INTERSPECIFIC INTERACTIONS, MYCELIAL MORPHOGENESIS AND EXTRACELLULAR METABOLITE PRODUCTION IN PHLEBIA-RADIATA (APHYLLOPHORALES)

In Phlebia radiata, dense, localized zones of salmon- to orange-colour ed, septate hyphae emerge from the mycelium in response to encounters with other fungi and the bacterium Bacillus subtilis on malt agar-base d media. In monoculture such emergent growth develops more gradually a nd homogeneously, and is accompanied by the accumulation of four hydro phobic aromatic metabolites in culture extracts. Production of emergen t mycelium could be induced in P. radiata by a wide variety of factors , including culture extracts from B. subtilis and compounds known to a ffect mitochondrial metabolism or phenoloxidase activity. In particula r, the uncoupling agent, 2,4-dinitrophenol, when supplied heterogeneou sly, induced patterns of localized emergence strongly resembling those induced by biotic interactions. Induction of emergent development was associated quantitatively with shifts in phenoloxidase activity.