Novel glucosinolate metabolism in larvae of the leaf beetle Phaedon cochleariae.

Novel glucosinolate metabolism in larvae of the leaf beetle Phaedon cochleariae. Insect Biochem Mol Biol. 2020 Jul 09;:103431 Authors: Friedrichs J, Schweiger R, Geisler S, Mix A, Wittstock U, Müller C Abstract Plants of the Brassicales are defended by a binary system, in which glucosinolates are degraded by myrosinases, forming toxic breakdown products such as isothiocyanates and nitriles. Various detoxification pathways and avoidance strategies have been found that allow different herbivorous insect taxa to deal with the glucosinolate-myrosinase system of their host plants. Here, we investigated how larvae of the leaf beetle species Phaedon cochleariae (Coleoptera: Chrysomelidae), a feeding specialist on Brassicaceae, cope with this binary defence. We performed feeding experiments using leaves of watercress (Nasturtium officinale, containing 2-phenylethyl glucosinolate as major glucosinolate and myrosinases) and pea (Pisum sativum, lacking glucosinolates and myrosinases), to which benzenic glucosinolates (benzyl- or 4-hydroxybenzyl glucosinolate) were applied. Performing comparative metabolomics using UHPLC-QTOF-MS/MS, N-(phenylacetyl) aspartic acid, N-(benzoyl) aspartic acid and N-(4-hydroxybenzoyl) aspartic acid were identified as major metabolites of 2-phenylethyl-, benzyl- and 4-hydroxybenzyl glucosinolate, respectively, in larvae and faeces. This suggests that larvae of P. cochleariae metabolise isothiocyanates or nitriles to...
Source: Insect Biochemistry and Molecular Biology - Category: Biochemistry Authors: Tags: Insect Biochem Mol Biol Source Type: research