Performing Infection Assays of Sporisorium reilianum f. sp. Zeae in Maize

Corn head smut fungus Sporisorium reilianum f. sp. zeae is a biotrophic pathogen belonging to the class of basidiomycetes. Under field conditions, it infects maize (Zea mays L.) still in the soil at early stages of development. Later, the infection spreads systemically to all aerial parts of the plant with mild symptoms of anthocyanin accumulation until the development of inflorescences, where it causes a replacement of maize inflorescences with spore-filled sori or leaf-like structures. Recently, Sporisorium reilianum (S. reilianum) is being established as a model organism to study fungal-plant interactions and corresponding virulence factors. Here, we describe a detailed protocol for a method that has been described and employed previously (Ghareeb H, Zhao Y, Schirawski J, Molecular plant pathology 20:124–136, 2019) to test the virulence of S. reilianum in maize under controlled laboratory conditions.