Researchers at the University of California, Davis, have used CRISPR gene-editing to develop wheat that boosts its own fertiliser supply by enhancing nitrogen fixation in the soil.
The modified wheat produces higher levels of a naturally occurring chemical that encourages soil bacteria to convert atmospheric nitrogen into a form plants can absorb. Wheat consumes around 18% of global nitrogen fertiliser, but only 30% to 50% of applied nitrogen is taken up, with the remainder entering waterways or releasing nitrous oxide, a greenhouse gas.
The technology could reduce fertiliser usage on the nearly 500 million acres of cereal crops planted in the US, potentially saving over a billion dollars annually. It may also benefit small-scale farms in developing regions, where access to fertiliser is limited.
Unlike legumes, wheat lacks root nodules for nitrogen-fixing bacteria, so fertiliser has been essential. Previous efforts to equip cereals with nodules or to colonise roots with nitrogen-fixing bacteria have not been widely successful. The new approach relies on soil bacteria activity near the roots rather than direct colonisation, allowing plants to access the nitrogen produced.
CRISPR and similar gene-editing techniques differ from genetic modification. Genetically modified wheat remains prohibited in the United States.