Metabolic engineering of xanthophyll content in tomato fruits.
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.
Dharmapuri
Sridhar
S
ENEA, Casaccia Research Center, P.O. Box 2400, Rome 00100AD, Italy.
Rosati
Carlo
C
Pallara
Patrizia
P
Aquilani
Riccardo
R
Bouvier
Florence
F
Camara
Bilal
B
Giuliano
Giovanni
G
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
D065366:Cryptoxanthins; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; D006899:Mixed Function Oxygenases; C079232:beta-carotene hydroxylase; D019753:Intramolecular Lyases; C070925:lycopene cyclase-isomerase