By Jeff Mulhollem
A team of plant scientists in Penn State’s College of Agricultural Sciences has received a $1.96 million, five-year grant from the National Institutes of Health (NIH) to fund a study of how beneficial plant-bacteria partnerships evolve, persist, and can be harnessed to improve health and agriculture.
This grant, called a Maximizing Investigator’s Research Award, supports a lab's long-term research vision rather than an individual project.
“Most research focuses on harmful microbes known as pathogens, but this team studies mutualisms — relationships in which both partners benefit,” said team leader Liana Burghardt, an assistant professor in the Department of Plant Science and the director of the Huck Center for Root and Rhizosphere Biology.
Her laboratory group studies a well-known plant-bacteria partnership involving a plant called Medicago truncatula with the bacteria Sinorhizobium meliloti. The plant, commonly called barrel medic, is a small, annual, clover-like legume native to the Mediterranean region. It is widely used as a model organism for legume biology, a nutrient conversion process called nitrogen fixation and the study of symbiotic partnerships. It is also closely related to the forage crop alfalfa.
According to Burghardt, the mutually beneficial relationship works like this: Bacteria in the soil infect plant roots. The plant forms nodules — tiny structures — on the roots. Inside those nodules, bacteria convert the atmospheric nitrogen into usable nutrients for the plant, and the plant provides the bacteria with sugars for food. In other words, she noted, the plant gets nutrients and the bacteria get energy and a place to live.
“Similar to many environmental pathogens, these beneficial partners can live independently, and they re-form their relationship every generation,” Burghardt said. “Bacteria spend much of their time in soil, not inside plants. This creates a complex situation where bacteria must survive in soil, compete to infect plants and adapt to different plant hosts.”
This NIH-funded research project focuses on three big unknowns, Burghardt explained: What genes make bacteria successful inside plants, what happens outside the host and how these partnerships stay stable over time.
Source : psu.edu