The touch-me-not plant’s leaves close on touching due to a touch stimulus known as ‘thigmonasty’. This is a mechano-sensory response in the plant. Generally, the water and cell contents apply pressure to the cell wall allowing the plant and leaf to have a rigid structure, in the process. However, when disturbed, certain chemicals are released including potassium ions in the plant. These chemicals reduce the cell pressure in the leaf of the plant, forcing it to close or shrink.
Why do the leaves of a touch-me-not plant close when we touch them?
