תאריך: יוני 27, 2022 | קטגוריות: קידום אתרים
Wild plants might be able to resist herbicides.
Credit Xiao Yang
One common genetic-modification method employed to make crops resistant to herbicides was shown to offer advantages over rice varieties that are weedy. ラウンドアップ These findings suggest that such modifications may have a wide spectrum of effects that extend beyond farms and in the wild.
Many crops are genetically modified in order to ward off the effects of glyphosate. This herbicide was first offered under the trade name Roundup. This allows farmers to eliminate most weeds from their fields without causing harm to their crops.
Glyphosate slows the growth of plants by blocking EPSP synthase (an enzyme that is involved in the production of specific amino acids as well as other molecules). The enzyme can make up as much as 35% or more of the plant's total mass. Genetic modification — utilized, for instance, in Roundup Ready crops made by the biotechnology giant Monsanto, based in St Louis, Missouri -generally involves inserting genes into a plant's genome to increase the production of EPSP synthase. The genes are typically derived from bacteria that have been infected by plants.
The extra EPSP synthase helps the plant resist the effects of glyphosate. https://shop.takii.co.jp/products/detail/MSH997 https://search.yahoo.co.jp/image/search?rkf=2&ei=UTF-8&gdr=1&fr=wsr_gs&p=%E3%83%A9%E3%82%A6%E3%83%B3%E3%83%89%E3%82%A2%E3%83%83%E3%83%97 Biotechnology labs also tried to use plants' genes to boost EPSP-synthase levels, in part to exploit an American loophole which permits the approval of regulatory authorities of transgenes that are not derived from bacterial pests.
A few studies have looked into the possibility that transgenes like glyphosate-resistant genes could — after introduction to wild or weedy plants via cross-pollination enhance the competition of plants in survival, reproduction and growth. Norman Ellstrand of the University of California, Riverside, said that the traditional expectation was that any transgene would confer disadvantage in nature if there is no selection pressure. ラウンドアップ This is because any extra machines would reduce the effectiveness of.
Lu Baorong (an ecologist at Fudan University, Shanghai) has now challenged that view. ラウンドアップ 時間 It has shown that resistance to glyphosate can provide significant benefits to fitness for a weedy rice crop known as Oryza sativa even when not in use.
Lu and his coworkers modified cultivars of rice to produce 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 group then allowed breeding offspring from the cross to mix with one another, creating second-generation hybrids genetically identical to one another except in the amount of copies of the gene encoding EPSP synthase. The team found that those who had greater copies of the gene that encodes EPSP synthase had more enzyme expression and produced more tryptophan, which is what we expected.
The researchers also found that the hybrids with transgenic genes had greater rates of photosynthesis, produced more flowers and shoots and produced 48-125% more seeds than the non-transgenic hybridswithout the use of glyphosate.
Lu believes that making weedy Rice more competitive may increase the risk for the farmers around the globe whose fields are infested with the pest.
Brian Ford-Lloyd is an UK plant geneticist who says, "If the EPSP synthase gene becomes present in wild rice species their genetic diversity will be threatened which is really important because the genotype with transgene is superior to the natural species." "This is a prime illustration of the most likely and harmful negative effects of GM crops on the environment."
The public belief that genetically-modified crops with additional copies their genes are safe is disproved by this research. Lu says that Lu's study does not support this notion.
According to some scientists this finding suggests that the future regulation of genetically engineered plants should be reviewed. Ellstrand states "Some people believe that regulation of biosafety should be looser." Ellstrand addsthat "But the study proved that new products require careful analysis."