HYPHAL REGENERATION AND HISTOGENESIS IN AGARICUS-BISPORUS

Growing fruit bodies of Agaricus bisporus and Amanita muscaria respond ed with regenerating white hyphae to cell and tissue injuries caused b y intrapileal needle insertion and leucofuchsin injection. We point ou t reserve cells as a possible source of regenerating hyphae in the wou nd repair. Such reserve cells were not found in the partial veil and i n the surface covering. Damage of the partial veil remained unrepaired and caused lamellar dysplasia. Hydrophilic, somatic tissues reacted i mmediately and strongly with leucofuchsin, whereas hyphae of the surfa ce covering and partial veil showed a delayed and weak reaction. We ex plain this by the presence of an extracellular matrix, which consists of hydrophilic mucilaginous substances around tissue-forming hyphae. T ransmission and scanning electron microscopical studies revealed that white hyphae were deprived of such matrix material. We conclude that f or fungal tissue formation the hyphae have to be capable of producing a substantial amount of extracellular matrix material beyond the cell wall.