Phytocromes

• Phytocromes are photoreceptors that absorb light, Pr & Pfr
• conversion

  • Pr absorbs red light (daylight) -> active Pfr
  • Pfr absorbs far-red light (sunset/rise) ->incative Pr
  • (Quick conversions)
  • Pfr slowly converts to Pr in night

  
• • Pfr is active form
  • Evidence:
  • Flashes on red light on plant
  • Triggered germination
• Pfr as transcription factors

  Direct -

  • Can bind to DNA & act as a TF

  Indirect -

  • Activate other proteins to act as TF

  TF for production of auxin!!!!