TREHALASE ACTIVITY IN MYCORRHIZAL AND NONMYCORRHIZAL ROOTS OF LEEK AND SOYBEAN

Root extracts of leek (Allium porrum L.) and soybean (Glycine max L. M err.) showed trehalase ac activity which was inhibited by phloridzin a nd was several times higher than the activity of general cr-glucosidas e. The activity had an acidic optimum. Trehalase activity in extracts of sporocarps and extraradical mycelium of the arbuscular mycorrhizal fungus Glomus mosseae Nicol. & Gerd. (Trappe & Gerd.) was higher than in root extracts and had an optimum at pH 7. Following inoculation wit h G. mosseae, trehalase activity increased in mycorrhizal roots above the levels observed in nonmycorrhizal roots. Irrespective of fungal co lonization, root trehalase activity increased in the presence of Mg2+, decreased in the presence of Mn2+ and Zn2+, and was unaffected by Na( 2)EDTA.