Ultrastructural localization of a cuticle-degrading protease produced by the entomopathogenic fungus Metarhizium anisopliae during penetration of host cuticle
Journal of General Microbiology
Gold-labelled rabbit antiserum was used to demonstrate that a cuticle-degrading protease (Pr 1) is produced by Metarhizium anisopliae during penetration of host (Manduca sexta) procuticle. The protease was secreted by infection structures (appressoria) on the cuticle surface and by the penetrant hyphae within the cuticle. Penetration of the procuticle was by a combination of enzymic degradation and mechanical pressure. Initially Prl was confined to the immediate vicinity of the fungal structures; however the enzyme diffused throughout the cuticle during later stages of pathogenesis. When hyphae were labelled during growth in culture under conditions conducive to rapid synthesis of Prl, gold particles distributed over the fungal cell wall, indicating binding of Prl to hyphae.
Goettel, M.S., R.J. St. Leger, N.W. Rizzo, R.C. Staples and D.W. Roberts. 1989. Ultrastructural localization of a cuticle-degrading protease produced by the entomopathogenic fungus Metarhizium anisopliae during penetration of host cuticle. J. Gen. Microbiol. 135: 2233-2239.