Timelines: 1994

Antisense fruit

Flavr Savr tomato (left) and normal tomato (right)

Calgene's FlavrSavr® tomato becomes the first genetically-modified food to be approved for sale and human consumption by the FDA. Field tests conducted by the USDA in 1992 had already determined that the tomato is not a plant-pest risk. 

The FlavrSavr® is engineered to resist rotting. Natural rotting occurs in tomatoes as the enzyme polygalacturonase breaks down pectin in cell walls. This softens the fruit and makes it susceptible to fungal infections. For this reason, growers ordinarily pluck tomatoes from the vine before ripening, which results in less flavorful fruit. The FlavrSavr® contains an antisense gene that interferes with the production of polygalacturonase, retards rotting, and extends shelf-life. It also allows natural ripening on the vine, which reduces processing and storage expenses, and enhances flavor. 

Still, the FlavrSavr® does not become a successful product. Although it reduces certain costs of production, ripened fruit are more easily bruised in handling and transport. Calgene is forced to invest in expensive machinery to prevent damage. The company also lacks breeding experience, and has selected a variety of tomato with suboptimal growth and yield characteristics. A relatively low percentage of harvested fruit can be sold at the premium prices that would make the FlavrSavr® profitable. Faced with increasingly stiff competition from conventionally bred long shelf-life tomatoes, Calgene elects to halt production in 1997.

The FlavrSavr® also carries the unhappy distinction of being the only bioengineered food subject to special regulatory review simply because it is genetically modified. The company submitted an application for FDA evaluation of the product in 1990. In 1992, the agency issued a revised policy statement holding that “nucleic acids, in and of themselves, do not raise safety concerns.” According to the new guidelines, safety evaluations are properly focused not on recombinant genes but rather on intended or unintended metabolic effects. Calgene had been required to document the safety of the inserted antisense gene prior to a standard regulatory review of the whole tomato.