The function of gibberellin are given below;
- Stem elongation: Gibberellins cause system elongation and leaf expansion. It is believed that certain types of dwarfness are due to gibberellin deficiency. But it has no roots.
- Bolting: Gibberellins includes stem elongation in rosette plants. Cabbage is a rosette plant with profuse leaf growth and retarded internodal length. Just prior to flowering, internodes, elongate enormously. This is called bolting. Bolting needs either long days or cold nights. When a cabbage head is kept under warm nights, it retains its rosette habit. Bolting can be induced artificially by the application of gibberellins under normal conditions.
- Seed Germination: Gibberellins promote seed germination in lettuce, cereals.
- Breaking of seed dormancy: Gibberellins break the dormancy of buds and tubers. But in root tubers, it inhibits the development of the root tubers.
- Parthenocarpy: Gibberellins cause parthenocarpy in apples and pears.
- Increasing Fruit Size: Gibberellins along with auxin, control the growth and development of fruit.
- Flowering and sex expression: Gibberellins control flowering in long-day plants. Gibberellins promote the production of male flowers, either in place of female flowers in monoecious or in genetically female plants such as cucurbits.