Studies on Cloning and Transcription of atp9 from Cotton(Gossypium hirsutum L.) Mitochondria

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.