Ultrastructural detection of fucosyl residues at the surface of axenically grown maize roots/sequential use of UeA lectin and fucosyl ferritin as the specific glycosylated marker.

This study reports the ultrastructural detection of fucosyl residues at the surface of axenically grown roots of Zea mays. The method used involved sequential binding of UeA lectin to the root and coupling of the bound UeA with fucosyl ferritin. Superficial dense ferritin labelling was found in the slime droplet ensheathing the root cap and in the external layer of the three-layered epidermal root surface. This pattern of binding of the fucose-specific lectin UeA suggests an overall distribution of the fucosyl residues on the root surface. Their localization within slime components of the root cap and the root epidermis is also assessed by the use of PATAg controls. Treatment of whole roots with alpha-L-fucosidase was ineffective in removing the fucosyl residues present at the root surface. The biological role of the fucosyl residues at the root-soil interface is discussed.