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The wild plants may possess the advantage of resistance to herbicides.

ラウンドアップ Credit Xiao Yang
It has been established that a genetic modification technique is extensively used to make crops herbicide-resistant, confers advantages on a weedy variety of rice. This suggests that the effects of such modification could extend beyond farms and out into the wild.

A variety of crop varieties have been genetically modified to make them resistant to Roundup herbicide glyphosate. This allows farmers to remove the majority of the weeds that grow in their fields without harming their crops.

Glyphosate slows the growth of plants by blocking an enzyme referred to as EPSP synthase, which is responsible for the production of certain amino acids and other molecules that account for as much as 35% of a plant’s mass. Genetic modification, such as the Roundup Ready crops manufactured by Monsanto in St. Louis, Missouri, involves inserting genes to a crop’s genetic code to boost EPSP production. The genes are often derived from bacteria that has infected the plant.

This additional EPSP synthase enables the plant to withstand the effects from glyphosate. Biotechnology labs have also tried to utilize plants’ genes instead of bacteria to boost the production of EPSP synthase partly to make use of the loophole in US law that permits regulatory approval of organisms carrying transgenes that are not that are derived from bacteria.

Few studies have explored the possibility that transgenes that confer glyphosate tolerance may — once they become weedy or wild relatives via cross-pollinating — increase the plants’ survival and reproduction. Norman Ellstrand of the University of California, Riverside, explained that the standard assumption was that any transgene could confer disadvantage in nature if there was no selection pressure. This is because any extra machines would reduce the effectiveness of.

Lu Baorong, an ecologist from Fudan University in Shanghai has rewritten that view. He has discovered that glyphosate resistance gives an impressive fitness boost to the weedy version of the popular rice crop Oryza sativa.

Lu and his associates modified the cultivars of rice to make more EPSP synthase. They also crossed the modified rice with a weedy related. ラウンドアップ ハイロード Their work was published in NewPhytologist 1.

The researchers allowed offspring of cross-breeding to mix with one another, resulting in second-generation hybrids that are genetically identical to one another, except for the number of copies of the gene encodes EPSP synase. As expected, those with more copies expressed greater amounts of the enzyme and also produced more amino acids tryptophan than their unmodified counterparts.

ラウンドアップ The researchers also found that the hybrids with transgenic genes had greater rates of photosynthesis, produced more flowers and shoots and produced 48-125% more seeds per plant than non-transgenic hybrids -with or without glyphosate.

Making the weedy rice more competitive may exacerbate the problems it causes for farmers around the world who’s plots are infested by pests, Lu says.,2084008038,2084034075&rewrite_ok_wand_re_search=1 Brian Ford-Lloyd (a UK plant geneticist) says that if the EPSP-synthase genes gets into wild rice species, then their genetic diversity that is so important to conserve could be at risk. ラウンドアップ The transgene would be more competitive than natural species. “This is a prime instance of the most plausible and damaging impacts of GM crops on the environment.”

This study also challenges the idea that genetically modified crops containing extra copies of their genes are safer than those containing microorganism genes. Lu says that Lu’s study does not support this view.

Researchers believe that these findings should prompt an overhaul of how genetically modified plants will be controlled in the near future. Ellstrand says that “some people are now of the opinion that biosafety regulations could be relaxed since we have a the most comfort with genetic engineering for the past two decades.” “But this study has shown that novel products still need to be evaluated with care.”