辣椒线粒体基因转录本编辑位点研究

EDITING SITES IN TRANSCRIPT OF MITOCHONDRIAL GENE IN HOT PEPPER

以辣椒细胞质雄性不育系北A及其相应保持系北B为材料,比较分析了nad2、atpA和cob 3个线粒体基因转录本的编辑位点。结果表明,atpA基因转录本在不育系与保持系中都未发生编辑。nad2基因在不育系中的编辑位点共有10处,与保持系相比增加了3处非C-U的特异编辑位点。cob基因在不育系与保持系中的编辑位点都有6处,除5处共同的C-U编辑外,不育系和保持系各有1处U-C和G-U的特异编辑位点。保持系比不育系相应位点的编辑频率偏高。编辑大多改变了编码氨基酸的种类,增加了编码蛋白质的疏水性。推测不育胞质特异的线粒体基因转录本编辑可能与辣椒细胞质雄性不育有关。

RNA editing status of three mitochondrial genes had2, atpA and cob from hot pepper CMS line North A and its maintainer line North B were studied. For had2 the results showed that had2 and cob were edited at different degree except atpA. For had2 there were ten editing sites in CMS line, of which seven sites occurred as C-to-U changes, one as U-to-C change, the other two as C-to-G and A-to-U. However, maintainer line had only seven C-to-U editing sites. For cob gene there were six editing sites in ＇ North A＇ , of which five sites occurred as C-to-U changes and one as U-to-C change. The maintainer line preserved the five editing sites of C-to-U while lacked of the U-to-C change and added a G- to-U unique editing site. The maintainer line had obviously higher editing frequency at each editing site than the CMS line. The amino acid and hydrophobicity of the deduced protein were changed after editing, suggesting that the RNA editing might contribute to CMS property in pepper.