression level in mycelium than conidia, and their expressions increased dramatically in the host roots at 3 days post inoculation, indicating that Fo CFEM_DR genes have roles while colonizing and infecting their hosts.  相似文献   

20.
产抗菌蛋白芽孢杆菌的筛选及抗菌蛋白性质   总被引:23,自引:1,他引:23  
对小麦赤霉病菌(JF-12)有拮抗作用的76个芽孢杆菌菌株中有30个能产生抗菌物质。根据无细胞培养滤液对氯仿和热处理的稳定性将30个菌株分成三类。属于类型I的14个菌株中,B3、Ant-27和Ant-64的抗菌物质可以被80%饱和度硫酸铵沉淀,不能通过透析膜。B3的粗提抗菌蛋白对胰蛋白酶、蛋白酶K和RNA酶均不敏感;在pH5.0 ̄10.0范围内,抑菌活性与对照无显著差别;热处理(60℃/30min  相似文献   

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