Embedded Files
Gravitropism, the process of plant roots growing in the direction of gravity and plant shoots growing opposite to gravity, is dependent on the location and concentration of auxin in the roots and shoots.
In shoots not parallel to the pull of gravity, high concentration of auxin moves towards the bottom side of the root to stimulate elongation of the bottom cells, while suppressing cell growth on the top of the shoot. This allows the bottom cells of the shoot to continue a curved growth and elongate its cells upward with the auxin, opposite the pull of gravity as the auxin moves towards the bottom of the root.
Maddieahola, Wikimedia Commons
In roots not parallel to the pull of gravity, high concentration of auxin moves towards the bottom side of the root to suppress growth of the bottom cells, while allowing cell elongation on the top of the root. This allows the top cells of the root to continue a curved growth and elongate its cells downward with little auxin, towards the pull of gravity as the auxin moves towards the bottom of the root.
Maddieahola, Wikimedia Commons
Touch sensitivity of Mimosa pudica.
Hrushikesh, Wikimedia Commons
Page updated
Report abuse