McNair Scholar 2022 Christos Robertson
Christos Robertson is a senior at the University of Minnesota College of Biological Sciences majoring in Plant and Microbial Biology. His research interests include improving agricultural sustainability through soil microecology and plant-microbe interactions. Christos plans on getting his Ph.D. in Plant and Microbial Biology.
My dream is to lead a research lab within the U.S.D.A that focuses on increasing sustainability in agriculture by studying plant-microbe interactions and soil microbes.
Research project
The Fitness Implications of Rhizopine Synthesis in Alfalfa and its Rhizobial Symbionts
Abstract: Symbiosis between legume crops and rhizobia, which provide (“fix”) nitrogen, reduces the need for fertilizer. Plants impose sanctions on “cheating” rhizobia, which divert resources from nitrogen fixation to their own reproduction. In alfalfa nodules, rhizobia that fix nitrogen cannot benefit from hoarding resources because they have lost the ability to reproduce, but they may divert resources (rhizopines) to their still-reproductive sisters. What are the fitness implications of rhizopine synthesis for rhizobia and alfalfa? We are testing three hypotheses: reproductive rhizobia benefit from rhizopines; making rhizopines diverts enough resources from nitrogen fixation to harm the plant; and this is enough to trigger sanctions. We are conducting two concurrent 8-week experiments: one with single-inoculated plants to measure the cost to the host plant of rhizopine synthesis, and the other with dual-inoculated plants to measure effects of rhizopine synthesis/use on rhizobial fitness. Plants are growing but data will not be collected until August.
Faculty mentor
Ford Denison is an adjunct professor in the department of Ecology Evolution and Behavior. He has a bachelors in ecology from Evergreen College, and a masters and a PhD in crop science from Cornell. His research interests involve the evolution of cooperation specifically the rhizobia legume symbiosis and how that applies to agriculture. Dr. Denison was a full professor at U.C. Davis for many years. He has published over 100 articles in the fields of ecology, microbiology, and agronomy. This is his first year as a McNair faculty Advisor.