An acidic water-soluble cell wall polysaccharide: a chemotaxonomic marker for Fusarium and Gibberella

Alkali-extractable and water-soluble cell-wall polysaccharides were purifie d from cell walls of some species of Fusarium and Gibberella. Their structu res were determined by chemical analysis and NMR. The polysaccharides consi sted of a main chain of beta-(1 --> 6)-linked galactofuranose units almost fully branched at positions O-2 by single residues of glucopyranose or acid ic chains containing glucuronic acid and mannose. Individual differences we re found concerning the proportion of neutral and acidic side chains. These polysaccharides showed major differences from those of Microdochium nivale , Plectosphaerella cucumerina, Fusarium ciliatum, F. aquaeductuum and F. ca vispermum. Highly specific polyclonal antibodies were raised against this s tructure, which were used in immunocompetence and immunofluorescence experi ments.