CRISPR excels at precise cuts and small edits, but inserting large stretches of DNA into plant genomes efficiently has remained a stubborn bottleneck. Researchers in Magdy Mahfouz's Laboratory for Genome Engineering and Synthetic Biology at KAUST have now demonstrated an alternative: harnessing R2 retrotransposons, mobile genetic elements that naturally copy themselves into host genomes, to write multi-kilobase DNA sequences into defined safe-harbour sites.
Reported in Nature Biotechnology, the system writes DNA from an RNA template and integrates it without creating a conventional double-strand break, a feature that distinguishes it from many standard editing approaches. In proof-of-concept experiments, the team inserted test genes conferring antibiotic and herbicide resistance into a reliably active region of the rice genome, achieving insertion in up to 17 per cent of treated rice cell clusters, and showed the method also works in tobacco.
The researchers additionally installed recombinase landing pads, short docking sequences that allow much larger DNA payloads to be added in later steps. That modularity points towards assembling entire biosynthetic pathways in crops, turning plants into low-cost, sunlight-powered factories for medicines and industrial enzymes. Stable inheritance across generations has yet to be demonstrated, the key test before agricultural deployment.