'CRISPR-Combo' system speeds regeneration of hard-to-breed perennial crops
Editing a plant's genes is only half the battle. Before a new, improved trait can ever reach a farmer's field, scientists must be able to grow a whole plant from just a few edited cells—a process that can be slow, unreliable and, for some plant species, impossible.
A new CRISPR-Combo system developed by researchers from Texas A&M AgriLife Research, the University of Maryland, and the USDA could significantly speed up the regeneration of perennial crops, making it easier and more efficient to breed improved varieties for farmers. The CRISPR-Combo technique allows scientists to edit a specific gene of interest while simultaneously activating the plant's own natural morphogenic genes, which control cell division and growth into roots, shoots, and entire plants.
By using the plant's own versions of these growth-promoting genes, CRISPR-Combo can coax a faster and more reliable regeneration process compared to current methods that often rely on additional hormones or extra genetic material.
The study, published in Nature Communications, demonstrates the potential of CRISPR-Combo in improving the regeneration of crops such as citrus, strawberry, poplar, and potatoes. Perennial crops like citrus and poplar typically take years to complete a breeding cycle, and many high-value fruit and nut crops have been particularly challenging to work with in the lab.
By activating the plant's own regeneration genes, CRISPR-Combo offers a more streamlined and scalable approach, potentially benefiting a wide range of commercially important crops that currently struggle with typical regeneration methods.
In potatoes, the team identified four genes that increased hairy root production, with three of those also improving shoot regeneration to 45%–70% efficiency. For citrus, five genes were found to significantly boost hairy root formation, with shoot regeneration reaching 80% or higher in lab conditions. In wild strawberry and poplar, activating two morphogenic genes at once shortened the time needed to produce a fully regenerated, gene-edited plant by over a month in strawberry and less than a month in poplar, without requiring external plant hormones.
This hormone-free approach resulted in taller, higher-biomass plants in the greenhouse with no observable abnormalities.
Written by urgent.news from Phys.org's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
