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Herbicide resistance might give plants an advantage in the wild.

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

Several types of crops are genetically modified to be intolerant to the herbicide glyphosate. It was initially marketed under the trade name Roundup. This resistance to glyphosate permits farmers to eradicate most plants without doing any harm to their crop.

Glyphosate is a deterrent to the growth of plants. ラウンドアップ al It blocks an enzyme known as EPSP synthase. This enzyme plays a role for the production of certain amino acids as well as other molecule. These compounds can make up as much as 35% of a plant’s mass. The genetic modification technique, which is used by Monsanto’s Roundup Ready crops, which are located in St Louis (Missouri), typically involves inserting genes in the DNA of a plant to boost EPSP synthase production. ラウンドアップ Genes are usually derived from bacteria that have been infected by plants.

The plant can withstand the effects glyphosate thanks to the addition of EPSP synthase. Biotechnology labs also tried to utilize the genes of plants to boost EPSP-synthase levels, in part to exploit an American loophole which permits the approval of regulatory authorities of transgenes which are not derived from bacterial pests.

There aren’t many studies that have examined whether transgenes such as ones that confer resistance to glyphosate are able to — once they become wild or weedy relatives by cross-pollination, make plants more competitive in terms of survival and reproduction. Norman Ellstrand is a University of California Riverside plant geneticist. “The hypothesis is that any kind of transgene will cause disadvantage in the wild, in absence of selective pressure since it could reduce fitness,” Ellstrand said. 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 gives an impressive fitness boost to a weedy version of the common rice plant Oryza sativa.

Lu and his colleagues genetically modified the cultivated Rice species to express its EPSP synthase. Then, they crossed-bred it to an weedy parent.

The team then let the offspring of crossbreeding to cross-breed with each other to create second-generation hybrids. They were identical genetically apart from the number of EPSP synthase genes they had. The team found that those with greater than one copy of the gene that encodes EPSP synthase expressed more enzyme and also produced more tryptophan, as expected.

Researchers also discovered that transgenic hybrids produced 48-125% 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 that making weedy, aggressive rice more competitive could make it harder for farmers to repair the damage caused by this bug.

“If the EPSP-synthase gene is introduced in the wild rice plant, their genetic diversity, which is really important to conserve, could be threatened because the transgene’s genetic make-up could outcompete normal species,” Brian Ford-Lloyd who is a plant geneticist at the University of Birmingham, UK. “This is among the clearest examples of extremely plausible damaging effects (of GM crops] on the environment.”

The study also challenges the belief that crops modified genetically with additional copies of their genes are safer than those that contain genes from microorganisms. Lu states, “Our study shows this is not necessarily true.”

According to some researchers, the finding suggests that the future regulation of genetically engineered plants should be reviewed.ラウンドアップ+マックスロード/ Ellstrand thinks that biosafety laws may be relaxed because we are able to have a great level of satisfaction from the two decades of genetic engineering. “But the study shows that novel products still need an unbiased evaluation.”