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Signal signature of aboveground-induced resistance upon belowground herbivory in maize
Auteur(s)
Karlen, Danielle
de Lange, Elvira S.
D’Alessandro, Marco
Ton, Jurriaan
Date de parution
2009
In
The Plant Journal, wi, 2009/59/2/292-302
Résumé
Plants activate local and systemic defence mechanisms upon exposure to stress. This innate immune response is partially regulated by plant hormones, and involves the accumulation of defensive metabolites. Although local defence reactions to herbivores are well studied, less is known about the impact of root herbivory on shoot defence. Here, we examined the effects of belowground infestation by the western corn rootworm <i>Diabrotica virgifera virgifera</i> on aboveground resistance in maize. Belowground herbivory by <i>D. v. virgifera</i> induced aboveground resistance against the generalist herbivore <i>Spodoptera littoralis</i>, and the necrotrophic pathogen <i>Setosphaeria turcica</i>. Furthermore, <i>D. v. virgifera</i> increased shoot levels of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), and primed the induction of chlorogenic acid upon subsequent infestation by <i>S. littoralis</i>. To gain insight into the signalling network behind this below- and aboveground defence interaction, we compiled a set of 32 defence-related genes, which can be used as transcriptional marker systems to detect activities of different hormone-response pathways. Belowground attack by <i>D. v. virgifera</i> triggered an ABA-inducible transcription pattern in the shoot. The quantification of defence hormones showed a local increase in the production of oxylipins after root and shoot infestation by <i>D. v. virgifera</i> and <i>S. littoralis</i>, respectively. On the other hand, ABA accumulated locally and systemically upon belowground attack by <i>D. v. virgifera</i>. Furthermore, <i>D. v. virgifera</i> reduced the aboveground water content, whereas the removal of similar quantities of root biomass had no effect. Our study shows that root herbivory by <i>D. v. virgifera</i> specifically alters the aboveground defence status of a maize, and suggests that ABA plays a role in the signalling network mediating this interaction.
Identifiants
Type de publication
journal article
