Producing toxins is a common plant defense against herbivory, as it makes the plant unpalatable or even toxic to herbivores.

Herbivory is the term for the relationship between a plant and a herbivore that feeds on it.

Deer are herbivores that feed on plants.

Plant defense is the term for the process by which plants defend themselves against herbivores.

Growing thorns is an example of a plant adaptation that reduces herbivory, as it makes the plant less palatable to herbivores.

Mutualism is the term for the relationship between a plant and a herbivore that benefits both species.

Bees pollinating flowers is an example of a mutualistic relationship between a plant and a herbivore, as both species benefit from the interaction.

Parasitism is the term for the relationship between a plant and a herbivore that benefits one species and harms the other.

Aphids feeding on plant sap is an example of a parasitic relationship between a plant and a herbivore, as the aphids benefit from the interaction while the plant is harmed.

Commensalism is the term for the relationship between a plant and a herbivore that has no effect on either species.

Birds eating fruits is an example of a commensalistic relationship between a plant and a herbivore, as the birds benefit from the interaction while the plant is not affected.

Competition is the term for the process by which plants compete with each other for resources.

Plants competing for sunlight is an example of competition between plants.

Adaptation is the term for the process by which plants adapt to their environment.

Producing toxins is an example of a plant adaptation, as it helps the plant to defend itself against herbivores.