Metabolic engineering of beta-carotene and lycopene content in tomato fruit
Article first published online: 25 DEC 2001
The Plant Journal
Volume 24, Issue 3, pages 413–420, November 2000
How to Cite
Rosati, C., Aquilani, R., Dharmapuri, S., Pallara, P., Marusic, C., Tavazza, R., Bouvier, F., Camara, B. and Giuliano, G. (2000), Metabolic engineering of beta-carotene and lycopene content in tomato fruit. The Plant Journal, 24: 413–420. doi: 10.1046/j.1365-313x.2000.00880.x
- Issue published online: 25 DEC 2001
- Article first published online: 25 DEC 2001
- Received 17 May 2000; revised 15 August 2000; accepted 15 August 2000.
- lycopene beta-cyclase;
Ripe tomato fruits accumulate large amounts of the red linear carotene, lycopene (a dietary antioxidant) and small amounts of its orange cyclisation product, beta-carotene (pro-vitamin A). Lycopene is transformed into beta-carotene by the action of lycopene beta-cyclase (β-Lcy). We introduced, via Agrobacterium-mediated transformation, DNA constructs aimed at up-regulating (OE construct) or down-regulating (AS construct) the expression of the β-Lcy gene in a fruit-specific fashion. Three transformants containing the OE construct show a significant increase in fruit beta-carotene content. The fruits from these plants display different colour phenotypes, from orange to orange-red, depending on the lycopene/beta-carotene ratio. Fruits from AS transformants show up to 50% inhibition of β-Lcy expression, accompanied by a slight increase in lycopene content. Leaf carotenoid composition is unaltered in all transformants. In most transformants, an increase in total carotenoid content is observed with respect to the parental line. This increase occurs in the absence of major variations in the expression of endogenous carotenoid genes.