小麦TaDRLea3-2基因的克隆及胁迫诱导表达分析

摘要

Late embryogenesis abundant protein(LEA)are a suite of important family proteins found in or-ganisms,which are generally involved in osmoregulation and are expressed abundantly when subj ected to environmental stresses.In this study,we isolated a novel LEA3 gene TaDRLea3-2 from wheat‘Zhengyin No.1’.The full length of TaDRLea3-2 is 668 bp,whose ORF is 570 bp,encoding 189 amino acids,and consists of 9 conserved 1 1-mer repeating motifs;Protein prediction shows that the protein is highly hydro-philic and located in the cytoplasm,with three phosphorylation sites and has no transmembrane domain or signal peptide;Secondary structure analysis shows that the main structure is alpha helix;Homology com-parison and regenerating phylogenetic tree were carried out by MEGA5 .1 .Expression analyses revealed that TaDRLea3-2 gene was induced by drought,low-temperature,high-salt stress and also moreover,can be induced by ABA treatment.These results suggested that TaDRLea3-2 is an ABA-dependent LEA3 gene,participating in the response process of wheat under the abiotic stresses in different mechanisms and can lay a foundation for elucidating LEA3 gene protection mechanism under abiotic stresses in wheat.%胚胎发育后期丰富蛋白(late embryogenesis abundant protein,LEA蛋白)是植物体中广泛存在的一类与渗透调节相关的家族蛋白,植物受非生物胁迫会大量表达。该研究采用同源克隆技术,从干旱诱导的小麦品种‘郑引1号’(Triticumaestivum L.)中获得1个新的 LEA3家族基因(TaDRLea3-2),该基因全长668 bp,编码区为570 bp,编码189个氨基酸。生物信息学分析表明该蛋白为亲水性蛋白,二级结构以α-螺旋为主,含有9个由11个氨基酸组成的保守结构域,为典型的 LEA3蛋白,存在3个磷酸化位点,无信号肽结构域及跨膜结构域,可能定位于细胞质中；实时定量PCR结果表明,TaDRLea3-2基因受干旱、高盐、低温诱导表达,同时也受外源 ABA 诱导,推测TaDRLea3-2为 ABA依赖型 LEA3基因,以不同机制参与小麦对非生物胁迫的应答过程,为深入分析小麦LEA3家族蛋白的抗逆机制奠定了基础。