The family of gibberellins have a similar effect to that of auxins; they promote cell division and elongation. The major difference is that gibberellins in no way inhibit growth.
Gibberellic Acid is an example of one of the gibberellin family. Regardless of genotype (tall or small plants), more gibberellin equals more lateral growth.
Gibberellins and Germination
Gibberellins are responsible for promoting growth in the embryo of a seed. It does this the following way
- Gibberellin released by the embryo travels towards the aleurone layer, its target tissue situated in the endosperm region of the seed (alongside the embryo).
- Gibberellin acts as the inducer, as its presence allows the enzyme induction of amylase, which can break down starch INTO a sugar to be used in the embryo.
- Sugar is used in the plant to synthesise proteins and break out of dormancy.
Gibberellins initiate this process in Summer, when the external environment exhibits favourable conditions for plant growth.
The previous pages have investigated the various hormones involved in plant growth. The next page investigates the sites of this growth, the meristems.