The common milkweed plant may unveil the connections between root systems and plant defenses and how humans one day may control those links, a U-M researcher says.
The research data will contribute to the understanding of how diverse plant species, from agricultural crops through forest trees, use root fungi in their defense strategies, says Mark Hunter, a professor with dual appointments in the School of Natural Resources and Environment and the Department of Ecology and Evolutionary Biology at LSA. Using the data, researchers may be able propose how to manipulate root fungi to protect plants important to humans or render defenseless those considered to be invasive pests.
The National Science Foundation is funding the work through a four-year, $650,000 grant.
The work builds on a common understanding of plant biology. All plants worldwide must defend themselves from being damaged by their enemies, including insects, deer and pathogens. These defenses range from the physical, such as thorns, spines and tough leaves, to chemical, such as cyanide and steroids. As plants try to defend themselves, most make use of nutrients provided to them by fungi (called mycorrhizae) that live in their roots.
In what is basically a barter system, plants provide the fungi with sugar while the fungi provide plants with minerals such as phosphorus and nitrogen.
The strength of plant defenses may vary with the amount of fungus in their roots and the identity of their fungal partners, but this has never been studied in detail, Hunter says. Using the common milkweed as a study plant, his research will explore how the strength of plant defense varies with the fungal colonization of roots. It also will examine how variation in plant and fungal identity contributes to the defense, and how natural variation in soil nutrients influences the barter system. His experiments will explore the effects of root fungi on insect herbivores.
Understanding the role of mycorrhizal fungi in plant defense is of value to insect pest managers and those wishing to control invasive plant species, Hunter says.
The research is important for another reason: It provides a forum through which to train future biologists in universities and local area schools. Moreover, the project will be linked to the education and research mission of the Frontiers Master’s Program, which Hunter directs. Each summer, the program hosts groups at the U-M Biological Station that are underrepresented in the ecological sciences. The Frontiers program is housed within the Department of Ecology and Evolutionary Biology.
The research project also will contribute to other UMBS programs including Research Experiences for Undergraduates, Integrative Graduate Education and Research Traineeship and public outreach initiatives.
