GM tomato gets purple hue

Farm scientists in Bangalore have developed a purple coloured genetically engineered tomato, which is rich in anti-oxidants and may protect people from a host of diseases including cancer and heart ailments.

The transgenic tomato contains two genes from the flowers of Snapdragon plant, rendering it a purple colour. The change, however, does not take away health benefits of a regular tomato.

“The fruit has been transformed in such a way that only the ripened or semi-ripened tomato will show the purple colour. The level of anthrocyanin – source of anti-oxidant as well as the colour – has gone up by 70 to 100 per cent in the transformed fruit,” M Manamohan, leader of the team at the Indian Institute of Horticulture Research (IIHR), Bangalore, told Deccan Herald.

Anti-oxidants are natural chemicals that prevent cell death or cell damage in the body. All healthy diets include food rich in anti-oxidants.

Dietary anthocyanins are potent anti-oxidants. Their consumption provides protection against cardiovascular diseases, cancers, diabetes and arthritis. They are abundant in pomegranate, Indian black berry or jamun, blue berry, cranberry, purple grapes, purple corn and purple cabbage. In cabbage, only the outer layer contains dietary anthocyanins.

The IIHR team chose tomato because of its widespread dietary intake in fresh, cooked and processed forms.

The crop's higher productivity, round-the-year availability and amenability to genetic engineering made it a suitable choice for genetic transformation.

Using sophisticated genetic engineering technology, the IIHR team inserted two genes into a commercially cultivated tomato cultivar, known as Arka Vikas, for enhancing its anthocyanin content.

The transformed tomato plants accumulated high levels of anthocyanin throughout the fruit on maturity, the scientists reported in the July 10 issue of “Current Science.”

Asked if the purple tomato would be accepted in Indian kitchens, Manamohan said such tomatoes were available in the US market where they were sold at a premium.

Oregon State University produces such tomatoes. But in the US tomatoes, anthrocyanin is found only in the skin, whereas the Bangalore product has large quantities of it in the pulp as well.

The purple tomatoes were grown at a research farm on the IIHR premise, maintaining bio-safety standards. The institute now plans to carry out safety studies on animals in collaboration with either the National Institute of Nutrition, Hyderabad or the Central Food Technology Research Institute, Mysore.

These fruits can also be utilised to extract biological food colourants and anthocyanin compounds, used as nutraceuticals in the wellness industry.

Commercial release of the purple tomato, however, is not on the horizon as the IIHR has to carry out multiple field trials. Besides, the Central government will have to lift its moratorium on genetically modified (GM) crops and permit their release in the market. At present, there is no field trial of any GM crop in India because of a Supreme Court directive.