An Apple a Day Keeps the Gray Mold Away

Most consumers dispose of rotten food without a second thought; however, they also throw away a dynamic group of plant pathogens that can be utilized for inquiry-driven investigations into host/pathogen interactions. Botrytis cinerea is a common necrotrophic fungus that can infect most plants but causes substantial losses to the grape and fresh berry industries. Because most store-bought strawberries eventually succumb to this pathogen (due to the presence of spores from the field or packing facility), they are a dependable source of fungal inoculum to test novel hypotheses about the nature of disease. Across the produce aisle, apples are a diverse, well-characterized, and susceptible host population that enables students to construct individualized experiments about the nature of disease with adequate replication for meaningful analysis. This experimental protocol will outline how to conduct an infection assay with B. cinerea and commercially available apple varieties for students to develop their own experiments, inoculate their own plants, and analyze their own data to answer important questions about how pathogens cause disease.