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Wild plants might be resistant to herbicides.

Credit Xiao Yang
The most common method for genetic modification of crops to make them herbicide resistant is found to confer advantages to weedy varieties rice even when herbicide is not present. This finding suggests that these changes could have an impact on the natural environment beyond farms.

ラウンドアップ A variety of crops have been genetically modified to make them immune to Roundup herbicide glyphosate. This resistance to glyphosate allows farmers to eradicate the majority of herbicides in their fields without damaging their crop.

Glyphosate prevents plant growth by stopping EPSP synthase (an enzyme that plays a role in the production of specific amino acids as well as various other molecules). This enzyme can be as large as 35 percent or more of the plant’s total mass. The method of genetic modification, which is used in Roundup Ready crops by Monsanto (based in St Louis in Missouri), involves inserting genes in a plant to boost EPSP-synthase output. The genes are usually derived from bacteria that infect the plants.

The plant is able to endure the negative effects of glyphosate due to its additional EPSP-synthase. Biotechnology labs have also attempted to create EPSP-synthase that is more plant-based than bacteria using genes that come from plants. This was partly made to make use of a loophole found in US law that allows regulatory approval for species which aren’t the result of bacteria or parasites.

There aren’t many studies that have looked into the possibility that transgenes similar to those which confer glyphosate resistance can increase the competitiveness of plants in reproduction and survival once they are introduced to wild or weedy cousins by cross-pollination. Norman Ellstrand of University of California Riverside says, “The conventional expectation is that any type of transgene in the wild will cause disadvantages if there is no selection pressure because the extra machinery could decrease the health.”

Lu Baorong, an ecologist from Fudan University in Shanghai has rewritten that view. ラウンドアップ He has discovered that glyphosate resistance provides significant fitness benefits to the weedy version of the popular rice plant Oryza sativa.

Lu and his associates modified cultivated rice varieties to make more EPSP synthase. They also crossed the modified rice with a weedy-related. Their work was published in NewPhytologist 1.

ラウンドアップ The researchers then allowed offspring that were cross-bred to breed with one-another, creating second-generation hybrids that are genetically similar to their parents, except for the number of copies of the gene that encodes EPSP synthase. As one would expect, the more copies produced higher levels of enzyme, and also more tryptophan, than their unmodified counterparts.

ラウンドアップ Researchers also discovered that plants with transgenic genes had higher rates for photosynthesis and produced more flowers and produced 48-125percent less seeds per plant than nontransgenic hybrids. ラウンドアップラウンドアップマックスロード/ ラウンドアップ This was in spite of the fact that glyphosate wasn’t present.

ラウンドアップ Making the weedy rice more competitive can cause more problems for farmers across the globe where plots are ravaged by the pest, Lu says. Brian Ford Lloyd, a UK plant scientist, said that the EPSP Synthase gene could get in wild rice varieties. This would threaten the genetic diversity of their species, which is extremely vital. “This is a clear illustration of the extremely plausible detrimental impacts of GM plantson the surroundings.”

The public has a perception that genetically engineered crops with additional copies of microorganisms’ genes are less risky than those containing only the genes of their owners. Lu says, “Our study shows this is not necessarily true.”

Researchers believe this discovery requires reconsideration of the regulation for genetically modified crops. Ellstrand claims that some people think that biosafety rules can be relaxed since we have two years of genetic engineering. “But the research shows that the new technologies require careful assessment.”