Why do Flowers Wilt?. Osmosis explains it all!. Plasmolysis the loss of water from a cell by osmosis hypertonic solutions plants in air or dry soil.
The pressure against the cell wall is called turgor pressure. A plant that has plenty of water will have high tugor pressure and will stand upright.. A plant that lacks water will have low turgor pressure and will wilt.
Turgor pressure is the cause of rigidity in living plant tissue. It causes the cell walls to stiffen similar to the inflating of a pneumatic tire when you pump the air.