Head, Plant and Microbial Biology Department
Wardle Chair in Microbial Ecology
Evolution of biotic interactions (mutualisms and pathogens), Population genomics, Association genetics (GWAS)
Evolution and genomics mutualism
We are using population genetic analsyes, GWAS, and empirical manipulations in a model system, the model legume Medicago truncatula and its rhizobial symbionts (Ensifer sp.) to further our understanding of the evolution of mutualism. We are particularly interested in identifying and characterizing the evolutionary history of genes responsible for host genome x symbiont genome variation, and the extent to which this variation depends on the environment (population densities, nitrogen availability, etc.). This work has also led us to pursue work on association analsyes (GWAS) in Ensifer bacteria as well as investigating the genomic deteriminants of strain fitness in the soil. The vast majority of Ensifer are found in the soil, but in comparison to Ensifer interactions with legume hosts, we know very little about the determinants of fitness variation in soil environments. Much of this work is conducted in collaboration with Nevin Young and Mike Sadowsky at UMN, and Katy Heath at U. Illinois.
Evolutionary history and targets of selection in cacao
Identifying the plants genes that confer resistance against pathogens is challenging. This is esecially true for large and long-lived species for which standard genetic analysis are particularly difficult. Working with collaborators at Penn State University we are applying population genomic analyses to identify candidate resistant genes that can then be subjected to functional analyses -- basically, use statistical genomic approaches to filter through the genome to identify genes that warrant the labor intensive functional analyses. The data generated are also alowing us to gain a broader understanding of the genes responsible for past adaptation in cacao.
Dept. of Plant and Microbial Biology
Univ. of Minnesota
St. Paul, MN 55108