转CpTI基因杨树对美国白蛾幼虫中肠解毒酶及乙酰胆碱酯酶的影响

以转CpTI基因毛白杨回交杂种 [(Populustomentosa×Populusbolleana)×Populustomentosa]叶片饲喂 4～ 5龄美国白蛾 (HyphantriacuneaDrury)幼虫 ,对其中肠解毒酶和乙酰胆碱酯酶活性进行了测定。结果表明 ,酯酶、羧酸酯酶的活力受到明显抑制 ,且随时间的延长抑制强度增加 ,饲喂 48h后 ,上述两种酶的活力分别比对照降低 76 .42 %和 73.91% ;多功能氧化酶在饲喂的前 12h ,表现为受到抑制 ,最大抑制率为 35 .78% ,2 4h后酶活力反而高于对照 ;谷胱甘肽S -转移酶和乙酰胆碱酯酶活力受到抑制 ,而且两者表现极为相似 ,均在饲喂后 4h抑制作用最强 ,酶活力分别比对照降低 5 1.40 %和 40 .5 7% ,但在整个试验过程中 ,均没有表现出随时间加强的趋势。     

百脉根谷胱甘肽硫转移酶基因的载体构建与检测

[目的]探讨百脉根谷胱甘肽硫转移酶基因（LcGST）的作用。[方法]通过DNA重组技术将LcGST与中间表达载体pGN连接。[结果]成功构建了植物表达载体pGN-LcGST。[结论]pGN-LcGST载体的获得为进一步研究其在异源植物中的功能奠定了基础。     

不同浓度重铬酸钾溶液胁迫对洋葱根尖生理生化特性的影响

研究不同浓度重铬酸钾溶液及不同处理时间对洋葱(Allium cepa L.)根尖细胞有丝分裂和植物保护酶系统的影响,旨在为探究重金属铬作用于植物体的生理生化机理提供参考。分别用0、12.5、25.0、50.0、100.0、200.0 mg/L重铬酸钾溶液处理洋葱根尖6、12、18、24 h,而后收集洋葱根尖组织,分别用于洋葱根尖组织石蜡切片、苏木素染色观察和测定根尖细胞中的超氧化物歧化酶、过氧化氢酶、谷胱甘肽-S转移酶活性及丙二醛含量。结果表明,不同浓度重铬酸钾溶液处理洋葱根尖不同时间后,细胞有丝分裂出现异常分裂,并伴有微核的产生;无论处理时间长短,随着处理浓度的增加,细胞中的超氧化物歧化酶、过氧化氢酶、谷胱甘肽-S转移酶活性都呈现先上升、后下降的变化趋势,而丙二醛含量先缓慢下降、后迅速上升;当处理浓度一定时,随着处理时间的延长,细胞中的超氧化物歧化酶、过氧化氢酶、谷胱甘肽-S转移酶活性呈上升趋势,而丙二醛含量呈缓慢下降趋势。说明重铬酸钾溶液对洋葱具有一定的细胞毒性作用,可能与调控细胞中各种酶系统的活性及含量有关。     

几种植物源提取物对毒死蜱的增效作用及机理

毒死蜱是一种广谱、高效、低残留的有机磷农药,由美国Dow化学公司开发,是迄今世界上产量最大的农药品种之一[1],也是中国规划用于替代高毒有机磷农药的品种之一.毒死蜱具有触杀、胃毒和熏蒸作用[2],能有效地防治水稻、小麦、玉米、棉花、甘蔗、茶叶、果树、花卉和畜牧等方面百余种害虫,已经在美国、日本、澳大利亚、加拿大等10多个国家和地区登记注册[3],有广阔的市场和应用前景.     

mRNA差异显示技术分离羊草基因体外培养过程中特定基因及特性分析

羊草种质资源中储存着潜在的优良基因,本研究从分子生物学角度,对来自羊草基因型W4不同幼穗的愈伤组织中差异表达的基因进行了研究。采用DDRT-PCR技术对其差异表达的基因进行了分离,通过银染技术显示差异片段。将得到的差异片段进行回收、克隆测序,得到2个差异片段序列,经过序列分析表明,其中1个片段是与水稻翻译延伸因子eEF-1基因高度同源;另一差异片段与水稻谷胱甘肽转移酶GST基因高度同源。     

Application of recombinant Sjc26GST for serodiagnosis of Schistosoma japonicum infection in water buffalo (Bos buffelus)

Schistosomiasis japonica is currently the most serious parasitic disease in mainland China and it is estimated that several million people are infected. Furthermore, it is also responsible for the deaths of many domestic animals. In order to establish an effective diagnostic method, the gene encoding Sjc26GST was cloned and expressed in Escherichia coli as a fusion protein with His-tag. The purified reSjc26GST was used as an antigen for an enzyme-linked immunosorbent assay (ELISA) and for immunoblotting detection of Schistosoma japonicum antibodies in water buffaloes. Our results showed that mean OD values of specific serum IgG antibodies from egg-positive buffaloes were 3.37-fold higher than what was found in egg-negative buffaloes from non-endemic areas. The data also showed the OD value of the endemic egg-negative group reached as high as 1.69 times as that found in non-endemic areas. The positivity rate of egg-positive buffaloes was 100%, but was 30.3% in the endemic egg-negative group. Infected bovine antisera also recognized reSjc26GST, a 27 kDa protein as determined by Western blot. These results suggest that the recombinant GST expressed in E. coli should be an effective diagnostic reagent for detection of antibody against S. japonicum in buffaloes. Due to straightforward production, excellent sensitivity and high specificity, the reSjc26GST described in this study can be considered as a candidate protein for immunological diagnosis of bovine schistosomiasis. Developing reSjc26GST, with its potential diagnostic values, will be useful for diagnosis and surveillance of schistosomiasis in controlling the spread of this parasitic disease in domestic animals.     

聚乙二醇胁迫对假俭草谷胱甘肽转硫酶活性的影响

为探明谷胱甘肽转硫酶(GST)在水分胁迫中的作用，分别用聚乙二醇6000模拟干旱处理假俭草不同时间后，测定假俭草植株的质膜电解质渗透率，GST活性，H2O2和还原型谷胱甘肽(GSH)含量．结果表明：PEG胁迫使幼苗H2O2积累，质膜电解质渗透率增加，GSH含量升高；胁迫处理后幼苗中GST活性明显高于对照，在4d内，随着水分胁迫处理时间的延长，GST活性逐渐升高．GST活性与H2O2的含量相关，表明GST不但能清除H2O2引起的有害物质，同时还很可能受H2O2的调节．     

小鼠Nanog基因原核表达载体的构建及表达

【目的】构建小鼠Nanog基因原核表达载体并进行表达，以期得到大量GST融合蛋白。【方法】根据GeneBank中的Nanog序列及pGEX-KG中的多克隆位点设计引物，以含有Nanog基因片段的pNA992重组质粒为模板，经PCR扩增出918 bp的DNA片段。将所得片段与pGEX-KG载体连接，转化TGⅠ大肠杆菌，筛选阳性克隆，其扩增片段测序结果与原序列一致，表明原核表达载体pGEX-KG-Nanog已构建成功。提取pGEX-KG-Nanog质粒转化到BL21（DE3）表达菌株中，经IPTG诱导后收集菌体进行SDS-PAGE电泳鉴定，并优化其表达条件。【结果】在大肠杆菌中获得Nanog基因融合表达，主要以包涵体形式存在；融合蛋白的分子量为63 kD；以IPTG终浓度为0.8 mmol•L-1，诱导5 h后融合蛋白产量最高。【结论】小鼠Nanog基因在大肠杆菌中获得了高效表达，为今后Nanog蛋白的多克隆抗体制备奠定基础。     

Construction of Prokaryotic Expression Vector of Mouse Nanog Gene and Its Expression

The aim of this study is to construct a prokaryotic expression vector of mouse Nanog gene and to express it in E. coli. A pair of primers was designed according to digestion sites in plasmid pGEX-KG and the Nanog gene sequence published by GenBank. The DNA fragment of 918 bp was amplified by polymerase chain reaction （PCR） from the pNA992 recombinant plasmid with Nanog gene, then cloned into pGEX-KG and transformed into the host E. coli strain TG Ⅰ. The sequence of the fragment was matched with the original sequence of pNA992. It indicated that fusion expression vector, pGEX-KG- Nanog, was constructed successfully. The pGEX-KG-Nanog plasmid was extracted from E. coli strain TG Ⅰ and was transformed into BL21（DE3） for expression. After induction by isopropyl-β-D-thiogalactoside （IPTG） at 37℃, the expression product of Nanog gene was identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）, and the expression condition was optimized. Nanog fusion protein was successfully expressed in the form of inclusion bodies. The molecular weight of the inclusion body was 63 kDa. Meanwhile, the optimum condition for the expression of Nanog fusion protein was induced with 0.8 mmol L^-1 IPTG for 5 h. The mouse Nanog gene was successfully expressed in E. coli, which laid a foundation for the purification of Nanog protein and for the preparation of polyclonal antibody.