Get access

Priming of indirect defences


  • Martin Heil,

    Corresponding author
    1. Department of General Botany/Plant Ecology, FB BioGeo, University of Duisburg-Essen, Universitätsstraße 5, D-45117 Essen, Germany
      * E-mail:
    Search for more papers by this author
  • Christian Kost

    1. Department of Bioorganic Chemistry, Max-Planck-Institute for Chemical Ecology, Hans-Knöll-Straße 8, Beutenberg Campus, D-07745 Jena, Germany
    Search for more papers by this author

* E-mail:


Leaf damage induces in many plant species the secretion of extrafloral nectar (EFN) and/or the release of specific odours (volatile organic compounds, VOCs). Both traits attract carnivorous arthropods and function as indirect plant defences by increasing the predation pressure on attacking herbivores. We have conducted field experiments in Mexico and found that plants that had been exposed to VOCs thereafter responded to subsequent leaf damage with an increased EFN secretion. VOCs ‘primed’ the plants to respond more efficiently once they were attacked themselves. Such priming effects are well known for induced resistance to pathogens, yet this is the first description of VOCs priming EFN secretion, a taxonomically widespread anti-herbivore defence. Plants can use chemical signals in their environment to assess the risk of herbivory and make use of this information to adjust their own defensive strategy accordingly.

Get access to the full text of this article