DPD of a certain cell is the measure of the capacity of the cell to draw water from the surrounding. When the DPD of a cell [A] is higher than the DPD of an adjacent cell [B], Cell (A) will draw water from cell (B) till the DPD of the two cells becomes equal i.e. the state of equilibrium is reached This difference in the value of DPD between two cells results in to a deficiency gradient, which is called as diffusion pressure gradient.
