Hyponastic response

The hyponastic response is an upward bending of leaves or other plant parts, resulting from growth of the lower side. This can be observed in many terrestrial plants and is thought to be linked to the plant hormone auxin. The hyponastic response is an upward bending of leaves or other plant parts, resulting from growth of the lower side. This can be observed in many terrestrial plants and is thought to be linked to the plant hormone auxin. Submerged plants often show the hyponastic response, where the upward bending of the leaves and the elongation of the petioles might help the plant to restore normal gas exchange with the atmosphere.