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In nature, herbicide resistance might confer an advantage to plants.

Credit goes to Xiao Yang
The most common method for the genetic modification of plants to make them herbicide resistant is found to confer advantages to the weedy varieties of rice even when the herbicide is not present. This indicates that these modifications may affect the environment beyond farm.

Many kinds of crops are genetically modified to be resistive to glyphosate. Roundup was the first herbicide to be marketed. Farmers are able to eliminate the weeds that grow in their fields by using this glyphosate-resistant crop without causing damage to their crops.

Glyphosate inhibits growth of plants by blocking EPSP synthase (an enzyme involved in the production of specific amino acids and various other molecules). This enzyme could make up as much as 35% or more of the plant’s total mass. Genetic modification, which is used by Monsanto’s Roundup Ready crops, which are located in St Louis (Missouri), typically involves inserting genes into the DNA of a plant to boost EPSP synthase’s production. The genes are typically derived from bacteria that are infected with plants.

This extra EPSP synthase enables plants to resist the effects of glyphosate. Biotechnology labs also tried to use plants’ genes to increase the EPSP synthase enzyme, in part to exploit an American loophole that allows for regulatory approval of transgenes that are not derived from bacterial pests.

Few studies have explored the possibility that transgenes that confer glyphosate tolerance can — once they become weedy or wild relatives by cross-pollinatingcan boost the plant’s longevity and reproductive. Norman Ellstrand is a University of California Riverside plant geneticist. “The assumption is that any transgene can cause disadvantage in the wild in the absence of selective pressure since it could reduce the fitness of the plant,” Ellstrand said.

But now a study led by Lu Baorong, an ecologist at Fudan University in Shanghai, is challenging that notion: it shows that the weedy form of the common rice plant, Oryza sativa, gets an important boost in fitness due to glyphosate resistance, even when glyphosate is not used.

In their study, which was published this month in New Phytologist 1, Lu and his colleagues genetically modified the rice cultivar to enhance its own EPSP synthase. They crossed the altered rice with a weedy ancestor.

The team then allowed the offspring of cross-breeding to be bred together to produce second-generation hybrids. These were genetically identical except for the number and count of EPSP synthase gene. ラウンドアップ amazon ラウンドアップ As one would expect, hybrids with more copies were more likely to produce more tryptophan and had more enzyme levels than their unmodified counterparts.

Researchers also discovered that transgenic hybrids were more photogenic, had more seeds per plant, and produced 48 to 125 percent higher yields of seeds than non-transgenic varieties.

Lu believes making weedy, invading rice more competitive might hinder farmers to recover from the harm caused by this insect.

ラウンドアップ 安全性 Brian Ford-Lloyd is a UK plant geneticist. He says, “If the EPSP synthase gene is introduced into wild rice species, their genetic diversity would be at risk, which is significant because the genotype with transgene is superior to the natural species.” “This is one of the most clear examples of extremely plausible damaging impacts of GM crops on the environment.”

The research also challenges the idea that genetically modified plants with more copies of their genes are less risky than crops that have microorganism genes. Lu states that the study “shows that this is not always true”.

The research results call for a rethinking of future regulations for genetically modified crops, some scientists say. Ellstrand claims that some people believe biosafety regulations can be relaxed given the past over two years of genetic engineering. The study does not prove that novel products are safe.

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