While we understand in great detail the biochemical mechanisms of plant immunity, we still know very little about the interaction of plant populations with pathogens and other microbes in nature.

Most species on Earth are parasites, and organisms that parasitize plants are ubiquitous. What has been holding the field back is a lack of understanding which parasites drive immune system diversity in natural populations, and which host plants in turn drive diversity in the parasites. Beginning with  samples from the wild collected on field trips, we apply both genome-sequencing and pathogen testing to determine the role of local adaptation in plant-pathogen interactions.

These efforts draw on an increasing number of complete genome assemblies of both plants, especially Arabidopsis thaliana, and pathogens, which are beginning to reveal a highly complex picture of variation at host immune receptors and matching pathogen effectors. In parallel, we are developing high-throughput methods with which we can directly determine which pathogen effector variants can be detected by which host receptor variants.