The wild plants could have an herbicide resistance advantage.
ラウンドアップ Credit: Xiao Yang
Genetic modification of crops to make them resistant to herbicides is widely used to produce advantages for weedy rice varieties. This suggests that the benefits of such modifications could extend beyond farms and out into the wild.
A range of crops have been genetically modified so that they become immune to Roundup herbicide glyphosate. ラウンドアップ Farmers can get rid of the weeds that grow in their fields with glyphosate, without harming their crops by having this resistance.
ラウンドアップ Glyphosate may hinder the growth of plants by blocking EPSP synase, an enzyme involved in the production of amino acids, as well as other chemical compounds which comprise around 35% of plant mass. The genetic modification method used in Roundup Ready crops by Monsanto (based in St Louis in Missouri), involves inserting genes into the crop to increase EPSP-synthase output. Genes usually come from bacteria that infects plants.
The plant can endure the negative effects of glyphosate because it has an additional EPSP-synthase. Biotechnology labs also tried to make use of the genes of plants to increase the EPSP synthase enzyme, in part to make use of an American loophole that allows for regulatory approval of transgenes that are not derived from bacterial pests.
There aren’t many studies that have examined the possibility that transgenes, such as glyphosate-resistant ones are able to — when introduced to wild or weedy plants by cross-pollination — enhance the competition of plants in survival, reproduction and growth. Norman Ellstrand of the University of California, Riverside, explained that the standard assumption was that any transgene could cause disadvantage in nature when there is no selection pressure. This is because extra machinery could reduce the effectiveness of.
A new study, led by Lu Baorong, an ecologist at Fudan University in Shanghai, is challenging that notion It reveals that a weedy variant of the standard rice crop, Oryza sativa, gets a significant fitness boost from glyphosate resistance, even when glyphosate has not been used.
ラウンドアップ 価格 Lu and his colleagues modified cultivars of rice to make more EPSP synthase. They also crossed the modified rice with a weedy related. Their work was published in NewPhytologist 1..
The group then permitted the offspring from cross-breeding to cross-breed with one other to create second generation hybrids. http://www.greenjapan.co.jp/roundup_max.htm They were identical genetically with the exception of the amount of EPSP synthase genes they had. The team found that those who had more copies of the gene encoding EPSP synthase expressed more enzymes and also produced more tryptophan, as expected.
Researchers also found that transgenics have higher rates of flowering, more flowers and 48 to 125 percent more seeds per plant than nontransgenics.
Lu states that making weedy crops more competitive may cause more problems for farmers across the world whose crops are affected by the insect.
Brian Ford-Lloyd is an UK plant geneticist. He states, “If the EPSP synthase gene is introduced into wild rice varieties their genetic diversity will be at risk, which is important because the genotype with transgene outcompetes the normal species.” “This is an instance of the most probable and damaging negative effects of GM crops on the environment.”
The belief of the public that genetically modified crops with additional copies their genes are safer is challenged by this study. Lu states, “Our study shows this is not the case.”
Researchers say this discovery requires rethinking the future regulation on genetically modified crops. Ellstrand says “Some people think that the biosafety regulations should be looser.” Ellstrand says: “But the study still suggests that new products need careful evaluation.”