PT  - JOURNAL ARTICLE
AU  - Xi Zhang
AU  - Cong van Doan
AU  - Carla C.M. Arce
AU  - Lingfei Hu
AU  - Sandra Gruenig
AU  - Christian Parisod
AU  - Bruce E. Hibbard
AU  - Maxime Hervé
AU  - Christelle A.M. Robert
AU  - Ricardo A.R. Machado
AU  - Matthias Erb
TI  - Plant defense resistance in natural enemies of a specialist insect herbivore
AID  - 10.1101/710681
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 710681
4099  - http://biorxiv.org/content/early/2019/07/25/710681.short
4100  - http://biorxiv.org/content/early/2019/07/25/710681.full
AB  - Plants defend themselves against herbivores through the production of toxic and deterrent metabolites. Adapted herbivores can tolerate and sequester these metabolites, allowing them to feed on defended plants and become toxic to their own enemies. Can herbivore natural enemies overcome sequestered plant defense metabolites to prey on adapted herbivores? To address this question, we studied how entomopathogenic nematodes cope with benzoxazinoid defense metabolites that are produced by grasses and sequestered by a specialist maize herbivore, the western corn rootworm. We find that nematodes from US maize fields in regions in which the western corn rootworm was present over the last 50 years are behaviorally and metabolically resistant to sequestered benzoxazinoids and more infective towards the western corn rootworm than nematodes from other parts of the world. Exposure of a benzoxazinoid-susceptible nematode strain to the western corn rootworm for five generations results in higher behavioral and metabolic resistance and benzoxazinoid-dependent infectivity towards the western corn rootworm. Thus, herbivores that are exposed to a plant defense sequestering herbivore can evolve both behavioral and metabolic resistance to plant defense metabolites, and these traits are associated with higher infectivity towards a defense sequestering herbivore. We conclude that plant defense metabolites that are transferred through adapted herbivores may result in the evolution of resistance in herbivore natural enemies. Our study also identifies plant defense resistance as a novel target for the improvement of biological control agents.