Two Penn State-led research teams have received funding from the U.S. Department of Agriculture's National Institute of Food and Agriculture for projects investigating the ways microbiomes - the microorganisms in a particular environment, such as in soil or a living organism - can affect disease dynamics in agriculture.
The grants, totaling a combined $1.1 million, are part of the institute's Agriculture and Food Research Initiative competitive grants program.
Fabricio Vieira, postdoctoral scholar in the Department of Plant Pathology and Environmental Microbiology in the College of Agricultural Sciences, will lead a project aimed at better understanding the microbiome associated with mushroom development and disease suppression.
"Understanding agricultural developmental microbiomes - called devomes - has the potential to improve agricultural production systems, human well-being and environmental health," Vieira said. "We are studying a host that is economically and agriculturally important to Pennsylvania: Agaricus bisporus, the button mushroom that is commonly found in any grocery store."
Throughout the project, the team will identify which microbes and biochemicals contribute to mushroom development and help suppress disease, as well as how best to utilize those pathways. They also will establish the best ways to develop the microbe communities that will help suppress disease in substrate environments, such as those used to grow mushrooms.
In addition to helping mushroom farmers, Vieira said, a deeper understanding of fungal devomes will have implications far beyond commercial mushroom production.
"Fungi - including those with edible fruiting bodies - play a significant role in agronomic crop production, decomposition, nutrient cycling, and the reestablishment and stabilization of habitats through their services to plants and animals," he said. "Therefore, this project has the potential to improve our understanding of agricultural microbiomes as a whole."
Francisco Dini-Andreote, assistant professor of phytobiomes, will lead the second project, which will explore the microbiome of disease-suppressive soils - or soils with natural capacities to suppress pathogens' growth and infection. It also will investigate how resilient these soils are to common agricultural practices and conditions, such as herbicides and soil acidification.
Dini-Andreote said the work is important because soil-borne plant pathogens represent about 90% of the 2000 major crop diseases in the U.S. and lead to major yield losses in the production of food, fiber and ornamental crops.
"There's a diverse set of soil-borne pathogens that are difficult to control with conventional strategies, due to both chemical resistance and the pathogens developing ways to circumvent host resistance," he said. "With these challenges, efforts to develop alternative control measures are critical to alleviating the impacts of soil-borne pathogens while promoting a stable food supply system."
The project will begin with identifying microbes and functions that help control the pathogen Verticillium dahlia, a common fungus capable of attacking a wide range of plants. Next, researchers will test specific bacteria obtained from suppressive soils for their potential to control V. dahlia growth in vitro. Lastly, the project will examine how herbicides and soil acidification affect the ability of these disease-suppressive soils to protect against V. dahlia infection.
Dini-Andreote said the development of new strategies to control V. dahlia and other soil-borne pathogens is critical to sustaining agricultural productivity under global change.
"Disease-suppressive soils are ideal systems for exploring novel microbial-mediated mechanisms of soil-borne pathogen control," he said. "Discovering more about the metabolic potential of soil and plant-associated microbiomes to drive down soil-borne pathogens offers a sustainable strategy to reduce chemical inputs and increase crop protection in agroecosystems."
Also working on Vieira's team are Carolee Bull, professor of bacterial systematics and plant pathology; Kevin Hockett, associate professor of microbial ecology; John Pecchia, associate research professor; and Eoin O'Connor, postdoctoral scholar in the Department of Plant Pathology and Environmental Microbiology.
