What is Thigmonasty ? Explain with suitable example.

Explanation

1) Movement of plants in response to touch is called thigmonesty.
2) Mimosa pudica (touch me not plant) shows this type of movement. It is also called nastic movement.
3) Mimosa plant leaves has pad like swellings at the base called pulvini. Here calls contain lot of water and large intercellular spaces.
4) Due to water pressure pulvini hold the leaf erect.
5) When we touch the leaves an electrical impulse is generated. This impulse acts on plant hormones.
6) Because of this hormone water in the pulvini cells which are closer to the leaf vein migrate to other side of the cells.
7) Then pulvini lacs its firmness. Hence, leaves become fold.
8) After 20 to 30 minutes water comes back pulvini get firm and leaves become erect.
9) This shows plants responding to a certain stimulus.