Insect eggs suppress plant defence against chewing herbivores
Article first published online: 10 MAR 2010
© 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd
The Plant Journal
Volume 62, Issue 5, pages 876–885, June 2010
How to Cite
Bruessow, F., Gouhier-Darimont, C., Buchala, A., Metraux, J.-P. and Reymond, P. (2010), Insect eggs suppress plant defence against chewing herbivores. The Plant Journal, 62: 876–885. doi: 10.1111/j.1365-313X.2010.04200.x
- Issue published online: 25 MAY 2010
- Article first published online: 10 MAR 2010
- Received 5 January 2010; revised 18 February 2010; accepted 2 March 2010; published online 23 April 2010.
- salicylic acid;
- jasmonic acid;
- plant defence
Plants activate direct and indirect defences in response to insect egg deposition. However, whether eggs can manipulate plant defence is unknown. In Arabidopsis thaliana, oviposition by the butterfly Pieris brassicae triggers cellular and molecular changes that are similar to the changes caused by biotrophic pathogens. In the present study, we found that the plant defence signal salicylic acid (SA) accumulates at the site of oviposition. This is unexpected, as the SA pathway controls defence against fungal and bacterial pathogens and negatively interacts with the jasmonic acid (JA) pathway, which is crucial for the defence against herbivores. Application of P. brassicae or Spodoptera littoralis egg extract onto leaves reduced the induction of insect-responsive genes after challenge with caterpillars, suggesting that egg-derived elicitors suppress plant defence. Consequently, larval growth of the generalist herbivore S. littoralis, but not of the specialist P. brassicae, was significantly higher on plants treated with egg extract than on control plants. In contrast, suppression of gene induction and enhanced S. littoralis performance were not seen in the SA-deficient mutant sid2-1, indicating that it is SA that mediates this phenomenon. These data reveal an intriguing facet of the cross-talk between SA and JA signalling pathways, and suggest that insects have evolved a way to suppress the induction of defence genes by laying eggs that release elicitors. We show here that egg-induced SA accumulation negatively interferes with the JA pathway, and provides an advantage for generalist herbivores.