Unexpected complexity: A 3-D look into plant root relationships with nitrogen-fixing bacteria

February 28, 2019, US Department of Energy
Root nodules, which allow some bacteria to fix nitrogen into soils for greater plant productivity, have a surprisingly complex metabolism, which could be optimized to develop more sustainable agriculture. Credit: US Department of Energy

By taking nitrogen out of the air and turning it into plant nutrients, some bacteria help plants like beans, peas, and clovers thrive. How? A study shows that the traditional view of this symbiotic relationship doesn't capture the entire picture. Scientists resolved a 3-D map of the metabolic products of bacteria found in plant root nodules. This spatial perspective could help unravel the overall complexity of these highly interdependent organisms.

As these bacteria interact with legumes like soybeans, nodules grow on the roots of the plant. In these nodules, bacteria convert atmospheric nitrogen into molecules the plants need to grow. Understanding the occurring within these nodules is essential to develop more sustainable agricultural practices for used all over the world.

Previous studies led scientists to believe the distribution of bacterially derived metabolic by-products within the nodules was uniform. Scientists from EMSL, the Environmental Molecular Sciences Laboratory, a Department of Energy Office of Science user facility, joined with colleagues at the University of Missouri and the George Washington University to dig deep into the metabolic structure of soybean root nodules. They used one of EMSL's high-field Fourier transform ion cyclotron resonance to visualize the array of metabolites within the nodules. Of the approximately 140 regulating substances identified, some were located together in distinct anatomical compartments. A few, however, were more unevenly distributed throughout the middle of the nodule, where the bacteria reside. This discovery points to a previously unrecognized biochemical complexity in the nodules that are key for symbiotic plant-microbe interactions. Armed with this understanding, scientists can suggest ways to optimize crop production and sustainability.

Explore further: Fixing soybean's need for nitrogen

More information: Dušan Veličković et al. Observed metabolic asymmetry within soybean root nodules reflects unexpected complexity in rhizobacteria-legume metabolite exchange, The ISME Journal (2018). DOI: 10.1038/s41396-018-0188-8

Related Stories

Fixing soybean's need for nitrogen

March 21, 2018

Soybean is rich in protein, which is great for the humans and animals eating it. But this high protein content comes at a cost.

Study sheds light on how plants get their nitrogen fix

February 16, 2018

Legumes are a widely consumed family of plants that serve as a significant source of dietary protein, fiber, and other essential nutrients. They obtain nitrogen through a specialized process known as nodulation, a symbiotic ...

For legume plants, a new route from shoot to root

September 19, 2014

A new study shows that legume plants regulate their symbiotic relationship with soil bacteria by using cytokinins—signaling molecules— that are transmitted through the plant structure from leaves into the roots to control ...

Recommended for you

Catalyst advance removes pollutants at low temperatures

March 25, 2019

Researchers at Washington State University, University of New Mexico, Eindhoven University of Technology, and Pacific Northwest National Laboratory have developed a catalyst that can both withstand high temperatures and convert ...

EPA adviser is promoting harmful ideas, scientists say

March 22, 2019

The Trump administration's reliance on industry-funded environmental specialists is again coming under fire, this time by researchers who say that Louis Anthony "Tony" Cox Jr., who leads a key Environmental Protection Agency ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.