title: Tomato fruits expressing a bacterial feedback-insensitive 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase of the shikimate pathway possess enhanced levels of multiple specialized metabolites and upgraded aroma.
abstract: Tomato (Solanum lycopersicum) fruit contains significant amounts of bioactive compounds, particularly multiple classes of specialized metabolites. Enhancing the synthesis and accumulation of these substances, specifically in fruits, are central for improving tomato fruit quality (e.g. flavour and aroma) and could aid in elucidate pathways of specialized metabolism. To promote the production of specialized metabolites in tomato fruit, this work expressed under a fruit ripening-specific promoter, E8, a bacterial AroG gene encoding a 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (DAHPS), which is feedback-insensitive to phenylalanine inhibition. DAHPS, the first enzyme of the shikimate pathway, links between the primary and specialized metabolism derived from aromatic amino acids. AroG expression influenced the levels of number of primary metabolites, such as shikimic acid and aromatic amino acids, as well as multiple volatile and non-volatile phenylpropanoids specialized metabolites and carotenoids. An organoleptic test, performed by trained panellists, suggested that the ripe AroG-expressing tomato fruits had a preferred floral aroma compare with fruits of the wild-type line. These results imply that fruit-specific manipulation of the conversion of primary to specialized metabolism is an attractive approach for improving fruit aroma and flavour qualities as well as discovering novel fruit-specialized metabolites.
authors.affiliation: Department of Plant Sciences, Weizmann Institute of Science, PO Box 26, Rehovot 76100, Israel.
authors.forename: Vered
authors.initials: V
authors.lastname: Tzin
authors.forename: Ilana
authors.initials: I
authors.lastname: Rogachev
authors.forename: Sagit
authors.initials: S
authors.lastname: Meir
authors.forename: Michal
authors.initials: M
authors.lastname: Moyal Ben Zvi
authors.forename: Tania
authors.initials: T
authors.lastname: Masci
authors.forename: Alexander
authors.initials: A
authors.lastname: Vainstein
authors.forename: Asaph
authors.initials: A
authors.lastname: Aharoni
authors.forename: Gad
authors.initials: G
authors.lastname: Galili
mesh_terms: D010723:3-Deoxy-7-Phosphoheptulonate Synthase / Q000378:metabolism*; D024322:Amino Acids, Aromatic / Q000096:biosynthesis; D004926:Escherichia coli / Q000201:enzymology*; D025461:Feedback, Physiological; D005638:Fruit / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D018551:Solanum lycopersicum / Q000201:enzymology* / Q000235:genetics; D053858:Metabolic Networks and Pathways; D055442:Metabolome; D009812:Odorants; D030821:Plants, Genetically Modified; D012765:Shikimic Acid / Q000378:metabolism*; D055549:Volatile Organic Compounds / Q000378:metabolism
chemical_list: D024322:Amino Acids, Aromatic; D055549:Volatile Organic Compounds; D012765:Shikimic Acid; D010723:3-Deoxy-7-Phosphoheptulonate Synthase
keywords: 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase; Aromatic amino acids; metabolism; shikimate pathway; tomato; volatiles.