CRISPR/Cas-mediated genome editing: playing a versatile role in mitigating the challenges of sustainable rice improvement.

Abstract

Just as Gregor Mendel's laws of inheritance laid the foundation for modern genetics, the emergence of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas systems has catalyzed a new era in precision genome engineering. CRISPR/Cas has revolutionized rice (Oryza sativa L.) breeding by enabling precise, transgene-free edits to improve yield, nutrition, and stress tolerance. Advanced tools like base and prime editing further refine these capabilities, offering powerful solutions for climate-resilient agriculture and global food security. The review synthesizes the CRISPR-mediated strategies for improving resistance against major biotic (bacterial blight, blast, sheath blight) and abiotic (drought, salinity, submergence, nutrient deficiency) stresses. Additionally, we explore the critical prerequisites for efficient genome editing in rice, ranging from target site design, PAM specificity, delivery systems (like Agrobacterium, RNPs, and nanoparticle-mediated delivery), to screening and validation of mutants. This review also highlights recent breakthroughs in multiplex genome editing for complex traits, including the development of haploid inducer lines and clonal seed technology. Haploid inducers accelerate breeding by producing homozygous lines without tissue culture, while engineered apomixis enables clonal propagation of elite hybrids. Beyond technical dimensions, this review underscores the broader socio-economic and regulatory implications of genome-edited rice, addressing the emerging ethical concerns, intellectual property issues, farmer access, and equitable technology dissemination in resource-limited agricultural regions. As the global policy landscape transitions to accommodate CRISPR-edited crops, transparent regulatory frameworks, stakeholder engagement, and public perception will play pivotal roles in ensuring sustainable, safe, and inclusive adoption of genome editing in agriculture.