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Browsing by Author "Koellner, Tobias G."

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    Ancient origin and conserved gene function in terpene pheromone and defense evolution of stink bugs and hemipteran insects
    Rebholz, Zarley; Lancaster, Jason; Larose, Hailey; Khrimian, Ashot; Luck, Katrin; Sparks, Michael E.; Gendreau, Kerry L.; Shewade, Leena; Koellner, Tobias G.; Weber, Donald C.; Gundersen-Rindal, Dawn E.; O'Maille, Paul; Morozov, Alexandre, V; Tholl, Dorothea (Pergamon-Elsevier Science, 2023-01)
    Insects use diverse arrays of small molecules such as metabolites of the large class of terpenes for intra-and inter -specific communication and defense. These molecules are synthesized by specialized metabolic pathways; however, the origin of enzymes involved in terpene biosynthesis and their evolution in insect genomes is still poorly understood. We addressed this question by investigating the evolution of isoprenyl diphosphate synthase (IDS)-like genes with terpene synthase (TPS) function in the family of stink bugs (Pentatomidae) within the large order of piercing-sucking Hemipteran insects. Stink bugs include species of global pest status, many of which emit structurally related 15-carbon sesquiterpenes as sex or aggregation pheromones. We provide evidence for the emergence of IDS-type TPS enzymes at the onset of pentatomid evolution over 100 million years ago, coinciding with the evolution of flowering plants. Stink bugs of different geographical origin maintain small IDS -type families with genes of conserved TPS function, which stands in contrast to the diversification of TPS genes in plants. Expanded gene mining and phylogenetic analysis in other hemipteran insects further provides evidence for an ancient emergence of IDS-like genes under presumed selection for terpene-mediated chemical interactions, and this process occurred independently from a similar evolution of IDS-type TPS genes in beetles. Our findings further suggest differences in TPS diversification in insects and plants in conjunction with different modes of gene functionalization in chemical interactions.
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    Secondary metabolite biosynthetic pathways shared between plants and animals: convergent mechanisms and functions
    Beran, Franziska; Koellner, Tobias G.; Gershenzon, Jonathan; Tholl, Dorothea (2019)
    Despite the phylogenetic distance between plants and insects, these two groups of organisms produce some secondary metabolites in common. Identical structures belonging to chemical classes such as the simple monoterpenes and sesquiterpenes, iridoid monoterpenes, cyanogenic glycosides, benzoic acid derivatives, benzoquinones and naphthoquinones are sometimes found in both plants and insects. In addition, very similar glucohydrolases involved in activating twocomponent defenses, such as glucosinolates and cyanogenic glycosides, occur in both plants and insects. Although this trend was first noted many years ago, researchers have long struggled to find convincing explanations for such co-occurrence. In some cases, identical compounds may be produced by plants to interfere with their function in insects. In others, plant and insect compounds may simply have parallel functions, probably in defense or attraction, and their cooccurrence is a coincidence. The biosynthetic origin of such co-occurring metabolites may be very different in insects as compared to plants. Plants and insectsmayhave different pathways to the same metabolite, or similar sequences of intermediates, but different enzymes. Further knowledge of the ecological roles and biosynthetic pathways of secondary metabolites may shed more light on why plants and insects produce identical substances.