| Title: | "Molecular interactions between the specialist herbivore Manduca sexta (Lepidoptera, Sphigidae) and its natural host Nicotiana attenuata. VIII. An unbiased GCxGC-ToFMS analysis of the plant's elicited volatile emissions" |
| Author(s): | Gaquerel E; Weinhold A; Baldwin IT; |
| Address: | "Department of Molecular Ecology, Max-Planck-Institute for Chemical Ecology, Jena 07745, Germany" |
| ISSN/ISBN: | 0032-0889 (Print) 1532-2548 (Electronic) 0032-0889 (Linking) |
| Abstract: | "Treating wounds in Nicotiana attenuata leaves with Manduca sexta oral secretions (W+OS) mimics most changes elicited by M. sexta herbivory, but an unbiased analysis of the effect of the different OS constituents on volatile emissions is lacking. We used two-dimensional gas chromatography/time-of-flight (GCxGC-ToF) mass spectrometry combined with multivariate statistics to parse volatiles into regulatory patterns. Volatiles released by wounding alone and by the alkalinity of OS were assessed by applying a buffer known to mimic the pH-mediated changes of OS elicitation (pectin methyl esterase activation and methanol release). The activities of fatty acid amino acid conjugates, well-known elicitors of antiherbivore defenses, and of 2-hydroxyoctadecatrienoic acid, a newly discovered signal in OS, were determined. Approximately 400 analytes were detected after deconvolution and alignment of GCxGC data; 35 volatiles were significantly regulated upon W+OS. Two-thirds of these were specifically regulated by OS, being either amplified (most terpenoids and certain hexenylesters) or strongly repressed (many short-chain alcohols and some aromatic and hexenylester derivatives). Fatty acid amino acid conjugates played a central role in this pattern of regulation, since they induced the emission of half of OS-elicited volatiles and inhibited the production of almost all OS-repressed volatiles; 2-hydroxyoctadecatrienoic acid influenced emission of trans-alpha-bergamotene, while other unknown OS constituents amplified hexenylester production. We conclude that the complex bouquet of herbivory-elicited volatiles results from the complex modulations of the wound response by diverse cues found in OS. This work also underscores the value of ultra-high-resolution GCxGC-ToF analysis combined with the nontargeted mining of the resulting data" |
| Keywords: | "Animals Chromatography, Gas Cluster Analysis Fatty Acids/analysis/chemistry *Feeding Behavior Manduca/*physiology *Mass Spectrometry Principal Component Analysis Tobacco/*parasitology Volatile Organic Compounds/*analysis/chemistry;" |
| Notes: | "MedlineGaquerel, Emmanuel Weinhold, Alexander Baldwin, Ian T eng 2009/01/13 Plant Physiol. 2009 Mar; 149(3):1408-23. doi: 10.1104/pp.108.130799. Epub 2009 Jan 9" |
