CAJ | 학술논문

EREBP/AP2类蛋白是一个仅存在于植物中的DNA结合蛋白(DBP)大家族.其中一些成员如APETALA2和AtDREB/CBF分别调控花的发育和植物对环境胁迫的反应.为了阐明在植物响应盐胁迫过程中所涉及的转录因子的特点,用高盐浓度处理盐生植物山菠菜,构建了cDNA文库,并从此文库中分离得到了一个编码EREBP/AP2类蛋白的基因.此cDNA包含一个723bp的开放读码框和一个长达655bp的3＇端非编码区,推导的氨基酸序列显示其有一个保守的EREBP/AP2的DNA结合域,此基因被命名为AhDREB1.将AhDREB1置于CaMV 35S启动子下转入烟草,获得9个独立的转基因株系,对其进行了长期的盐胁迫实验.结果显示,AhDREB1的组成性表达显著提高了转基因烟草的耐盐能力,这可能是由于其激活了一些具有抗盐效应的下游基因.通过与拟南芥的全基因组进行同源性比较得到了具有较高相似性的7个EREBP/AP2家族成员,二级结构预测显示了它们在DNA结合区段的α螺旋结构上具有相似性.
EREBP/AP2류단백시일개부존재우식물중적DNA결합단백(DBP)대가족.기중일사성원여APETALA2화AtDREB/CBF분별조공화적발육화식물대배경협박적반응.위료천명재식물향응염협박과정중소섭급적전록인자적특점,용고염농도처리염생식물산파채,구건료cDNA문고,병종차문고중분리득도료일개편마EREBP/AP2류단백적기인.차cDNA포함일개723bp적개방독마광화일개장체655bp적3＇단비편마구,추도적안기산서렬현시기유일개보수적EREBP/AP2적DNA결합역,차기인피명명위AhDREB1.장AhDREB1치우CaMV 35S계동자하전입연초,획득9개독립적전기인주계,대기진행료장기적염협박실험.결과현시,AhDREB1적조성성표체현저제고료전기인연초적내염능력,저가능시유우기격활료일사구유항염효응적하유기인.통과여의남개적전기인조진행동원성비교득도료구유교고상사성적7개EREBP/AP2가족성원,이급결구예측현시료타문재DNA결합구단적α라선결구상구유상사성.
EREBP/AP2-type proteins are members of a large DNA binding protein (DBP) family found in plants. Some members like APETALA2 and AtDREB/CBF can regulate flower development and response to environmental stresses, respectively. To characterize transcription factors involved in plant responses to salt stress, we constructed cDNA library from salt-treated halophyte (Atriplex hortensis ) and isolated a novel gene Untranslated-Region (UTR) of 655 bp. The deduced amino acid sequence showed one conserved DNA binding domain of EREBP/AP2, thus the corresponding gene was named AhDREB1 with a calculated molecular mass of 26.1 kD. AhDREB1 under the control of CaMV 35S promoter was then transformed into tobacco and nine independent transgenic lines were obtained and subjected to long term salt stress. The results suggested that overexpression of AhDREB1 improved the salt tolerance in transgenic tobacco through functioning as a regulatory molecule in response to salt stress. Analysis of Arabidopsis genome in database resulted in dozens of EREBP/AP2-type homologous proteins, of which seven members showed high similarity to AhDREB1. Secondary structure analysis predicted similar arrangement of α-helix in their DNA binding domains.