Next-Generation Genome Editing for Climate-Smart Agriculture: A Critical Appraisal of the Transition from CRISPR-Cas Nucleases to Large-Scale Genome Engineering
Akshay Kumar Verma *
Sahibganj College, Sahibganj, SKM University, Dumka, Jharkhand, 816109, India.
*Author to whom correspondence should be addressed.
Abstract
Genome editing has moved from a proof-of-concept technology to a central instrument in proposals for adapting agriculture to a warming and more variable climate. The claim that editing can deliver climate-smart crops rests on a chain of assumptions that has rarely been examined as a whole: that climate-relevant traits are tractable at the level of a small number of edited loci, that editing reagents can be delivered into agronomically relevant germplasm, that laboratory phenotypes translate into field performance, and that regulatory and institutional systems will allow the resulting varieties to reach the farmers most exposed to climate risk. This review evaluates that chain critically. It traces the technical trajectory from double-strand-break nucleases through base and prime editing to multi-kilobase insertion and chromosome-scale engineering, and asks what each capability adds to climate adaptation rather than to precision as an end in itself. The evidence is strongest for single-gene and cis-regulatory modifications affecting disease resistance, tillering and grain traits, where independent field data exist. It is considerably weaker for abiotic stress tolerance, where most reports rest on controlled-environment phenotyping of single genotypes, and weakest for mitigation traits, where genetic interventions have rarely been evaluated under realistic management. Delivery and regeneration, not nuclease design, remain the binding constraint for most crops that matter for adaptation in low-income regions. Chromosome-scale engineering has been demonstrated convincingly in model species and offers a route to manipulating recombination and linkage, yet no crop application has been reported at agronomic scale. Regulatory divergence and unequal institutional capacity now shape the distribution of benefits at least as strongly as technical capability. Priorities that follow include multi-environment field evaluation with transparent reporting of null and negative results, systematic quantification of trade-offs, transfer of chromosome engineering to crop species, and investment in delivery platforms for vegetatively propagated and orphan crops.
Keywords: CRISPR-Cas, prime editing, chromosome engineering, climate-resilient crops, abiotic stress tolerance, plant transformation, agricultural biotechnology policy