LOCALIZATION AND CHARACTERIZATION BY ELECTRON-ENERGY-LOSS SPECTROSCOPY (EELS) OF THE BROWN CELLULAR-SUBSTANCES OF BEECH ROOTS

Degradation of roots from beech trees was investigated by a novel appr oach: localization and elemental characterization of predominant brown substances were performed at an ultrastructural scale using electron energy loss spectroscopy (EELS). This technique allowed us to detect l ight elements such as C and N, main constituents concerned in the degr adation of plant tissues, within cellular constituents observed with a transmission electronic microscope, after having localized them by li ght microscopy. The results showed that there was no relationship betw een the brown pigmentation of the cellular substances and the presence of N, a relationship previously found in studies of degrading leaves. Other elements such as Si and Ca were also found to be involved in th ese root degradation processes. This approach seem powerful for detail ed descriptions of the process of root degradation in soil. Copyright (C) 1996 Elsevier Science Ltd