Flavr Savr, also known as CGN-89564, a genetically modified tomato, was the first commercially grown genetically engineered food to be granted a license for human consumption. It was produced by the Californian company Calgene, and submitted to the U.S. Food and Drug Administration in 1992. On May 18, 1994, the FDA completed its evaluation of the Flavr Savr tomato and the usage of APH(3’)II, concluding that the tomato “is as safe as tomatoes bred by conventional means” and “that the use of amino glycoside 3’-phophotransferase II is safe for the usage as a processing aid in the development of new varieties of tomato, rapeseed oil, and cotton that is intended for food use.” It was initially sold in 1994, and was only available for a few years before production ceased in 1997. Calgene made history, but mounting costs prevented the company from becoming profitable, and eventually it was acquired by Monsanto Company.
Through genetic engineering, Calgene hoped to slow the ripening process of the tomato, thus preventing it from softening, while still enabling the tomato to retain its natural color and flavor. The tomato was made more resistant to rotting by adding an antisense gene which obstructs the production of the enzyme polygalacturonase. The enzyme usually degrades pectin in the cell walls and results in the softening of fruit which makes them more susceptible to being damaged by fungal infections. Unmodified tomatoes are picked before they are fully ripened and are then artificially ripened utilizing ethylene gas which acts as a plant hormone. Picking the fruit while unripe enables easier handling and extended shelf-life. Flavr Savr tomatoes, on the other hand, could be allowed to ripen on the vine, without compromising their shelf-life. The intended effect of slowing down the softening of Flavr Savr tomatoes would enable the vine-ripe fruits to be harvested like green tomatoes without greater damage to the tomato itself. The Flavr Savr tomato turned out to disappoint researchers in that respect, as the antisensed PG gene had a positive effect on the shelf life, but not on the fruits firmness, so the tomatoes still had to be harvested like any other unmodified vine-ripe tomatoes. An improved flavor, later achieved through traditional breeding of Flavr Savr and better tasting varieties, would also contribute to selling Flavr Savr at a premium price within the supermarket.
The FDA stated that special labeling for these modified tomatoes was not necessary due to having the key characteristics of non-modified tomatoes. Specifically, there was no evidence of health risks, and the nutritional content was not changed.
Image Caption: Plant physiologist Athanasios Theologis compares Florida-grown Endless Summer tomatoes to his greenhouse-grown fru. Credit: Wikipedia