Glutamate dehydrogenases in ectomycorrhizas of spruce (Picea excelsa L.) and beech (Fagus sylvatica L.).

The ammonia assimilation enzyme glutamate dehydrogenase as studied in extracts of spruce (Picea excelsa L.) roots, mycelium of a mycorrhizal fungus (Hebeloma sp.) and associated ectomycorrhizas. Evidence from enzyme reactions in crude extracts, electrophoretic patterns and immunological tests Using antibodies raised against purified NADP-GDH of Cenococcum geophilum Fr. consistently showed that Hebeloma NADP-dependent GDH was active in spruce ectomycorrhizas. Histochemical studies associated some NADP-GDH activity with the Hartig net. By contrast, the NADP-GDH fungal pathway was strongly suppressed in beech (Fagus sylvatica L.) associations with Hebeloma crustuliniforme (Bull. ex St Amans) Quél. and Paxillus involutus (Batsch ex Fr.) Fr.