[目的]获得苏云金芽胞杆菌QL32-1中杀虫晶体蛋白基因,并分析其杀虫活性。[方法]采用cyt基因通用引物、两步法染色体步移的方法对QL32-1中cyt基因进行鉴定和全长克隆,再构建重组质粒pET-28a-2Ba16,并转化到大肠杆菌BL21(DE3)中,经IPTG诱...[目的]获得苏云金芽胞杆菌QL32-1中杀虫晶体蛋白基因,并分析其杀虫活性。[方法]采用cyt基因通用引物、两步法染色体步移的方法对QL32-1中cyt基因进行鉴定和全长克隆,再构建重组质粒pET-28a-2Ba16,并转化到大肠杆菌BL21(DE3)中,经IPTG诱导表达,最后对表达蛋白进行杀虫活性分析。[结果]克隆得到1个全长783 bp cyt2B基因,其编码260个氨基酸,推导分子量约29.69 kDa,此氨基酸序列与已知的Cyt2Ba1蛋白同源性最高,为92.4%。该基因被国际杀虫晶体蛋白基因命名委员会正式命名为cyt2Ba16。杀虫活性分析表明:cyt2Ba16对双翅目的库蚊(Culex quinquefasciatus)具有显著的杀虫活性,LC50为9.73μg/mL。[结论]cyt2Ba16基因是一个对库蚊具有较高杀虫活性的新型cyt基因,为QL32-1菌株的应用提供理论基础。展开更多
Earlier studies have shown that various stimuli can induce specific cytosolic calcium （[Ca^2＋]cyt） oscillations in guard cells and various oscillations in stomatal apertures. Exactly how [Ca^2＋]cyt oscillation sig...Earlier studies have shown that various stimuli can induce specific cytosolic calcium （[Ca^2＋]cyt） oscillations in guard cells and various oscillations in stomatal apertures. Exactly how [Ca^2＋]cyt oscillation signaling functions in stomatal oscillation is not known. In the present study, the epidermis of broad bean （Vicia faba L.） was used and a rapid ion-exchange treatment with two shifting buffers differing in K^＋ and Ca^2＋ concentrations was applied. The treatment for fivetransients at a 10-min transient period induced clear and regular stomatal oscillation. However, for other transient numbers and periods, the treatments induced some Irregular oscillations or even no obvious oscillations in stomatal aperture. The results indicate that stomatal oscillation Is encoded by parameter-specific [Ca^2＋]cyt oscillation： the parameters of [Ca^2＋]cyt oscillation affected the occurrence rate and the parameters of stomatal oscillation. The water channel inhibitor HgCl2 completely Inhibited stomatal oscillation and the inhibitory effect could be partially reversed by β-mercaptoethanol （an agent capable of reversing water channel inhibition by HgCl2）. Other Inhibitory treatments against Ion transport （i.e. the application of LaCIs, EGTA, or tetraethylammonlum chloride （TEACI）） weakly impaired stomatal oscillation when the compounds were added after rapid ion-exchange treatment. If these compounds were added before rapid-ion exchange treatment, the inhibitory effect was much more apparent （except In the case of TEACI）. The results of the present study suggest that water channels are involved In stomatal oscillation as a downstream element of [Ca^2＋]cyt oscillation signaling.展开更多
文摘[目的]获得苏云金芽胞杆菌QL32-1中杀虫晶体蛋白基因,并分析其杀虫活性。[方法]采用cyt基因通用引物、两步法染色体步移的方法对QL32-1中cyt基因进行鉴定和全长克隆,再构建重组质粒pET-28a-2Ba16,并转化到大肠杆菌BL21(DE3)中,经IPTG诱导表达,最后对表达蛋白进行杀虫活性分析。[结果]克隆得到1个全长783 bp cyt2B基因,其编码260个氨基酸,推导分子量约29.69 kDa,此氨基酸序列与已知的Cyt2Ba1蛋白同源性最高,为92.4%。该基因被国际杀虫晶体蛋白基因命名委员会正式命名为cyt2Ba16。杀虫活性分析表明:cyt2Ba16对双翅目的库蚊(Culex quinquefasciatus)具有显著的杀虫活性,LC50为9.73μg/mL。[结论]cyt2Ba16基因是一个对库蚊具有较高杀虫活性的新型cyt基因,为QL32-1菌株的应用提供理论基础。
文摘Earlier studies have shown that various stimuli can induce specific cytosolic calcium （[Ca^2＋]cyt） oscillations in guard cells and various oscillations in stomatal apertures. Exactly how [Ca^2＋]cyt oscillation signaling functions in stomatal oscillation is not known. In the present study, the epidermis of broad bean （Vicia faba L.） was used and a rapid ion-exchange treatment with two shifting buffers differing in K^＋ and Ca^2＋ concentrations was applied. The treatment for fivetransients at a 10-min transient period induced clear and regular stomatal oscillation. However, for other transient numbers and periods, the treatments induced some Irregular oscillations or even no obvious oscillations in stomatal aperture. The results indicate that stomatal oscillation Is encoded by parameter-specific [Ca^2＋]cyt oscillation： the parameters of [Ca^2＋]cyt oscillation affected the occurrence rate and the parameters of stomatal oscillation. The water channel inhibitor HgCl2 completely Inhibited stomatal oscillation and the inhibitory effect could be partially reversed by β-mercaptoethanol （an agent capable of reversing water channel inhibition by HgCl2）. Other Inhibitory treatments against Ion transport （i.e. the application of LaCIs, EGTA, or tetraethylammonlum chloride （TEACI）） weakly impaired stomatal oscillation when the compounds were added after rapid ion-exchange treatment. If these compounds were added before rapid-ion exchange treatment, the inhibitory effect was much more apparent （except In the case of TEACI）. The results of the present study suggest that water channels are involved In stomatal oscillation as a downstream element of [Ca^2＋]cyt oscillation signaling.
