Question

Leaves of the sensitive plant wilt and droop sown on a slight touch. What mechanism brings about this change?

Answer 1

Leaves of the sensitive plant wilt and droop down on a slight touch due to turgor movement. Petiole of the sensitive plant is held up by turgid pulvinus tissue. The stimulus of touch leads to loss of turgor at the base of the leaflets and at the base of the petioles i.e. pulvinus. The cells on the lower side of pulvinus lose water and the petiole collapses. This causes the wilting and drooping of the leaves.