Elevation of the provitamin A content of transgenic tomato plants

@article{Rmer2000ElevationOT,
  title={Elevation of the provitamin A content of transgenic tomato plants},
  author={S. Kerdine R{\"o}mer and Paul D. Fraser and Joy W. Kiano and Cathie A. Shipton and Norihiko Misawa and Wolfgang Schuch and Peter M. Bramley},
  journal={Nature Biotechnology},
  year={2000},
  volume={18},
  pages={666-669}
}
Tomato products are the principal dietary sources of lycopene and major source of β-carotene, both of which have been shown to benefit human health. To enhance the carotenoid content and profile of tomato fruit, we have produced transgenic lines containing a bacterial carotenoid gene (crtI) encoding the enzyme phytoene desaturase, which converts phytoene into lycopene. Expression of this gene in transgenic tomatoes did not elevate total carotenoid levels. However, the β-carotene content… 
Effect of the Citrus Lycopene β-Cyclase Transgene on Carotenoid Metabolism in Transgenic Tomato Fruits
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In this study, tomato constitutively express LyCB-1 was engineered and microarray analysis in the ripe stage revealed that the constitutive expression of Lycb-1 affected a number of pathways including the synthesis of fatty acids, flavonoids and phenylpropanoids, the degradation of limonene and pinene, starch and sucrose metabolism and photosynthesis.
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TLDR
Progress made in the genetic engineering of carotenoids in tomato fruit is reviewed, highlighting the limiting regulatory mechanisms that have been observed experimentally and the predictability and efficiency of the present engineering strategies are questioned.
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TLDR
The data suggest that enhancement of carotenoids can be achieved by metabolic engineering of the pathway, but intrinsic regulatory mechanisms such as feedback inhibition and metabolite channelling may limit the potential shown by the increased enzyme activities.
Evaluation of transgenic tomato plants expressing an additional phytoene synthase in a fruit-specific manner
  • P. Fraser, S. Romer, +6 authors P. Bramley
  • Biology, Medicine
    Proceedings of the National Academy of Sciences of the United States of America
  • 2002
TLDR
Metabolic control analysis suggests that the presence of an additional phytoene synthase reduces the regulatory effect of this step over the carotenoid pathway, and the activities of other enzymes in the pathway (isopentenyl diphosphate isomerase, geranylgeranyl diph phosphate synthase, and incorporation of isopentanyl dphosphate into phy toene) were not significantly altered.
Metabolic engineering of beta-carotene and lycopene content in tomato fruit.
TLDR
This work introduced, via Agrobacterium-mediated transformation, DNA constructs aimed at up-regulating (OE construct) or down- Regulating (AS construct) the expression of the beta-Lcy gene in a fruit-specific fashion, and observed an increase in total carotenoid content with respect to the parental line.
Genetic modification of tomato with the tobacco lycopene β-cyclase gene produces high β-carotene and lycopene fruit
TLDR
Transgenic Solanum lycopersicum plants expressing an additional copy of the lycopene β-cyclase gene (LCYB) from Nicotiana tabacum, under the control of the Arabidopsis polyubiquitin promoter (UBQ3), have been generated and ripe fruit showed an orange pigmentation, due to increased levels of β-carotene.
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