Structural analysis of secreted slime from wheat and cowpea roots

Abstract

The water-soluble, high M r components of slime secreted from the roots of wheat and cowpea are composed primarily of carbohydrate (95.5 and 97.5% w/w, respectively and some protein (5 and 3% w/w, respectively). For wheat, arabinose, xylose, glucose and galactose are the major neutral monosaccharides whereas for cowpea, arabinose, galactose and glucose predominate. Fucose is a minor constituent of both wheat and cowpea root slimes. Cowpea root slime contains significantly more uronic acids than that from wheat roots (11.5 vs 4% w/w). Methylation analysis suggests the presence of a range of polymers in the root slimes. In general, their composition appears to reflect that characteristically found for cell wall preparations from dicotyledons and graminaceous monocotyledons. In addition, arabinogalactan-proteins are components of both root slimes.