【摘要】 在NCBI网站BLAST得到5个烟草表达序列标签(EST),据此设计引物,从烟草(Nicotianabenthamiana)品种本塞母氏中分离出2条DREB(dehydration-responsiveelementbindingprotein)-like转录因子基因,分别命名为NbDREB1和NbDREB2。与相关AP2/EREBP类转录因子比对结果显示,NbDREB1和NbDREB2都具有典型的AP2/EREBP转录因子家族EREBP亚族A类AP2区特征,并且都能在大肠杆菌(Escherichiacoli)中表达。酵母单杂交结果显示,都不具有激活功能。连接pGADT7反式激活载体进行酵母单杂交结果显示:NbDREB1能与DRE顺式作用元件结合,NbDREB2则不能,表明NbDREB1为抑制型DREB类转录因子。比较NbDREB1和NbDREB2的AP2区发现:两者在第2位和第49位氨基酸处不同,NbDREB1为Y和K,NbDREB2为N和R。更多还原

【Abstract】 Five EST (expressed sequence tag) sequences were obtained in NCBI web BLAST according to the AP2 domain sequence of DREB(dehydration-responsive binding protein)1a gene from Arabidopsis. Specific primers were designed based on the EST sequences, and two DREB-like genes were amplified from tobacco (Nicotiana benthamiana) cDNA by PCR, and named NbDREB1 and NbDREB2 respectively and could be expressed in Escherichia coli. Comparing with other dehydration-responsive element binding related protein found that NbDREB1 and NbDREB2 possessed typical structural characteristics of A type of EREBP subgroup in AP2/EDREBP transcription factor family . The yeast one-hybrid (expression vector YepGap) showed that the two genes had no active function. Anti-activator yeast one-hybrid (expression vector pGADT7containning GAL4 domain) assay showed that NbDREB1 could bind to DRE cis-element in yeast, but NbDREB2 could not. The difference of AP2 domain between NbDREB1 and NbDREB2 was only in the 2nd and 49th amino acid, which was Y and K in NbDREB1 and N and R in NbDREB2.更多还原