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Wild plants could be capable of resisting herbicides.

Credit Xiao Yang
A genetic-modification technique used widely to make crops herbicide resistant has been shown to provide advantages to the weedy rice even in absence of herbicide. The results suggest that the benefits of such modification have the potential to extend beyond the confines of farms into the wild.

Many varieties of crops are genetically modified to resist the glyphosate. Roundup was the first herbicide to be sold. This resistance to glyphosate enables farmers to eradicate most herbicides, without causing damage to their crops.

Glyphosate acts as an inhibitor of the growth of plants. It blocks an enzyme known as EPSP synthase. This enzyme plays a role in the production certain amino acids and other molecules. These compounds can be responsible for as much as 35% of the plant’s mass. Genetic modification, like the Roundup Ready crops manufactured by Monsanto in St. ラウンドアップ Louis, Missouri, involves inserting genes into a plant’s genetic code to increase EPSP production.ラウンドアップ/?dispNo=&codeSearch=0&searchFirst=1 These genes usually come from bacteria that have affected the plants.

The additional EPSP synase makes it possible for the plant to resist the effects of glyphosate. Biotechnology labs have tried using plant genes to boost EPSP synthase activity. This was partially to make use of a loophole that is in US law that permits the regulatory approval of organisms containing transgenes that are not derived from pests of bacteria.

A few studies have explored the possibility that transgenes similar to those that confer resistance to glyphosate help plants compete in reproduction and survival once they are introduced to wild or weedy cousins by cross-pollination. ラウンドアップ Norman Ellstrand of University of California Riverside declares, “The conventional expectation is that any transgene that is found in nature will cause disadvantages if there is no selection pressure , because the additional machinery may decrease the health.”

However, a new study conducted by Lu Baorong, an ecologist from Fudan University in Shanghai, is challenging that notion: it shows that a weedy version of the popular rice crop, Oryza sativa is given an important boost in fitness due to glyphosate resistance, even when glyphosate isn’t used.

The study was published in 1. Lu and his coworkers altered the genetics of cultivated rice to enhance its EPSP synthase expression , and then crossed it with a weedy relative.

The group then permitted the offspring from cross-breeding to cross-breed with one other to create second-generation hybrids. They were identical genetically apart from the number of EPSP synthase genes they carried. As expected, those with more copies expressed higher levels of the enzyme, and produced more of the amino acid tryptophan than their non-modified counterparts.

ラウンドアップ Researchers also discovered that transgenic hybrids were photogenic, they produced more plants per plant and had 48-125% higher yields of seeds than the non-transgenic varieties.

ラウンドアップ Lu believes that making rice that is weedy less competitive can make it harder for farmers who have their land infested by the pest.

Brian Ford-Lloyd (a UK plant geneticist) states that if the EPSP synthase gene is introduced into wild rice species, then their genetic diversity which is essential to protect could be threatened. ラウンドアップ The transgene could surpass the normal species. “This is one clear example of the very real negative consequences [of GM plantson the environment.”

The public has a perception that genetically engineered plants with extra copies or microorganisms genes are safer than ones that only contain their own genes. Lu states that his study doesn’t support this belief. Researchers have concluded that the findings call for a reconsideration of how genetically modified crops will be regulated in the near future. Ellstrand states “Some people believe that biosafety regulation should be looser.” Ellstrand says: This study isn’t proof that the new products are secure.