title: Altered metabolite accumulation in tomato fruits by coexpressing a feedback-insensitive AroG and the PhODO1 MYB-type transcription factor.
abstract: Targeted manipulation of phenylalanine (Phe) synthesis is a potentially powerful strategy to boost biologically and economically important metabolites, including phenylpropanoids, aromatic volatiles and other specialized plant metabolites. Here, we use two transgenes to significantly increase the levels of aromatic amino acids, tomato flavour-associated volatiles and antioxidant phenylpropanoids. Overexpression of the petunia MYB transcript factor, ODORANT1 (ODO1), combined with expression of a feedback-insensitive E. coli 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (AroG), altered the levels of multiple primary and secondary metabolites in tomato fruit, boosting levels of multiple secondary metabolites. Our results indicate that coexpression of AroG and ODO1 has a dual effect on Phe and related biosynthetic pathways: (i) positively impacting tyrosine (Tyr) and antioxidant related metabolites, including ones derived from coumaric acid and ferulic acid; (ii) negatively impacting other downstream secondary metabolites of the Phe pathway, including kaempferol-, naringenin- and quercetin-derived metabolites, as well as aromatic volatiles. The metabolite profiles were distinct from those obtained with either single transgene. In addition to providing fruits that are increased in flavour and nutritional chemicals, coexpression of the two genes provides insights into regulation of branches of phenylpropanoid metabolic pathways.
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Provincial Key Laboratory of Plant Molecular Breeding, South China Agricultural University, Guangzhou, 510642, China.|Department of Plant and environmental Science, Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Qingjun
authors.initials: Q
authors.lastname: Xie
authors.affiliation: Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611-0690, USA.
authors.forename: Zhongyuan
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Plant and environmental Science, Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Sagit
authors.initials: S
authors.lastname: Meir
authors.affiliation: Department of Plant and environmental Science, Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Ilana
authors.initials: I
authors.lastname: Rogachev
authors.affiliation: Department of Plant and environmental Science, Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Asaph
authors.initials: A
authors.lastname: Aharoni
authors.affiliation: Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611-0690, USA.
authors.forename: Harry J
authors.initials: HJ
authors.lastname: Klee
authors.affiliation: Department of Plant and environmental Science, Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Gad
authors.initials: G
authors.lastname: Galili
mesh_terms: D005638:Fruit / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D018551:Solanum lycopersicum / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors
keywords: AroG; ODO1; fruit; secondary metabolism; shikimate pathway; tomato