Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, PR China; Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing,100081, PR China.
Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, PR China.
Gene. 2014 Feb 10;535(2):140-9. doi: 10.1016/j.gene.2013.11.047. Epub 2013 Dec 3.
The dehydration-responsive element binding proteins (DREBs) are important transcription factors in the regulation of plant responses to abiotic stresses. In this study, BpDREB2, an AP2/DREB-type transcription factor gene, was cloned from a woody plant, Broussonetia papyrifera by RACE-PCR. Sequence analyses revealed that BpDREB2 protein has three characteristic domains, including an AP2/EREBP, a nuclear localization signal and an acidic activation domain. Yeast one-hybrid assays showed that BpDREB2 protein specifically binds to the DRE sequence and activates the expression of reporter genes in yeast. These results suggested that BpDREB2 protein could function as a transcription factor of DREB family. The expression of BpDREB2 gene was remarkably induced by dehydration and high-salt treatments, but no significant change was observed under ABA or low-temperature conditions. Importantly, transgenic expression of BpDREB2 gene in Arabidopsis significantly enhanced its tolerance to salt and freezing without causing growth retardation. Taken together, these results suggested that BpDREB2 is a novel member of the AP2/EREBP trans-acting factor family which could enhance salt stress tolerance of plants and has the potential application in the improvement of crops and economical tree species.
脱水应答元件结合蛋白（DREBs）是植物响应非生物胁迫的调控中的重要转录因子。本研究通过 RACE-PCR 从木本植物构树中克隆到一个 AP2/DREB 型转录因子基因 BpDREB2。序列分析表明，BpDREB2 蛋白具有三个特征结构域，包括一个 AP2/EREBP、一个核定位信号和一个酸性激活结构域。酵母单杂交实验表明，BpDREB2 蛋白特异性地结合 DRE 序列并激活酵母中报告基因的表达。这些结果表明 BpDREB2 蛋白可以作为 DREB 家族的转录因子发挥作用。BpDREB2 基因的表达在脱水和高盐处理下显著诱导，但在 ABA 或低温条件下没有明显变化。重要的是，BpDREB2 基因在拟南芥中的转基因表达显著增强了其对盐和冻害的耐受性，而不会导致生长迟缓。综上所述，这些结果表明 BpDREB2 是 AP2/EREBP 转录因子家族的一个新成员，可增强植物的耐盐性，具有在改良作物和经济树种中的潜在应用价值。
