STUDY AT THE ULTRASTRUCTURAL LEVEL OF TRA NSFERS IN TRUFFLE ECTOMYCORRHIZAS

The study of transferts between the soil and the root through the fung us were carried out : (i) by microlocalization of elements present in the substratum (calcium, nitrogen) using electron energy loss spectros copy and imaging (EELS and ESI) and by X-ray microanalysis; (ii) by us e of cationic stainers (cerium and lanthanum) easily detected by elect ron microscopy and electron energy loss spectroscopy and imaging. Thes e studies show that some ectomycorrhiza structures can accumulate abso rbed elements (polyphenols, fungal matrix). Other structures aren't al lowed to transfered ions.