Scientists at the University of California, Davis have developed a new type of wheat that can help produce its own fertilizer. The research, led by Eduardo Blumwald, a professor in the Department of Plant Sciences, used the CRISPR gene-editing tool to increase production of a natural chemical in wheat plants. When released into the soil, this chemical helps certain bacteria convert nitrogen from the air into a form usable by plants through nitrogen fixation.
The study was published online in Plant Biotechnology Journal and builds on previous work with rice. Research is ongoing to apply this technology to other cereal crops.
“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!”
Globally, wheat is the second most produced cereal crop and accounts for about 18% of all nitrogen fertilizer usage. According to United Nations Food and Agriculture Organization data, more than 800 million tons of fertilizer were produced worldwide in 2020.
However, only 30% to 50% of applied nitrogen fertilizer is absorbed by plants; much of the rest enters waterways or contributes to greenhouse gas emissions such as nitrous oxide.
Blumwald explained how his team took a different approach compared to past efforts: “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,” he said. “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 team identified chemicals produced naturally by plants that help create biofilms—a protective layer around bacteria allowing them to fix nitrogen efficiently. They then modified wheat using CRISPR so it would make more apigenin—a flavone—resulting in excess apigenin being released into soil and supporting beneficial bacterial activity.
In tests with low-nitrogen fertilizer levels, these genetically modified wheat plants yielded more grain than control plants.
Farmers could see significant economic benefits from this innovation. In 2023 alone, U.S. farmers spent nearly $36 billion on fertilizers across roughly 500 million acres planted with cereals (https://www.usda.gov/media/press-releases/2023/12/05/usda-releases-updated-annual-farm-sector-income-forecasts). Even modest reductions in fertilizer use could save over one billion dollars each year.
“Imagine, if you could save 10% of the amount of fertilizer being used on that land,” Blumwald said. “I’m calculating conservatively: That should be a savings of more than a billion dollars every year.”
The University of California has filed for a patent related to this technology; Bayer Crop Science and UC Davis Will Lester Endowment supported this research effort.
Other contributors include Hiromi Tajima (first author), Akhilesh Yadav, Javier Hidalgo Castellanos, Dawei Yan, Benjamin P. Brookbank and Eiji Nambara.
###
