German team has used only a marker gene in its experiments - to prove the approach works. More useful genes will now be incorporated into the tomatoes. The scientists write: "Given the generally very high foreign protein accumulation rates that can be achieved in transgenic chloroplasts, this system paves the way to efficient production of edible vaccines, pharmaceuticals, and antibodies in tomato."
And in an accompanying article, a US expert agreed that GM tomatoes with transformed plastids could make it easier to develop edible vaccines.
Pal Maliga, from Rutgers University in Piscataway, New Jersey, writes: "The report of plastid transformation in tomato is... a milestone achievement, and the capacity to express foreign proteins at a high level in consumable fruit should open new opportunities for engineering the next generation of medicinal products that are more palatable to the consumer."
A number of research groups are now looking to produce food crops that have enhanced nutritional or medicinal value. These new foods are sometimes referred to as nutraceuticals.
