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Wild plants could be resistant to herbicides. Credit goes to Xiao Yang
A technique of genetic modification widely used to make crops herbicide resistant has been shown to provide advantages to a weedy form of rice, even in absence of the herbicide. This suggests that such genetic modifications could also have the potential to affect wild animals.

A wide range of crops have been modified genetically so that they become immune to Roundup herbicide glyphosate. Farmers can eliminate most the weeds that grow in their fields with glyphosate, without harming their crops because of this resistance.

Glyphosate blocks an enzyme called EPSP synthase, which is responsible for the creation of specific amino acids as well as other molecules. It can also hinder plant growth. The technique of genetic modification used, for instance, in Roundup Ready crops made by the biotechnology giant Monsanto which is headquartered in St Louis, Missouri — typically includes inserting genes into a plant’s genome to increase EPSP-synthase’s production. The genes are often derived from bacteria that has affected the plants.

The extra EPSP synthase lets the plant resist the effects of glyphosate. Biotechnology laboratories are looking to utilize genes that come from plants instead of bacteria to boost EPSP synthase. This is mainly due to the US law allows for regulatory approval to allow organisms that carry transgenes to get accepted.

A few studies have explored whether transgenes, such as those that confer resistance glyphosate, could increase the resilience of plants in survival and reproduction once they cross-pollinate with wild or weedy species. “The traditional expectation is that any sort of transgene can cause disadvantages in the wild in absence of selection pressure, because the additional machinery could lower the fitness,” says Norman Ellstrand an expert in plant genetics at the University of California in Riverside.

ラウンドアップ Lu Baorong of Fudan University in Shanghai is now challenging that view. The study demonstrates that resistance to glyphosate even when applied to an weedy varieties of the rice crop can give a significant health boost.

In the study which was published this month in New Phytologist 1, Lu and his coworkers genetically altered the rice cultivar to increase the expression of the species’ own EPSP synthase.ラウンドアップ 除草剤 They also crossed-bred the altered rice with a weedy ancestor.

The group then let offspring cross-bred to breed with one-another, creating second generation hybrids that were genetically identical to their parents with the exception the number of duplicates of the gene that codes for EPSP synthase. The hybrids that had more copies of the gene had a higher chance to make more tryptophan and had higher enzyme levels than the unmodified hybrids.

Researchers also discovered that transgenic hybrids are more photogenic, they produced more plants per plant and yielded 48-125 percent more seeds than the non-transgenic varieties.

Lu believes that making rice that is weedy more competitive may increase the risk for farmers across the world who’s fields are being infested by the pest.

Brian Ford Lloyd, a UK plant scientist, said that the EPSP Synthase gene may be introduced into wild rice species. This could threaten the genetic diversity of their species, which is very important. “This is a prime example of the most likely and harmful negative effects of GM crops on the environment.”

This research also challenges the idea that crops with genetically modified genes containing additional copies of their genes are less risky than crops that have microorganism genes. Lu claims that the research “shows that this isn’t always the case”.

ラウンドアップ Some researchers believe this finding needs to be reviewed in light of future regulation of genetically modified crops. Ellstrand claims that “some people believe that biosafety regulations could be relaxed because we have a high degree of comfort with genetic engineering over the last two decades.” “But this study has shown that novel products still need to be evaluated with care.”