Mostly electrolytes penetrate into the cells as ions. In general, entry of one type of ion into the cells of root is accompanied by entry of another type of ion of equal but opposite electrostatic charge.
It has also been observed that salts of monovalent cations are taken up and accumulated at a more rapid rate by the cells of root than salts of di or polyvalent cations. Sometimes the cells of root absorb the anions and cations to different extents.
In such cases the electrical balance of anions and cations both inside and outside the cell is maintained by certain changes in the ionic composition of the cell and the nutrient solution. If cation uptake is more than that of anion, the cell produces organic acids- anions of which remain within the cell to balance the excess cations and the hydrogen ions of the organic acids pass out into the external medium.