Notes

Genetically modified crops offer advantages to Weeds

Herbicide resistance could provide advantages to plants in the wild.

Credit: Xiao Yang
A technique of genetic modification widely used to make crops herbicide resistant has been shown to confer advantages on the weedy rice even in the absence of the herbicide. These results suggest that such modifications could have a wide variety of impacts that extend beyond farms, and possibly in the wild.

A variety of varieties of crops are created genetically to be resistant to the glyphosate. The herbicide, originally known as Roundup and then introduced to the market in 1996 under the trade name Roundup. The resistance to glyphosate allows farmers to eliminate herbicides, without causing damage to their crop.

Glyphosate blocks the enzyme EPSP synthase that is responsible for the creation of certain amino acid and various other molecules. https://www.yodobashi.com/product/100000001002109951/ It can also inhibit the growth of plants. Genetic modification -- employed, for example in Roundup Ready crops made by the biotech giant Monsanto located in St Louis, Missouri -usually involves inserting genes into a plant's genome to increase EPSP-synthase's production. Genes typically come from bacteria that infects plants.

The plant can resist the adverse effects of glyphosate because it has an additional EPSP-synthase. Biotechnology labs attempted to utilize plants' genes to increase EPSP synthase production. https://search.yahoo.co.jp/video/search?rkf=2&ei=UTF-8&fr=wsr_gvu&p=%E3%83%A9%E3%82%A6%E3%83%B3%E3%83%89%E3%82%A2%E3%83%83%E3%83%97 This was done in part to make use of a loophole that is in US law that permits the regulatory approval of organisms containing transgenes that are not derived from pests caused by bacteria.

Few studies have explored the possibility that transgenes that confer tolerance could -- after they become weedy , or wild relatives by cross-pollinatingcan boost the plant's survival and reproduce. "The common belief is that any transgene can cause disadvantages in the wild in the absence of any selection pressure because the additional machinery could reduce the fitness," says Norman Ellstrand an expert in plant genetics at the University of California in Riverside.

Lu Baorong (an ecologist at Fudan University, Shanghai) has since challenged this view. It shows that resistance to glyphosate can provide significant benefits to fitness for the weedy rice crop known as Oryza sativa even when it is not in use.

ラウンドアップ 古い https://search.rakuten.co.jp/search/mall/%E3%83%A9%E3%82%A6%E3%83%B3%E3%83%89%E3%82%A2%E3%83%83%E3%83%97+%E3%83%9E%E3%83%83%E3%82%AF%E3%82%B9%E3%83%AD%E3%83%BC%E3%83%89/ Lu and his colleagues modified cultivars of rice to make more EPSP synthase. They also crossed the modified rice with a weedy-related. Their findings were published in NewPhytologist 1..

The team then allowed breeding offspring that were cross-bred together to produce second-generation hybrids. These were genetically identical with the exception of the copy count and number of the EPSP synthase gene. As expected, the ones with more copies of the gene had higher enzyme levels and produced more amino acid tryptophan in comparison to their unmodified counterparts.

Researchers also discovered that transgenic hybrids grew between 48 to 125 percent more seeds per plant, had higher photosynthesis rates and produced more shoots than non-transgenic ones.

ラウンドアップ Lu believes making weedy, aggressive rice more competitive could hinder farmers to recover from the harm caused by this pest.

ラウンドアップ 英語 Brian Ford-Lloyd (a UK plant geneticist) says that if the EPSP-synthase genes are introduced into wild rice species, their genetic diversity which is essential to protect could be threatened. The transgene could surpass the natural species. "This is among the clearest instances of the extremely damaging consequences (of GM crops on the environment."

ラウンドアップ The research also challenges the perception that crops with genetically modified genes containing more copies of their genes are safer than those that contain microorganisms' genes. "Our study proves that this isn't necessarily the case" Lu says. Lu.

The finding calls for a review of future regulation of genetically modified crops, some scientists say. Ellstrand says that some people believe that biosafety regulations could be relaxed because we've had over two decades of genetic engineering. "But the study still indicates that innovative products require careful evaluation."

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