A new study led by researchers from Texas A&M AgriLife Research, the University of Maryland, and the U.S. Department of Agriculture (USDA) introduces a groundbreaking system called CRISPR-Combo. This system allows scientists to edit a specific gene in plants while simultaneously activating the plant’s own natural "morphogenic" genes—those that control cell division and the development of roots, shoots, and entire plants. The findings, published in the journal Nature Communications, offer a potential solution to one of the major challenges in plant genetic research: getting edited plants to grow properly in the real world. CRISPR-Combo uses the same CRISPR tool typically used for gene editing to also turn on the plant’s existing growth-promoting genes, rather than inserting new copies of those genes. This method avoids the complications that can come with adding foreign genetic material. According to Krishna Mandadi, director of the Texas A&M AgriLife Research and Extension Center at Weslaco, regeneration—getting edited plants to grow into full, healthy crops—is a major hurdle in moving laboratory discoveries into practical use. "This work shows that we can coax a plant's own genes to regenerate faster and more reliably," Mandadi explained. The approach could be especially useful for perennial crops like citrus, which are notoriously difficult to work with in the lab. To identify which genes to activate, the team used a fast, high-throughput "hairy root" system developed by AgriLife Research. This system encourages root growth on plant cuttings without the need to grow an entire plant from scratch. Using this method, the researchers tested various candidate genes in potatoes and citrus. In potatoes, they found four genes that significantly increased root growth, with three of those also improving shoot regeneration. This boosted the regeneration efficiency to 45%–70%, compared to 30%–35% in control plants. In citrus, a crop that is typically resistant to genetic modification, the team found five genes that greatly improved root formation. In lab conditions, all five genes pushed shoot regeneration efficiency to 80% or higher, compared to under 60% in controls. The researchers took their work a step further by testing the system in wild strawberries and poplar trees. In strawberries, they activated two morphogenic genes at once, which reduced the time needed to produce a fully regenerated, gene-edited plant by more than a month compared to standard methods. In poplar, co-activating two genes had an even more dramatic effect: shoots regenerated in less than a month, and no external plant hormones—normally required in tissue culture—were needed. Poplar lines with both genes activated showed the highest rates of edited cells and grew into taller, higher-biomass plants in the greenhouse, with no obvious issues. These results suggest that CRISPR-Combo could significantly speed up the development of new plant varieties for agriculture and environmental restoration.