The aggregation of wheat rhizoplane fibrils and the accumulation of soil-bound cations

Abstract

Some surface materials of roots can accumulate bound cations from the soil environment by contact exchange. This paper describes the physical relationships between rhizoplane fibril aggregates and other root surface structures in the zone of active cation uptake. Sheets and tufts of rhizoplane fibrils project from wheat roots and establish a discrete and intimate physical connection between root cell walls and the solid phase of the soil environment. These aggregates of fibrils may provide a direct channel for the movement of soil-bound cations to the surface of root cells. Consideration is given to a possible mechanism of extraction of soil-bound cations by rhizoplane fibrils and the transfer of these cations to the walls of cells actively engaged in cation uptake.