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Definition

noun, plural: plasmolyses

noun

The shrinking of protoplasm away from the cell wall of a plant or bacterium due to water loss from osmosis, thereby resulting in gaps between the cell wall and cell membrane.

Supplement

When a plant cell is placed in a highly concentrated solution, water diffuses out of the cell, and turgor pressure is lost causing the cell to become flaccid. Further loss of water will result in plasmolysis, and finally to cytorrhysis, the complete collapse of cell wall.

Plasmolysis only occurs in extreme conditions and rarely happens in nature. It is induced in the laboratory by immersing cells in strong saline or sugar solutions to cause exosmosis, often using Elodea plants or onion epidermal cells.

Word origin: plasma » Greek plásma + -o- + -lysis » New Latin, from Greek lusis, a loosening.

Related forms: plasmolytic (adjective), plasmolytically (adverb).

Compare: cytolysis, crenation.
See also: turgidity, clasmatosis.