Headspace Volatiles from 52 oak Species Advertise Induction, Species Identity, and Evolution, but not Defense
- 503 Downloads
Leaf volatiles convey information about a plant to other organisms in their proximity. Despite increasing interest in understanding the relevance of volatile emissions for particular ecological interactions, there has been relatively little effort to assess generally what information volatile profiles transmit. We surveyed the volatile profiles of wounded and unwounded leaves of 52 oak (Quercus) species. We used phylogenetic comparison and multivariate techniques to assess in what circumstances oak individuals advertised their species identity, evolutionary history, direct defenses, or damage. We found that both species identity and evolutionary history were advertised when leaves were wounded, but species could not be differentiated by odor when leaves were not wounded. Various fatty-acid derivative compounds showed the strongest phylogenetic signal suggesting that they may best disclose taxonomic affiliations in oaks. We tested whether oak volatile composition or diversity advertised high defensive investment, but we found no evidence for this. Wounded leaves disclose much about an oak species’ identity and taxonomic affiliation, but unwounded leaves do not. This is consistent with the idea that volatile information is targeted toward natural enemy recruitment.
KeywordsVOC Volatile Quercus Aposematic Green leaf volatiles Macroevolution
Many thanks to Divya Donthi for performing compound verifications, to Nate Pope for advice on statistical analyses, and to Klaus Dragull for advice on analytical methods. The manuscript was improved by comments from Richard Karban, Kathy Hughes, and two anonymous reviewers.
- Halitschke, R., Schittko, U., Pohnert, G., Boland, W., and Baldwin, I. T. 2001. Molecular interactions between the specialist herbivore Manduca sexta (Lepidoptera, Sphingidae) and its natural host Nicotiana attenuata. III. Fatty acid-amino acid conjugates in herbivore oral secretions are necessary and sufficient for herbivore-specific plant responses. Plant Physiol. 125:711–717.PubMedCrossRefGoogle Scholar
- Harbourne, J. B. and Turner, B. L. 1984. Plant Chemosystematics. Academic, London.Google Scholar
- Legendre, P. and Legendre, L. 1998. Numerical Ecology. Elsevier Science, Amsterdam.Google Scholar
- Oksanen, J., Blanchet, F. G., Kindt, R., Legendre, P., O’Hara, B., Simpson, G., Solymos, P., Stevens, M. H. H., and Wagner, H. 2010. vegan: Community Ecology Package. R package version 1.17.1. http://CRAN.R-project.org/package=vegan.
- Pagel, M. D. and Harvey, P. H. 1991. The Comparative Method in Evolutionary Biology. Oxford University Press, Oxford, GB.Google Scholar
- Pinheiro, J., Bates, D., Debroy, S., Sarkar, D., and The R Core Development Team. 2009. nlme: Linear and Nonlinear Mixed Effects Models: R package version 3.1-93. http://cran.r-project.org/web/packages/nlme/index.html.
- R Development Core Team. 2010. R: A language and environment for statistical computing. Version 2.12.1. R Foundation for Statistical Computing, Vienna, Austria.Google Scholar
- Sabelis, M. W., Takabayashi, J., Janssen, A., Kant, M. R., van Wijk, M., Sznajder, B., Aratchige, N. S., Lesna, I., Belliure, B., and Schuurink, R. C. 2007. Ecology meets plant physiology: Herbivore-induced plant responses and their indirect effects on arthropod communities, pp. 188–217, in T. Ohgushi, T. P. Craig, and P. W. Price (eds.), Ecological Communities: Plant Mediation in Indirect Interaction Webs. Cambridge University Press, Cambridge, UK.CrossRefGoogle Scholar
- Savchenko, T., Pearse, I. S., Ignatia, L., Karban, R., and Dehesh, K. 2012. Insect herbivores selectively suppress the HPL branch of the oxylipin pathway in host plants. Plant J. doi: 10.1111/tpj.12064.
- Staudt, M., Mandl, N., Joffre, R., and Rambal, S. 2001. Intraspecific variability of monoterpene composition emitted by Quercus ilex leaves. Can. J. For. Res. Rev. Can. Rech. For. 31:174–180.Google Scholar
- van Wijk, M., de Bruijn, P. J. A., and Sabelis, M. W. 2011. Complex odor from plants under attack: Herbivore’s enemies react to the whole, not its parts. PLoS One 6:7.Google Scholar