Scientists at the University of California, Davis have developed a new type of wheat that can help produce its own fertilizer. The research team, led by Eduardo Blumwald, used CRISPR gene-editing technology to increase the production of a naturally occurring chemical in wheat plants. When released into the soil, this chemical encourages certain bacteria to convert nitrogen from the air into a form usable by plants—a process known as nitrogen fixation.
The findings were published in Plant Biotechnology Journal. According to Blumwald, this advancement could improve food security in developing countries where farmers often cannot afford fertilizers and operate on small plots of land. “In Africa, people don’t use fertilizers because they don’t have money, and farms are small, not larger than six to eight acres,” Blumwald said. “Imagine, you are planting crops that stimulate bacteria in the soil to create the fertilizer that the crops need, naturally. Wow! That’s a big difference!”
Wheat is currently the second most-produced cereal crop worldwide and accounts for about 18% of all nitrogen fertilizer usage. Despite over 800 million tons of fertilizer being produced globally in 2020 according to United Nations Food and Agriculture Organization data (https://www.fao.org/faostat/en/#data/RFN), only 30-50% of applied nitrogen is absorbed by plants. The remainder can enter waterways—creating oxygen-poor “dead zones”—or become nitrous oxide gas that contributes to climate change.
Traditionally, legumes like beans and peas support nitrogen-fixing bacteria through root nodules; wheat does not form these structures and thus relies on added fertilizers. For years, scientists have tried various methods to enable cereals like wheat to fix their own nitrogen without success. “For decades, scientists have been trying to develop cereal crops that produce active root nodules, or trying to colonize cereals with nitrogen-fixing bacteria, without much success. We used a different approach,” Blumwald explained. “We said the location of the nitrogen-fixing bacteria is not important, so long as the fixed nitrogen can reach the plant, and the plant can use it.”
The UC Davis team identified 20 plant chemicals capable of stimulating biofilm formation around beneficial soil bacteria—biofilms create low-oxygen environments needed for bacterial enzymes called nitrogenase to function properly. Using CRISPR technology, they increased production of one such compound: apigenin. This extra apigenin was secreted into soil by modified wheat roots during experiments and enabled more effective nitrogen fixation by surrounding microbes.
In trials with limited synthetic fertilizer application, these genetically edited wheat plants yielded more grain than control groups grown under similar conditions.
U.S. farmers spent nearly $36 billion on fertilizers in 2023 according to USDA estimates (https://www.nass.usda.gov/Publications/Highlights/2024/fertilizer-expenses.pdf). With almost 500 million acres planted with cereals nationwide (https://www.nass.usda.gov/Charts_and_Maps/Field_Crops/cerealma.php), even modest reductions in fertilizer use could lead to significant cost savings for growers. “Imagine, if you could save 10% of the amount of fertilizer being used on that land,” said Blumwald. “I’m calculating conservatively: That should be a savings of more than a billion dollars every year.”
Other contributors include Hiromi Tajima (first author), Akhilesh Yadav, Javier Hidalgo Castellanos, Dawei Yan, Benjamin P. Brookbank and Eiji Nambara.
A patent application has been filed for this technology by the University of California and is pending review.
Bayer Crop Science and funding from UC Davis Will Lester Endowment supported this research.
