University of Wisconsin-Madison researchers received a $5.5 million grant from the U.S. Department of Energy on Jan. 10 to study methods to reduce synthetic nitrogen fertilizer use in crops.
The multi-university project, led by Dr. Jean-Michel Ané, UW-Madison professor in the Department of Plant and Agroecosystem Sciences and the Department of Bacteriology, looks to reduce synthetic nitrogen use in corn and sorghum. These two crops are used in the United States’ biofuel production, with corn accounting for 94% of ethanol production in the U.S.
With the U.S. producing over 389 million tons of corn every year, Ané and his team hope to reduce overall fertilizer use through the cross-breeding of non-native corn variants and the genetic modification of nitrogen-fixing bacteria.
Nitrogen fixation, a biological codependency which is vital for all plants, occurs when certain types of bacteria create a symbiotic relationship with their host plant. The bacteria is given a safe place to culture in exchange for converting nitrogen in the air into ammonia that both the bacteria and plant can use to grow.
Traditionally, American variants of corn fix only about 0.5% of available nitrogen for use in bacteria and the host plant, but Ané said with his team’s research and ongoing discoveries, he’s optimistic that number could be increased to 20%.
Ané said his scientific journey with this experiment first started over 10 years ago, when researchers discovered a strain of corn in Oaxaca, Mexico which could receive over 50% of its needed nitrogen from fixation.
“My first reaction was, ‘no way.’ And it took us about eight or nine years for us to convince ourselves that it was true,” Ané told The Daily Cardinal.
The key difference between American breeds of corn and the Oaxaca corn, locally known as olotón, is the large open-air roots that line the plant and secrete a mucus-like gel, which hosts nitrogen-fixing bacteria and allows olotón to effectively self-fertilize.
Ané’s team is now looking for ways to cross-breed this corn with American variants, creating a crop that harnesses more of an ecosystem’s available atmospheric nitrogen through the same open-air roots.
However, a key limitation with olotón corn is the U.S.’s comparatively shorter growing season, Ané said. Some regions in Mexico allowed the corn to grow for multiple years, something he said wasn’t possible in many regions of the U.S.
To adapt to the high demand and faster turnover rate of American agricultural practices, Ané and his colleagues are looking to introduce genetically modified nitrogen-fixing bacteria into the soil, which would act as a nitrogen source before the development of the open-air roots, combining his decades worth of research in a “complimentary” way.
“I've been looking into approaches to take microbes that already fix nitrogen on corn and modify them genetically to force them to fix more nitrogen and to release that nitrogen to the plant,” Ané said.
Their process of genetic modification is a less traditional route than what the average person might think of, Ané said. His team uses a process called cisgenic modification. Unlike traditional genetic engineering which uses foreign DNA, cisgenic modification simply involves “moving pieces of DNA within the same bacterium,” he said.
Project(ed) future
Ané worries the future of his research may be in jeopardy with President Donald Trump in office. He said he has had little communication with the U.S. Department of Energy since the government agency canceled a meeting between them.
However, Ané said he was still “a bit optimistic” about receiving funding despite current setbacks.
“Because it's a project which is fairly applied, it's really to translate the basic research that I've done for decades to practical applications. And I guess that’s what people want now. So it's really translating the science we do in academia, to industry,” Ané said.