紫稻型水稻线粒体cox Ⅲ基因转录本的RNA编辑

Mitochondrial RNA Editing of cox Ⅲ Gene Transcripts of Zidao Type Rice

紫稻细胞质雄性不育系是本实验室构建的新型细胞质雄性不育系。使用PCR、RT-PCR、DNA测序等技术,得到了紫稻细胞质雄性不育水稻不育系(樱香A)及其保持系(樱香B)线粒体细胞色素C氧化酶亚基coxⅢ基因转录本cDNA序列。通过与水稻"93-11"线粒体基因组序列比对发现,樱香AcoxⅢ cDNA序列中,没有发生RNA编辑;而樱香BcoxⅢ cDNA序列中有13个编辑位点,11个为C-T编辑,2个为T-C编辑。在樱香B cDNA序列中的13个编辑位点位于13个密码子中,所编码的氨基酸有10个发生改变,这些氨基酸的改变大大增加了蛋白质的疏水性。研究表明,RNA编辑在合成具正常功能的COXⅢ多肽的过程中具有至关重要的作用,同时也说明RNA编辑可能与细胞质雄性不育相关。

On the base of construction of a new type of cytoplasmic male sterile line Zidao A, we analyzed the editing of transcripts of mitochondrial cytochrome C oxidase subunit Ⅲ gene （cox Ⅲ） from CMS line and its maintainer line. With PCR and RT-PCR, complete nucleotide sequences were determined for the mitochondrial cox Ⅲ gene cDNA from two lines of Zidao type： cytoplasmic male sterile line Yingxiang A and its maintainer line Yingxiang B. The coxnl transcript of Yingxiang A was shown to have no editing site and the transcript of Yingxiang B was shown to have 13 editing sites with changes affecting 10 amino acid residues, which significantly increased protein＇s hydrophobicity. The results demonstrated the important role of RNA editing in the production of the functional cox m subunit and suggested that RNA editing be likely associated with cytoplasmic male sterility.