Commercial Uses of Plant Hormones

• What are the three uses of auxins?

  • Killing weeds
  • Growing from cuttings with rooting powder
  • Growing cells in tissue culture
• How can auxins be used for killing weeds?

  Most weeds are broad-leaved in contrast to grasses and cereals. Selective weedkillers only affect broad-leaved plants by disrupting normal growth patterns and therefore killing them.
• How can auxins be used for growing from cuttings with rooting powder?

  Normally if you stick cuttings in the soil they won't grow but if you add rooting powder, which contains auxins, they will produce roots rapidly and start growing as new plants. This means you can produce clones very quickly
• How can auxins be used for growing cells in tissue culture?

  Tissue culture can be used to grow clones of a plant from a few cells. To do this hormones such as auxins need to be added to the growth medium as well as nutrients to stimulate cell division to form roots and shoots
• What is a gibberellin?


  A plant hormone which stimulates:

  • Seed germination
  • Stem growth
  • Flowering
• What are the uses of gibberellin?

  • Controlling dormancy
  • Inducing flowering
  • Growing larger fruit
• How can gibberellin be used to control dormancy?

  Seeds can be treated with gibberellin to alter dormancy and make them germinate at times of year that they wouldn't normally and makes sure all seeds in a batch germinate at the same time
• What is dormancy?


  A state where seeds won't germinate until they've been through certain conditions like a period of cold or dryness
• How can gibberellin be used to induce flowering?

  Some plants require certain conditions to flower like longer days or low temperatures. If they are treated with gibberellin they will flower without any environment change. It can also be used to grow bigger flowers
• How can gibberellin be used to grow larger fruit?


  Seedless fruits often do not grow as large as seeded fruit but if gibberellin is added they will grow larger to match normal types
• How can ethene stimulate the ripening of fruit?

  • Ethene is a gas produced by aging parts of plants and influences the growth of the plant by controlling cell division
  • It stimulates enzymes that cause fruit to ripen
  • It can be used commercially to speed up ripening while on the plant or during transport
  • This means unripe fruit can be picked
  • Ripening can also be delayed while the fruit is in storage that block ethene's effect or reduce the amount of ethene produced