Minireview: DNA replication in plant mitochondria

• Plant mitochondrial genomes replicate by a unique mechanism(s).
• All plant mtDNA replication proteins are nuclear-encoded.
• Many of these proteins are dual-localized to mitochondria and chloroplasts.
• There appears to be partial redundancy for some replication protein functions.
• Mutations in some replication proteins have complex effects on plant development.

Higher plant mitochondrial genomes exhibit much greater structural complexity compared to most other organisms. Unlike well-characterized metazoan mitochondrial DNA (mtDNA) replication, an understanding of the mechanism(s) and proteins involved in plant mtDNA replication remains unclear. Several plant mtDNA replication proteins, including DNA polymerases, DNA primase/helicase, and accessory proteins have been identified. Mitochondrial dynamics, genome structure, and the complexity of dual-targeted and dual-function proteins that provide at least partial redundancy suggest that plants have a unique model for maintaining and replicating mtDNA when compared to the replication mechanism utilized by most metazoan organisms.