CHICAGO -- Mycorrhizal fungi are among the most common beneficial fungi for plants, mining soil nutrients and delivering them to plants in exchange for sugars, explained Bala Chaudhary, an environmental scientist at DePaul University.
All plants on Earth, from farm crops to fruit trees, delicate herbs to vegetables in backyard gardens, prairie grasses and exotic flowers, need a little help from these often overlooked partners in order to survive and thrive. However, the impact they have on plants depends on the type of fungal species present, noted Chaudhary, whose research focuses on the ecology of mycorrhizas, the common symbiotic associations between plants and fungi.
"Environmental factors and dispersal determine microbial community structure, but little is known about how microbes disperse long distances," she said.
Chaudhary, an assistant professor of environmental science at DePaul, is embarking on a deep dive into mycorrhizal dispersal mechanisms with support from the National Science Foundation. She is a recent recipient of a Faculty Early Career Development (CAREER) grant, NSF's most prestigious award in support of early-career faculty who have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization. The $715,000, five-year research grant will support a multifaceted project that combines trait-based ecology, macroecology and physical laws to study dispersal of mycorrhizal fungi.
"The microbial communities that associate with plants can have large implications for agriculture, forestry and ecosystems. We know that environmental factors and dispersal determine microbial community structure, but little is known about how microbes disperse long distances," said Chaudhary.
"For nearly 100 years, the 'everything is everywhere' hypothesis has dominated microbial ecology, suggesting that microbial dispersal is unlimited and community assembly mechanisms are primarily deterministic," Chaudhary noted. "However, certain fungi vary with respect to traits that could impact their long-distance dispersal capabilities. Coupling knowledge of traits with physical laws that govern movement could provide a powerful framework to predict dispersal, a key component of biogeography."
Chaudhary will use a few different approaches to study how symbiotic plant microbes will disperse at large continental scale. One is using data from the NSF-funded National Ecological Observatory Network (NEON), a system of sites across the U.S. where there is an established infrastructure that documents the exact same measurement in the exact same way -- common protocol -- at the exact same time, Chaudhary said.
While NEON is a resource, it doesn't have data on the plant symbiotic microbes that Chaudhary studies so she will gather soil samples from 16 core terrestrial sites in the NEON system and set up dust collectors at those sites to trap particles that have traveled long distances in the wind.
"For three years, dust and soil samples will be collected and brought back to the lab where we'll analyze mycorrhizal communities using DNA sequencing. We'll have all of the NEON ecological and climatic data to use as predictor variables, to determine the best eco-climatic predictors of mycorrhizal communities," she said.
The other "cool part" of the project, said Chaudhary, will be looking at the shape, size and physical traits of the microbes -- if they are round or smooth or spiny or ornamented. "We want to get an idea to try and understand not just what's there, but if we want to predict the future, how well this organism can disperse. We're going to measure some of their morphological traits to try and predict how far they can travel in the wind," she said.
The big picture in studying tiny microbes
"Microbes are the majority of biodiversity on Earth, yet, we still don't understand the rules for biodiversity; why we see more species here versus species there. This research is going to help us better understand those rules for biodiversity. And that gets at the function of these microbes and how they are linked to plant growth; how they are linked to agriculture and ecosystem function," Chaudhary said.
She explained that crops, like corn or soybeans, need these plant symbionts to grow. "However, if the soil doesn't have them and they can't disperse on their own, farmers may need to spend a lot of money purchasing a product to add that microbe back in the soil to help the crop grow better."
Another outcome of this research can apply to ecosystem restoration -- restoring prairies in Illinois, for example. "Prairie restoration has been historically difficult and one of the reasons could be these symbiotic fungi are no longer present in the soil. But which symbiotic fungi should be added to the soil? Which species are more likely to disperse on their own? We can use this information to tailor products that contain the species that don't blow in and help restoration practitioners restore their prairies faster," Chaudhary said.
However, it isn't only large farms, prairies or forests that can benefit from this research. Chaudhary also cited urban restoration projects, including vacant lots and contaminated sites. "We need to go in and restore them and oftentimes we use plants and microbes to bring those sites back to life," she said.
An educational component
A CAREER grant is different from typical NSF grants in that there is a large educational component, noted Chaudhary. One of the educational objectives of this project is the development of an ecological data analysis course using open-access NEON data and data collected in this study. Students in the course will be able to proficiently manage large datasets, conduct and interpret complex statistical tests used in ecology, and conduct original data analysis projects using real data.
Another educational objective will involve Chicago-area high school and DePaul University students in "schoolyard science." The high school students, mentored by DePaul undergraduate and graduate students, will learn how to install dust collectors and collect and analyze urban ecological data. A public project website will be created to distribute video protocols, map sites and share data, Chaudhary said.
A third educational objective stems from Chaudhary's passion to improve systems to increase participation in ecology and the environmental sciences by underrepresented minority students. "Students of color often approach me with concerns of feeling isolated in our field and wanted to know what we could do about it," Chaudhary said. Through student interviews, Chaudhary will research barriers for undergraduate minority students studying ecology and inform best practices for recruitment and retention.
Early career commitment
Chaudhary has been teaching courses in plant biology, environment data analysis and climate change at DePaul since 2016 as an assistant professor in the College of Science and Health. In her lab in the Department of Environmental Science and Studies, Chaudhary examines soil ecological questions, with a focus on mycorrhizal fungi, something she has been studying since her own undergraduate days at the University of Chicago, where she earned a bachelor's degree in biological sciences.
Mycorrhizal fungi also was the topic of her doctoral dissertation and her master's thesis. Both her doctorate and master's degree in biological sciences were earned at Northern Arizona University.
More information about Chaudhary's mycorrhizal ecology lab is online at http://www.