EFFECTS OF ALUMINUM ON MEMBRANE FLUIDITY OF THE MYCORRHIZAL FUNGUS AMANITA-MUSCARIA

The effect of aluminum on the ordering and dynamics of lipid molecules in plasma-lemma was studied by electron paramagnetic resonance via th e membrane-inserted reporter spin label molecules (methyl ester of 5-d oxyl-hexadecanoic acid) in situ in mycelia of the ectomycorrhizal fung us Amanita muscaria. It was found, first, that the plasmalemma is stru ctured into coexistent regions of lipids with different ordering and d ynamics, and second, that aluminum stress is accompanied by the corres ponding relative decrease of the proportion of the less ordered membra ne domains. This effect is opposite to that found previously for Lacta rius piperatus, where the membrane responded by an increase of the por tion of the less ordered membrane domains. Such qualitatively diverse effects of aluminum at the membrane level is of interest as it coincid es with the opposite effect on growth, i.e. inhibition of Amanita musc aria and stimulation of Lactarius piperatus.