This can be defined as the shrinking of protoplasm away from the cell wall of a plant or bacterium as a result of water loss from osmosis and in so doing leading to gaps between the cell wall and cell membrane.
When a plant cell is immersed into a highly concentrated solution, water diffuses out of the cell, and turgor pressure of the cell is lost. This makes the cell to become flaccid. Additional loss of water will lead to plasmolysis, and finally to cytorrhysis which means the total collapse of cell wall.
Plasmolysis only occurs in severe situations and seldom happens in nature. It is induced in the laboratory by immersing cells in strong saline or sugar solutions to give rise to exosmosis, frequently with the use of Elodea plants or onion epidermal cells.