Gibberellin and germination of Barley

• Gibberellins are a type of plant growth regulator involved in controlling seed germination and stem elongation
• hen barley seed is shed from mparent plant, it is in a state of dormancy (little water, metabolically inactive)
• allows seeds to survive harsh conditions until conditions are right for germination
• A barley seed contains:

  • Embryo: Grow into new plants when germinate
  • Endosperm: starch containing energy store surrounding the embryo
  • Aleurone layer: protien rich layer outer edge of endosperm
• When conditions are right, barley seed starts to absorb water to begin germination
• stimulates the embryo to produce gibberellins
• Gebberellin molecules diffuse into the Aleurone layer and stimuulate the cells there to synthesize the enzyme Amylase

  • in Barley seeds, shown that gibberellin does this by regulating genes involved in the synthesis of Anylase, causing increase in the transcription of mRNA coding for amylase