Define water potential .
Explain pressure potential . How is it build up???
Water potential is the measure of relative tendency of water to move from one region of higher water concentration to another region of lower water concentration through diffusion. It is denoted by ψw. Solute potential and pressure potential are the two main components that determine water potential.
Solute potential (ψs) − Magnitude of lowering of water potential when a solute is added to the water.
Pressure Potential (ψp) − Magnitude of increase of water potential when pressure greater than atmospheric pressure is applied to pure water or a solution.
ψw = ψs + ψp
Pressure can be build up in a plant system when water enters a plant cell due to diffusion causing a pressure built up against the cell wall, it makes the cell turgid, this increases the pressure potential.