**Introduction**

Mimosa pudica, commonly known as the sensitive plant, is a fascinating species that exhibits a unique defense mechanism in response to touch or physical disturbance. The leaves of the Mimosa pudica plant have the ability to fold and droop when touched, giving rise to its intriguing nickname.

**Turgor Pressure**

The movement of Mimosa pudica leaves is primarily driven by changes in turgor pressure within specialized cells called pulvinus. The pulvinus is located at the base of each leaflet and acts as a motor organ, responsible for the leaf movement.

**Role of Water and Ions**

When the plant is undisturbed, water and ions are actively pumped into the specialized cells of the pulvinus. This influx of water creates a state of high turgor pressure, causing the leaflets to remain in an open and expanded position.

**Mechanical Stimulation**

When the leaflets of Mimosa pudica are touched or physically stimulated, the plant initiates a rapid response mechanism. This mechanical stimulation triggers a series of biochemical events that lead to the loss of turgor pressure in the pulvinus cells.

**Ion Movement**

Upon stimulation, the plant releases ions, particularly potassium ions, from the cells in the pulvinus. This rapid efflux of ions reduces the osmotic potential within the cells, causing water to move out of the cells through osmosis.

**Water Loss and Cell Collapse**

As water moves out of the pulvinus cells, the turgor pressure decreases significantly. Consequently, the leaflets lose their rigidity and the pulvinus collapses, causing the leaflets to fold and droop downwards. This folding and drooping response is an adaptive strategy to protect the sensitive plant from potential harm caused by physical contact or grazing by herbivores.

**Recovery and Resetting**

After a period of time, usually within minutes, the pulvinus cells regain their turgor pressure through the reabsorption of water and ions. This allows the leaflets to extend and assume their original position. This recovery and resetting mechanism ensures that the plant can resume normal photosynthesis and growth.

In conclusion, the drooping of Mimosa pudica leaves when touched is a result of a rapid loss of turgor pressure in the pulvinus cells, triggered by mechanical stimulation. This unique defense mechanism allows the plant to protect itself from potential harm and resume normal function once the threat has passed.

It is the plant which is very senstive .................when it is touched by anyone then it shed its water present in it........this why it gets shrink due to touch........and one thing more it does not fall down .........