Low risk of pollen-mediated gene flow in transgenic plants under greenhouse conditions

Abstract

There is concern about the potential for transgene contamination in wild type (WT) plants via pollen-mediated gene flow from transgenic plants. In this study, we investigate pollen-mediated gene flow using tobacco transgenic lines carrying recombinant protein GA733-FcK, which is a putative candidate for producing colorectal cancer vaccine. Transgenic and WT plants were grown in greenhouse, with WT plants placed 0.3, 1, 5, 10, and 20m away from transgenic plants. Seeds were harvested from randomly selected WT plants and sown on germination media supplemented with or without kanamycin. At 30days after sowing, none of the WT seedlings produced true leaves and roots when grown on selective media. Polymerase chain reaction analysis revealed that GA733-FcK and nptII genes were expressed in shoots of transgenic plants but not of WT plants. Expression of GA733-FcK and nptII proteins was also abolished in WT leaves when compared to that of transgenic plants. Our findings suggested that there is low risk of pollen-mediated gene flow from transgenic plants expressing GA733-FcK when grown in greenhouse conditions.