The production of genetically modified plants usually requires the use of marker genes, which allow the targeted selection of transformed cells and their regeneration to whole plants. Most of these are antibiotic resistance marker genes (ARMG), which are irrelevant after successful regeneration for the possible practical use of the plants.
As part of a joint project of the German Federal Ministry of Education and Research (BMBF) on "Optimizing the biological safety of transgenic plants" AlPlanta has tested the Cre / loxP recombination system of bacteriophage P1 for the elimination of ARMG in grapevines. For this purpose, a vector system was developed which makes it possible, after transformation and regeneration, to remove the ARMG by means of induced activity of the Cre recombinase. The peculiarity is that the cre gene cassette located on the vector together with the ARMG is also removed from the genome through a sequence-specific recombination event, induced by an external stimulus (autoexcision). For this control, various inducible promoters have been and are being tested.