Linking aboveground and belowground inducible plant resistance

Induced resistance of plants against pests and diseases via plant defense responses is well documented and can occur aboveground, in the leaves, and belowground in the roots. A number of recent studies have shown that soil-borne pests can also induce plant resistance aboveground and vice versa. Since plants are frequently exposed to aboveground and belowground pests simultaneously, interactions between induced plant defense responses in the foliage and in the roots can have major implications for induced resistance. On the one hand, induction in one plant part may result in systemically induced resistance in the other part. On the other hand, simultaneously occurring aboveground and belowground induced plant defenses may interfere, for example, when the activities of root feeders alter the effectiveness of induced resistance against foliar herbivores. Such aboveground-belowground interactions can also potentially influence tritrophic interactions between plants, herbivores and their natural enemies such as parasitoids or predators