Chemical defence in chrysomelid larvae and adults

Pasteels, Jacques; Braekman, Jean Claude; Daloze, Désiré; Ottinger, Robert

doi:10.1016/0040-4020(82)80038-0

Cited by 129 publications

(68 citation statements)

References 21 publications

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“…GDP is needed for the de novo synthesis of the cyclopentanoid monoterpene iridoids, defensive compounds that are produced during the entire larval stage of P. cochleariae (21,22) (Fig. 1) , and Mg 2+ in the juvenile beetles supports the notion that these organisms may control the product specificity of scIDSs by means of changes in local concentrations of these metal ions.…”

Section: +mentioning

confidence: 66%

Metal ions control product specificity of isoprenyl diphosphate synthases in the insect terpenoid pathway

Frick¹,

Nagel

Schmidt

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

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Isoprenyl diphosphate synthases (IDSs) produce the ubiquitous branched-chain diphosphates of different lengths that are precursors of all major classes of terpenes. Typically, individual shortchain IDSs (scIDSs) make the C 10 , C 15 , and C 20 isoprenyl diphosphates separately. Here, we report that the product length synthesized by a single scIDS shifts depending on the divalent metal cofactor present. This previously undescribed mechanism of carbon chainlength determination was discovered for a scIDS from juvenile horseradish leaf beetles, Phaedon cochleariae. The recombinant enzyme P. cochleariae isoprenyl diphosphate synthase 1 (PcIDS1) yields 96% C 10 -geranyl diphosphate (GDP) and only 4% C 15 -farnesyl diphosphate (FDP) in the presence of Co 2+ or Mn 2+ as a cofactor, whereas it yields only 18% C 10 GDP but 82% C 15 FDP in the presence of Mg 2+. In reaction with Co 2+ , PcIDS1 has a K m of 11.6 μM for dimethylallyl diphosphate as a cosubstrate and 24.3 μM for GDP. However, with Mg 2+ , PcIDS1 has a K m of 1.18 μM for GDP, suggesting that this substrate is favored by the enzyme under such conditions. RNAi targeting PcIDS1 revealed the participation of this enzyme in the de novo synthesis of defensive monoterpenoids in the beetle larvae. As an FDP synthase, PcIDS1 could be associated with the formation of sesquiterpenes, such as juvenile hormones. Detection of Co , or Mg 2+ in the beetle larvae suggests flux control into C 10 vs. C 15 isoprenoids could be accomplished by these ions in vivo. The dependence of product chain length of scIDSs on metal cofactor identity introduces an additional regulation for these branch point enzymes of terpene metabolism.cobalt | kinetic | prenyltransferase | secretions | silencing

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Section: +mentioning

confidence: 66%

Metal ions control product specificity of isoprenyl diphosphate synthases in the insect terpenoid pathway

Frick¹,

Nagel

Schmidt

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

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“…Leaf beetles cover a range of color patterns such as iridescence, contrasting, and mottled coloration (see Reid, 2006 for details on the diversity of the color patterns of Australian chrysomelines). Chrysomeline beetles are also chemically defended, producing noxious secretions of metabolites derived from their host plants (Pasteels et al, 1982(Pasteels et al, , 1983Selman, 1985a;Schulz et al, 1997;Termonia et al, 2002), or synthesized de novo (Blum et al, 1972;Hilker and Schulz, 1994). The conspicuous appearance of many chrysomelines, together with their defensive chemical secretions and diurnal lifestyle, have led to the widespread assumption that these color patterns are aposematic and deter potential predators (Selman, 1985b(Selman, , 1994Pasteels et al, 1989;Matthews and Reid, 2002).…”

Section: Introductionmentioning

confidence: 99%

The Role of Life-History and Ecology in the Evolution of Color Patterns in Australian Chrysomeline Beetles

et al. 2017

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The variation in animal coloration patterns has evolved in response to different visual strategies for reducing the risk of predation. However, the perception of animal coloration by enemies is affected by a variety of factors, including morphology and habitat. We use the diversity of Australian chrysomeline leaf beetles to explore relationships of visual ecology to beetle morphology and color patterns. There is impressive color pattern variation within the Chrysomelinae, which is likely to reflect anti-predatory strategies. Our phylogenetic comparative analyses reveal strong selection for beetles to be less distinct from their host plants, suggesting that the beetle color patterns have a camouflage effect, rather than the widely assumed aposematic function. Beetles in dark habitats were significantly larger than beetles in bright habitats, potentially to avoid detection by predators because it is harder for large animals to be cryptic in bright habitats. Polyphagous species have greater brightness contrast against their host plants than monophagous species, highlighting the conflict between a generalist foraging strategy and the detection costs of potential predators. Host plant taxa-Eucalyptus and Acacia-interacted differently with beetle shape to predict blue pattern differences between beetle and host plant, possibly an outcome of different predator complexes on these host plants. The variety of anti-predator strategies in chrysomelines may explain their successful radiation into a variety of habitats and, ultimately, their speciation.

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“…When disturbed, the larvae display droplets of defensive secretions on their backs by everting the nine pairs of glandular reservoirs located under their dorsal cuticle [7]. The defensive droplets contain chemically diverse deterrents [8][9][10][11][12][13]. Phylogenetic analyses of Chrysomelina sensu stricto species revealed that the composition of their secretions reflects a stepwise scenario of host -plant adaptation [5].…”

Section: Introductionmentioning

confidence: 99%

Independently recruited oxidases from the glucose-methanol-choline oxidoreductase family enabled chemical defences in leaf beetle larvae (subtribe Chrysomelina) to evolve

et al. 2014

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Larvae of the leaf beetle subtribe Chrysomelina sensu stricto repel their enemies by displaying glandular secretions that contain defensive compounds. These repellents can be produced either de novo (iridoids) or by using plant-derived precursors (e.g. salicylaldehyde). The autonomous production of iridoids, as in Phaedon cochleariae, is the ancestral chrysomeline chemical defence and predates the evolution of salicylaldehyde-based defence. Both biosynthesis strategies include an oxidative step of an alcohol intermediate. In salicylaldehyde-producing species, this step is catalysed by salicyl alcohol oxidases (SAOs) of the glucose-methanol-choline (GMC) oxidoreductase superfamily, but the enzyme oxidizing the iridoid precursor is unknown. Here, we show by in vitro as well as in vivo experiments that P. cochleariae also uses an oxidase from the GMC superfamily for defensive purposes. However, our phylogenetic analysis of chrysomeline GMC oxidoreductases revealed that the oxidase of the iridoid pathway originated from a GMC clade different from that of the SAOs. Thus, the evolution of a host-independent chemical defence followed by a shift to a host-dependent chemical defence in chrysomeline beetles coincided with the utilization of genes from different GMC subfamilies. These findings illustrate the importance of the GMC multi-gene family for adaptive processes in plant-insect interactions.

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Chemical defence in chrysomelid larvae and adults

Cited by 129 publications

References 21 publications

Metal ions control product specificity of isoprenyl diphosphate synthases in the insect terpenoid pathway

Metal ions control product specificity of isoprenyl diphosphate synthases in the insect terpenoid pathway

The Role of Life-History and Ecology in the Evolution of Color Patterns in Australian Chrysomeline Beetles

Independently recruited oxidases from the glucose-methanol-choline oxidoreductase family enabled chemical defences in leaf beetle larvae (subtribe Chrysomelina) to evolve

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