Article first published online: 13 FEB 2013
No claim to original US government works. New Phytologist © 2013 New Phytologist Trust
Volume 198, Issue 1, pages 241–251, April 2013
How to Cite
Estrada, C., Wcislo, W. T. and Van Bael, S. A. (2013), Symbiotic fungi alter plant chemistry that discourages leaf-cutting ants. New Phytologist, 198: 241–251. doi: 10.1111/nph.12140
- Issue published online: 25 FEB 2013
- Article first published online: 13 FEB 2013
- Manuscript Accepted: 7 DEC 2012
- Manuscript Received: 4 OCT 2012
- Smithsonian Institute Scholarly Studies Program
- Smithsonian Institute Postdoctoral Fellowship. Grant Number: NSF DEB-0949602
- Panama's Authority
- Atta colombica ;
- Colletotrichum tropicale ;
- Cucumis sativus ;
- endophytic fungi;
- leaf-cutting ants;
- plant defenses;
Fungal symbionts that live asymptomatically inside plant tissues (endophytes) can influence plant–insect interactions. Recent work has shown that damage by leaf-cutting ants, a major Neotropical defoliator, is reduced to almost half in plants with high densities of endophytes. We investigated changes in the phenotype of leaves that could influence ants' behavior to result in the reduction of foliar damage.
We produced cucumber seedlings with high and low densities of one common endophyte species, Colletotrichum tropicale. We used the leaves in bioassays and to compare chemical and physical leaf characteristics important for ants' food selection.
Ants cut about one-third more area of cucumber leaves with lower densities of endophytes and removed c. 20% more paper disks impregnated with the extracts of those leaves compared with leaves and disks from plants hosting the fungus. Colletotrichum tropicale colonization did not cause detectable changes in the composition of volatile compounds, cuticular waxes, nutrients or leaf toughness.
Our study shows that endophytes changed leaf chemistry and suggests that compounds with relative low volatility released after leaf wounding are a major factor influencing foraging decisions by ants when choosing between plants with low or high endophyte loads.