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

Credit to Xiao Yang
One of the most common methods that makes crops resistant to herbicides was found to offer advantages over the weedy varieties of rice. These findings suggest that these modifications can have a broad spectrum of effects that extend beyond farms and into the wild.

ラウンドアップ Many varieties of crops are modified genetically to be resistant to glyphosate, an herbicide first marketed under the trade name Roundup. This allows farmers to eradicate the weeds that grow in their fields without harming their crops.

Glyphosate inhibits an enzyme known as EPSP synthase that is responsible for the creation of specific amino acids and various other molecules. It can also hinder plant growth. The genetic modification technique, which is used by Monsanto’s Roundup Ready crops, which are based in St Louis (Missouri), typically involves inserting genes in the DNA of a plant to boost EPSP synthase production. Genes are typically derived from bacteria that infects crops.

ラウンドアップ The addition of EPSP synase makes it possible for the plant to resist the effects of glyphosate. Biotechnology labs have also attempted to utilize the genes of plants to boost EPSP-synthase levels, in part to take advantage of a loophole in the American system which permits the approval of regulatory authorities of transgenes that are not derived from bacterial pests.

ラウンドアップ Few studies have tested whether transgenes , such as those that confer glyphosate resistance are able to — once they become weedy or wild relatives through cross-pollination -make plants more competitive in survival and reproduction. Norman Ellstrand of the University of California, Riverside, said that the traditional expectation was that any transgene would confer disadvantage in nature if there was no selection pressure. This is because any extra machines would reduce the fitness.

Lu Baorong, an ecologist from Fudan University in Shanghai has changed the way that he views this. He discovered that glyphosate resistance provides a significant fitness lift to the weedy variant of the standard rice plant Oryza Sativa. Their study was published in 1. Lu and his collaborators have genetically modified rice to increase its EPSP synthase expression , and then crossed it with a weedy relative.

The team permitted the offspring from cross-breeding to cross-breed to create second generation hybrids. They were identical genetically apart from the number of EPSP synthase genes they had. The team discovered that the ones that had more than one copy of the gene that encodes EPSP synthase expressed more enzyme and produced more tryptophan, which is what we expected.

The researchers also found that the transgenic hybrids had higher rates of photosynthesis. They also they grew larger flowers and shoots and produced 48 to 125 percent more seeds per plant than non-transgenic hybrids -with or without glyphosate.

Lu believes making weedy, invasive rice more competitive may make it more difficult for farmers to recoup the damage caused by this bug.

Brian Ford-Lloyd (a UK plant geneticist) says that if the EPSP-synthase gene is introduced into wild rice species, their genetic diversity that is vital to preserve could be at risk. The transgene will surpass the normal species. “This is one instance of the most plausible and damaging effects of GM crops on the environment.”

The general public believes that genetically modified plants that have more copies of their own genes than microorganisms are safer. This notion is not supported by the study. Lu says that Lu’s research does not contradict this view.

The finding calls for a review of future regulations for genetically modified crops, some scientists suggest. “Some individuals are claiming that biosafety regulation can be eased because we’ve reached a high level of comfort with the two decades of genetic engineering,” says Ellstrand. ラウンドアップ “But the research shows that the new technologies require careful examination.”