Notes

Genetically modified crops pass advantages to weeds

Wild plants may be resistant to herbicides.

Weedy rice can absorb transgenes derived from genetically modified rice by cross-pollinating. Credit: Xiao Yang
Genetic modification of crops to make them resistant to herbicides has been extensively used to produce advantages for weedy rice varieties. The results suggest that the benefits of such modification could extend beyond farms and out into the wild.

Many varieties of crops are genetically modified to resist glyphosate. Roundup was the first herbicide that was marketed. This glyphosate-resistant crop allows farmers to eradicate the majority of weeds from the fields without causing damage to their crop.

Glyphosate inhibits an enzyme known as EPSP synthase that is responsible for the production of specific amino acids as well as other molecules. It can also hinder plant growth. The genetic-modification technique is used, for example, in Roundup Ready plants made by Monsanto, a biotechnology company based out of St Louis, Missouri. It involves inserting genes into the genome of the crop to boost EPSP synthase synthase synthase production. Genes are usually derived from bacteria that infect the crops.

The extra EPSP synthase allows the plant to be resistant to the effects of glyphosate. ラウンドアップ tried to use plants' genes to boost EPSP-synthase levels, in part to exploit an American loophole that permits regulatory approval of transgenes not derived bacterial pests.

There aren't many studies that have examined the possibility that transgenes, like those that confer resistance to glyphosate, can help plants to be more resilient in their survival and reproduction after they cross-pollinate with wild or weedy species. ラウンドアップ , a University of California plant geneticist, claims that, without selection pressure, any kind of transgene is likely to create disadvantages in wild plants. https://www.amazon.co.jp/%E6%97%A5%E7%94%A3%E5%8C%96%E5%AD%A6-%E9%99%A4%E8%8D%89%E5%89%A4-%E5%8E%9F%E6%B6%B2%E3%82%BF%E3%82%A4%E3%83%97-%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%89-500%EF%BD%8D%EF%BD%8C/dp/B001GH6XVQ would decrease fitness.

Lu Baorong, an ecologist from Fudan University in Shanghai has rewritten that view. He found that glyphosate resistance provides an impressive fitness boost to a weedy version of the popular rice crop Oryza sativa.

Lu and colleagues modified cultivars of rice to increase its EPSP synthase. The modified rice was then crossed with a wild-type relative.

The group then permitted breeding offspring that were cross-bred with each other to produce second-generation hybrids. They were genetically identical except for the number and copy count of EPSP synthase gene. Like one might expect, the higher number of copies resulted in higher levels of enzyme and more tryptophan than the unmodified counterparts.

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

Lu believes that making weedy rice less competitive could make it harder for farmers who have their land infested by pests.

ラウンドアップ -Lloyd (a UK plant geneticist) states that if the EPSP synthase genes are introduced into wild rice species, then their genetic diversity that is so important to conserve could be endangered. The transgene will surpass the normal species. "This is among the most clear examples of highly plausible harmful impacts (of GM crops] on the natural environment."

The study also challenges the popular perception that genetically modified crops with additional copies of their genes are safer than the ones that have the genes of microorganisms. "Our study shows that this is not necessarily the case," Lu says. Lu.

ラウンドアップ say the findings call for a reconsideration of how genetically modified crops will be regulated in the future. Ellstrand says "Some people believe that regulation of biosafety should be eased." Ellstrand adds: "But the study demonstrates that the new technologies require an unbiased evaluation."


Read More: https://www.amazon.co.jp/%E6%97%A5%E7%94%A3%E5%8C%96%E5%AD%A6-%E9%99%A4%E8%8D%89%E5%89%A4-%E5%8E%9F%E6%B6%B2%E3%82%BF%E3%82%A4%E3%83%97-%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%89-500%EF%BD%8D%EF%BD%8C/dp/B001GH6XVQ