title: Improving the nutritional value of Golden Rice through increased pro-vitamin A content.
abstract: "Golden Rice" is a variety of rice engineered to produce beta-carotene (pro-vitamin A) to help combat vitamin A deficiency, and it has been predicted that its contribution to alleviating vitamin A deficiency would be substantially improved through even higher beta-carotene content. We hypothesized that the daffodil gene encoding phytoene synthase (psy), one of the two genes used to develop Golden Rice, was the limiting step in beta-carotene accumulation. Through systematic testing of other plant psys, we identified a psy from maize that substantially increased carotenoid accumulation in a model plant system. We went on to develop "Golden Rice 2" introducing this psy in combination with the Erwinia uredovora carotene desaturase (crtI) used to generate the original Golden Rice. We observed an increase in total carotenoids of up to 23-fold (maximum 37 microg/g) compared to the original Golden Rice and a preferential accumulation of beta-carotene.
authors.affiliation: Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK.
authors.forename: Jacqueline A
authors.initials: JA
authors.lastname: Paine
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Shipton
authors.forename: Sunandha
authors.initials: S
authors.lastname: Chaggar
authors.forename: Rhian M
authors.initials: RM
authors.lastname: Howells
authors.forename: Mike J
authors.initials: MJ
authors.lastname: Kennedy
authors.forename: Gareth
authors.initials: G
authors.lastname: Vernon
authors.forename: Susan Y
authors.initials: SY
authors.lastname: Wright
authors.forename: Edward
authors.initials: E
authors.lastname: Hinchliffe
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Adams
authors.forename: Aron L
authors.initials: AL
authors.lastname: Silverstone
authors.forename: Rachel
authors.initials: R
authors.lastname: Drake
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics; D004885:Erwinia / Q000201:enzymology; D017343:Genes, Plant; D005818:Genetic Engineering; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase; D009753:Nutritive Value; D012275:Oryza / Q000201:enzymology* / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000378:metabolism*; D014802:Vitamin A Deficiency / Q000517:prevention & control; D003313:Zea mays / Q000201:enzymology / Q000235:genetics; D019207:beta Carotene / Q000096:biosynthesis*
chemical_list: D019207:beta Carotene; D019883:Alkyl and Aryl Transferases; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase