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In nature, resistance to herbicides could confer advantages to plants.

Credit Xiao Yang
One common genetic-modification method employed to make crops resistant to herbicides has been shown to have advantages over weedy forms of rice. The finding suggests that the benefits of such modification could extend beyond farms and out into the wild.

A range of crop varieties have been genetically modified so that they become resistant to Roundup herbicide glyphosate. Farmers can get rid of weeds in their fields using glyphosate and not harm their crops because of this resistance.

ラウンドアップ Glyphosate may hinder the growth of plants by blocking EPSP synase which is an enzyme involved in the creation of amino acids as well as other chemicals that comprise about 35% of plant mass. The genetic modification technique that is employed by Monsanto’s Roundup Ready crops, which are based in St Louis (Missouri), typically involves inserting genes in a crop’s DNA to increase EPSP synthase’s production. Genes usually come from bacteria that infects plants.

The extra EPSP synase makes it possible for the plant to resist the effects of glyphosate. Biotechnology labs also tried to make use of the genes of plants to increase the EPSP synthase enzyme, in part to take advantage of a loophole in the American system which permits the approval of regulatory authorities of transgenes not derived by bacterial pests.

Few studies have tested whether transgenes , such as those that confer glyphosate resistance are able to — once they get into wild or weedy relatives via cross-pollination -make plants more competitive in terms of survival and reproduction. Norman Ellstrand, a University of California plant geneticist, states that in the absence of competition, any kind of transgene could be expected to create disadvantages in wild plants. The additional machinery could reduce fitness.

A new study, led by Lu Baorong, an ecologist from Fudan University in Shanghai, disproves that belief: it shows that the weedy variant of the standard rice crop, Oryza sativa is given a significant fitness boost from glyphosate resistance, even when glyphosate isn’t applied.

Their study was published in 1. ラウンドアップ Lu and his collaborators altered the genetics of cultivated rice to increase its EPSP synthase expression , and then crossed it with a weedy counterpart.

The researchers then allowed the hybrid offspring of crossbreds to reproduce with each other, resulting in second-generation hybrids that were genetically identical to one another apart from the amount of copies of the gene encoding EPSP synthase. As expected, those who had more copies expressed higher amounts of the enzyme and produced more amino acid tryptophan than their non-modified counterparts.

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

Making the weedy rice more competitive could exacerbate the problems it causes for farmers around the world whose plots are invaded by pests, Lu says.

Brian Ford-Lloyd is an UK plant geneticist. He says, “If the EPSP synthase gene is introduced into wild rice species their genetic diversity could be threatened which is really crucial because the genotype that has transgene outcompetes the normal species.” This is among the clearest examples of extremely likely negative effects of GM crop] on the environment.”

The general public believes that genetically modified plants containing more than one copy of their genes than those from microorganisms are safe. This is also challenged by the study. Lu states that his study doesn’t support this notion.

A few researchers believe this discovery requires a review of the future regulation of crops that have been genetically modified. ラウンドアップ ラウンドアップ al3 “Some individuals are claiming that biosafety regulations are eased because we’ve reached an incredibly high level of confidence with two decades of genetic engineering,” Ellstrand says. The study found that any new products need to be carefully evaluated.