Genome editing reagent delivery in plants

Genome editing holds the potential for rapid crop improvement to meet the challenge of feeding the planet in a changing climate. The delivery of gene editing reagents into the plant cells has been dominated by plasmid vectors delivered using agrobacterium or particle bombardment. This approach involves the production of genetically engineered plants, which need to undergo regulatory approvals. There are various reagent delivery approaches available that have enabled the delivery of DNA-free editing reagents. They invariably involve the use of ribonucleoproteins (RNPs), especially in the case of CRISPR/Cas9-mediated gene editing. The explant of choice for most of the non-DNA approaches utilizes protoplasts as the recipient explant. While the editing efficiency is high in protoplasts, the ability to regenerate individual plants from edited protoplasts remains a challenge. There are various innovative delivery approaches being utilized to perform in planta edits that can be incorporated in the germline cells or inherited via seed. With the modification and adoption of various novel approaches currently being used in animal systems, it seems likely that non-transgenic genome editing will become routine in higher plants.