Farmers often are required to apply nitrogen fertilizers to their crops to maintain quality and improve yields. Worldwide, farmers used more than 100 million tons of nitrogen in 2011, according to the United Nations Food and Agriculture Organization. In the same year, the U.S. alone produced and imported more than $37 billion in nitrogen. Now, researchers at the University of Missouri are working toward less reliance on nitrogen in plants, which could help decrease costs for farmers, develop heartier plants, eliminate runoff in water supplies and provide food for a growing global population.
Fernanda Amaral, an MU postdoctoral fellow and researcher in the , found that less dependence on nitrogen could start with a simple type of grass, Setaria viridis, and its relationship with naturally occurring bacteria.
“Biological nitrogen fixation—where bacteria fix atmospheric nitrogen and convert it to ammonium—provides a free way for plants to assimilate and metabolize nitrogen,” Amaral said. “Farmers have long known that legumes like soybeans fix nitrogen because of the symbiosis between the plant and bacteria in the soil. Normally, plants develop nodules on their roots. However, since grass plants that produce food, such as corn, rice and sugarcane, don’t form these specialized structures, that relationship has been trickier to explore in these plants. Therefore, we needed a plant model to help us study how nitrogen fixation naturally happens.”
Amaral worked with , MSMC Endowed Professor of and at MU, as well as scientists in Brazil from the Federal University of Paraná and University of Santa Catarina to find a plant model system that would be easy to germinate, small enough to study and already had a sequenced genome. They screened more than 30 genotypes of Setaria viridis grass looking for a strong nitrogen fixing response when three different bacteria strains were introduced.
Reviewed 2015-07-28