小麦α-双加氧酶cDNA克隆及表达分析  

cDNA Cloning and Expression Pattern Analysis ofα-Dioxygenase in Wheat(Triticum aestivum L.)

作　　者：范三红[1] 陈志刚[1] 王欣[1] 魏少华[1] 齐亚飞[1] 单丽伟[1] 

机构地区：[1]旱区作物逆境生物学国家重点实验室/西北农林科技大学生命科学学院,陕西杨凌712100

出　　处：《西北农业学报》2014年第7期39-45,共7页Acta Agriculturae Boreali-occidentalis Sinica

基　　金：中央高校基本科研业务费专项(QN2009070);西北农林科技大学博士科研启动基金(Z109021120)

摘　　要：以普通小麦陕225为材料,同源克隆小麦脂肪酸α-双加氧酶基因(TaDOX)cDNA,全面分析其基因结构、染色体定位、进化关系及蛋白结构特征,并利用实时定量RT-PCR分析其在PEG和盐胁迫下的表达模式。克隆的cDNA片段长1 854bp,编码617个氨基酸残基的小麦脂肪酸α-双加氧酶。TaDOX基因组DNA长5 529bp,位于小麦5D染色体长臂,包含10个外显子。小麦、水稻等禾本科植物α-DOX序列高度同源,聚集在同一独立进化枝,而双子叶植物存在2类DOX蛋白,聚集在另外2个分枝中。TaDOX具有脂肪酸α-双加氧酶以α-螺旋为主的空间结构特征,包含血红素结合位点及保守氨基酸His310、Thr315、Tyr378、Arg558组成的活性中心。TaDOX主要在叶和根中表达,花序和种子中也有痕量表达;叶片中TaDOX的表达在PEG和盐胁迫条件均明显下降;根中TaDOX的表达在PEG胁迫条件下无显著变化,但在盐胁迫条件下表达水平急剧升高。The cDNA of fatty acid alpha-dioxygenase （ TaDOX ） was obtained from common wheat Shaan 225 by homologous cloning; its gene structure, chromosomal localization, evolution relation- ship and protein structure were analyzed comprehensively; and its expression patterns under PEG and salt stress were investigated by real-time quantitative RT-PCR. The cDNA fragment is 1 857 bp enco- ding integral wheat α-DOX with 617 amino acids. TaDOX is located on the long arm of 5D chromo- some with a length of 5 529 bp including 10 Exons. Fatty acid α-DOX of wheat, rice and other grasses show high level of homology to each other and are clustered as a separate phylogenetic clan;dicotyle- donous plants have two kinds of α-DOX which are clustered into two other separate phylogenetic clans. Wheat α-DOX process typical three-dimensional structure of dioxygenase, including predomi- nantly α-helix, heine binding site and conservative His310, Thr315, Tyr378, Arg558 formed active site. Expression of TaDOX could be mainly detected in roots, leaves and developing seeds. The transcript of TaDOX in leaves was decreased under PEG or salt stress; the expression level of TaDOX in roots had not significant change under PEG stress, hut elevated quickly and sharply under salt stress.

关 键 词：小麦 脂肪酸α-双加氧酶 染色体定位 结构预测 表达模式 

分 类 号：S512.1[农业科学—作物学]