Plastid-nuclear coevolution of ribosomal protein genes in papilionoid legumes.

In plants, cellular function is orchestrated by three distinct genomes located within the nucleus, mitochondrion, and plastid. These genomes are interdependent, requiring tightly coordinated maintenance and expression. Plastids host several multisubunit protein complexes encoded by both the plastid and nuclear genomes.

Genome copy number predicts extreme evolutionary rate variation in plant mitochondrial DNA.

Nuclear and organellar genomes can evolve at vastly different rates despite occupying the same cell. In most bilaterian animals, mitochondrial DNA (mtDNA) evolves faster than nuclear DNA, whereas this trend is generally reversed in plants. However, in some exceptional angiosperm clades, mtDNA substitution rates have increased up to 5,000-fold compared with closely related lineages.