In nature, resistance to herbicides might confer an advantage to plants.
Weedy rice is able to pick up transgenes from genetically modified crops through cross-pollination. Credit: Xiao Yang
A method of genetic modification used extensively to make crops herbicide resistant has been shown to provide advantages to the weedy rice even in the absence of herbicide. This suggests that the genetic modifications could also have the potential to affect wild animals.
A variety of crop varieties are genetically altered in order to resist glyphosate. This herbicide was first sold under the tradename Roundup. Farmers can get rid of the weeds that grow in their fields with glyphosate without harming their crops because of this resistance.
ラウンドアップ Glyphosate blocks the enzyme EPSP synthase which is responsible for the production of certain amino acid and various other molecules. It can also hinder plant growth. ラウンドアップ 持続期間 Genetic modification, for instance, the Roundup Ready crops manufactured by Monsanto in St. Louis, Missouri, involves inserting genes into the genetic code to increase EPSP production. The genes are usually derived from bacteria that infect the plants.
The plant is able to withstand the effects glyphosate thanks to the addition of EPSP synthase. Biotechnology labs have tried using plants’ genes to increase EPSP synthase production. This was partially to make use of a loophole that is in US law that permits regulatory approval of organisms containing transgenes which have not come from bacteria pests.
Few studies have looked into whether transgenes, such as those that confer resistance to the chemical glyphosate can help plants to be more resilient in their survival and reproduction after they cross-pollinate with weedy or wild species. Norman Ellstrand of University of California Riverside declares, “The conventional expectation is that any transgene found in the wild could cause disadvantages if there is no pressure to select because the additional machinery may decrease the fitness.”
A new study, led by Lu Baorong, an ecologist from Fudan University in Shanghai, is challenging that notion It reveals that the weedy form of the common rice plant, Oryza sativa, gets an important boost in fitness due to resistance to glyphosate, even when glyphosate is not applied.
Lu and his colleagues modified the cultivars of rice to produce more EPSP synthase. They also crossed the modified rice with a weedy-related. Their research was published in NewPhytologist 1..
The team allowed the offspring of cross-breeding to cross-breed to produce second-generation hybrids. They were genetically identical with the exception of the amount of EPSP synthase genes they carried. As one would expect, more copies produced higher levels of enzyme and more tryptophan than their unmodified counterparts.
Researchers also found that plants with transgenic genes were more photosynthesis-intensive as well as produced more flowers and produced 48-125percent less seeds per plant than nontransgenic hybrids. This was despite the fact that glyphosate was never present.
Lu believes that making rice that is weedy less competitive might make it more difficult for farmers whose plots are invaded by pests.
ラウンドアップ Brian Ford-Lloyd (a UK plant geneticist) claims that if the EPSP-synthase gene is introduced into wild rice species, their genetic diversity which is so important to conserve could be at risk. The transgene could outcompete natural species. ラウンドアップ “This is among the most clear instances of extremely plausible negative effects [of GM crops] upon the environment.”
This research also challenges the idea that crops with genetically modified genes containing extra copies of their genes are more safe than those containing microorganism genes. Lu declares, “Our study shows this is not necessarily true.”
ラウンドアップ Researchers say this discovery calls for a rethinking the future regulation on genetically modified crops. Ellstrand states “Some people believe that the biosafety regulations should be looser.” Ellstrand addsthat The study does not prove that new products are safe.