ERF类转录因子OPBP1基因的超表达提高烟草的耐盐能力

Overexpression of an ERF Transcription Factor,OPBP1 Gene Enhances Salt Tolerance in Tobacco

ERF是植物中的一类重要的转录因子 ,参与调节植物的生长、发育以及抗胁迫等过程。对一烟草OPBP1基因 (属于ERF类基因 )的烟草转化 ,获得了该基因超表达的植株 ,转基因植株明显地增加了耐盐能力。Northern杂交结果表明 ,OPBP1基因有不同程度的表达 ,而且表达丰度与其耐盐性有一定的正相关性。凝胶阻滞实验结果证明OPBP1融合蛋白能特异地与含GCC盒的DNA序列结合。这些结果说明OPBP1基因可能作为一转录因子来调节烟草耐盐相关的基因。

ERFs (ethylene responsive element binding factors) are involved in many processes of plant, such as growth, development, and adaptation to biotic and abiotic stresses. In this study, OPBP1 gene, an ERF transcription factor gene was constructed under control of 35S promoter, and transformed into tobacco by Agrobacterium mediated method (Fig.1). The regenerated plants were detected by PCR using primers from OPBP1 and 35S promoter. The transgenic plants obtained were studied for their resistance to salt stress. T 1 seeds of the transgenic lines were treated with NaCl in the presence or absence of kanamycin. The seeds of the trangenics germinated and grew in the presence of NaCl (200 mol/L), whereas seeds of a control plant grew germinated rarely (Table 1). The result indicated enhanced salt tolerance of the transgenic lines. Overexpression of the transgene was observed by Northern blot analysis (Fig.4). It can be found that higher level of expression of the transgene had a higher salt tolerance (Table 1 and Fig.4). The recombinant OPBP1 protein can bind specifically to a nucleotide fragment containing the GCC box (Fig.3) . These results suggested that OPBP1 , as a transcription factor is involved in the regulation of salt stress related genes.