烟草Mlo基因的克隆及其序列特性分析

Cloning and Sequence Characterizing a Mlo Gene in Nicotiana tabacum

Mlo基因家族是一类植物抗病的负调控因子,该基因的突变能产生广谱的抗病性。以GenBank公布的水稻Mlo基因序列(登录号:AK099399.1)为信息探针对烟草的EST数据库进行同源搜索,并将获得的同源性高的EST序列进行拼接,最后得到了烟草Mlo基因的cDNA序列。采用RT-PCR方法成功克隆了与预期大小一致的Mlo基因cDNA片段951 bp,该基因可编码304个氨基酸。采用生物信息学方法预测分析了该基因编码蛋白的一、二级结构,并对其功能进行了预测。结果表明,该烟草Mlo基因编码蛋白包含有一个保守的Tmemb_40结构域,可能是一种类似于植物G蛋白偶联受体的膜结合转运蛋白。

Mlo（barley powdery mildew resistance gene） gene family is a kind of negative regulator of plant resistant to disease,mutations in this gene can be resistant to a wide variety of diseases.The rice Mlo gene（GenBank accession number： AK099399.1） was served as an information probe in the tobacco EST database and a cDNA sequence of tobacco Mlo was obtained by assembling the obtained ESTs with high homology.A cDNA fragment of tobacco Mlo gene with the expected size（951bp） has been successfully cloned by RT-PCR,the cloned gene could encode 304 amino acids.The primary and secondary structure of protein encoded by the cloned gene was predictively analyzed by bioinformatics and the functions of the same were predicted as well.The results showed that the encoded protein had a conservative structural domain Tmemb_40 and it might be a membrane-bound transporter protein similar to the G protein-coupled receptor in plant.