Last week, I wrote about a pathogenic nematode that infects the roots of soybean plants and the identification of a mutation responsible for nematode resistance in the Forrest soybean cultivar. In the post I mused,
what if an already existing gene variant with a desired trait from one organism is genetically engineered into another organism of the same species? Would this make GMOs a little bit more palatable to their detractors?
While intended to be more of a thought experiment, a commenter alerted me to a very similar scenario playing out in Ireland, where potato crops are still affected by blight–yes, as in the blight responsible for the Great Famine of the mid-1840s. Blight, which makes potatoes rot, is caused by infestation of a fungus-like organism (oomycetes) called Phytophthora infestans.
In recent years, scientists have developed blight-resistant GMO strains of potato plants by introducing into the potato’s genome a blight-resistance gene called RB. This gene was identified in Solanum bulbocastanum, a wild potato plant native to Mexico that is closely-related to potatoes. Resistance to blight most likely developed as a result of coevolving with P. infestans, which is considered to be native to Mexico as well.
The scenario facing GMO potatoes, however, is a little bit different from the question I posed earlier since the RB gene isn’t found in cultivated potato plants. Furthermore, traditional breeding methods have been unsuccessful in making hybrids between cultivated potatoes and S. bulbocastanum, therefore necessitating genetic engineering. There are, however, other blight-resistant wild Solanum plants, such as Solanum venturii, that can be hybridized with cultivated potatoes. But using the RB gene from S. bulbocastanum remains the most attractive option since S. bulbocastanum displays resistance to the most number of blight-causing P. infestans strains.
The response from one anti-GM campaigner to using genetic engineering in this case?
It is just there to make GM more palatable to the general public. The fact that it comes from a related plant doesn’t make it any different. The real danger is the process.
I guess that sort of answers my question.