physical barriers-plant

• • Passive– physical and chemical barrier to prevent infection
  • Active defence– prevent further growth of the pathogen once it has infected and been recognised by the plant
• Thick, waxy cuticles & epidermis in leaves, bark and cell walls in cells are effective barriers and prevent the entry of pathogens 
• • Stomata are closed when signalled to prevent the entry of pathogens. 
• • Vertical hanging leaves help prevent the build-up of water, which reduces the likelihood of infection by pathogens reliant on water