Plant Hormones

Auxins

Promotes cell growth, causing cells to elongate.

Promotes tropic movements.

Stops leaves and fruit from falling early in some plants.

Stimulate plants to produce fruit.

Apical dominance

Stimulates rapid growth of the apical bud, allowing the plant to quickly increase in height whilst simultaneously inhibiting the growth of lateral buds below the tip.

Phototropism

The growth movement of a part of a plant in response to the direction of a light stimulus.

Geotropism

The growth response of part of a plant in response to the effect of gravity.

Gibberellins

Elongates the main stem by causing the internodes to lengthen.

Stimulates seed germination.

Breaks dormancy in bud.

Abscisic acid

Helps plants cope in adverse conditions.

Causes stomata to close.

Promotes dormancy in buds and seeds.

Promotes abscission.