plant defences

• plants have both physical and chemical defences
• plants have physical barriers to prevent the entry of pathogens, for example the waxy cuticle, bark, closing of stomata and thick cellulose wall
• physical defences also prevent the spread of pathogens in a plant for example the plant produces a polysaccharide called callose which reinforces cell wall to stop pathogen entering the cell
• chemical defences are specific chemical a plant produces to kill, repel or prevent the growth of a pathogen
• plants produce antibacterial chemicals and enzymes to defend against bacteria infections