What is thigmotropism?

Thigmotropism is the growth of a plant around a support. Tropism is a phenomena by which a plant, usually climber like money plant and ivy, responds to a stimulus. Stems of the pea plant, for instance, are weak and have coil-like structures called tendrils. When tendrils approach a support (stick), a phytohormone called auxin is released in the side of the tendril away from the support. Auxin, a growth hormone, elongates the cells of that portion and makes it strong. The other portion, devoid of auxin, becomes weak and coils around the support.