Wednesday, January 08, 2003
It's a bit of accepted knowledge that bacteria can transfer genes to plants (the mechanism for introducing GE DNA into plants), but DNA cannot go from plants to bacteria. Some research indicates that such a view is wrong. The experiment was done on potatoes and bacteria, and it was found that less than 20 nanograms of GE potato DNA was necessary to produce a bacterium with the engineered gene. Doing the rough math, assuming 1 billion base pairs per genome (1 genome per cell), it would take 10,000 to 100,000 cells to make one transformed bacterium. Going further, one potato plant could make a lot of transformed bacteria. A whole field of plants could make a lot more.
So what does this have to do with anything? Well, that's a demonstration that it's possible for bacteria (soil and otherwise) to pick up transgenes from plants. I had mentioned earlier about the lack of wisdom in planting normal soybeans for the growing season after the field had been used for cultivation of transgenic corn. If I may quote myself...
During the season, the GE material in the corn would have gotten into the soil, and therefore soil bacteria like Agrobacterium. The bacteria could then pass that material to the bean crop. Voila - contaminated beans.It may have appeared that I pulled that one out from thin air. However, it is significant that such activity can occur even in a controlled lab environment. Transgenes were made to jump from bacteria to plants, and the elements that makes the transgene jump could possibly make a gene jump from plants to bacteria that might not have the transgene. Such a transfer is eminently possible in a less controlled environment, like a farmer's field. If that were found, it would have serious implications about the possible risk transgenic plants would pose to the food supply.
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