Composition of Root Mucilage Polysaccharides fromLepidium sativum

Abstract

Root mucilage polysaccharides were recovered from roots of 3-d-old cress seedlings by washing with water, followed by ethanol precipitation of the high molecular weight material. The redissolved polysaccharide was fractionated by combined gel filtration chromatography on Biogel A50 and ion exchange chromatography on DEAE-Sepharose/DEAE-Trisacryl into four heterogeneous fractions. The fractions could be assigned to two groups based on monosaccharide composition and behaviour during ion-exchange chromatography. Group One polysaccharides contained fucose as the major 6-deoxyhexose and were low in uronic acid, not binding to the ion-exchange column. Group Two polysaccharides contained rhamnose as the major 6-deoxyhexose and were uronic acid rich. It is suggested that these represent root cap and root epidermal mucilage components respectively.