FIGURE 1.

Basic concept of the early stage of plant infection by an appressorium‐forming filamentous fungus. To penetrate the plant cuticle and cell wall, a germinating conidium forms an appressorium that has a thick melanin‐enriched cell wall to withstand the high turgor pressure generated by glycerol. By the development of a haustorium or a related feeding structure, a close contact site between both organisms is formed that facilitates the secretion of fungal effectors into the plant cytosol and the capture of plant nutrients by the fungus in the biotrophic stage of its life cycle. An invasive hypha mediates further colonization of the plant.