Botany - Transport in Plants Question with Solution | TestHub

The negative pressure difference formed between two points that enables flow of gas or liquid to a lower state from higher state is called suction pressure.

The pressure that enables entry of water into the cell due to osmosis is the osmotic pressure (OP) and it is considered negative. The pressure developed in cell due to entry of water and acting opposite to the OP is called turgor pressure (TP). It is a negative pressure as it resists entry of water in cell. The difference between these two results in diffusion pressure deficit (DPD) that equates to the suction pressure. It is directly proportional to the height of the plant/tree.