The scene – It’s sunny and warm, a light breeze is blowing, and I’ve just been fertilized and watered, looking down at my long slender body, I’m sure I’ve had a growth spurt, I’ve definitely got bigger than those weeds over there, but what’s this……an angry mob……great, chopped down before even reaching my prime. This kind of thing can occur for open-field trials of genetically modified (GM) plants, but it needn’t be like this, the fear surrounding the technology may be unwarranted and allayed through an increased knowledge of the subject.
The beginnings, DNA – Deoxyribonucleic acid, is a long sequence of nucleotide bases that the cell uses as a sort of ‘’instruction manual’’ to make products, such as proteins, that help the cell to function. Generally, a single gene gives rise to a single product; typical DNA can contain thousands of genes (Hartl & Jones 11).
DNA in Genetic Engineering – The good thing about DNA is that it doesn’t matter where the genes come from, meaning that they can be transferred between organisms (Morin 334) and even species, this is quite handy and allows an organism to be provided with desirable, or removed of, unwanted traits that may then allow its useful application, which can be anything from herbicide resistance to chemical production for industry (Morin 336-337).
Natural Genetic Engineering – You may say that genetic engineering is wrong, and that scientists are just tampering with nature, but no, this process occurs quite frequently in nature, such as gene swapping during the formation of reproductive cells (meiosis) (Hartl & Jones 139-148), now admittedly this doesn’t introduce any new genetic material into the cell but it is an example of everyday gene rearrangement that causes no harm, and is even required to ensure variability of individuals within the species. There are, however, many instances where ‘’extra genes’’ are delivered into a cell, and viruses provide a good example, these bodies require a viable cell for replication – with the genome of retroviruses integrating into the host cell DNA without causing harm (Hartl & Jones 566-567). Other forms of ‘’foreign’’ genetic material exist, such as transposable elements, these short sequences of DNA can move freely around the host genome and integrate into any site (Hartl & Jones 274-275), ok, so sometimes these can cause problems, but only through their indiscriminate insertion into other genes, or by affecting the functioning of those nearby.
In some situations, natural genetic engineering involves removing or duplicating, sometimes large sections, of the genome, an essential action that ensures correct development, or viability of the organism (Latchman 14-17 & 22-24). Sometimes, it is genomic rearrangements that are essential; the immune system, for example, would be ineffective without the re-assortment that gives rise to many different antibody structures that can recognise a multitude of foreign invaders that get into our bodies (Latchman 28-32). Red blood cells, once matured, lose their entire load of DNA (Latchman 14-16) but remain functional, transporting gasses around the body. Also, many microbial species actively take up DNA from their surroundings and then incorporate it into their genome (Hartl & Jones 403). All these examples demonstrate that genetic engineering is nothing new, and is, in some cases, essential to life.
Safety of Genetic Engineering – This is an important aspect and many safeguards exist to ensure that genes have inserted into the correct position (Hartl & Jones 58), and not interrupted others, they are functioning as expected, not producing products that are toxic to humans or animals that may later consume them, and no other unexpected side effect has occurred. Other concerns must also be addressed, for example, if a gene produces a toxin designed to kill insect pests, then this may affect wildlife that rely on these insects for food, leading to the collapse of bird and animal populations. Another big worry is that the engineered genes may ‘’escape’’ the plant and be transferred to other organisms, but studies have also shown that the transfer of genes from genetically modified organisms is quite rare in the natural environment. There has also has been legitimate concern about antibiotic-resistance genes being taken up by microorganisms living in the mammalian gut, and so, conferring this trait to them which could then become a serious problem if these microbes later initiated an infection, but scientists have been working hard to overcome this by finding alternative methods that have enabled the reduction of the use of antibiotic-resistance genes in biotechnology (Hartl & Jones 552-553). Admittedly, as the technology has only been around for a relatively short time, worries over the long term effects on the biosphere and human health have not been fully alleviated, but the initial results provide hope, serving to dispel the early fears arising over ‘’mutant’’ and ‘’glow-in-the-dark’’ vegetables.
Applications – The progression of this technology has enabled scientists to identify, and then work towards providing real solutions to serious problems. Currently, many GM plants are already in use with others being developed, but forget about onions being engineered as the new ‘’fashion accessory pet’’, these are worthwhile projects that either improve the plants fitness and productivity, provide it with the ability to produce important molecules, or enable an environmental use (Morin 336-337).
Plants can be attacked by viruses and fungi, it’s not a great look, and losses can be large, leading to an increased market price and financial difficulty for the farmer, or in extreme cases, famine. Also, there are many insects that can ‘’get at’’ crops and reduce the yield, so being able to protect the plants against these is of considerable benefit, as is the ability to prolong the shelf life after harvesting by delaying the ripening process, this allows distribution and delivery to customers of the produce in the best possible condition and nutritional content which ensures acceptance and minimal wastage. Some gene additions can also help the plant manufacture products of nutritional value, many people worldwide suffer a deficiency of vitamin A, which causes night blindness and skin problems, but this can be overcome by the production of rice plants that produce pro-vitamin A that accumulates in thegrains (Hartl & Jones 565). In the field, crop yields can be reduced by competition from weeds, and so, the introduction of genes that confer herbicide resistance on crops allows the weeds to be selectively targeted by herbicides to keep them under control.
Genes can be also be inserted that result in plants that can have a significant benefit to the environment, for instance, some allow the plant to grow using less fertiliser (Morin 337), this is good news as nitrogen fertilizers can be washed from the land and accumulate within watercourses, which then encourages the rapid growth of phytoplankton, soon large blooms appear, and when these algae die they accumulate at the bottom of the lake for decomposers, whose actions lower the oxygen content of the water, anaerobic bacteria then produce all kinds of noxious gasses such as ammonia and hydrogen sulphide which can fill the whole water column making it impossible for most aquatic life to survive. Small lakes can be dredged in order to fix the problem, with aeration for larger ones, however, this is very expensive, and not effective for the very largest lakes, which therefore remain unfit for most life to exist in, not good, so anything that can help prevent this would be beneficial. Additionally, crops that require less fertilisers and pesticides would also have a role in reducing carbon emissions (Morin 333), for instance, less ‘’tractor miles’’ are needed to look after the crop.
Other gene additions prepare the plant for growth in dryer conditions, handy, as in some countries rainfall is meagre or unpredictable, and irrigation essential in order to support crops, also, with climate change threatening to alter rainfall patterns and produce warmer conditions at the higher latitudes, crop varieties that can better withstand these altered conditions would be required. Some plants can be ‘’fitted’’ with genes that allow them to remove pollutants from the soil (Morin 337), this is great, especially since many of these chemicals are toxic, for instance, mercury and lead, whilst others or an environmental nuisance such as PCBs. This application is particularly useful especially where there is a requirement for the construction industry to provide new houses whilst having a concurrent requirement to preserve suburban green spaces and countryside, therefore, the reclamation of so-called ‘’brown sites’’ is needed, however, these may be heavily contaminated from industry and not suitable for ‘’new build’’ projects, therefore, a substantial cleanup operation may be required and a good solution would be the use of specific GM plants.
GM Plants may also offer a cheaper, convenient, way of producing medicinally important proteins or industrial chemicals (Morin 337); the process may be more suitable and efficient for some applications that currently use microbial fermentation methods. Additionally, genetic alterations that improve the fitness and yield of a crop may be essential in the future as the world’s population continues to grow, presently, some parts of the world already face food insecurity (Morin 333) so there is a real threat that this can only get worse, ultimately, it may be that GM crops offer a reasonable solution to this serious problem.
Engineered versus conventional crops – I know that there is this feeling that conventional crop breeding programs are more natural, they’ve been around for many years, and we’re all used to them, but hang on, some of these techniques mess around with the plants genome, I mean, one technique bombards the plants DNA with X-rays (Morin 338), which damages it and produces mutant organisms, the hope being that at least some surviving cells will have the characteristics required for a certain purpose, but this could be worse than bioengineering, oh the plant could appear ‘’normal’’ but could have a mutation in a second, or even other, genes leading to toxic products which could later harm consumers. The plant could even disrupt ecosystems, at least genetic engineering is specific in its manipulation of the genome and that the goals and targets are achieved in a more controlled and logical manner that produces anticipated results, in a usually faster timeframe than is achieved with traditional plant breeding methods.
Playing God – Some people may see geneticists as ‘’playing God’’ by producing new species, however, the world is faced with many challenges and science gives us the power to find answers, should we sit back and stick to the old methods or should we forge ahead with the new tools that could help feed the world, assist in environmental protection, and produce important products for medicine and industry?
Crop trials – Although the plants may grow well in the lab under carefully controlled conditions, sooner or later they have to go outside and handle the natural environment, but this causes public concern, however, safeguards exist to ensure the theoretical and true safety of the plants before they ever make it outside, but regardless, growth in the outside world is essential to enable unanswered questions to be addressed, and although the controllability of the natural environment is lower than in the lab, all efforts are made to protect the immediate surroundings as far as is realistically possible, but we need to know how natural wildlife is affected, if genes can spread to natural populations, and how the crop will ultimately perform.
Acceptance – As more scientific evidence emerges as to the safety of GM crops, a lot of farmers are now accepting them; tomatoes, cotton (for oil), corn, soybean, canola and squash are all being grown with some countries investing substantially in the technology (Morin 334-335). The main problem is of public acceptance, and although there have been few cases of side effects following consumption of such foods, people remain sceptical and suspicious over the safety, and scientists claims over the benefits, thinking that profits are more important to the companies involved in this industry than safety (Morin 335-339). Such issues require resolving, possibly through independent agencies that could monitor advances and distribution of products and help educate the public as to the motives behind each project.
Summary – GM crops have been viewed rather negatively, but as the scare stories over GM crops have not materialized more farmers are adopting the technology, governments investing, and products reaching the market. But public perception remains suspicious, and other problems exist, such as the long term effects on the biosphere, but in a world where climate change and fears over the environment, food security, and the need for cheaper medicines and chemicals present challenges, it is genetically modified plants that could help us cut carbon emissions, feed the world, reduce chemical use, provide fuel alternatives (biodiesel) and produce important compounds, the benefits, therefore, may far outweigh the risks if sufficient safeguards are in place to offer maximal protection.
- Hartl, Daniel L., and Elizabeth W. Jones. Genetics: Analysis of Genes and Genomes 5th ed. London: Jones and Bartlett Publishers, 2001.
- Latchman, David. Gene Regulation: A eukaryotic perspective 4th ed. United Kingdom: Nelson Thornes LTD, 2002.
- Morin, Xenia K. ‘’Genetically modified food from crops: progress, pawns and progress.’’ Analytical and Bioanalytical Chemistry 392 (2008): 333-340.