Giant mitogenomes in <i>Rhynchospora</i> are a result of nuclear gene and retrotransposon insertions in intergenic spaces

Our findings show that the Rhynchospora mitogenome is the largest among the monocotyledons. These mitogenomes feature giant intergenic spaces, incorporation of chloroplast DNA and numerous rearrangements. Gigantism of the intergenic spaces is associated with the movement of nuclear DNA segments, suggesting a mechanism of DNA transfer from the nuclear genome to the mitochondrial genome.