The wild plants may possess the advantage of resistance to herbicides.
Credit Xiao Yang
A method of genetic modification used extensively to create crops that are resistant to herbicides has been found to give advantages to the weedy rice, even in absence of the herbicide. The results suggest that this modification could be beneficial to wild rice varieties as well as the crops.
ラウンドアップ 価格 A range of crops has been modified genetically to make them immune to Roundup herbicide glyphosate. This resistance allows farmers to eradicate the weeds that grow in their fields without harming their crops.
Glyphosate inhibits growth of plants by stopping EPSP synthase (an enzyme that is involved in the creation of certain amino acids, and various other molecules). This enzyme could make up as much as 35 percent or more of a plant’s total mass. The technique of genetic modification utilized, for instance, in the Roundup Ready crops made by the biotechnology giant Monsanto which is headquartered in St Louis, Missouri -usually includes inserting genes into a crop’s genome to increase the production of EPSP synthase. Genes are typically obtained from bacteria that infects the crops.
The extra EPSP synthase helps the plant be resistant to the effects of glyphosate. Biotechnology labs also have tried to create EPSP-synthase that is more plant-based than bacteria, using genes derived taken from plants. This was made to make use of an inconsistency found in US law which allows regulatory approval for species that aren’t derived from bacteria or parasites.
Few studies have explored the possibility that transgenes that confer glyphosate tolerance can — once they become weedy , or wild relatives via cross-pollinating -can boost the plant’s survival and reproduce. Norman Ellstrand, a University of California plant geneticist says that without selection pressure, any type of transgene is likely to create disadvantages in wild plants. The added machinery will decrease fitness.
Lu Baorong, an ecologist from Fudan University in Shanghai has rewritten that view. He found that resistance to glyphosate provides a significant fitness lift to the weedy version of the popular rice plant Oryza Sativa.
Lu and his colleagues modified cultivars of rice to increase the production of EPSP synthase. They also crossed the modified rice with a weedy related. Their research was published in NewPhytologist 1..
The researchers then allowed the hybrid offspring of crossbreds to reproduce with one another, resulting in second-generation hybrids genetically identical to one another except in the number of copies of the gene that encodes EPSP synthase. Likely, the ones who had more copies expressed higher amounts of the enzyme and also produced more amino acid tryptophan than their unmodified counterparts.
ラウンドアップ Researchers also discovered that transgenic hybrids are more photogenic, they produced more plants per plant and had 48-125 percent higher yields of seeds than varieties that were not transgenic.
Lu believes that making weedy, invading rice more competitive might make it harder for farmers to recover from the harm caused by this insect.
Brian Ford-Lloyd (a UK plant geneticist) states that if the EPSP synthase genes gets into wild rice, then their genetic diversity that is so important to conserve could be endangered. The transgene could be more competitive than natural species. This is among the most clear examples of plausible negative effects [of GM crop] on the environment.”
The public belief that genetically-modified crops that contain additional copies of their genes are safe is disproved by this research. Lu declares that “our study does not prove that this is the case.”
A few researchers believe this discovery needs to be reviewed in light of future regulation of genetically modified crops. Ellstrand believes that some think that biosafety rules can be relaxed since we have more than two years of genetic engineering. ラウンドアップ “But the research still shows that novel products require careful analysis.”