plant hormones

• hormones


  chemical messenger that travels through the plant (xylem + phloem)
• tropism


  plant response to a stimulus
• ethene 


  produced: fruit

  effect: ripens fruit (increase mitosis)

  human use: control ripening in transport
• gibbrellin


  produced: seeds

  effect: germination

  human use: more flowers, more fruits
• auxins


  produced: shoot and root of plants

  effect: increase and decrease cell growth (mitosis)

  human use: weed killer
• phototropism


  plant's response to light
• shoot - phototropism

  positive (grows towards the light)
• root - phototropism

  negative (grows away from light)
• gravitropism


  plant's response to gravity
• root - gravitropism

  positive (grows towards water and ions - nitrate and mg+)
• shoot - gravitropism


  negative (grows away from ground/ gravity) therefore more light is usually available for photosynthesis
• auxin distribution


  uneven causing uneven growth as they control plant responses