A specialist root herbivore exploits defensive metabolites to locate nutritious tissues

Christelle Aurélie Maud Robert, Nathalie Veyrat, Gaëtan Glauser, Guillaume Marti, G. R. Doyen, Neil Villard, Mickaël David Philippe Gaillard, Tobias G. Köllner, David Giron, Mélanie Body, Benjamin A. Babst, Richard A. Ferrieri, Ted Turlings & Matthias Erb

Résumé The most valuable organs of plants are often particularly rich in essential elements, but also very well defended. This creates a dilemma for herbivores that need to maximise energy intake while minimising intoxication. We investigated how the specialist root herbivore Diabrotica virgifera solves this conundrum when feeding on wild and cultivated maize plants. We found that crown roots of maize seedlings were vital for plant development and, in accordance, were rich in nutritious primary metabolites and contained higher amounts of the insecticidal 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) and the phenolic compound chlorogenic acid. The generalist herbivores Diabrotica balteata and Spodoptera littoralis were deterred from feeding on crown roots, whereas the specialist D. virgifera preferred and grew best on these tissues. Using a 1,4-benzoxazin-3-one-deficient maize mutant, we found that D. virgifera is resistant to DIMBOA and other 1,4-benzoxazin-3-ones and that it even hijacks these compounds to optimally forage for nutritious roots.
Mots-clés diabrotica virgifera, dimboa, optimal defence, optimal foraging, plant-insect interactions, root herbivore, zea mays, western corn-rootworm, hydroxamic acids, plant defense, maize, chrysomelidae, coleoptera, resistance, inhibitor, insect, larvae
Citation Robert, C. A. M., Veyrat, N., Glauser, G., Marti, G., Doyen, G. R., Villard, N., Gaillard, M. D. P., Köllner, T. G., Giron, D., Body, M., Babst, B. A., Ferrieri, R. A., Turlings, T., & Erb, M. (2012). A specialist root herbivore exploits defensive metabolites to locate nutritious tissues. Ecology Letters, 15(1), 55-64.
Type Article de périodique (Anglais)
Date de publication 2012
Nom du périodique Ecology Letters
Volume 15
Numéro 1
Pages 55-64