The localized incorporation of (3)H-L-fucose into cell-wall polysaccharides of the cap and epidermis of corn roots : Autoradiographic and biosynthetic studies.
When (3)H-L-fucose is provided to corn roots, a large proportion of the radioactivity is recovered in the polysaccharides extracted from the cell wall. Hydrolysis of this material yields (3)H-L-fucose as the sole radioactive product. Two metabolites, identified tentatively as L-fucose-1-phosphate and a nucleoside diphosphate derivative of L-fucose have been isolated from the ethanol soluble fractions of the roots and are possibly precursors of the polysaccharide. Autoradiographs of tissue sections indicate that the synthesis of polysaccharides containing L-fucose is confined largely to the root-cap and epidermis. The outer epidermal wall and root-cap slime are particularly radioactive and, therefore, likely to be relatively rich in fucose. By contrast the cell walls from more deeply lying tissues incorporate negligible amounts of the sugar.
Department of Botany, University of Florida, Gainesville.
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Kirby
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Roberts