Cytoplasmic male sterility and abortive seed traits generated through mitochondrial genome editing coupled with allotopic expression of atp1 in tobacco

<p>Genome editing tools have recently been developed that are capable of generating deletions and/or rearrangements in plant mitochondrial genomes. We utilized custom-designed meganuclease constructs targeting the essential mitochondrial gene <em>atp1</em> in tobacco plants carrying a version of atp1 that had been repurposed to function as a nuclear gene. Leaf extracts enriched in mitochondria from three independent genome editing events were evaluated by PacBio sequencing and analysis. Contigs that display sequence homology to the reference mitochondrial genome BA000042 are deposited here. Some of the contigs correspond to the tobacco mitochondrial genome as expected, while others corresponded to sequences from the nucleus where the ancient transfer of portions of the mitochondrial genome became incorporated into the nuclear genome. Still other contigs correspond to the chloroplast genome, or pieces of the chloroplast genome anciently transferred to the nucleus, as small fragments of the chloroplast genome are interspersed in plant mitochondrial genomes. Analysis of contigs of genuine mitochondrial origin demonstrated that the double-strand breaks imposed by the genome editing enzymes resulted in the deletion of <em>atp1</em> and neighboring sequences, along with rearrangements in overall genome structure.</p>