title: Terrein biosynthesis in Aspergillus terreus and its impact on phytotoxicity.
abstract: Terrein is a fungal metabolite with ecological, antimicrobial, antiproliferative, and antioxidative activities. Although it is produced by Aspergillus terreus as one of its major secondary metabolites, not much is known about its biosynthetic pathway. Here, we describe an unexpected discovery of the terrein biosynthesis gene locus made while we were looking for a PKS gene involved in production of conidia coloration pigments common for Aspergilli. The gene, ATEG_00145, here named terA, is essential for terrein biosynthesis and heterologous production of TerA in Aspergillus niger revealed an unusual plasticity in the products formed, yielding a mixture of 4-hydroxy-6-methylpyranone, orsellinic acid, and 6,7-dihydroxymellein. Biochemical and molecular genetic analyses indicate a low extension cycle specificity of TerA. Furthermore, 6-hydroxymellein was identified as a key intermediate in terrein biosynthesis. We find that terrein production is highly induced on plant-derived media, that terrein has phytotoxic activity on plant growth, and induces lesions on fruit surfaces.
authors.affiliation: Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstrasse 11a, 07745 Jena, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Zaehle
authors.affiliation: Research Group Microbial Biochemistry and Physiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstrasse 11a, 07745 Jena, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Gressler
authors.affiliation: Research Group Systems Biology/Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstrasse 11a, 07743 Jena, Germany.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Shelest
authors.affiliation: Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstrasse 11a, 07745 Jena, Germany.
authors.forename: Elena
authors.initials: E
authors.lastname: Geib
authors.affiliation: Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstrasse 11a, 07745 Jena, Germany. Electronic address: christian.hertweck@hki-jena.de.
authors.forename: Christian
authors.initials: C
authors.lastname: Hertweck
authors.affiliation: Research Group Microbial Biochemistry and Physiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstrasse 11a, 07745 Jena, Germany; Institute for Microbiology, Friedrich-Schiller University, 07743 Jena, Germany. Electronic address: matthias.brock@hki-jena.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Brock
mesh_terms: D001230:Aspergillus / Q000235:genetics / Q000378:metabolism*; D003517:Cyclopentanes / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity*; D005638:Fruit / Q000187:drug effects*; D005800:Genes, Fungal / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D010944:Plants / Q000187:drug effects* / Q000382:microbiology; D048630:Polyketide Synthases / Q000378:metabolism; D012639:Seeds / Q000187:drug effects*
chemical_list: D003517:Cyclopentanes; C439087:terrein; D048630:Polyketide Synthases