Recombinase-Based Engineering of Plant Genomes in the Era of Genome Editing

Abstract The rapidly evolving CRISPR/Cas-based genome editing technologies, which have dominated nearly all areas of molecular biology over the past decade, still face several unresolved challenges. One of the major limitations of current genome editing tools is the low efficiency of targeted long-sequence insertions. This issue is particularly critical in plant systems, where genome editing efficiency is hindered by specific cellular characteristics. Site-specific recombinases (SSRs), which have long been employed in genetic engineering to mediate various genomic rearrangements—including deletions, duplications, insertions, and inversions—are limited in their application by the requirement for preexisting recombination recognition sites in the genome. However, CRISPR/Cas and recombinase tools complement each other, and their combined use offers a powerful strategy to overcome key limitations of genome editing. The discovery of CRISPR-associated transposons such as CAST and OMEGA, which naturally utilize their own recombinases, marks a significant advance in genome engineering, providing an elegant example of the natural convergence between CRISPR and recombinase technologies.