gibberellins

• Gibberellins are growth hormones that are produced in young leaves and in seeds. They stimulate seed germination, stem elongation, side shoot formation and flowering.
• Gibberellins stimulate the stems of plants to grow by stem elongation- this helps plants to grow very tall. If a dwarf variety of a plant is treated with gibberellin, it will grow to the same height as the tall variety. Unlike auxins, gibberellins don't inhibit plant growth in any way.
• Gibberellins stimulate seed germination by triggering the breakdown of starch into glucose in the seed. The plant embryo in the seed can then use the glucose to begin respiring and release the energy it needs to grow.
• Gibberellins are inhibited (and so seed germination is prevented) by the hormone abscisic acid.
• fruit production

  • extends the time fruit can be left unpicked and making them available for longer in shops
  • gibberellins and cytokinins make apples elongate to improve their shape
  • make grape stalks elongate so they are less compact producing bigger grapes
• brewing

  • adding gibberellins speed up the process of amylase production in barley seeds
  • barley seeds germination+ aleurone layer produces amylase enzymes that break down stores starch into maltose
  • to make beer you need malt
• sugar production:

  • spraying sugar canes with it stimulates growth between the nodes = stems elongate
  • sugar cane stores sugar in cells of internodes making more sugar available from each plant
• plant breeding 


  an speed up the process of breeding plants together
• inhibiting gibberellins keep flowers short and stocky and ensures internodes of crop plants stay short- prevents lodging. lodging happens in wet summers when stems bend due to weight of water collected on ripened seed heads which makes crops difficult to harvest