The difference in diffusion pressure between pure water and solution is referred to as diffusion pressure deficit (DPD). When a plant cell is immersed in a hypotonic solution, water enters the cell via osmosis, causing turgor pressure to develop in the cell in solution. B.S. Meyer first mentioned DPD in 1938.
The potential for molecules to diffuse from a higher concentration area to a lower concentration area is expressed as the diffusion pressure deficit.
It can be calculated as DPD=OPTP, where OP is the cell’s osmotic pressure and TP is the cell’s turgor pressure.
The turgor pressure is the amount of pressure that a cell feels as a result of its water content.
Final Answer: Diffusion pressure deficit (DPD) refer as the difference in diffusion pressure between pure water and solution.