Abstract:

With cotton(Gossypium hirsutum L.) cytoplasmic male-sterile line P30A, maintainer line P30B and restorer line Y18 as plant materials, 1 627 bp flanking sequences of atp9 gene was obtained in fertile cytoplasm using Tail-PCR method, and different expression patterns of atp9 among young buds of three-line hybrid cotton were analyzed by Northern blot. The result showed that two transcripts of atp9 gene were detected in three-line hybrid cotton. One band showed clear hybridizing signal and another was weak. There were no obvious differences in transcription level. There were seven editing sites in the coding region of atp9, and the codon at 7th editing site changed into a termination codon, shortening the protein of ATP9 to the “standard” size. The atp9 gene editing frequency of maintainer line was significantly lower than sterile line and restorer line in the organ of young bud. We found that the editing frequency of atp9 had close relationship with the form of cotton cytoplasm, and nuclear background could also affect the editing frequency. Our study shows that mitochondrial atp9 gene may be related to cytoplasmic male sterility, but further analysis is needed.

Key words: cotton, mitochondrion, atp9 gene, tail-PCR, northern blot, RNA Editing

摘要：

以三系杂交棉胞质雄性不育系P30A、保持系P30B和恢复系Y18为材料,通过Tail-PCR从可育胞质获得线粒体atp9基因序列,并利用Northern blot分析了atp9基因在棉花幼蕾的的转录情况。结果显示:在三系中atp9基因均存一个0.5 kb的强杂交带和一个1.0 kb的弱杂交带,杂交结果无明显差异；三系中atp9基因编码区共有7个编辑位点,第7个编辑位点密码子由于编辑转变为终止密码子使翻译提前终止；atp9基因在保持系中幼蕾的编辑频率要明显低于不育系和恢复系；发现atp9基因的编辑与棉花胞质形式相关,而且不同的核背景也会影响编辑率,推测线粒体atp9基因与棉花的胞质雄性不育具有一定的相关性,但有待更进一步分析。

关键词: 棉花;线粒体;atp9基因;Tail-PCR;Northern blot;RNA编辑