More food, cleaner food – gene technology and plants
Box 3 | Concerns about gene technology
While the potential benefits of gene technology are immense (eg, higher yields, resistance to pests and diseases, adaptation to particular environments, and increased convenience in harvesting and storage), many people have a number of concerns about genetically modified organisms.
Pesticide resistance
It is now possible to genetically engineer plants that produce their own pesticide. This exposes pests to the pesticide every day rather than as burst of pesticide application by the grower. If the pesticide-producing capability is introduced into a number of different plant species, it could accelerate the development of pesticide resistance among pests. (To reduce this concern the US Environmental Protection Agency has restricted the sales of pesticide-producing corn to states that do not grow pesticide-producing cotton.)
Increased use of herbicides
When farmers spray a herbicide to remove weeds growing among crops, the sprayed chemical often damages the crop plants. If the crop is engineered to be resistant to the chemical, the weeds will be killed but the crop plants will remain undamaged.
At first glance, this seems like a good thing. But it is likely to lead to greater use of the particular herbicide, which would have two negative effects:
- The crop is likely to contain greater herbicide residues; and
- the increased spraying will contaminate the rest of the environment.
Of course, not all herbicides are dangerous, but it seems safer to minimise rather than encourage their use.
Herbicide-resistant weeds
Genetic engineers are producing crops that are herbicide-resistant and pesticide-resistant. If the genes for these characteristics were to end up in a weed species, the weed would thrive and be difficult to control. (Field trials in Denmark of a genetically engineered, herbicide-resistant rape showed that the gene for herbicide resistance had jumped into a closely related plant.)
To label or not to label
One of the main points of controversy surrounding the release of genetically modified organisms is the question of labelling food products. Supporters of labelling point to potential problems for people with food intolerances. An investigation carried out in the mid-1990s found that seven out of nine people allergic to brazil nuts were also allergic to soya beans that had been genetically modified to contain a protein usually found in the nuts. These people showed no reaction to unmodified soya beans, so the protein taken from the brazil nuts must have been responsible for their allergic reaction. Because serious food reactions can kill, people need to know when genetically modified products might cause allergic reactions.
Supporters of labelling also point to the principle of the consumer's right to know what is in their food. Opponents point out that we don't know exactly what is in our food at the moment anyway. Many plants contain natural toxins to protect them against insect attack. These toxins are not good for us, and yet when we eat a parsnip we are not told the concentration of the potentially carcinogenic chemical that occurs naturally.
Concerns about marker genes
More serious worries stem from the use of marker genes. These are genes that are inserted into the genetically modified organism along with the desired gene. The presence of marker genes, which are easy to spot, allows researchers to recognise organisms that contain the desired gene. The problem arises with those marker genes that give antibiotic resistance to the organism.
Some people believe it is risky to allow genetically modified plants with marker genes for antibiotic resistance into the environment. For example, the British government objected to a proposal to import genetically modified corn from the United States into Europe because the plants contained a marker gene for resistance to the commonly used antibiotic, ampicillin. The government feared that the gene for antibiotic resistance could spread to bacteria that inhabit the human gut. In turn, these could pass the gene on to more dangerous bacteria. Or the marker gene could move from the plant into soil bacteria and then into disease-causing bacteria.
After much debate, in late 1996 the European Commission decided to allow the corn to be sold in Europe.
The role of big business
It is expensive to develop the potential that gene technology offers and it requires a long-term financial commitment to research. While large and well-funded corporations are able to provide this amount of money, there is some concern that the results of this research will not be readily accessible to small companies or developing countries. Some people are also concerned about placing responsibility for the world's food supply into the hands of a few large companies.
Tampering with nature
Critics of gene technology suspect that we still know too little about the systems that we are tampering with. Could an inserted gene have effects that we are unaware of? Could it upset the balance of existing genes, causing the plant to produce greater quantities of natural toxins, or to change its nutritional content?
Most researchers argue that there is no evidence of such unexpected changes. They point out that gene technology is much less likely to have unwanted effects on a plant than traditional selective breeding methods. These traditional methods, which have been carried out for thousands of years, involve the movement of thousands of genes from one organism to another. Modern gene technology, on the other hand, moves only a few targeted genes.
Safeguards
Food Standards Australia New Zealand (formerly ANZFA) develops food standards for composition, labelling and contaminants that apply to all foods produced or imported for sale in Australia and New Zealand. Food standards are developed with advice from other government agencies, stakeholders and food regulatory policies, and apply to the entire food supply chain from ‘the gate to the plate’.
The Office of the Gene Technology Regulator (OGTR) is the government agency responsible for gene technology regulation in Australia. The OGTR provides administrative support to the Gene Technology Regulator, who is responsible for enforcing the Gene Technology Act 2000. According to the OGTR web site, the Act is ‘a national scheme for the regulation of genetically modified organisms in Australia, in order to protect the health and safety of Australians and the Australian environment by identifying risks posed by or as a result of gene technology, and to manage those risks by regulating certain dealings with genetically modified organisms’.
‘Dealings’ include research, production, manufacture, import, storage, transport and disposal of genetically modified organisms (GMOs). To release a GMO into the environment, the Regulator prepares a risk assessment and risk management plan by consulting scientific experts, stakeholders and the public. The Regulator then decides whether or not to issue a licence to allow the release of a GMO.
Boxes
Box 1. Adding a gene to an organism
Box 2. Some examples of Australian gene technology research
Related sites
Arguments for and against gene technology (Biotechnology Australia)
Gene technology and food (National Science and Industry Forum report – Australian Academy of Science) Genetically modified plants for food use and human health – an update (The Royal Society, UK)
GM or not GM (transcript of The Science Show, Australian Broadcasting Corporation, 20 July 2002)
The public perception of risk in genetic modification (transcript of Ockham's Razor, Australian Broadcasting Corporation, 27 January 2002)
Assessing the safety of new foods and technologies (Food Standards Australia New Zealand)
About the OGTR (Australian Government Department of Health and Aging)
Page updated August 2006.