Genetically engineered purple tomatoes have been created by researchers at the Leibniz Institute for Plant Biochemistry (IPB) in Halle. To accomplish this, the researchers introduced the genes necessary for the production of betanin into the plants and turned them on in the ripening fruit. A natural food dye, betanin is not normally produced by tomatoes, but rather by red beets. In the future, genetic engineering methods for generating substances in plants will play an increasingly important role in drug production, especially in pharmaceuticals. Researchers are already working on producing vaccines and antibodies from plants.
The main objective of this study was not to create a new tomato variety for human consumption. By producing an easily observable pigment, the goal was to refine Genetic Engineering methods, which are much easier to analyze. Plants are very effective production systems, but they are also very complex. Many of these mechanisms regulate the biosynthesis of the substance being produced, sometimes inhibiting the entire process.
“These complex feedback mechanisms are still poorly understood”, explains Sylvestre Marillonnet, the study’s lead researcher. “A lot of research work is still needed in this regard”.
The plants had to be planned and adjusted in order to achieve the desired synthesis output, even when it came to betanin. They implanted not only the three genes needed for betanin biosynthesis in tomato plants, but also several genetic switches that enabled the inserted genes to be activated at the same time in the fruit during ripening. Despite this, betanin production was initially low in the fruit.
Adding a fourth gene ensures that an important precursor substance is made available, thus enabling higher pigment biosynthesis levels. Therefore, the tomatoes yielded deep purple colors, which contain additional betanin than red beets.
Read more : www.ipb-halle.de
