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 (32)P 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 (32)P and 4) rinsing the mycelia before incubation with or without plant. The main point is to rinse very carefully the mycelia after (32)P supply in order to avoid overestimation of (32)P efflux into the medium.