Using CRISPR technology, scientists have developed a variety of wheat that produces higher levels of apigenin—a compound that stimulates soil bacteria to naturally fix nitrogen. This approach could reduce fertilizer costs, lessen environmental harm, and increase crop yields.

A New Approach to Soil Fertilization

Researchers at the University of California, Davis, have engineered wheat capable of promoting the formation of its own fertilizer. This innovation could significantly cut air and water pollution worldwide and lower agricultural expenses. The project is led by Professor Eduardo Blumwald from the Department of Plant Sciences.

By employing the CRISPR gene-editing tool, the team enhanced the production of one of the plant’s natural compounds. When wheat roots release this compound into the soil, it helps certain bacteria convert atmospheric nitrogen into a form that plants can absorb—a process known as nitrogen fixation.

Significance for Developing Regions

For many developing countries, this discovery could support stable agricultural production. In Africa, fertilizers are often unaffordable, and farms are typically small—no more than six to eight acres. The ability to grow crops that naturally stimulate soil bacteria to create essential fertilizer could be a real breakthrough.

Background and Scale of the Problem

Wheat is the world’s second most-produced grain crop and uses about 18% of all nitrogen fertilizers. According to the UN Food and Agriculture Organization, over 800 million tons of fertilizer were produced in 2020.

However, plants typically absorb only 30–50% of the nitrogen fertilizers applied. The rest ends up in rivers and coastal areas, causing “dead zones” with low oxygen levels that harm aquatic ecosystems. Excess nitrogen in soil also leads to the formation of nitrous oxide, a potent greenhouse gas.

How Nitrogen Fixation Works

Nitrogen-fixing bacteria produce the enzyme nitrogenase, which enables nitrogen fixation, but this enzyme only functions inside bacteria and in low-oxygen conditions. Legumes like beans and peas naturally form root nodules—structures that create the right environment for these bacteria. Wheat and most other crops lack such nodules, so synthetic nitrogen fertilizers are widely used.

For years, scientists have tried to create grain crops with active root nodules or to colonize them with nitrogen-fixing bacteria, but with little success. The new approach focuses on the idea that the location of the bacteria is less important if the fixed nitrogen can reach and be used by the plant.

Searching for Effective Compounds

The researchers studied 2,800 natural compounds produced by plants and identified 20 that can stimulate bacteria to form biofilms. These sticky coatings create a microenvironment with low oxygen, ideal for nitrogenase activity. The team then determined how plants synthesize these compounds and identified the relevant genes.

Using this information, they used CRISPR to modify wheat plants so they would produce more of one such compound—the flavone apigenin. The excess apigenin is released into the soil, where it stimulates bacteria to form protective biofilms, allowing nitrogenase to fix nitrogen in a form wheat can absorb. Under conditions of very low nitrogen fertilizer input, the modified wheat also showed higher yields compared to control plants.

Economic and Environmental Impact

In the United States, farmers spent nearly $36 billion on fertilizers in 2023, with about 500 million acres planted with grain crops. Even a 10% reduction in fertilizer use on these lands could save over a billion dollars annually.

Future Prospects

This innovation builds on the group’s previous success with rice, and similar research is underway for other major grain crops. The adoption of such technologies could fundamentally change agriculture, making it more sustainable and environmentally friendly.