【作者】 关尔鑫；

【导师】 李玥莹； 蔺瑞明；

【作者基本信息】 沈阳师范大学 ， 生物化学与分子生物学， 2011， 硕士

【摘要】 植物的生长和发育常常会受到逆境胁迫的影响,逆境胁迫包括生物胁迫与非生物胁迫。这些逆境胁迫对植物的生长发育及作物的与品质造成了严重的影响。而在胁迫发生时,植物感知并传递胁迫信号,通过激活响应转录因子,启动抗逆功能基因的表达,使植物体内发生一系列的生理生化反应,使植物在一定程度上能够抵御胁迫对其的伤害。大量研究表明,植物AP2/EREBP类转录因子对于植物应答外界胁迫及提高植物的抗逆性方面起着极为重要的作用。因此研究ERF类转录因子的作用机制具有重要的理论与实践意义。采用同源克隆法从构建的非亲和小种侵染诱导的小麦cDNA文库(由中国农业科学院植物保护研究所麦类作物病害课题组构建)中得到了两个小麦ERF类转录因子基因的全长cDNA克隆,命名为TaERF4、TaERF5。根据其预测的氨基酸序列分析表明,它们含有一个保守的AP2结构域,与已公布的ERF亚家族成员有较高同源性。同源性分析表明,TaERF4、TaERF5与典型的ERF亚家族成员在进化树上的距离较近,TaERF4/5可能是一个新的AP2/EREBP转录因子基因。半定量RT-PCR分析结果表明,TaERF5对脱落酸ABA做出了应答、TaERF4、TaERF5对茉莉酸甲酯MeJA做出了应答,在经处理后,其转录水平升高；在低温、干旱和高盐处理中,两个基因的表达水平均有显著的提高。利用基因枪转化的方法对TaERF4/5的亚细胞定位进行了研究,结果表明TaERF4/5具有核定位功能。通过以上实验表明,TaERF4/5因具有AP2/EREBP类转录因子基因的基本特征。TaERF4/5基因受到低温、干旱及高盐等非生物胁迫的诱导。这些研究结果为小麦的分子抗性育种提供了理论基础,具有重要的实际意义。更多还原

【Abstract】 Plant growth and development are invariably influenced by various abiotic and biotic stresses, and those environmental stresses seriously limit the increase of yield and improvement of quality of crops. However, plants could sense and transduce the signals caused by stress to transcription factors through a series of phosphorization responses. The functional genes related to stress tolerance are then initiated; a series of physiochemical reactions are activated to alleviate the damage caused by abiotic stress to a certain degree. Extensive research suggests that plant AP2/EREBP superfamily transcription factors played important roles in response to environment stresses. Therefore, to study the ERF transcription factors contain important significance in understand the mechanism of plant response to environment stresses.A full lengh cDNA designated as TaERF4, TaERF5 was isolated from a wheat cDNA library (the State Key Laboratory for Biology of Plant Diseases and Pest Insects, Institute of plant Protection, Chinese Academy of Agricultural Sciences) using the near-isogenetic line Taichung29*6/Yr5 seedlings challenged by incompatible yellow rust race CY32 through homology-based cloning method. The amino acid sequenced contains of TaERF4/5 contains a highly conserved AP2 domain, which shares quite high homology with members of ERF subfamily. The cluster analysis showed that TaERFL4/5 belong to ERF subfamily, thus TaERF4/5 are probably a new member of ERF subfamily genes. Semi-quantitative RT-PCR analysis revealed that the expression of TaERF5 was induced by ABA (abscisic acid), TaERF4, TaERF5 were induced by MeJa (methyl jasmonate), cold, salt and dehydration respectively. We studied the subcellular localization of TaERF4/5 using PDS 1000/He Gene System(Bio-Rad), results show that TaERF4/5 can localize into the nuclei. These results suggest that TaERF4/5 was AP2/EREBP transcription factor with basic characteristics, and it may be involved in process of plant response to both abiotic and biotic stresses. The experiment offered theoretical foundation to molecular breeding of wheat.更多还原