Question

Plants sometimes use other organisms as defences against herbivores. Provide two examples of biological defences used by plants to reduce the negative effects of herbivory. For each of them indicate what are the costs for the plant.

Answer 1

Macaranga tress

This kind of tree have modified their thin stem walls, creating housing for ants of the genus Crematogaster. This will develop a protection system to the plant because ants will damage some herbivores defending their colonies. Providing housing to the ants, the tree will provide exclusive food source from the food bodies produced by the tree.

Festuca arrundinacea

This type of grass is able to use a fungi as endophytic in defense. This fungi will produce toxins (without producing any disease to the plant) to protect the grass from herbivores or pathogenic microbes. Fungi produce alkaloids which are very harmful for animals. In exchange, the fungi will receive carbon for energy from the plant host.