Designer Strawberries

Genetically-modified strawberries are paving the way to more vitamin-rich fruit.

Photo courtesy of Barry Whyte Transformed: Foreign DNA has successfully been introduced in this ripening strawberry .

The food pyramid is a guideline, but considering the ridiculously low amounts of fruits and vegetables people are eating in the Western world, it may have more in common with the ancient monuments in Egypt. In 2000, 81% of men and 73% of women in the United States reported eating fewer than the recommended five servings of fruits and vegetables a day. Changing people's eating habits is one way of dealing with the problem, but some molecular biologists are taking a different approach: they are developing a way to transfer genetic material into the genome of fruits to increase the health benefits of even the fewest bites.

The scientists are specifically looking at strawberries, although the method can be applied to a variety of crops. Like all fruits, strawberries provide compounds that are essential to life. They are a major source of phytochemicals, antioxidants that are thought to reduce the risk of cancer, and they also happen to be an especially important source of vitamin C.

But although strawberries already have a high nutritional content, scientists claim that these fleshy, red fruits could be engineered to be even better for our health. Until now, it has been possible to engineer foods like corn and soybeans, but scientists haven't been able to manipulate the genome of the commercial strawberry in the way that they would like. The first step involves identifying the different genes in the strawberry and understanding their function and this requires a process called transformation to occur in the fruit. Transformation involves introducing foreign DNA from one type of cell into cells of a different organism with a different genome and to do this, scientists must engineer small, independent DNA molecules called plasmids to carry genetic information to the new host genome. The process is successful when genes from the foreign DNA are incorporated into the genome of the host, in this case the strawberry, causing a permanent change in its properties. So far, attempts at transformation in different varieties of strawberries have proved to be unsuccessful.