Transformation of tomato cv. Arka Ahuti (Solanum lycopersicum L.) with phytoene desaturase (CrtI) and lycopene b-cyclase (CrtY) genes increases carotenoid content and antioxidant potential.

In recent years, there has been a considerable
interest in the dietary carotenoids due to their pro-vitamin
A activity, high antioxidant potential, ability to prevent
onset of certain cancers and age related macular degeneration.
To enhance the carotenoid content, agroinjection of
tomato fruits was carried out with Agrobacterium tumefaciens
GV 3101 containing binary vector pRI 101(I) (harbouring
Phytoene desaturase (CrtI) gene), and pRI
101(Y) (harbouring Lycopene b-cyclase (CrtY) gene)
individually. The presence of transgenes was confirmed by
PCR, and transgenes integration was seen in Southern blot
analysis. The b-carotene and lycopene content in pRI
101(I) agro-infiltrated tomato fruits showed up to 2.4- and
1.2-fold increase, respectively, over control fruits; whereas
up to 2- and 1.2-fold increase was observed in pRI
101(Y) agro-infiltrated tomato fruits. The total antioxidant
potential was also found to be higher (5–6-fold) for
hydrophilic and lipophilic extracts from agro-infiltrated
tomatoes when compared to extracts from control tomatoes,
probably due to the combined effect of enhanced
carotenoids, phenolics and ascorbic acid. A relatively new
method of introducing transgenes directly into tomato
fruits was carried out, and the levels of b-carotene and
lycopene were enhanced in comparison to control fruits.
The present study indicated the usefulness of
agroinfiltration in transformation of tomatoes for
enhancement of carotenoid content, however, stability of
transgenes in future generation needs to be ascertained.
Once stable transformation is achieved, the fruits can be
used to derive maximal health benefits associated with
carotenoids.