1. The gibberellins are plant hormones that, among other things, are involved in stem elongation, seed germination, early development, and flower production.
  2. There are 126 known natural and synthetic gibberellins found in not only plants, but also in fungi and bacteria.
  3. Gibberellic acid (GA or GA3), the prototypical gibberellin, is the only hormone named after a fungus.
  4. Researchers in pre-World War II Japan discovered that the rice pathogen Gibberella fugikuroi produced a substance causing “foolish seedling disease” in young plants. This substance turned out to be gibberellic acid.
  5. If GA is applied to a plant it generally results in rapid stem elongation with increased inter-nodal distance.
  6. Dwarfism in a plant is often, but not always, caused by a genetic defect in the pathway for GA production.
  7. The dwarf-tall trait in pea plants that Gregor Mendel studied to unravel the basic laws of genetics results from either a defective or properly functioning gene coding for a protein required for the synthesis of GA.
  8. GA is an “anti-inhibitor.” It binds to other molecules inside the cell to prevent them from inhibiting the activation of specific genes. This allows the gene to be “turned on” to produce its product.
  9. GA is used commercially in some countries to control plant development. For example, to delay fruit ripening.
  10. Since the activity of GA is quite powerful, the amount found in plants is relatively low. However, some studies indicate that concentrated GA is a carcinogen.