Feeding the future from the soil up
New research finds that friendly soil microbes can boost protein in staple crops, offering a path to fight global malnutrition
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Alex Pipinos is the lead author of a new study that suggests microbes could increase protein in staple crops. Pipinos is a University of Delaware Class of 2025 graduate with a master’s in microbiology. Here, she looks at a bacterial culture of Streptomyces coelicolor.
view moreCredit: Kathy F. Atkinson/ University of Delaware
The Green Revolution of 1950-1970 helped agriculture flourish around the world. Advances in technology enabled farmers to scale up their production, improving the way they watered and fertilized their crops.
The technology advancements — particularly in using chemical fertilizers — paved the way for taller plants, richer soils, and greater crop yields. All of these are known as “above-ground” traits.
But Harsh Bais, a professor of plant biology at the University of Delaware who was named an Innovation Ambassador earlier this year, said plants’ “below-ground” traits, such as how nutrient-dense they are, have long been overlooked.
“As far as food security, we will have significant challenges by 2050 when the world’s population doubles,” Bais said. “We incentivize our farmers for crop yield; we don’t incentivize them for growing nutrient-dense crops. Growing nutrient-dense plants will enable the population to be fed better and avoid any potential nutrient deficiencies.”
The problem, Bais said, is that most staple crops, such as corn and soybeans, are not grown in a way that boosts their amount of nutrients.
“We have to care about nutrients because we eat plants for our food,” Bais said. "At this juncture, the majority of our stable crops are mass-produced and not cultivated for elevated nutrient contents.”
Nutrients help nourish the human body, keeping people healthy. People need nutrient-rich amino acids for their bodies to produce protein. In new research published in the journal Frontiers in Microbiology, Bais and a team of researchers from the University of Delaware, Stroud Water Research Center and the Rodale Institute investigated how a bacteria naturally found in the soil that is beneficial to human health can enhance the levels of the amino acid and antioxidant ergothioneine in spring wheat. The findings offer insight into improving the nutritional value of crops in the future. The study was funded by the U.S. Department of Agriculture and the Foundation for Food and Agriculture Research.
The researchers grew spring wheat — one of the most widely consumed cereal crops — in a laboratory. After letting the seeds germinate and grow for seven days, they added a strain of bacteria called Streptomyces coelicolor M145 to the spring wheat roots.
After combining the bacteria and the plant, they separated the plant’s leaves and roots. Then, they extracted the amino acid ergothioneine from the samples, working to determine how much protein was in the plant’s roots and shoots.
They found that 10 days after S. coelicolor had been added to the spring wheat roots, the bacteria was able to inhabit spring wheat’s roots and shoots, producing ergothioneine, bypassing the plant’s innate defense mechanisms, and fortifying the spring wheat.
“It’s unusual," Bais said. “Unless there is a mutual advantage for either the plant or the microbe.”
The findings suggest that an alternative plant breeding approach could be utilized to associate plants with benign microbes to increase protein content in staple crops. All of our cereal crops are very low in protein. Think rice and breakfast cereals, common foods people eat, derived from these crops.
“This approach of harnessing a natural association of microbes with plants may facilitate fortifying our staple crops, enhancing global nutritional security,” Bais said.
Bais said he believes using microbes to transport nutrients depends on the microbes’ relationship with plants’ roots. He continues to work to catalyze the colonization of plant roots by beneficial microbes.
“Establishing a partnership with the appropriate types of microbes or microbial consortia for plants represents a method of engineering the rhizosphere — the region of the soil near plant roots — to foster a more favorable environment for either microbial associations that stimulate plant growth traits or enhance nutrient availability, which is the path forward,” Bais said.
Scientists have become more interested in soil bacteria as a means to solve issues with malnutrition and nutrient deficiencies. Alex Pipinos, the lead author and a UD Class of 2025 graduate with a master’s in microbiology, said climate change is one factor diminishing protein content in plants.
“Essentially, crops are becoming less nutrient-dense,” Pipinos said. “The more nutrients in crops, the more healthy humans can be.”
Pipinos points to a strong link between soil microbes, plant health and human health. Ergothioneine, she said, has already been shown to lower the risk of cardiovascular disease. It’s also been shown to combat cognitive decline, with a strong link to healthy cognitive aging.
“By enhancing ergothioneine in plants, we can improve human health,” Pipinos said.
But it will take efforts to boost human health. Andrew Smith, one of the paper’s co-authors and the CSO of the Rodale Institute, the lead foundation of the Foundation for Food and Agriculture Research grant, said soil health is the key. And that means farmers can play a big role.
“If compounds like ergothioneine are so important, how can we farm in a way that will support greater amounts of those phytonutrients?” Smith said. “This is just the beginning of basic research that could lead to more applied applications in agriculture and in food.”
It is, in fact, just the beginning. UD’s Harsh Bais said the next step is to do the study under stressed conditions, such as high temperatures and drought, in the field.
“We want to find out the whys and hows,” Bais said. “Why is ergothioneine fortifying the plants? How is it entering the plants? How is it bypassing a plant’s 10,000 levels of defense? And how is it helping plants under different stress conditions?”
The researchers grew spring wheat — one of the most widely consumed cereal crops — in a laboratory. After letting the seeds germinate and grow for seven days, they added a strain of bacteria called Streptomyces coelicolor M145 to the spring wheat roots.
Credit
Harsh Bais/ University of Delaware
Caption
A new study suggests that an alternative plant breeding approach could be utilized to associate plants with benign microbes to increase protein content in staple crops. “This approach of harnessing a natural association of microbes with plants may facilitate fortifying our staple crops, enhancing global nutritional security,” said Harsh Bais, professor of plant and soil sciences at the University of Delaware,
Credit
Kathy F. Atkinson/ University of Delaware
Journal
Frontiers in Microbiology
