Changes in mitochondrial DNA levels during early embryogenesis in Torenia fournieri and Arabidopsis thaliana

Summary Changes in the amount of mitochondrial DNA (mtDNA) have never been investigated in plant zygotes or early plant embryos due to the difficulty in isolating these cells, although such changes have been investigated in mammalian embryos. Using the single‐cell quantitative real‐time polymerase chain reaction (PCR) and laser confocal microscopy, we surveyed the changes in mtDNA levels during early embryogenesis in Torenia fournieri and Arabidopsis thaliana. In contrast with the amount of mtDNA in early mammalian embryos, which does not change, we found that mtDNA doubling occurred during zygotic development in T. fournieri and during two‐cell proembryo development in A. thaliana. These findings reveal that mtDNA doubling occurs during early embryogenesis in T. fournieri and A. thaliana, indicating that the dynamics of mtDNA in early plant embryos differs from that in early mammalian embryos. Significance Statement Replication of mtDNA occurs during zygotic development in Torenia fournieri and during two‐cell proembryo development in Arabidopsis thaliana. Given that the mtDNA levels do not change during early mammalian embryogenesis, our results reveal that early plant embryos have different mtDNA dynamics from early mammalian embryos.