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

Allotopic expression is the term given for deliberate relocation of gene function from an organellar genome to nuclear genome. We hypothesized that allotopic essential mitochondrial using a promoter expressed efficiently in all cell types except those responsible male reproduction would yield cytoplasmic sterility (CMS) phenotype once endogenous was inactivated via editing. To test this, we repurposed mitochondrially encoded atp1 tobacco nucleus under transcriptional control CaMV 35S (construct 35S:nATP1), has been shown be minimally early stages anther development. The eliminated (Δ ) 35S:nATP1 plants custom-designed meganucleases directed mitochondria. Vegetative growth most 35S:nATP1/Δ appeared normal, but upon flowering produced malformed anthers failed shed pollen. When were cross-pollinated, ovary/capsule development vast majority resultant seeds small, largely hollow and germinate, akin seedless trait known as stenospermocarpy. Characterization genomes three independent Δ events suggested spontaneous recombination over regions microhomology substoichiometric shifting mechanisms elimination rearrangement response exposure -targeting meganucleases. Should results reported here prove translatable other crop species, then multiple applications followed by its through editing can envisaged. Depending on promoter(s) used drive gene, this technology may have potential application areas of: (1) CMS use hybrid seed production; (2) fruit (3) transgene containment.