Molecular interactions between the specialist herbivore Manduca sexta (Lepidoptera, Sphigidae) and its natural host Nicotiana attenuata

• Verfasst von: Gaquerel, Emmanuel [VerfasserIn]
• Verfasst von: Weinhold, Alexander [VerfasserIn]
• Verfasst von: Baldwin, Ian T. [VerfasserIn]
• Titel: Molecular interactions between the specialist herbivore Manduca sexta (Lepidoptera, Sphigidae) and its natural host Nicotiana attenuata
• Titelzusatz: VIII, an unbiased GCxGC-ToFMS analysis of the plant's elicited volatile emissions
• Verf.angabe: Emmanuel Gaquerel, Alexander Weinhold, and Ian T. Baldwin
• Umfang: 26 S.
• Fussnoten: Gesehen am 15.05.2017
• Titel Quelle: Enthalten in: Plant physiology
• Jahr Quelle: 2009
• Band/Heft Quelle: 149(2009), 3, S. 1408-1423
• ISSN Quelle: 1532-2548
• DOI: doi:10.1104/pp.108.130799
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1558603042

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-α-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.