Abstract: In this research,the pepper cytoplasmic male sterile line 9704A and the homologous maintainer line 9704B were used as experimental materials to study the differences between the primary structure of gene CaATP9 and the editing of RNA,and the real-time quantitative PCR was used to study the spatiotemporal expression of gene CaATP9. The results showed that the primary structure of gene CaATP9 did not differ between the two materials;the gene CaATP9 has five C→T editing sites during transcription,resulting in the conversion of four hydrophilic amino acids（DNA template）into four hydrophobic amino acids and enhancing the stability of the protein;gene CaATP9 is expressed in different tissues of pepper,but the expression level in reproductive tissues is generally higher than that in vegetative tissues;the expression level of gene CaATP9 in the male sterile line differed from that of the homologous maintainer line in the development of flower buds. It is speculated that this difference in expression leads to the disorder of the energy supply of the buds of the cytoplasmic male sterile line,affecting the normal development of microspores and showing infertility.

Key words: pepper（Capsicum annuum L.）, cytoplasmic male sterility, energy metabolism, gene expression, transcript