Chemical defences against pathogens in plants
Chemicals are usually produced after a plant develops an infection and requires lots of energy.
>Tannis create a bitter taste and enzymes precipitate out, not allowing tree to get infected
>Insect repellent like pine resin and lemongrass
>Antibacterial compounds disrupt the cell wall and membranes of the bacteria
>Hydrolytic enzymes like Chitinases are released to break down the chitin in the cell wall
>Anti-oomycetes break down the cell walls on fungi like eukaryotic organisms
Silica in grass - influences growth of organisms when eaten