aroA基因的克隆和优化

除草剂草甘膦 (glyphosate ,N_phosphonomethylglycine )的靶标酶是由aroA基因编码的EPSP (5_烯醇式丙酮酰莽草酸_3_磷酸 ,5_enolpyruvylshikimate_3_phosphate)合成酶。采用先进的基因优化技术 ,以鼠伤寒沙门氏杆菌和大肠杆菌的EPSP合成酶基因为模板 ,通过随机结合 ,交错延伸的PCR扩增过程 ,克服定点突变的局限性 ,使基因获得多位点突变 ,并使之在大肠杆菌中得到表达。对纯化后的表达产物的酶动力学性质的测定结果表明 ,获得了与作为模板的野生型相比 ,具有高得多的酶活力 (降低的Km (PEP) )和大大增强的草甘膦抗性 (升高的Ki(glyphosate) )的突变基因     

Characterization of Halomonas Varabilis Strain HTG7 Conferring Glyphosate Resistance

Bcterial strain HTG7 is isolated from extremely glyphosate-polluted soil. It is identified as Halomonas Varabilis. It can tolerate in 500m mol/L glyphosate concentration. Physiological characterization of strain HTG7 shows that the optimum pH and temperature are 7.0 and 30℃, respectively. It grows well in the NaCl concentrations ranging from 0% to 10%. A plasmid pACYC184 carrying a 3.5kb DNA fragment, which confers increased glyphosate tolerance, is cloned. The DNA fragment is able to complement with an E coli auxotrophic aroA mutant.     

Novel layered pesticide slow/controlled release materials——supramolecular structure and slow release property of glyphosate intercalated layered double hydroxides

Two different interlayer structured glyphosate(GLY) intercalated MgAI layered double hydroxides, as novel pesticide slow/controlled release materials, have been synthesized by co-precipitation method under various reaction pH values. The slow/controlled release properties have been tested in Na2CO3 aqueous solution. The release mechanism has been interpreted on the basis of the ion-exchange between the guest GLY anions in the lamellar host and CO3^2- in the release media, and the diffusion process of GLY anions in the interstice and interlayer of GLY intercalates, i.e.diffusion through the particles, is the rate-limiting step of GLY release process. The GLY intercalate assembled at lower pH, possessing higher interlayer gallery height and vertical monolayered arrangement of guest anions in the interlayer with larger packing density, exhibits better slow release property than that assembled at higher pH. The results reveal that the layered double hydroxides have potential application in the pesticide slow/controlled release area.     

草甘瞵含量液相色谱检测衍生化条件的优化筛选

对液相色谱测定水体及水葫芦中草甘膦含量的对甲基苯磺酰氯衍生化反应条件进行了优化筛选，得出最佳衍生化条件为反应缓冲液pH10．5-11．0、盐浓度0．4mol／L，对甲苯磺酰氯与草甘膦质量比大于7，5：1，于50℃水浴中反应30min。     

用反相高效液相色谱法测定农药草甘膦含量的研究

建立了柱前衍生紫外检测的反相高效液相色谱法,并用其测定了草甘膦原药压制剂中草甘膦的含量．色谱条件为ODS色谱拄,流动相y（甲醇）：y（水）=2：98,其中水相含w=0．1％的磷酸,流速为0＋8mL／min,紫外检测波长为240nm,拄温为室温．实验表明,草甘膦的线性范围为0．008～0．040mg／mL,平均回收率为101％．该方法简便、灵敏、准确,可作为草甘膦农药质量控制的一种新方法．     

除草剂"草甘膦"对鲫鱼外周血红细胞微核及核异常的影响

利用“草甘膦”染毒鲫鱼,以外周血红细胞的微核率和核异常率为指标,研究了“草甘膦”对鲫鱼的毒性。结果显示：“草甘膦”对鲫鱼具有一定的毒性;但不具有剂量效应;与染毒时间的长短也无明显相关性。     

转EPSPS基因抗草苷膦油菜基因漂移的初步研究

草苷膦是一种广谱内吸传导型除草剂[1].草苷膦通过竞争性抑制植物莽草酸代谢过程中磷酸烯醇式丙酮酸莽草酸-3-磷酸合酶(简称为EPSPS)活性,阻断芳香族氨基酸的生物合成导致植物死亡[2].因此,转EPSPS基因(来自微生物的基因)作物对草苷膦类型的除草剂具有抗性.在1996~2004年的9年间,抗除草剂生物技术产品一直占市场的主导地位.2004年,全球种植的抗除草剂的转基因作物有油菜、大豆、玉米及棉花等,种植面积共计有5,860万公顷,占全球转基因作物总种植面积(8,100万公顷)的72%.抗除草剂油菜品种在国外已广泛种植,据国际农业生物技术应用服务组…