Two transcription factors, DREB1 and DREB2, with an EREBP/AP2 DNA binding domain separate two cellular signal transduction pathways in drought- and low-temperature-responsive gene expression, respectively, in Arabidopsis
Two transcription factors, DREB1 and DREB2, with an EREBP/AP2 DNA binding domain separate two cellular signal transduction pathways in drought- and low-temperature-responsive gene expression, respectively, in Arabidopsis
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DOI：
10.1105/tpc.10.8.1391
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发表时间：
1998-08-01
期刊：
影响因子：
11.6
通讯作者：
Shinozaki, K
中科院分区：
文献类型：
--
作者：
Liu, Q;Kasuga, M;Shinozaki, K
植物生长受干旱和低温的影响很大。干旱和低温都能诱导许多基因的表达，尽管这两种胁迫是完全不同的。先前的实验已经确定，一个名为DRE（dehydration-responsive element）的cia作用元件在拟南芥中脱水和低温诱导的基因表达中起着重要作用。利用酵母单杂交筛选技术，从大肠杆菌中分离到两个DRE结合蛋白的cDNA克隆DREB 1A和DREB 2A。这两个cDNA文库分别从脱水和冷处理的莲座丛植物中制备。DREB 1A和DREB 2A的推导的氨基酸序列没有显示出显着的序列相似性，除了在EREBP和APETALA 2蛋白中发现的保守的DNA结合结构域，分别在乙烯响应表达和花形态建成中发挥作用。DREB 1A和DREB 2A蛋白在体外特异性结合DRE序列，并激活拟南芥叶原生质体中由DRE序列驱动的β-葡萄糖醛酸酶报告基因的转录。DREB 1A基因及其两个同源物的表达诱导低温胁迫，而DREB 2A基因及其单一同源物的表达诱导脱水。DREB 1A cDNA在转基因拟南芥中的过表达不仅在非胁迫条件下诱导了目的基因的强表达，而且在转基因植物中引起了矮化表型。这些转基因植物还表现出抗冻性和脱水耐受性。相反，DREB 2A cDNA的过表达诱导弱表达的目的基因在非胁迫条件下，并导致生长迟缓的转基因植物。这些结果表明，DREB蛋白的两个独立的家庭，DREB 1和DREB 2，作为反式作用因子在两个独立的信号转导途径在低温和脱水条件下，分别。
Plant growth is greatly affected by drought and low temperature. Expression of a number of genes is induced by both drought and low temperature, although these stresses are quite different. Previous experiments have established that a cia-acting element named DRE (for dehydration-responsive element) plays an important role in both dehydration- and low-temperature-induced gene expression in Arabidopsis. Two cDNA clones that encode DRE binding proteins, DREB1A and DREB2A, were isolated by using the yeast one-hybrid screening technique. The two cDNA libraries were prepared from dehydrated and cold-treated rosette plants, respectively. The deduced amino acid sequences of DREB1A and DREB2A showed no significant sequence similarity, except in the conserved DNA binding domains found in the EREBP and APETALA2 proteins that function in ethylene-responsive expression and floral morphogenesis, respectively. Both the DREB1A and DREB2A proteins specifically bound to the DRE sequence in vitro and activated the transcription of the beta-glucuronidase reporter gene driven by the DRE sequence in Arabidopsis leaf protoplasts. Expression of the DREB1A gene and its two homologs was induced by low-temperature stress, whereas expression of the DREB2A gene and its single homolog was induced by dehydration. Overexpression of the DREB1A cDNA in transgenic Arabidopsis plants not only induced strong expression of the target genes under unstressed conditions but also caused dwarfed phenotypes in the transgenic plants. These transgenic plants also revealed freezing and dehydration tolerance. In contrast, overexpression of the DREB2A cDNA induced weak expression of the target genes under unstressed conditions and caused growth retardation of the transgenic plants. These results indicate that two independent families of DREB proteins, DREB1 and DREB2, function as trans-acting factors in two separate signal transduction pathways under low-temperature and dehydration conditions, respectively.