烟草细胞质雄性不育线粒体基因sdh3和sdh4的生物信息学分析

线粒体基因异常可能导致烟草细胞质雄性不育。sdh3、sdh4是编码线粒体电子传递链复合体II 亚基的重要基因,为探讨线粒体基因sdh3、sdh4与细胞质雄性不育的关系,从3 个普通烟草不育系品种及其保持系中提取线粒体DNA,根据GenBank 报道的烟草线粒体DNA 序列设计特异引物扩增目的基因并克隆测序,应用生物信息学方法,分析烟草雄性不育系及保持系的sdh3、sdh4基因在其核苷酸、编码蛋白各结构层次上存在的差异。结果显示,不育系的sdh4基因第28 位碱基发生了改变;不育系的sdh3基因发生10 个碱基的缺失,以致其编码蛋白改变,这极可能成为干扰线粒体琥珀酸脱氢酶亚基3 功能的关键因素,从而成为可能导致烟草CMS 的根本原因之一。

Bioinformatics Analysis of Mitochondrial Genes sdh3 and sdh4 of Cytoplasmic Male Sterility in Tobacco

The abnormal mitochondrial gene may lead to tobacco cytoplasmic male sterility. sdh3 and sdh4 are important genes coding subunits of mitochondrial complex II. To study the relationship between mitochondrial genes sdh3, sdh4 and cytoplasmic male sterility, the mitochondrial DNA from 3 male sterile lines and their maintainer lines of Nicotiana tabacum cultivars were extracted, specific primers were designed according to the complete nucleotide sequence of the tobacco mitochondrial genome in GenBank to amplify purpose genes from tobacco mitochondrial DNA. PCR products were cloned and sequenced. The sdh3 and sdh4 nucleotides and encoded protein structures were analyzed with bioinformatics to find differences between male sterile lines and maintainer lines. The results showed that the 28th base of sdh4 of male sterile lines gene changed. The sdh3 of male sterile lines gene lost 10 bases, and lead to the encoded protein altered, this is much more likely to be the key factors interference with the function of mitochondrial succinic dehydrogenase subunit 3, and one of root factors generated tobacco CMS.