The fungal pathogen Sclerotinia sclerotiorum infects hundreds of plant species, including members of the Brassicaceae and Solanaceae families. These two botanical families diverged over 100 million years ago, whereas Sclerotinia lineage gained ability to infect them less than 10 million years ago. Is there a chance that today's Brassicacea and Solanaceae developped similar defense responses to S. sclerotiorum in parallel?
Yes! we found one example. But we had to identify genes controlling quantitative disease resistance to S. sclerotiorum in Arabidopsis (Brassicaceae) first. Using genome wide association mapping and reverse genetics, we found a prolyl-oligopeptidase (an enzyme predicted to cleave small peptides after a proline) that is important for disease resistance. We named it POQR, and played it as a wild card.