title: GAME9 regulates the biosynthesis of steroidal alkaloids and upstream isoprenoids in the plant mevalonate pathway.
abstract: Steroidal glycoalkaloids (SGAs) are cholesterol-derived molecules produced by solanaceous species. They contribute to pathogen defence but are toxic to humans and considered as anti-nutritional compounds. Here we show that GLYCOALKALOID METABOLISM 9 (GAME9), an APETALA2/Ethylene Response Factor, related to regulators of alkaloid production in tobacco and Catharanthus roseus, controls SGA biosynthesis. GAME9 knockdown and overexpression in tomato and potato alters expression of SGAs and upstream mevalonate pathway genes including the cholesterol biosynthesis gene STEROL SIDE CHAIN REDUCTASE 2 (SSR2). Levels of SGAs, C24-alkylsterols and the upstream mevalonate and cholesterol pathways intermediates are modified in these plants. Δ(7)-STEROL-C5(6)-DESATURASE (C5-SD) in the hitherto unresolved cholesterol pathway is a direct target of GAME9. Transactivation and promoter-binding assays show that GAME9 exerts its activity either directly or cooperatively with the SlMYC2 transcription factor as in the case of the C5-SD gene promoter. Our findings provide insight into the regulation of SGA biosynthesis and means for manipulating these metabolites in crops.
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.|Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
authors.forename: Pablo D
authors.initials: PD
authors.lastname: Cárdenas
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Prashant D
authors.initials: PD
authors.lastname: Sonawane
authors.affiliation: Department of Plant Systems Biology, Flanders Institute for Biotechnology (VIB), Gent B-9052, Belgium.|Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent B-9052, Belgium.
authors.forename: Jacob
authors.identifier: http://orcid.org/0000-0002-1134-9238
authors.initials: J
authors.lastname: Pollier
authors.affiliation: Department of Plant Systems Biology, Flanders Institute for Biotechnology (VIB), Gent B-9052, Belgium.|Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent B-9052, Belgium.
authors.forename: Robin
authors.initials: R
authors.lastname: Vanden Bossche
authors.affiliation: Plant Molecular Biology Unit, Division of Biochemical Sciences, Council of Scientific and Industrial Research-National Chemical Laboratory, Pune 411008, India.
authors.forename: Veena
authors.initials: V
authors.lastname: Dewangan
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Efrat
authors.initials: E
authors.lastname: Weithorn
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Lior
authors.initials: L
authors.lastname: Tal
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Sagit
authors.initials: S
authors.lastname: Meir
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Ilana
authors.initials: I
authors.lastname: Rogachev
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Sergey
authors.initials: S
authors.lastname: Malitsky
authors.affiliation: Plant Molecular Biology Unit, Division of Biochemical Sciences, Council of Scientific and Industrial Research-National Chemical Laboratory, Pune 411008, India.
authors.forename: Ashok P
authors.initials: AP
authors.lastname: Giri
authors.affiliation: Department of Plant Systems Biology, Flanders Institute for Biotechnology (VIB), Gent B-9052, Belgium.|Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent B-9052, Belgium.
authors.forename: Alain
authors.identifier: http://orcid.org/0000-0002-1599-551X
authors.initials: A
authors.lastname: Goossens
authors.affiliation: Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
authors.forename: Saul
authors.initials: S
authors.lastname: Burdman
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Asaph
authors.initials: A
authors.lastname: Aharoni
mesh_terms: D000470:Alkaloids / Q000096:biosynthesis*; D002784:Cholesterol / Q000096:biosynthesis*; D018506:Gene Expression Regulation, Plant; D055785:Gene Knockdown Techniques; D005947:Glucose / Q000378:metabolism; D017403:In Situ Hybridization; D018551:Solanum lycopersicum; D008798:Mevalonic Acid / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000235:genetics; D010940:Plant Proteins / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D011198:Solanum tuberosum; D013729:Terpenes / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D000470:Alkaloids; D010940:Plant Proteins; D012333:RNA, Messenger; D013729:Terpenes; D014157:Transcription Factors; D002784:Cholesterol; D010088:Oxidoreductases; D044925:Oxidoreductases Acting on CH-CH Group Donors; D005947:Glucose; D008798:Mevalonic Acid