List the functions of various phytohormones.

Explanation

i] Auxins control the tropic (growth related) movements of the plants in response to light, gravity, touch etc by increasing the size of cells. Under the influence of auxins, the plant stem bends towards unidirectional light where as the roots bend away from it.
ii] Gibberellins stimulate stem elongation and leaf expansion.
iii] Cytokinins are produced in regions of the plant body where rapid cell division occurs, such as root tips, developing shoot buds, young fruits and seeds.
iv] Ethylene causes ripening of the fruits.
v] Abscisic acid inhibits (i.e., slows down) the growth in different parts of the plant body. It causes the drying and falling of older leaves, flowers and fruits.