title: Geranyllinalool synthases in solanaceae and other angiosperms constitute an ancient branch of diterpene synthases involved in the synthesis of defensive compounds.
abstract: Many angiosperm plants, including basal dicots, eudicots, and monocots, emit (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene, which is derived from geranyllinalool, in response to biotic challenge. An Arabidopsis (Arabidopsis thaliana) geranyllinalool synthase (GLS) belonging to the e/f clade of the terpene synthase (TPS) family and two Fabaceae GLSs that belong to the TPS-g clade have been reported, making it unclear which is the main route to geranyllinalool in plants. We characterized a tomato (Solanum lycopersicum) TPS-e/f gene, TPS46, encoding GLS (SlGLS) and its homolog (NaGLS) from Nicotiana attenuata. The Km value of SlGLS for geranylgeranyl diphosphate was 18.7 µm, with a turnover rate value of 6.85 s(-1). In leaves and flowers of N. attenuata, which constitutively synthesize 17-hydroxygeranyllinalool glycosides, NaGLS is expressed constitutively, but the gene can be induced in leaves with methyl jasmonate. In tomato, SlGLS is not expressed in any tissue under normal growth but is induced in leaves by alamethicin and methyl jasmonate treatments. SlGLS, NaGLS, AtGLSs, and several other GLSs characterized only in vitro come from four different eudicot families and constitute a separate branch of the TPS-e/f clade that diverged from kaurene synthases, also in the TPS-e/f clade, before the gymnosperm-angiosperm split. The early divergence of this branch and the GLS activity of genes in this branch in diverse eudicot families suggest that GLS activity encoded by these genes predates the angiosperm-gymnosperm split. However, although a TPS sequence belonging to this GLS lineage was recently reported from a basal dicot, no representative sequences have yet been found in monocot or nonangiospermous plants.
authors: Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109 (V.F., E.P.); andDepartment of Population Biology, Institute for Biodiversity and Ecosystem Dynamics (J.M.A., M.R.K.), and Department of Plant Physiology (R.C.S.), University of Amsterdam, 1098 XH Amsterdam, The Netherlands.
authors: Vasiliki
authors: V
authors: Falara
authors: Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109 (V.F., E.P.); andDepartment of Population Biology, Institute for Biodiversity and Ecosystem Dynamics (J.M.A., M.R.K.), and Department of Plant Physiology (R.C.S.), University of Amsterdam, 1098 XH Amsterdam, The Netherlands.
authors: Juan M
authors: JM
authors: Alba
authors: Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109 (V.F., E.P.); andDepartment of Population Biology, Institute for Biodiversity and Ecosystem Dynamics (J.M.A., M.R.K.), and Department of Plant Physiology (R.C.S.), University of Amsterdam, 1098 XH Amsterdam, The Netherlands.
authors: Merijn R
authors: MR
authors: Kant
authors: Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109 (V.F., E.P.); andDepartment of Population Biology, Institute for Biodiversity and Ecosystem Dynamics (J.M.A., M.R.K.), and Department of Plant Physiology (R.C.S.), University of Amsterdam, 1098 XH Amsterdam, The Netherlands.
authors: Robert C
authors: RC
authors: Schuurink
authors: Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109 (V.F., E.P.); andDepartment of Population Biology, Institute for Biodiversity and Ecosystem Dynamics (J.M.A., M.R.K.), and Department of Plant Physiology (R.C.S.), University of Amsterdam, 1098 XH Amsterdam, The Netherlands lelx@umich.edu.
authors: Eran
authors: E
authors: Pichersky
mesh_terms: D000085:Acetates; D000408:Alamethicin; D019883:Alkyl and Aryl Transferases / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D003517:Cyclopentanes; D015870:Gene Expression; D017343:Genes, Plant; D018551:Solanum lycopersicum / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D054883:Oxylipins; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013729:Terpenes / Q000378:metabolism*; D014026:Nicotiana / Q000201:enzymology* / Q000235:genetics
chemical_list: D000085:Acetates; D003517:Cyclopentanes; D054883:Oxylipins; D010940:Plant Proteins; D013729:Terpenes; D000408:Alamethicin; C072239:methyl jasmonate; D019883:Alkyl and Aryl Transferases; C108877:terpene synthase