Priming by airborne signals boosts direct and indirect resistance in maize
Jurriaan Ton, Marco D'Alessandro, Violaine Jourdie, Gabor Jakab, Danielle Karlen, Matthias Held, Brigitte Mauch-Mani & Ted Turlings
| Résumé |
Plants counteract attack by herbivorous insects using a variety of
inducible defence mechanisms. The production of toxic proteins and
metabolites that instantly affect the herbivore's development are
examples of direct induced defence. In addition, plants may release
mixtures of volatile organic compounds (VOCs) that indirectly
protect the plant by attracting natural enemies of the herbivore.
Recent studies suggest that these VOCs can also prime nearby plants
for enhanced induction of defence upon future insect attack.
However, evidence that this defence priming causes reduced
vulnerability to insects is sparse. Here we present molecular,
chemical and behavioural evidence that VOC-induced priming leads to
improved direct and indirect resistance in maize. A differential
hybridization screen for inducible genes upon attack by Spodoptera
littoralis caterpillars identified 10 defence-related genes that
are responsive to wounding, jasmonic acid (JA), or caterpillar
regurgitant. Exposure to VOCs from caterpillar-infested plants did
not activate these genes directly, but primed a subset of them for
earlier and/or stronger induction upon subsequent defence
elicitation. This priming for defence-related gene expression
correlated with reduced caterpillar feeding and development.
Furthermore, exposure to caterpillar-induced VOCs primed for
enhanced emissions of aromatic and terpenoid compounds. At the peak
of this VOC emission, primed plants were significantly more
attractive to parasitic Cotesia marginiventris wasps. This study
shows that VOC-induced priming targets a specific subset of
JA-inducible genes, and links these responses at the molecular
level to enhanced levels of direct and indirect resistance against
insect attack. |
| Mots-clés |
priming, volatile organic compounds, induced resistance, jasmonic acid, Spodoptera littoralis, Cotesia marginiventris, HERBIVORE-INDUCED VOLATILES, INDUCED SYSTEMIC RESISTANCE, DEFENSE-RELATED GENES, GREEN LEAF VOLATILES, INDUCED PLANT ODORS, ZEA-MAYS, DISEASE RESISTANCE, ARABIDOPSIS, ETHYLENE, EXPRESSION |
| Citation | Ton, J., D'Alessandro, M., Jourdie, V., Jakab, G., Karlen, D., Held, M., Mauch-Mani, B., & Turlings, T. (2007). Priming by airborne signals boosts direct and indirect resistance in maize. Plant Journal, 49(1), 16-26. |
| Type | Article de périodique (Anglais) |
| Date de publication | 2007 |
| Nom du périodique | Plant Journal |
| Volume | 49 |
| Numéro | 1 |
| Pages | 16-26 |