One-step genome editing of elite crop germplasm during haploid induction

Genome editing using CRISPR-Cas9 works efficiently in plant cells(1), but delivery of genome-editing machinery into the vast majority of crop varieties is not possible using established methods(2). We co-opted the aberrant reproductive process of haploid induction (HI)(3-6) to induce edits in nascent seeds of diverse monocot and dicot species. Our method, named HI-Edit, enables direct genomic modification of commercial crop varieties. HI-Edit was tested in field and sweet corn using a native haploid-inducer line(4) and extended to dicots using an engineered CENH3 HI system(7). We also recovered edited wheat embryos using Cas9 delivered by maize pollen. Our data indicate that a transient hybrid state precedes uniparental chromosome elimination in maize HI. Edited haploid plants lack both the haploid-inducer parental DNA and the editing machinery. Therefore, edited plants could be used in trait testing and directly integrated into commercial variety development.