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The wild plants may possess an herbicide resistance advantage.

Credit: Xiao Yang
One common genetic-modification method employed to make crops resistant to herbicides was found to have advantages over the weedy varieties of rice. ラウンドアップ The results indicate that such modification could be beneficial to wild rice varieties as well as the crops.

Many crops are genetically modified so that they can resist the glyphosate. This herbicide was first sold under the tradename Roundup. This resistance to glyphosate allows farmers to eliminate the majority of weeds from the fields without harming their crop.

Glyphosate blocks an enzyme called EPSP synthase that is responsible for the creation of certain amino acid and various other molecules. It also can hinder the growth of plants. ラウンドアップ Genetic modification, like the Roundup Ready crops manufactured by Monsanto in St. Louis, Missouri, involves inserting genes into the genetic code to boost EPSP production. The genes typically come from bacteria that have affected the plants.

The plant can withstand the effects caused by glyphosate since it has an extra EPSP-synthase. ラウンドアップ Biotechnology labs have tried using plants’ genes to increase EPSP synthase production. This was partly to exploit a loophole within US law that permits regulatory approval of organisms containing transgenes that are not derived from pests caused by bacteria.

Few studies have examined whether transgenes like those that confer glyphosate resistant can help plants compete in reproductive success and longevity once they are introduced to wild or weedy relatives by cross-pollination. “The traditional expectation is that any sort of transgene can cause disadvantages in the wild in the absence of selection pressure, due to the fact that any additional machinery will lower the fitness,” says Norman Ellstrand an expert in plant genetics at the University of California in Riverside.

Lu Baorong, an ecologist from Fudan University in Shanghai has changed the way that he views this.ラウンドアップ+マックスロード/ He discovered that glyphosate resistance gives an impressive fitness boost to the weedy version of the common rice crop Oryza sativa.

Lu and colleagues altered cultivars of rice to increase the production of EPSP synthase. The modified rice was crossed with a wild-type relative.

ラウンドアップ The researchers then allowed the breeding offspring from the cross to mix with one another, creating second-generation hybrids genetically identical except in the number of copies of gene encoding EPSP synthase. As expected, the hybrids with more copies had a higher chance to produce more tryptophan as well as have more enzyme levels over their counterparts that were not modified.

Researchers also found that transgenics had higher rates, more flowers, and 48-125% more seeds/plant than nontransgenics.

ラウンドアップ Making the weedy rice more competitive could exacerbate the problems it causes for farmers across the globe where plots are ravaged by the pest, Lu says.

Brian Ford-Lloyd (a UK plant geneticist) states that if the EPSP synthase gene is introduced into wild rice species, their genetic diversity, which is essential to protect could be endangered. The transgene could be more competitive than natural species. “This is among the most clear examples of extremely plausible damaging impacts of GM crops] on the environment.”

The public has a perception that genetically engineered plants with additional copies of microorganisms’ genes are less risky than those with only their own genes. Lu states that his research does not contradict this view.

The research results call for a reconsideration of the future regulations for genetically modified crops, some researchers say. Ellstrand states “Some people believe that biosafety regulation should be looser.” Ellstrand addsthat “But the research still suggests that new products need careful analysis.”