摘要： 为烟草过氧化物酶基因的功能及结构研究奠定理论基础，采用同源克隆的方法，从烤烟品种K326中克隆出了过氧化物酶基因NtPOD1的cDNA全长，并进行了生物信息学分析；同时，运用qRT-PCR的方法，分析了该基因的组织器官及逆境胁迫表达模式。结果显示，该基因cDNA全长981 bp，编码326个氨基酸残基，预测分子量为37.19 ku，等电点为8.89。生物信息学分析表明，该蛋白是一个亲水性蛋白，结构域中含有4个保守的二硫键和2个保守的钙结合位点，可能定位在细胞外（包括细胞壁），属于植物血红素依赖性过氧化物酶超家族的Ⅲ类分泌氧化酶，与渐窄叶烟草POD42、美花烟草POD42、马铃薯POD42等具有很高的同源性。该基因在烟草根、茎、叶、花中均有表达，其中叶中表达量最高，花中表达量最低。同时，NtPOD1的表达受高盐、干旱、低钾、ABA和H₂O₂诱导。结果表明，NtPOD1基因属于烟草的过氧化物酶，并可能在烟草非生物逆境胁迫响应中发挥作用。

关键词: 烟草, 过氧化物酶, 基因克隆, 生物信息学分析, 表达模式, 非生物胁迫

Abstract: This study laid the theoretical foundation for the study of the function and structure of peroxidase genes in tobacco and cloned the cDNA of peroxidase gene NtPOD1 from tobacco cultivar K326 by homologous cloning and analyzed the bioinformatics. At the same time,qRT-PCR method was used to analyze the expression pattern of tissue and organ of this gene and its stress response. The results showed that the total length of cDNA was 981 bp,encoding 326 amino acid residues,the predicted molecular weight was 37.19 ku,and the isoelectric point was 8.89. Bioinformatics analysis showed that the protein was a hydrophilic protein containing four conserved disulfide bonds and two conserved calcium binding sites in the domain,which may be located in extracellular(including cell wall).The class Ⅲ secretion oxidase of the dependent peroxidase superfamily had high homology with Nicotuana attenuata POD42, Nicotiana sylvestris POD42,Solanum tuberosum POD42 and so on. The gene was expressed in tobacco roots,stems,leaves and flowers,with the highest expression in leaves and the lowest expression in flowers. Meanwhile, NtPOD1 expression was induced by high salt,drought,hypokalemia,ABA and H₂O₂. The results indicate that NtPOD1 belongs to tobacco peroxidase and may play a role in the response of tobacco to abiotic stress.

Key words: Tobacco, Peroxidase, Gene cloning, Bioinformatics analysis, Expression pattern, Abiotic stress

中图分类号: 

• S572.03

• Q78