Reglucosylation of the Benzoxazinoid DIMBOA with Inversion of Stereochemical Configuration is a Detoxification Strategy in Lepidopteran Herbivores |
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| Authors: | Felipe C Wouters Dr Michael Reichelt Dr Gaétan Glauser Eugen Bauer Dr Matthias Erb Prof Jonathan Gershenzon Dr Daniel G Vassão |
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| Affiliation: | 1. Department of Biochemistry, and Research Group Insect Symbiosis, Max Planck Institute for Chemical Ecology, Hans‐Kn?ll‐Strasse 8, 07745, Jena (Germany) http://www.ice.mpg.de/ext/biochemistry.html;2. Institute of Biology, University of Neuchatel, Neuchatel (Switzerland);3. Institute of Plant Sciences, University of Bern, Bern (Switzerland) |
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| Abstract: | Benzoxazinoids are chemical defenses against herbivores and are produced by many members of the grass family. These compounds are stored as stable glucosides in plant cells and require the activity of glucosidases to release the corresponding toxic aglucones. In maize leaves, the most abundant benzoxazinoid is (2R)‐DIMBOA‐Glc, which is converted into the toxic DIMBOA upon herbivory. The ways in which three Spodoptera species metabolize this toxin were investigated. (2S)‐DIMBOA‐Glc, an epimer of the initial plant compound, was observed in the insect frass, and the associated glucosyltransferase activity was detected in the insect gut tissue. The epimeric glucoside produced by the insect was found to be no longer reactive towards plant glucosidases and thus cannot be converted into a toxin. Stereoselective reglucosylation thus represents a detoxification strategy in Spodoptera species that might help to explain their success as agricultural pests on benzoxazinoid‐containing crops. |
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| Keywords: | detoxification diastereoselectivity glycosylation insect biochemistry plant defenses |
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