Evolution of the biosynthesis of two hydroxyacetophenones in plants |
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Authors: | Geneviève J. Parent Isabelle Giguère Melissa Mageroy Joerg Bohlmann John J. MacKay |
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Affiliation: | 1. Centre d'étude de la forêt, Département des sciences du bois et de la forêt, Université Laval, Québec City, Québec, Canada;2. Institut de biologie intégrative et des systèmes, Université Laval, Québec City, Québec, Canada;3. Department of Plant Sciences, University of Oxford, Oxford, UK;4. Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada;5. Norwegian Institute for Bioeconomy Research, ?s, Norway |
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Abstract: | Acetophenones are phenolic metabolites of plant species. A metabolic route for the biosynthesis and release of 2 defence‐related hydroxyacetophenones in white spruce (Picea glauca) was recently proposed to involve 3 phases: (a) biosynthesis of the acetophenone aglycons catalysed by a currently unknown set of enzymes, (b) formation and accumulation of the corresponding glycosides catalysed by a glucosyltransferase, and (c) release of the aglycons catalysed by a glucosylhydrolase (PgβGLU‐1). We tested if this biosynthetic model is conserved across Pinaceae and land plant species. We assayed and surveyed the literature and sequence databases for possible patterns of the presence of the acetophenone aglycons piceol and pungenol and their glucosides, as well as sequences and expression of Pgβglu‐1 orthologues. In the Pinaceae, the 3 phases of the biosynthetic model are present and differences in expression of Pgβglu‐1 gene orthologues explain some of the interspecific variation in hydroxyacetophenones. The phylogenetic signal in the metabolite phenotypes was low across species of 6 plant divisions. Putative orthologues of PgβGLU‐1 do not form a monophyletic group in species producing hydroxyacetophenones. The biosynthetic model for acetophenones appears to be conserved across Pinaceae, whereas convergent evolution has led to the production of acetophenone glucosides across land plants. |
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Keywords: | convergence enzyme gene expression phenolics secondary metabolism |
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