IU Bloomington biologists to receive funding from NSF’s Dimensions of Biodiversity Program

$1.9 million grant funds exploration of most abundant, diverse organisms on planet

Indiana University Bloomington biologists who specialize in the ecology and evolution of microbes have been named one of 12 teams in the nation to receive funding from the National Science Foundation's Dimensions of Biodiversity Program.

Associate professor Jay T. Lennon and postdoctoral research fellow Ken Locey, in collaboration with Notre Dame assistant professor Stuart Jones, have been awarded over $1.9 million to fund research over the next five years aimed at better understanding the role of dormancy in maintaining microbial diversity.

Microorganisms are the most abundant and diverse organisms on the planet, with tens of thousands of bacterial species coexisting in a single gram of soil. Some die from environmental stressors such as starvation within days, while other species seem to persist in a dormant state for millions of years.

Lennon's new work will seek to identify the key ecological and evolutionary processes that generate and maintain microbial diversity and to understand how that diversity influences ecosystem processes. He plans to do that by focusing on dormancy and the evolutionary history of a mechanism that has been recognized as a form of cell-to-cell communication that may affect pathogen suppression, plant-soil feedback and ecosystem processes.

"We plan to develop and test theories and predictions that dormant microbes use signaling molecules to directly alter microbial seed banks," said Lennon, a researcher in the College of Arts and Sciences' Department of Biology. "Then we want to analyze how these seed banks contribute to geographic patterns of diversity."

Seed banks are of interest to the National Science Foundation and to biodiversity researchers as reservoirs of inactive individuals that can potentially be resuscitated under different sets of environmental conditions.

"Our previous research has shown that in some soils, an estimated 90 percent of all bacterial cells are inactive, half of all species are dormant, and at least one-quarter contain genes that enable individuals to resuscitate from dormancy," Lennon said. "We now have the tools that will allow us to characterize the mechanisms of dormancy and to develop a theoretical framework for linking the structure and function of these communities in natural and managed ecosystems."

In contrast to traditional biodiversity research, NSF's Dimensions in Biodiversity Program doesn't focus on one taxonomic group or ecosystem, but instead integrates multiple aspects into research projects, linking functional, genetic and phylogenetic dimensions of biodiversity.

Research has already found that plant and animal extinctions are detrimental to human health and that species losses in ecosystems such as forests and fields result in increases in pathogens or disease-causing organisms. The species most likely to disappear as biodiversity declines are often those that buffer infectious disease transmission, and those that remain tend to be the ones that magnify diseases, such as West Nile virus, Lyme disease and hantavirus.

"Seed banks may be one of the largest global reservoirs of biodiversity on the planet, yet few studies have examined how dormancy is regulated in these complex communities," Lennon said. "And there has never been a theoretical exploration of how seed banks influence microbial diversity."

Still, microbial dormancy has been an attention-getter in the scientific community for a half-century or more. Microbiologists know dormancy plays a role in anthrax, cholera and gonorrhea, and it's estimated that a third of the world's population is infected with a dormant version of Mycobacterium tuberculosis, which causes tuberculosis.

"This year's portfolio of projects will accelerate our understanding of biodiversity across disciplines and across scales of time and space," said Penny Firth, director of NSF's Division of Environmental Biology. "Through this program, we're witnessing a transformation in our ability to bridge scientific approaches and perspectives."

The project will also allow for a collaboration with Transylvania University (Lexington, Ky.) associate professor of biology Sarah Bray, who spent a sabbatical in Lennon's lab last year and who will now send two different seniors to Lennon's lab for each of five consecutive summers. Those students will then return to Transylvania and mentor younger students about microbial diversity research.