Scientists on the University of California, Davis, have developed wheat plants able to boosting their very own composting, a development that would reduce global air and water pollution and lower farming costs.
This work comes from a research group directed by Eduardo Blomwald, a distinguished professor within the Department of Plant Sciences. Using the gene-editing tool CRISPR, the team increased the plant’s production of one in all its natural chemicals. When wheat roots release this excess compound into the encompassing soil, it supports specific bacteria that may convert nitrogen from the air right into a form that nearby plants can absorb. This process is often called nitrogen fixation.
The research was published in
Potential advantages for food safety
For many developing regions, this development could offer recent support for reliable crop production.
“In Africa, people don’t use fertilizer because they don’t have money, and the farms are small, no bigger than six to eight acres,” Blomwald said. “Just imagine, you’re planting crops that encourage bacteria in the soil to produce the fertilizers that crops naturally need. Wow! That’s a huge difference!”
This wheat innovation builds on the group’s previous success in rice, and similar work is underway to increase the technique to other major grain crops.
The global fertilizer problem
Wheat ranks because the world’s second most efficient cereal and accounts for the biggest share of nitrogen fertilizer use, accounting for about 18% of the worldwide level. According to the Food and Agricultural Organization of the United Nations, in 2020, greater than 800 million tons of compost were produced worldwide.
Plants typically absorb only 30 to 50% of applied nitrogen fertilizer. The remainder often runs into rivers and coastal areas, contributing to oxygen-deprived “dead zones” that damage aquatic ecosystems. Excess excess nitrogen within the soil can produce nitrous oxide, a robust greenhouse gas.
Why wheat needs a special strategy
Nitrogen-fixing bacteria produce an enzyme called nitrogenase, sometimes called a “fixer” since it fixes nitrogen. The enzyme works only inside these bacteria and only in a low-oxygen environment.
Legumes equivalent to beans and peas naturally form root nodules, specialized structures that create the oxygen-poor conditions these bacteria need.
Wheat and most other crops lack these nodules, which is why synthetic nitrogen fertilizers are widely used.
“For decades, scientists have been trying to develop grain crops that develop root nodules, or trying to colonize grain with nitrogen-fixing bacteria, without much success. We used a different approach,” Blomwald said. “We said that the location of the nitrogen-fixing bacteria is not important, as long as the fixed nitrogen can reach the plant, and the plant can use it.”
How the UC Davis team found a workable solution
The researchers reviewed 2,800 chemicals made by plants and identified 20 that may encourage nitrogen-fixing bacteria to form biofilms. These biofilms are sticky coatings that wrap around bacteria, making a low-oxygen microenvironment suitable for nitrogenase activity. The team then mapped how plants synthesized these compounds and identified the genes involved.
Armed with this information, they used CRISPR to switch wheat plants in order that they produced large amounts of 1 compound particularly, a flavon called apigenin. As plants produce more apigenin than they need, the excess is released into the soil. In experiments, this apigenin encouraged soil bacteria to form a protective biofilm, enabling nitrogenase to repair nitrogen right into a usable form that wheat could absorb.
Under very low nitrogen fertilizer conditions, the modified wheat yielded even higher than the control plants.
Huge economic advantages for farmers
According to U.S. Department of Agriculture estimates, farmers within the United States will spend about $36 billion on fertilizers in 2023. Blumwald notes that about 500 million acres of land within the country are planted with grain.
“Just imagine, if you could save 10% of the amount of fertilizer used on this land.” “I’m calculating conservatively: That should be more than a billion dollars in savings every year.”
Other authors include Hiromi Tajima, Akhilesh Yadav, Javier Hidalgo Castillos, Davi Yan, Benjamin P. Brookbank and Eiji Nambara.
The University of California has filed a patent application, which is now pending. Bayer Crop Science and the UC Davis Will-Lester Endowment provided funding for this work.