Two-way translocation of cations by the brown rot fungus Gloeophyllum trabeum

Wood decay fungi are known to translocate elements, but the details regarding mechanisms and specificity of translocation are not well understood. Gloeophyllum trabeum was grown on blocks of red spruce sapwood that had been previously soaked in salt solutions of CaCl2, KCl, NaCl, MgCl2 and MgSO4. Decay-associated weight loss in most salted blocks was decreased by 80%. However, the concentration of the salting cations (Ca, K, Na, Mg) was reduced after 6 weeks of decomposition resulting from fungal activity. During decay, exchangeable ions lost during soaking treatments were replenished simultaneously with the depletion of the excess salting cations. These results indicate that wood decay fungi are capable of selectively translocating metabolically important mineral nutrients from the soil into the wood, while translocating interfering quantities of other cations out of the wood to external depositories. (C) 1997 Elsevier Science Limited.