Scientists at the University of California, Davis have developed a new wheat variety that can stimulate the production of its own fertilizer. The development could help reduce environmental pollution and lower costs for farmers.
The research team, led by Eduardo Blumwald, used CRISPR gene-editing technology to increase the production of a naturally occurring chemical in wheat plants. This chemical, when released into the soil, helps certain bacteria convert nitrogen from the air into a form usable by plants. The process is known as nitrogen fixation.
“In Africa, people don’t use fertilizers because they don’t have money, and farms are small, not larger than six to eight acres,” said Blumwald. “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 one of the most widely grown cereal crops globally and accounts for about 18% of total nitrogen fertilizer use. According to United Nations Food and Agriculture Organization data, more than 800 million tons of fertilizer were produced worldwide in 2020.
Plants generally absorb only 30-50% of applied nitrogen fertilizer; unused amounts often enter waterways or produce nitrous oxide gas in soils. These outcomes contribute to water pollution and climate change due to “dead zones” lacking oxygen and increased greenhouse gas emissions.
Nitrogen-fixing bacteria contain an enzyme called nitrogenase necessary for converting atmospheric nitrogen into plant-available forms. Unlike legumes such as beans and peas—which house these bacteria within root nodules—wheat lacks such structures and typically relies on synthetic fertilizers.
“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,” said Blumwald. “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.”
Blumwald’s team examined 2,800 chemicals produced by wheat plants and identified several that stimulate beneficial bacterial activity through biofilm formation—a process essential for low-oxygen environments needed by nitrogenase enzymes. They then used CRISPR technology to boost production of apigenin in wheat roots. In trials with low levels of synthetic fertilizer present, these modified wheat plants demonstrated higher yields compared to control groups.
Farmers spent nearly $36 billion on fertilizers in 2023 across almost 500 million U.S.-planted cereal acres (https://www.nass.usda.gov/Publications/Ag_Statistics/2023/Complete%20Publication.pdf). Blumwald estimates even modest reductions in fertilizer use could result in annual savings exceeding $1 billion nationwide.
“Imagine, if you could save 10% of the amount of fertilizer being used on that land,” he pondered. “I’m calculating conservatively: That should be a savings of more than a billion dollars every year.”
Other contributors to this study 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 University of California officials; Bayer Crop Science and UC Davis Will Lester Endowment supported parts of this research effort.
###
