Extracellular Concanavalin A-binding sites during early interactions between Pinus banksiana and two closely related genotypes of the ectomycorrhizal basidiomycete Laccaria bicolor

Abstract

Pre-embedding and postembedding methods for labelling Concanavalin A (Con A)-binding sites were compared using five ectomycorrhizal fungi. Extracellular materials were more reliably labelled using the pre-embedding method. The pre-embedding method was therefore used to localize extracellular Con A-binding sites during the initial stages of association between Pinus banksiana and two Laccaria bicolor strains which have different root colonizing abilities. The labelling by Con A-colloidal gold complexes was particularly intensive at the hypha-root interfaces involving the more aggressive root colonizer, while labelling was very weak with the less aggressive strain.