Notes

Genetically modified crops provide greater benefits than weeds

In the wild, resistance to herbicides could confer advantages to plants.

Credit Xiao Yang
It has been demonstrated that a technique for genetic modification is extensively used to make crops resistant to herbicides, can provide advantages to a weedy variety of rice. This indicates that the modifications could affect the natural environment beyond farms.

Several types of crops have been modified genetically to be resistant to glyphosate, a herbicide that was first sold under the trade name Roundup. This glyphosate resistance enables farmers to eliminate the majority of herbicides in their fields without harming their crop.

ラウンドアップ 効果 Glyphosate acts as an inhibitor of plant growth. ラウンドアップ ラウンドアップ 原理 It blocks an enzyme known EPSP synthase. https://www.shopping-charm.jp/product/2c2c2c2c-2c2c-2c2c-2c2c-313038373831 ラウンドアップ This enzyme plays a role in the creation of specific amino acids as well as other molecule. These substances can account for up to 35% of a plant's mass. The genetic-modification technique is used, for example, in Roundup Ready plants made by Monsanto Biotechnology, a biotech company located in St Louis, Missouri. It involves inserting genes into the genome of the crop to boost EPSP synthase synthase synthase production. Genes usually come from bacteria that cause disease to plants.

ラウンドアップ 業務用 The extra EPSP synase allows for plants to resist the effects of glyphosate. Biotechnology labs have also attempted to make EPSP-synthase more plant-based than bacteria, using genes derived from plants. This was used to take advantage of an inconsistency found in US law which allows regulatory approval for organisms that are not derived from bacterial parasites.

There aren't many studies that have examined the possibility that transgenes that confer glyphosate tolerance could -- after they become weedy , or wild relatives through cross-pollinating- increase the plants' survival and reproduction. "The conventional belief is that any transgene will confer disadvantage in the wild, in the absence of pressure to select, because the additional machinery could decrease the fitness of the plant," says Norman Ellstrand who is a plant geneticist at the University of California in Riverside.

Lu Baorong (an ecologist at Fudan University, Shanghai) has now challenged that view. It has proven that resistance to glyphosate provides significant benefits to fitness for the weedy rice crop, called Oryza Sativa even when not used.

Lu and colleagues modified cultivars of rice to increase its EPSP synthase. The modified rice was then crossed with a wild relative.

The researchers then allowed the cross-bred offspring to breed with one another, resulting in second-generation hybrids that were genetically identical to one another with the exception of the number of copies of the gene that encodes EPSP synthase. The ones with more copies expressed higher amounts of the enzyme, and produced more of the amino acid tryptophan than their non-modified counterparts.

Researchers also found that plants with transgenic genes had higher rates for photosynthesis, produced more flowers, and produced 48 to 125 percent fewer seeds per plant than nontransgenic hybrids. This was in spite of the fact that glyphosate wasn't present.

Lu believes that making rice that is weedy less competitive might make it more difficult for farmers whose plots are invaded by pests.

Brian Ford-Lloyd of Brian Ford-Lloyd, a researcher at the University of Birmingham, UK Brian Ford-Lloyd, a researcher at the University of Birmingham in the "If the EPSP synthase gene is introduced to wild rice species, their genetic variety is crucial to conserve, may be at risk because it could outcompete the normal varieties." "This is one example of the most plausible and damaging effects of GM crops on the environment."

This study challenges popular belief that crops modified genetically with additional copies of their own genes are more secure than those containing the genes of microorganisms. "Our study proves that this isn't necessarily the case" says Lu.

Certain researchers believe that this finding needs to be reviewed in light of future regulation of crops that have been genetically modified. Ellstrand believes that biosafety regulations can be relaxed since we enjoy a high level security from two decades of genetic engineering. "But the research shows that the new technologies require an unbiased assessment."


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