| Title: | A tritrophic signal that attracts parasitoids to host-damaged plants withstands disruption by non-host herbivores |
| Author(s): | Erb M; Foresti N; Turlings TC; |
| Address: | "Laboratory for Fundamental and Applied Research in Chemical Ecology, Institute of Biology, University of Neuchatel, Neuchatel, Switzerland" |
| ISSN/ISBN: | 1471-2229 (Electronic) 1471-2229 (Linking) |
| Abstract: | "BACKGROUND: Volatiles emitted by herbivore-infested plants are highly attractive to parasitoids and therefore have been proposed to be part of an indirect plant defense strategy. However, this proposed function of the plant-provided signals remains controversial, and it is unclear how specific and reliable the signals are under natural conditions with simultaneous feeding by multiple herbivores. Phloem feeders in particular are assumed to interfere with plant defense responses. Therefore, we investigated how attack by the piercing-sucking cicadellid Euscelidius variegatus influences signaling by maize plants in response to the chewing herbivore Spodoptera littoralis. RESULTS: The parasitoid Cotesia marginiventris strongly preferred volatiles of plants infested with its host S. littoralis. Overall, the volatile emissions induced by S. littoralis and E. variegatus were similar, but higher levels of certain wound-released compounds may have allowed the wasps to specifically recognize plants infested by hosts. Expression levels of defense marker genes and further behavioral bioassays with the parasitoid showed that neither the physiological defense responses nor the attractiveness of S. littoralis infested plants were altered by simultaneous E. variegatus attack. CONCLUSIONS: Our findings imply that plant defense responses to herbivory can be more robust than generally assumed and that ensuing volatiles convey specific information about the type of herbivore that is attacking a plant, even in complex situations with multiple herbivores. Hence, the results of this study support the notion that herbivore-induced plant volatiles may be part of a plant's indirect defense stratagem" |
| Keywords: | "Animals Gene Expression Profiling Gene Expression Regulation, Plant Host-Parasite Interactions Insecta/*physiology Odorants Plant Diseases/genetics/parasitology Plants/genetics/*metabolism/*parasitology Signal Transduction/*physiology Spodoptera/physiolog;" |
| Notes: | "MedlineErb, Matthias Foresti, Nicolas Turlings, Ted C J eng Research Support, Non-U.S. Gov't England 2010/11/17 BMC Plant Biol. 2010 Nov 15; 10:247. doi: 10.1186/1471-2229-10-247" |
