Microbes: Essential mediators of plant-animal interactions?

Interactions between plants and animals form the basis for the study of coevolution, chemical ecology, and multitrophic interactions. But microbial communities hosted by plants and animals are often overlooked in these studies, despite their profound influence on traits that mediate plant-animal interactions. As examples, I show that plant-associated bacteria and fungi can alter plant chemistry and interactions with pollinators and herbivores. Predicting which microorganisms change the outcome of interactions, and when, remains a current challenge.