A Method for Radioactive Labelling of Hebeloma cylindrosporum to Study Plant-fungus Interactions

In order to quantify P accumulation and P efflux in the ectomycorrhizal basidiomycete fungus Hebeloma cylindrosporum, we supplied ³²P to mycelia previously grown in vitro in liquid medium. The culture had four main steps that are 1) growing the mycelium on complete medium with P, 2) transfer the mycelia into new culture solution with or without P, 3) adding a solution containing ³²P and 4) rinsing the mycelia before incubation with or without plant. The main point is to rinse very carefully the mycelia after ³²P supply in order to avoid overestimation of ³²P efflux into the medium.