Plant hormones

• Ethene triggers the ripening of bananas
• Uses of auxins

  • Weed killers
  • Rooting powders
  • Promoting growth in tissue culture
• Uses of gibberellins

  • End seed dormancy
  • Encourage plants to flower
  • Make food grow larger
• Gravitropism process

  1. Auxin is produced in the root

  2. Gravity causes auxin to concentrate on the lower side

  3. Auxin inhibits cell growth on the lower side

  4. Root grows towards the force of gravity
• A plants response to light is phototropism
• A plants response to gravity is Gravitropism or geotropism
• Plant hormones play a crucial role in how plants respond to light and gravity
• Other chemicals used by plants

  • Gibberellins are important in starting the germination of seeds
  • Ethene controls cell division and the ripening of fruits