The world’s population is expected to rise to 9.8 billion by the end of 2050 (United Nations , 2013). Due to the amount of high developing population rise, there will need to be affordable, sustainable safe food due to this will require a lot of food whilst, the resource limits and environmental degradation is becoming further evident as the days continue. Due to this, the difficulty of feeding the population is becoming much more of a significant issue, especially trying to feed a population as large as nine million (Peters, 2010). It is estimated that food production will need to be increased by 70% in order to feed everyone in 2050 (Hofstrand, 2012). There is a significantly increased demand for meat, eggs and dairy as which it emits the pressure of growing more produce like corn and soybeans, so animals like cows and pigs can be kept healthy (Foley, 2014). Some alternative solutions that can help to grow food are, the use of aquaponics, veganism, urban farming, city farming, indoor vertical farms, insect and organic food but, the most successful to use in the agricultural business is the use genetic engineering. This is a process where a unique set of genes gets insert new genetic information into existing cells in order to modify a specific organism for the purpose of changing its characteristics. This technique works on animals, plants and microorganisms. For example, some genetic modification crops are resistant to certain herbicides (BBC, 2014). So, despite all the different types of solutions, genetic modification of animals and plants is the best way to go into feeding a population.
What is Genetic Modification?
Genetic modification, also known as genetic engineering, refers to the direct manipulation of DNA to adjust an organism’s phenotypes in any particular way. This may mean that one of the base pairs (such as A-T or C-G) is altered, deleting or inserting a whole region of previously known DNA. It could also be interpreted as an introduction of an additional copy of genes. One way or another, the DNA is modified from one set of characteristics to another set. However, one thing for certain, it can be used to genetically modify plants to create a higher nutritional level. They can also be made to tolerate exposure to herbicides.
Genetic modification in agriculture
Genetic modification is a process that involves inserting DNA into the genome of an organism. To produce a genetic modification plant, new DNA is transferred into plant cells. Normally, the cells are then grown in tissue culture where they develop into plants. (The Royal Society, 2016) The seeds produced by these plants will inherit the new DNA.
The features of all living organisms are then determined by their genetic makeup and their interaction with the environment. This genetic makeup of an organism is called a genome which is in all plants and animals, the genome is made up of DNA. This genome contains genes, regions of DNA that usually carry the instructions for making proteins. It is these proteins that give the plant its characteristics. For example, the colour of flowers is determined by genes that carry the instructions for making proteins involved in producing the pigments that colour petals. (The Royal Society, 2016)
Genetic modification of plants involves adding a specific stretch of DNA into the plant’s genome, giving it new or different characteristics. This could include changing the way the plant grows or making it resistant to a particular disease. The new DNA becomes part of the genetic modification plant’s genome which the seeds produced by these plants will contain.
The first stage in making a genetic modification plant requires the transfer of DNA into a plant cell. One of the methods that are used to transfer DNA is to coat the surface of small metal particles with the relevant DNA fragment and bombard the particles into the plant cells. Another method includes using a bacterium or virus. There are many viruses and bacteria that transfer their DNA into a host cell as a normal part of their life cycle.
For genetic modification plants, the bacterium most frequently that is used is called Agrobacterium tumefaciens. The gene of interest is transferred into the bacterium and the bacterial cells then transfer the new DNA to the genome of the plant cells. The plant cells that have successfully taken up the DNA are then grown to create a new plant. This is possible because individual plant cells have a remarkable capacity to generate entire plants. On rare occasions, this process of DNA transfer can happen without deliberate human intervention. For example, sweet potato contains DNA sequences that were transferred thousands of years ago from an Agrobacterium bacterium into the sweet potato genome. (The Royal Society, 2016)
Four primary methods of genetically modifying crops
- Selective breeding: Two strains of plants are introduced and bred to produce offspring with specific features. Between 10,000 and 300,000 genes can be affected. (Oldest method of genetic modification and is typically not included in the GMO food category.
- Mutagenesis: Plant seeds are purposely exposed to chemicals or radiation in order to mutate the organisms. The offspring with the desired traits are kept and further bred. Mutagenesis is also no typically included in the GMO food category.
- RNA interference: Individual undesirable genes in plants are inactivated in order to remove any undesired traits.
- Transgenics: A gene is taken from one species and implanted in another in order to introduce a desirable trait.
Genetic Modifications in Crops
Scientists have already worked on a variety of plants to help benefit the population in terms of feeding.
Ingo Potrykus, a biotechnologist at the Swiss Federal Institute of Technology in Zurich, saw the possibility of using a complementary approach through the genetic modification of rice, the staple crop for many subsistence farmers. Rice grain does contain vitamin A but only in the husk. The husk is discarded for the reason that, it rapidly goes rancid during storage, especially in tropical countries. Potrykus aimed to produce a rice variety that would make provitamin A (beta-carotene, a precursor that humans can process into vitamin A) in its seed endosperm, the largest part of the seed that is eaten. A conventional breeding approach would not work because no conventional rice variety makes any pro-vitamin A at all in its endosperm. Rice endosperm synthesises a compound called geranylgeranyl diphosphate, which is an early intermediate in the pathway for beta-carotene production. Potrykus’ team successfully engineered the rest of the pathway (Figure 1) into rice, using phytoene synthase (psy) and lycopene β-cyclase genes from daffodil (Narcissus pseudonarcissus), and a phytoene desaturase (crtI) gene from the bacterium Erwinia uredovora.
The genetic modification of rice producing pro-vitamin A was crossed with another line containing high levels of available iron. Rice normally contains a molecule called phytate that ties up 95% of the iron, preventing its absorption in the gut. The genetic modification rice contains a gene encoding an enzyme called phytase that breaks phytate down. The high pro vitamin A/high available iron hybrid was called Golden Rice. Rice is not the only crop in which this technology for genetic modification to be potentially applicable as a programme to engineer pro-vitamin A synthesis into cassava, for example, is reported to be well advanced.
Golden rice can help combat extreme suffrage of vitamin A, which is edible all around the world. Vitamin A deficiency can ground for blindness to about half a million people each year, mostly in countries like Africa and Asia (Willis, 2017). The immune system can be destabilised by this deficiency and an estimate of two million people are deceased each year. Due to diseases from the weaken state of the immune system. It is estimated that because of the lack of vitamin A, 670 000 children die under the age of 5 (Willis, 2017).
The most controversial genetically modified plant in the world is that of golden rice as “this rice has become the tool to improve the lives of the poor” (Charles, 2013). This rice has been modified by inserting a gene from maize and a gene from bacteria found in soil a plant phytoene synthase (psy) and a bacterial phytoene desaturase (crt I) (Golden Rice Project, 2005-2018). By doing this, the plant is allowed to biosynthesise beta-carotene in the edible parts of rice. Beta-carotene is found in a variety of fruit and vegetables like squash and carrot. This gene gives the golden rice and the other vegetables it’s colour (Willis, 2017). Beta-carotene can be synthesised by the human body to make vitamin A which is essential in helping the immune system to function. Golden rice is harmless to consume due to the difference between GMO and standard rice by the beta-carotene which cannot cause allergies (Dubock, 2005-2018).
The beetle resistance on a tomato plant relies on a gene from a Gram-positive soil bacterium (Bacillus thuringiensis), which scientists inserted into a tomato plant’s genome. This gene is called cry1Ac and is encoded with a protein that is poisonous to certain types of insects (see figure 2 for the process). This poison kills insects from the inside to the outside. (Genetic Science Learning Center, 2018).
Pros and Cons of Genetic Modification
Some advantages that genetic modification has over other techniques are as it follows is that one: It allows genes to be introduced into a crop plant from any source. Biotechnologists can select a gene from anywhere in nature and with the modifications, it can make a version of it that will be active in a crop plant. Two: It is relatively precise in that single genes can be transferred. In contrast, conventional plant breeding involves the mixing of tens of thousands of genes, many of unknown function, from different parent lines, while radiation and chemical mutagenesis introduce random genetic changes with unpredictable consequences. Three: Genes can be designed to be active at different stages of a plant’s development or in specific organs, tissues or cell types. After this process, specific changes can be made to a gene to change the properties of the protein that it encodes. Lastly, the nature and safety of the protein produced by a gene can be studied before the gene is used in a genetic modification programme.
Researches have created a variety of modified plants that have been successful. Genetic engineering has allowed for plants to be resistant to insects, tolerated to herbicides, heat, cold or drought and crop yield (BBC, 2014). Seeds have also been modified to make stronger colours, increase shelf life or eliminate seeds hence why there are seedless melons and grapes. Some foods have also been modified to have higher levels of protein, calcium or folate. Genetic modification allows for sustainable ways to feed people especially in countries that lack access to foods that are nutrient-rich. So, by modifying plants, they are able to last in environments that are normally unachievable and be shipped to further distances (Colbert & Sullivan, 2016).
However, despite all these positives, there are many cons to genetic engineering. As this is a relatively new development, many question the safety and healthiness of these modified crops. Researchers and health staff believe that these developed foods are linked with allergies, antibiotic resistance or cancer (Colbert & Sullivan, 2016).
Soybeans were engineered with the protein from a brazil nut. This means that those who were suffering from an allergy to brazil nuts ended up being triggered by the soybean. However, those soybeans were quick to be removed from the shelves (Colbert & Sullivan, 2016) (BioeExplorer, 2018). Antibiotic-resistant bacteria can resist antibiotics, making it much more difficult to kill. These germs infect about two million people every year which results in about 23 000 deaths per year. As scientist often modify seeds using antibiotic resistant genes, scientists, food critics and health staff wonder if there is a link between genetically modified foods and the rising rates of antibiotic-resistant bacteria (Colbert & Sullivan, 2016).
Another potential issue of these genetically modified foods is the increase in cancer. Herbicide Roundup and Roundup-tolerant genetic modification corn has been linked to cancer and premature death in rats. However, it was late confirmed that there weren’t enough rats and the specific strain of rats were prone to cancer. Scientists aren’t entirely too sure about these potential cons are they need to conduct more tests to fully determine whether genetic modification foods would show up with these negatives (Colbert & Sullivan, 2016).
The most major issue with these genetically modified crops is that of cross contamination. This is where the species of genetic modification crops mingled with the original crop. By having this problem happen, the original produce would be lost amongst the genetically modified product which would result in difficulty with trying to remodify the genetic modification plants (Wooldridge, 2014).
Advances in Knowledge and Technology That is Needed for GMOs
There are seven important molecular tools that are used for genetic engineering. These are; Polymerase Chain Reaction, Restriction Enzymes (Molecular Scissor), Electrophoresis, DNA Ligase, Selection of Small Self-Replicating DNA, Method to Move a Vector into a Host Cell, Methods to Select Transgenic Organisms. Polymerase Chain Reactions made it possible to manipulate the replication of DNA. This is when primers that are specific to a region of DNA, are used and replication is stopped and started repeatedly. Restriction Enzymes (Molecular Scissor) are used to cut DNA at a specific spot depending on the nucleotide sequence. Gel electrophoresis is used to view cut DNA to detecting DNA inserts and knockouts. DNA Ligase can create covalent bonds between nucleotide chains. Small Self-Replicating DNA is plasmids that are used as vectors to transport genes between microorganisms. The method of moving a Vector into a Host Cell requires host cells being exposed to an environmental change which makes them “competent” or temporarily permeable to the vector. Finally, to select Transgenic Organisms, plasmids carry genes for antibiotic resistance and transgenic cells can be selected based on the expression of those genes and their ability to grow on media containing that antibiotic (Bidita, 2016).
Another way is Terminator technology. ‘Terminator’ technology is a term that has come to be used to describe the production of crop varieties that produce infertile seeds, or ‘suicide seeds’ as they are sometimes referred to. Pressure groups that oppose the use of genetic modification in plant breeding have long sought to associate genetic modification crops with ‘terminator’ technology, indeed the term ‘terminator’ and the prospect of biotechnology companies using such a technology to force farmers, particularly those in developing countries, to buy seed from them every year has been one of the most effective weapons in the anti-genetic modification campaign. This is astounding given that none of the genetic modification varieties in commercial use for food production produce infertile seed. It is certainly possible to render the seeds of plants infertile using genetic modification; it can and has been done using non-genetic modification methods as well. Similarly, both genetic modification and non- genetic modification methods can be used to render pollen infertile; indeed, it is an established technique in plant breeding for the production of hybrid seed (see next section), although the hybrid seed that is produced from such plants to be sold to farmers has its fertility fully restored. There may well be applications for the commercial use of sterile plants in specialist, small-scale applications such as the production of vaccines or other pharmaceuticals where it is important to prevent crossing and mixing with crops being grown for food. I am not aware of any breeder developing a variety genetic modification or otherwise, with sterile seeds for everyday use, and it is difficult to envisage why farmers would buy such a variety if it were launched.
To conclude, the above paragraphs show how the research question is explored in depth in terms of how genetically modified foods help to feed a growing population. By having these engineered crops, it is allowed for there to be an abundance more of food that is protected and healthy despite having its genes modified to create them. Therefore, GMOs are a successful way of helping to feed the population as the years go by.