Effects of potassium on the secretion of proton and oxalate by ectomycorrhizal fungi and the concentrations of nitrogen,phosphorus and potassium in their hyphae
钾对外生菌根真菌的分泌作用及氮、磷、钾含量的影响

Ectomycorrhizal fungi were grown in the liquid culture medium for 14 to 21 days.The efflux rates of H+ and oxalate by the fungi were increased as the concentration of potassium decreased in the medium.Taking into account of potassium replacement in the interlayer of 2∶1 clay minerals by H+ and the weathering of Al-O lattices by oxalate,the higher ability of potassium mobilization by ectomycorrhizal fungi could occur in insufficient potassium systems than that in sufficient ones.Moreover,H+ in the liquid culture medium at harvest was not mainly from oxalate but from some unknown matters such as organic acids.The concentrations of nitrogen,phosphorus and potassium in the fungi were influenced variedly by the potassium in the culture medium.It suggests that their absorption by the hyphae could be affected by the external supply of potassium.