Analysis Of Benefits And Unfavourable Impacts Of GM Crops
Genetically modified (GM) crops are a developing and expanding industry and are considered a new alternative to the natural and more conventional method of agriculture. The genome within GM crops is artificially altered and mixed with genes of desired traits, whether this is from plants or even bacteria to produce new crops with characteristics such as drought resistance. A variety of ecological and economic benefits can arise through engineering the genome of crops as well as many concerns and issues regarding its potentially unfavourable impacts on health and non-GM organisms. How GM crops are made There are two methods in producing a genetically modified crop, as illustrated in figure 1. The first method is through using Agrobacterium. The chosen gene that has the desired trait is selected and cut out using a restricting enzyme and is then inserted into the plasmid of the bacterium using DNA ligase to stick them together. Heat and electricity are used for the bacteria to accept the modified plasmid. This bacterium then infects the plant cells and transfers the DNA in its plasmid into the plant cell. The second method uses a Gene gun which takes the isolated gene and coats metal particles with it which are then shot into the plant cells to insert the DNA into the plant’s genome. Screening tests are done to identify the cells with the desired gene and these cells are then grown to produce GM plants. Implications to Health GM crops can potentially have undesirable effects on our health as shown in a study using GM soybeans on mice. When using mice as a model to analyse how GM soybeans would affect their liver, due to its lead function in metabolism, prominent changes in comparison to the control mice were observed. Several proteins involved in a variety of roles such as calcium signalling and hepatocyte metabolism were expressed differently. Nuclear modification also occurred with a sign of reduced metabolic rate. This study demonstrates how GM crops can alter transcriptions and slicing of genetic material. This proposes the issues of uncertainty on the health effects being presented with the introduction of GM crops into our diets, even with multiple testing, one cannot claim with certainty that the effect will be harmless for every individual. Moreover, testing in Quebec, Canada revealed that pesticides associated to genetically modified foods (PAGMF), which are designed to resist insecticides and herbicides were found to be circulating within women and their fetuses. This new toxicity within our cells could lead to unforeseen long-term consequences, as observed with the mice, the uncertainty with the potential harm this could inflict especially on a developing foetus is a large risk and requires more investigation. Hence, there is poor reasoning to support GM crops whilst there is little known on the lifelong impact it could have.
Contradictory to this, GM crops have been known to help alleviate malnutrition through developing crops to contain high levels of vitamins. As done through the production of GM golden rice (rice is the main diet of many Asian countries), which has the potential to combat deficiency in the diet of those in poverty that can not afford normal nutrient-rich diets due to the enhanced quantity of vitamin A that has been genetically added. It was also approved by the Food and Drug Administration (FDA) as being safe to consume. For this reason, GM crops can become a major asset due to the ability to develop nutrient dense products in improving the quality of life and health of people around the world. Religious opposition Many issues arise concerning the production and consumption of GM crops within numerous religions. One example being the unnatural production of GM crops being seen as highly unfavourably by Christians who may view this as altering God’s creations and plan. Another case of opposition would be within the Rastafari religion where it is believed that eating pure, organic food is sacred and a large part of their moral principles. This makes GM crops controversial as it gives rise to ethical issues by conflicting with religious perspectives and lifestyles. Therefore, the conventional production of crops would be more favoured over GM crops. Economic impacts The economy may be negatively impacted by the production of GM crops. Due to the uncommon practice of isolating crops in agriculture, it is highly likely for cross-pollination to transpire between crops that are in geographical proximity. This could lead to the devaluation of traditional crops due to genotypical and/ or phenotypical changes and would have to be re-labelled due to the traces of GM which would require additional costs for regulated testing. This could endanger the producer’s income as well as endanger the organic crop market. The long-term solution would be to put forward preventative actions for segregating crops in addition to new regulatory legislation on testing traces of GM products and insurance schemes. These measures will require extensive funding and so would cause economic loss. Although as a fairly recent innovation, GM crops would require quite the large amount of economic investment before making some revenue. As through all of this investment into legislation and insurance, farmers will greatly benefit from investing in GM crops. As countries that may suffer from unstable weather i.e. monsoons and droughts may have poorer fluctuating yields.
However, GM crops can be designed specifically for a countries climate and soil and therefore flourish in comparison to organic crops. This would result in higher yield and so increase in incomes of farmers which will contribute to the long-term investment in increasing in the economy worldwide. The genetics behind gene transfer through cross-pollination Through sexual reproduction, genes from GM crops can be transferred to non-GM crops. Pollen from a GM crop containing its genetic information is combined with the egg of a non-GM crop, both of which are haploid in that they only carry a single set of chromosomes. This transfer could occur in numerous ways such as through insects, animals, wind etc. The two gametes combine and form a genetically unique zygote which is diploid and will go on to create a new genetically unique organism. During meiosis, events such as recombination can occur during the stage of prophase I, when homologous chromosomes exchange sections of DNA. This can lead to genes from the GM crops chromosomes crossing over on to the non-GM crops chromosomes. This increases the genetic variability of the new organism and also accounts for how non-GM crops are able to acquire the genes from transgenic plants. Environmental Considerations Although GM crops could be environmentally advantageous as the use of pesticides and/ or herbicides could decrease. Insects have been known to affect the yield of crops worldwide by roughly 30-40%, with the growth of weeds also reducing production. Through the creation of GM crops, they can be developed to produce their own herbicide/ pesticide, as demonstrated by the crop known as Bt maize. This genetically engineered crop produces toxic crystal proteins using genes transferred from the bacterium Bacillus thuringiensis (Bt). Through this non-plant organism gene transfer, the maize is able to kill common pests such as corn rootworm larvae, resulting in much higher quality crop yields and a decrease in chemical use. This is advantageous as it solves pest issues without having to introduce toxic chemicals into the environment on a regular basis. On the other hand, the potential gene transfer of PAGMF to weeds could have a devastating impact for both present and future crop production. It has already been noted that weed populations such as horseweed (Conzya canadensis) have hybridized and acquired the herbicide-resistant gene found in GM crops. This could lead to more concentrated use of herbicide and pesticide use and even pose major environmental hazards for non-target organisms. One example of gene transfer is to the plant milkweed, which the monarch butterfly lays its larvae on. The milkweed plant has been able to hybridize and gain the Bt genes from GM crops. This has resulted in a surge of monarch butterfly deaths due to the increase in toxicity, and with the butterfly already endangered, the GM crops carry a large danger to their survival.
Consequently, this raises the issue of having a lack of control over the negative impacts GM crops could have on the environment. Additionally, GM crops will also decrease the biodiversity of crops created through conventional methods. As exhibited in the 19th century during the Irish potato blight, it was due to the lack of variety of potatoes that allowed the disease to spread quickly and cause a famine from food shortage. Even if GM crops were designed to resist certain diseases, if a disease were to simply mutate and infect a crop it would easily cause an event similar to the case of the Irish potato blight. Moreover, studies of more organic farming methods of using different seeds allowing more adaptability, in comparison to GM crop had a higher yield. In a study of 8,200 soybean fields, on average the non-GM fields produced 2 brushes more per acre than its GM counterpart. With the factors of the increased cost of farming GM crops, it is clear that GM crops are a wasteful use of resources and time when traditional methods can bear more fruitful results. However, there are cases where GM crop production is favoured over conventional methods i.e. under abiotic and biotic stress. Within extreme regions such as areas of severe drought, introducing genes such as SNAC1 (used for stress responses) can improve drought resistance and salt tolerance to allow crops to flourish in unfavourable regions. This provides great benefit to countries susceptible to drought-related famines. This can also provide the option to grow crops in areas of land never used and so increasing global crop yield which can help tackle world hunger issues. Preventative measures for GM crop gene transfers to non-GM plants Furthermore, the issues regarding GM crop genes spreading to other plants can be prevented. Whilst still in its early stages of testing, one strategy would be to bind the transgene to the chloroplast genome in order to avoid the transgene from being transported through pollen flow in strict maternal inheriting species as achieved with the tomato (Lycopersicon esculentum). More strategies include strategies such as apomixis (produce asexual seeds), genome incompatibility and cleistogamy (self-fertilizing) and many more. These methods mean it is less likely for cross-pollination to occur and so would solve issues regarding GM genes affecting non-target organisms. Conclusion There are many benefits to using GM crops such as mitigating hunger issue in more extreme environments by providing food security as well as decreasing the use of chemical pesticides and herbicides in comparison to conventional agriculture. Although there are currently issues regarding health impacts and the environmental impact of gene transfer to non-GM crops, with extensive research and the implementation of the preventative measures mentioned, these can be greatly mitigated. Therefore, even with some religious opposition, overall GM crops are a great investment into the future of agriculture and food consumption.
