plant surface microbiology.pdf

16 Cellular Basidiomycete–Fungus Interactions 273
identify them have been made. However, the change in the electron density of
the core material of the colacosome suggests that an alteration of the chemical
composition occurs after separation of the colacosome from the cytoplasm.
Furthermore, the penetration of the parasite and host cell wall appears
to be enzymatic since both cell walls are not distorted at the site of penetration.
This interpretation is reinforced by the mycoparasitic behavior of a currently
undescribed basidiomycete, called here “Mycospira”. In contact with its
host, a member of Tulasnella, this fungus develops colacosomes in exact spirals.
As a consequence, the host fungus grows in spirals around the colacosome-possessing
hyphae (Fig. 5). Thus, the formation of colacosomes results
Fig. 7. Host cell (H) intruding into a hyphal cell of Cryptomycocolax abnorme.Colacosomes
(arrows) surround the intracellular part of the host cell which lacks a cell wall.
Two fusion pores are visible at arrowheads. Note that the colacosomes are more electrontransparent
than in Fig. 6. Bar 1 µm