Cellulose
Resist invasion by microorganisms
Waxy cuticle on leaves
Resist invvasion by microorganisms
Bark on treees
dead cells form a protective layer that is hard for pathogen top penetrate
Leave fall
Pathogens fall off tree
Chemical barriers
Plants produce antibacterial chemicals that can be used in humans
Protecting from herbivores
Poisons
Thorns
Hairy stems
Drooping/curloing when touches
Mimicry