In nature, resistance to herbicides could confer advantages to plants.
Credit: Xiao Yang
Genetic modification of crops to make them resistant to herbicides is widely employed to create advantages for weedy rice varieties. This suggests that the benefits of such modification could extend beyond farms and out into the wild.
There are many varieties of crops have been genetically altered to resist glyphosate. Roundup was the first herbicide that was marketed. The resistance to glyphosate enables farmers to get rid of plants without doing any harm to their crop.
Glyphosate slows the growth of plants by stopping EPSP synthase (an enzyme that is involved in the creation of certain amino acids, and various other molecules). The enzyme can be as large as 35% or more of the plant’s total mass. The method of genetic modification, which is used for Roundup Ready crops by Monsanto (based in St Louis in Missouri) involves inserting genetic material into the crop to increase EPSP-synthase output. Genes are usually derived from bacteria that infect crops.
The added EPSP synthase lets the plant resist the effects of glyphosate. Biotechnology labs are also attempting to utilize genes from plants rather than bacteria to increase EPSP synthase. This is partly because the US law permits regulatory approval that allows organisms with transgenes to be accepted.
A few studies have explored whether transgenes, such as ones that confer resistance to the chemical glyphosate can make plants more resilient in survival and reproduction once they cross-pollinate with wild or weedy 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 selection pressure because the additional machinery may reduce the health.”
Lu Baorong, an ecologist from Fudan University in Shanghai has changed the way that he views this. He discovered that glyphosate resistance provides a significant fitness lift to the weedy version of the common rice plant Oryza Sativa.
Their study was published in 1. Lu and his colleagues genetically modified cultivated rice to increase its EPSP synthase expression , and then crossed it with a weedy relative.
The group then allowed hybrid offspring of crossbreds to reproduce with one another, resulting in second-generation hybrids genetically identical to one another apart from the number of copies of gene that encodes EPSP synthase. As was expected, those who had more copies had higher enzyme levels and produced more amino acid tryptophan compared to their unmodified counterparts.
ラウンドアップ ラウンドアップ Researchers also discovered that transgenic plants 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.
ラウンドアップ ラウンドアップ Lu believes that making weedy invading rice more competitive might hinder farmers to recover from the harm caused by this bug.
Brian Ford-Lloyd is a UK plant geneticist and states, “If the EPSP synthase gene becomes present in wild rice varieties their genetic diversity will be threatened which is really crucial because the genotype that has transgene is superior to the natural species.” “This is one of the most clear examples of highly plausible negative consequences [of GM crops on the environment.”
The public has a perception that genetically engineered plants with more copies or microorganisms’ genes are more secure than those containing only their own genes. ラウンドアップ Lu states that “our study is not proving that this is true.”
Researchers say this discovery calls for a reconsideration of the regulation for the use of genetically modified plants. Ellstrand thinks that biosafety laws may be relaxed because we are able to have a great level of comfort from two decades worth of genetic engineering. This study isn’t proof that the new products are secure.