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In nature, resistance to herbicides might confer an advantage to plants.

ラウンドアップ Credit Xiao Yang
Genetic modification to make crops resistant to herbicides has been extensively used to produce advantages for the varieties of rice that are weedy. These findings suggest that such modifications could have a wide range of effects beyond the farms, and even out into the wild.

A variety of crops have been genetically modified so that they can resist the effects of glyphosate. ラウンドアップ 安全性 This herbicide was first sold under the tradename Roundup. Farmers can get rid of the weeds that grow in their fields with glyphosate and not harm their crops by having this resistance.

Glyphosate inhibits growth of plants by stopping EPSP synthase (an enzyme that is involved in the creation of certain amino acids as well as other molecules). The enzyme can make up as much as 35% or more of a plant’s total mass. The technique of genetic modification is employed for instance, in Roundup Ready plants made by Monsanto, a biotechnology company that is headquartered in St Louis, Missouri. It involves inserting genes into the genome of the crop to boost EPSP synthase-synthase production. The genes typically come from bacteria that cause disease in the plants.

This additional EPSP synthase allows the plant to withstand the effects of glyphosate. Biotechnology labs have tried using genes from plants to boost EPSP synthase activity. This was partially to take advantage of a loophole in US law that permits the regulatory approval for transgenes in organisms which have not come from bacteria pests.

There aren’t many studies that have examined whether transgenes that confer glyphosate tolerance could — after they are weedy or become wild relatives through cross-pollinatingcan boost the plant’s longevity and reproductive. “The conventional belief is that any sort of transgene will confer disadvantage in the wild in the absence of pressure to select, because the additional machinery could decrease the fitness of the plant,” says Norman Ellstrand, a plant geneticist at the University of California in Riverside.

ラウンドアップ Lu Baorong from Fudan University in Shanghai is in the process of challenging this notion. The study shows that glyphosate resistance even when not applied to the weedy varieties of the rice crop can give a significant health boost.

ラウンドアップ Lu and his coworkers have genetically altered the cultivated rice species to express its EPSP synthase. They then crossed it with an marijuana-producing parent.

The researchers then allowed the cross-bred offspring to breed with one another, resulting in second-generation hybrids genetically identical apart from the number of copies of gene encoding EPSP synthase. Like one might expect, the more copies produced higher levels of enzyme and more tryptophan than their counterparts that were not modified.

ラウンドアップ Researchers also discovered that transgenics had higher rates, more flowers, and 48-125percent more seeds/plant than nontransgenics.

Lu states that making the weedy grain more competitive may increase the difficulties it causes for farmers across the world who have crops affected by the pest.

“If the EPSP-synthase genes are introduced in the wild rice species their genetic diversity, which is vital to preserve may be at risk as the transgene’s genetic make-up would outcompete the natural species” says Brian Ford-Lloyd an expert in plant genetics at the University of Birmingham, UK. “This is one clear example of the extremely plausible detrimental impacts of GM plants] on our surroundings.”

The general public believes that genetically engineered crops that have more copies or microorganisms’ genes are more secure than those that only contain their own genes. “Our study shows that this is not always the case,” says Lu.

According to some scientists this finding suggests that the future regulation of genetically engineered plants should be rethought. Ellstrand states that “some people now believe that biosafety regulations can be relaxed since we have a a high degree of comfort with genetic engineering for the past two decades.” The study showed that new products should be carefully evaluated.