Use of enzyme-gold complexes for the ultrastructural localization of hemicelluloses in the plant cell wall.

Enzyme-gold complexes have been prepared with an endo beta 1----4 xylanase (EC 3.2.1.8) and a beta 1----4 mannanase (EC 3.2.1.78). The complexes were applied to ultrathin sections of plant cell walls for the ultrastructural localization of xylans in different tissues of a graminea and for the localization of glucomannans in the tracheids of spruce wood. The method proved to be highly specific and gave a very good contrast of the substrate polysaccharides. Used in conjunction with other cytochemical staining the enzyme-gold labelling provided information about the relative distribution of pectic polymers and xylans in primary walls.