The use of complementary fractures and low-temperature scanning electron microscopy to study hyphal – host cell surface adhesion between Uromyces viciae-fabae and Vicia faba

A modified specimen stub, for use with the EMscope SP2000 Sputter Cryo Preparation Unit, that will facilitate the production of complementary fracture faces is described. The application of complementary fractures for studying hypha–host surface adhesion within freeze-fractured leaves is reported for the first time. Freeze fracturing results in the rupture of either the hyphal wall or the host cell wall or both, at the edge of, or just beyond, the adhesive matrix pad that binds the two together. The implication that the adhesive is stronger than either of the two individual apposed walls is discussed in relation to the mechanics of bonding and to the process of penetration of the host cell by the fungus.