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

摘要

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 beta-cyclase (CrtY) gene) individually. The presence of transgenes was confirmed by PCR, and transgenes integration was seen in Southern blot analysis. The beta-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 beta-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.