CRISPR-Cas9 Genome Editing in Crop Improvement: Progress, Regulation and Limitations

Abstract

CRISPR-Cas9 has become the working tool of plant genome editing within little more than a decade of its first use in crops, and claims about what it will deliver for agriculture now run well ahead of what has been demonstrated in the field. This narrative review follows the technology from its bacterial origin to its present range of nucleases, base editors and prime editors, describes how editing machinery is delivered into plant cells, and summarises the traits that have been edited in cereals, tomato and other crops. It then sets out how regulators in different jurisdictions treat edited plants and why their answers diverge. The published record shows rapid technical progress and many convincing proofs of concept, but most reports describe single genotypes, greenhouse conditions and short follow-up. Transformation and regeneration, not editing itself, still limit many species, unintended changes are documented less thoroughly in plants than the enthusiasm suggests, and field evidence of agronomic benefit is thin. Regulation remains uneven, which shapes which products reach farmers at all. The review draws on published literature only, reports no new data, and ends with the evidence needed before the promise can be judged.