Baculovirus-mediated expression of a Chinese scorpion neurotoxin improves insecticidal efficacy

An Buthus martensii Karsch Insect Toxin （BmK IT ） gene was inserted into the genome of Autographa californica multicapsid nucleopolyhedrovirus （AcMNPV） to construct a recombinant baculovirus, AcMNPV-BmK IT. The expression of BmK IT was confirmed using RT-PCR, dot blot and SDS-PAGE analysis. Dose-lethal time responses to Spodoptera exigua larvae were compared between wild-type baculovirus AcMNPV and recombinant virus AcMNPV-BmK IT. At the concentration of 1 × 10^7 PIBs/mL, the median lethal time of recombinant baculovirus （LT50 = 73.6 h） on third instar S. exigua larvae showed an improvement of 13.2% over the efficacy of wild type virus （LT50 = 84.8 h） during a 192 h infection.     

The role of β18-β19 loop structure in insecticidal activity of Cry1Ac toxin from Bacillus thuringiensis

The β18-β19 loop in domain Ⅲ of Cry1Ac toxin is unique among Bacillus thuringlensis Cry proteins. In this study, the role of the loop structure in insecticidal activity of Cry1Ac toxin was investigated. Alanine scanning mutations within the loop were initially generated and most mutants were over-expressed and reduced toxicity at different degrees, except mutant N546A that showed almost 2 times enhanced toxicity against Helicoverpa armigera larvae. Further mutagenic analysis of N546 revealed that a charged amino acid in this position would cause very unfavorable influence on insecticidal activity. In addition, the deletion of N546 led to protein instability because of destruction of the loop integrity. Besides, mutant W544F was much more toxic than W544Y, indicating that hydrophobic nature of the position was important for maintaining the stability and activity of Cry1Ac protein. These findings are the first biological evidence for a structural function of β18-β19 loop in insecticidal activity of the Cry1Ac toxin.     

杨树食叶害虫生物控制技术研究

为了有效、持续地控制舞毒蛾、天幕毛虫等杨树食叶害虫对林木的危害,同时还要尽量避免在对害虫进行化学防治时破坏生态环境,本次实验选用了苦参碱、蛇麻子素的植物提取液,还有Bt生物杀虫剂,以及天幕毛虫病毒分别对舞毒蛾幼虫、天幕毛虫幼虫进行杀虫试验.试验结果表明,上述药剂的不同浓度溶液对舞毒蛾幼虫、天幕毛虫幼虫均有不同程度的杀虫效果,其中对舞毒蛾幼虫以蛇麻子素提取液的杀虫效果较好,达到了100%,Bt生物杀虫剂的杀虫效果也达到了98%(400×溶液);对天幕毛虫幼虫的杀虫效果天幕毛虫病毒在13天后以1.824×106和1.824×107较好,达到了75%以上.     

烟碱型乙酰胆碱受体激动剂的3D-QSAR研究

对34个烟碱型乙酰胆碱受体激动剂采用比较分子场分析法(CoMFA)进行了结构与活性的关系研究,构建了CoMFA模型,该模型交叉验证相关系数为0.540,非交叉验证相关系数为0.952,证明该模型有较好的拟合能力和预报能力.通过等势图直观地给出了分子周围立体场(38.4 %)和静电场(61.6 %)对化合物活性的影响,为设计高活性的杀虫剂提供了理论依据.     

15%三·吡可湿性粉剂(商品名:稻麦灵)

该制剂系采用三唑酮和吡虫啉为有效成分的新型杀虫、杀菌剂,对蚜虫触杀速度快,是防治小麦病虫害的最佳新复配制剂.     

马拉硫磷对秀丽隐杆线虫的急性毒性研究

研究了马拉硫磷对秀丽隐杆线虫(Caenorhabditis elegans)形态、行为和生理生化等方面的影响,发现马拉硫磷可以导致线虫体型、繁殖能力、衰老、趋化性以及一些代谢酶类变化,但对线虫的寿命、运动能力和靶标酶并未产生显著影响.表明秀丽隐杆线虫对马拉硫磷有较强的耐受性,体内可能存在对马拉硫磷高效的代谢途径.     

蓖麻毒蛋白研究进展

蓖麻毒蛋白是在蓖麻中发现的,有很强的毒性,可抑制蛋白合成的蛋白质．作为一种重要的抗肿瘤药物及生物杀虫剂具有广阔的应用前景．对蓖麻毒蛋白的结构、毒性作用机理、纯化方法及其在肿瘤导向治疗和生物杀虫方面的研究进展进行了简述．     

五种杀虫剂对甜菜夜蛾的防效试验

通过室内测定和田间药效试验表明,除尽、米满和乐斯本杀虫剂对甜菜夜蛾具有优良的防效,生物杀虫剂虫瘟一号防治甜菜夜蛾也有较好的效果,它们可在生产中交替使用。抑太保对甜菜夜蛾防效差。     

一种改进的提取苏云金杆菌质粒DNA的方法

为了建立一种提取苏云金杆菌（Bacillus thuringiensis)质粒DNA的常规方法,介绍了一种改进的TritonX-100温和裂解法,与碱裂解法和SDS裂解法相比,具有简易、重复性好等优点,对采用该方法提取的质粒DNA进行电泳,取得了较理想的效果,说明这种方法较适用于苏云金杆菌质粒DNA的提取。     

苏云金杆菌4.0718菌株的发酵上清液中超氧化物歧化酶研究

将苏云金杆菌4.0718进行液体发酵培养，从发酵上清液中可以抽提得到SOD。经（NH4）2SO4分级沉淀、Sephadex G-75凝胶过滤和HPLC3步纯化得到均五性SOD，其比活力达1040U/mg。经检测该酶属Fe-SOD，分子量为39486D，由2个相同亚基组成，其N-末端氨基酸为丙氨酸，讨论了发酵上清液中SOD与晶体蛋白杀虫毒力的关系。