Plant hormones are chemicals that control:
- the growth of the shoots and roots
- flowering and the ripening on the fruit.
One group of plant hormones calles auxins move through the plant in solution. They affect the plant's growth by responding to gravity (geotropism) and light (phototopism).
- towards the light (positive phototropism)
- away from gravity (negative geotropism)
- away from light (negative phototropism)
- towards gravity (positive geotropism) to abosorb water and provide support for the plant.
Auxin is made in the shoot tip. Its distribution through the plant is determined by light and can, therefore, be unequal. This is what happens when…