Professor University of Florida Lake Alfred, Florida
A plant’s ability to defend itself against herbivores is dependent on its ability to activate defensive pathways and to attract third trophic level predators and parasites. Trophic cascades that mediate interactions in the phytobiome are part of a larger dynamic including the pathogens of the plant itself, which are known to greatly influence plant defenses. As such, we investigated the impact of a phloem-limited bacterial pathogen, Candidatus Liberibacter asiaticus (CLas), in cultivated citrus rootstock on a well-studied belowground tritrophic interaction involving the attraction of an entomopathogenic nematode (EPN), Steinernema diaprepesi, to their root-feeding insect hosts, Diaprepes abbreviatus larvae. We found the cues stimulated by the pathogen infection disrupted the known tritrophic interaction by causing both weevil larvae and EPNs to be attracted to suboptimal plants and plants without the insect host, respectively.
