
Evolutionary biologist Sara Branco, PhD, assistant professor in the Department of Integrative Biology at the University of Colorado Denver, received a nearly $800,000 grant from the National Science Foundation to study metal tolerance in a plant-fungal mutualistic system. She will team up with researchers from the University of Florida and Free University of Brussels for the four-year study.

Branco’s research will explore how certain species of fungi are able to tolerate high levels of metals. In soil with high zinc concentrations, like soil surrounding former mining areas, some fungi survive despite the pollutant’s presence. One particular species, called Suillus luteus, surrounds the root tips of the Scots Pine (Pinus sylvestris) in a symbiotic and protective relationship called mutualism. The fungus provides water and nutrients, and receives sugars in return. In addition, it reduces pine metal uptake, allowing the pine trees to grow in polluted soils.
“It is well known that fungal mutualists improve plant survival, growth, and reproduction, but our project will allow gathering crucial knowledge on how fungi can assist their plant partners under inhospitable environmental conditions,” writes Branco in the proposal. “Results from our work can therefore provide important insight on the development of technology and tools to enhance plant establishment and productivity, as well as assist in mitigating the impact of soil contamination on plant production.”
Branco’s research will dive into the genetic and molecular underpinnings of metal tolerance, test the role of the fungus in the pine’s zinc uptake, and use a gene editing technique to identify and validate the genes fungal genes underlying zinc tolerance.
For the final part of the grant, Branco will screen contaminated sites around Colorado to identify local, metal-tolerant fungi that could one day be used to plant new forests on contaminated land.