Nucleo-cytoplasmic interactions affect RNA editing of cox2, atp6 and atp9 in alloplasmic male-sterile rice (Oryza sativa L.) lines

RNA editing plays an important role in the regulation of mitochondrial gene expression in flowering plants. In this study, we examined RNA editing of the mitochondrial genes cox2, atp6 and atp9 in five isonuclear alloplasmic male-sterile lines (IAMSLs) of rice to investigate whether different cytoplasmic types affect RNA editing. Although many editing sites were conserved among the three genes, we found that the editing efficiency of certain sites was significantly different between different IAMSLs or between IAMSLs and their corresponding cytoplasmic donor CMS lines. Furthermore, several editing sites were found to be either present or absent in certain IAMSLs and their corresponding CMS lines. These results indicate that nuclear loci, as well as unknown editing factors within the mitochondria of different cytoplasmic types, may be involved in RNA editing, and they suggest that RNA editing in plant mitochondria is affected by nucleo-cytoplasmic interactions.

► RNA editing patterns of atp6, atp9 and cox2 were investigated in different CMS lines.
► Some novel editing sites were identified in the mitochondria of rice.
► RNA editing in rice mitochondria may be affected by nucleo-cytoplasmic interactions.
► RNA editing in ZD-type cytoplasm is different from that in other rice CMS lines.
► The “unedited” Atp9 proteins in Meixiang A may associate with ZD-type rice CMS.