title: Metabolic engineering of xanthophyll content in tomato fruits.
abstract: Ripe tomato fruits accumulate significant amounts of the linear carotene lycopene, but only trace amounts of xanthophylls (oxygenated carotenoids). We overexpressed the lycopene beta-cyclase (b-Lcy) and beta-carotene hydroxylase (b-Chy) genes under the control of the fruit-specific Pds promoter. Transgene and protein expression was followed through semi-quantitative reverse transcription-PCR, Western blotting, and enzyme assays. Fruits of the transformants showed a significant increase of beta-carotene, beta-cryptoxanthin and zeaxanthin. The carotenoid composition of leaves remained unaltered. The transgenes and the phenotype are inherited in a dominant Mendelian fashion. This is the first example of successful metabolic engineering of xanthophyll content in tomato fruits.
authors.affiliation: ENEA, Casaccia Research Center, P.O. Box 2400, Rome 00100AD, Italy.
authors.forename: Sridhar
authors.initials: S
authors.lastname: Dharmapuri
authors.forename: Carlo
authors.initials: C
authors.lastname: Rosati
authors.forename: Patrizia
authors.initials: P
authors.lastname: Pallara
authors.forename: Riccardo
authors.initials: R
authors.lastname: Aquilani
authors.forename: Florence
authors.initials: F
authors.lastname: Bouvier
authors.forename: Bilal
authors.initials: B
authors.lastname: Camara
authors.forename: Giovanni
authors.initials: G
authors.lastname: Giuliano
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D015153:Blotting, Western; D065366:Cryptoxanthins; D005638:Fruit / Q000737:chemistry / Q000378:metabolism; D015870:Gene Expression; D005799:Genes, Dominant; D005818:Genetic Engineering / Q000379:methods*; D019753:Intramolecular Lyases / Q000235:genetics* / Q000378:metabolism; D018551:Solanum lycopersicum / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019076:Transgenes; D024341:Xanthophylls / Q000032:analysis / Q000378:metabolism*; D065146:Zeaxanthins; D019207:beta Carotene / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism
chemical_list: D065366:Cryptoxanthins; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; D006899:Mixed Function Oxygenases; C079232:beta-carotene hydroxylase; D019753:Intramolecular Lyases; C070925:lycopene cyclase-isomerase