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Growing GM canola a smart move
Last week, the State Government of Victoria announced that the five-year moratorium on the cultivation of genetically-modified (GM) canola would be lifted in early 2008. New South Wales has also announced that it will lift its ban. South Australia is expected to follow soon whilst Tasmania wants to maintain its prohibition. The lifting of the moratorium is a highly controversial decision, but one that I welcome.
This story goes back to 2003 when the Commonwealth Government’s Office of the Gene Technology Regulator (OGTR) approved the cultivation of Bayer CropScience’s InVigor® and Monsanto’s Roundup Ready® herbicide-resistant canola (Brassica napus) for commercial oil production. In response, most Australian states (which have constitutional authority over agriculture) imposed 5-year moratoria on the basis that the economic and environmental risk was still unknown.
This was a sensible decision because it permitted more scientific and economic research to be conducted and for the community and farmers to express their concerns to government and industry.
GM canola has been grown in the United States and Canada since 1995. To date, there has been no evidence to suggest that there is a risk to the health of humans nor wildlife from growing such crops. In fact Bennett et al. (2004) found that growing a GM herbicide-tolerant crop would be less harmful to the environment and human health than growing the conventional crop, owing to the reduction of herbicide use. Indeed, there are many benefits that can come to Australia from the cultivation of GM crops.
Australia already cultivates GM cotton and carnations. The incorporation of genes for “drought resistance” in wheat and rice for instance could have dramatic environmental benefits, not least allowing us to grow more food with less water. The savings could be returned to our parched rivers and waterways.
Despite the potential benefits, there is a general paranoia amongst extremist environmental groups (such as Greenpeace) that GM-crops are somehow “unnatural” and “dangerous”. Such claims show a complete lack of scientific literacy. The labelling of GM crops as “Frankenfood” is a favourite scare-tactic amongst the environmental extremists.
A good example of the potential of GM was the FlavrSavr tomato, developed by Calgene. When tomatoes ripen, they become soft and are easily spoilt and so are picked green. The softening is caused by a protein called polygalacturonase, which is present in all tomatoes. Calgene scientists simply cloned the gene, flipped it backwards and re-inserted it back into the tomato. This antisense gene then blocked the function of polygalacturonase and the tomatoes stayed firm after ripening. No “foreign” genes were used, yet green groups went berserk and even suggested the tomatoes contained fish genes! (This claim was false).
Golden Rice provides another example of the positive potential of genetic modification. According to the World Health Organisation, dietary vitamin A deficiency (VAD) causes some 250,000 to 500,000 children to go blind each year. As a remedy to this problem, scientists Ingo Potrykus and Peter Beyer developed Golden Rice which contains elevated levels of β-carotene (provitamin A). Rice plants produce β-carotene in green tissues but not in the endosperm (the edible part of the seed). By addition of only two genes, phytoene synthase (psy) and phytoene desaturase (crt I), the pathway was reconstituted and β-carotene is consequently accumulated in the endosperm. The humanitarian benefit of cultivating this rice would be enormous, but for environmentalists objecting to the use of a “bacterial gene” in its development.
The notion that a “foreign” gene poses some risk to health or is unnatural is a myth. Aside from the lack of evidence of this process being dangerous in itself, gene transfer between bacteria and plants happens in nature, such as in the case of Agrobacterium tumefaciens. Sure, if a scientist were to transfer a gene encoding a toxin into an edible plant, that would be dangerous, but only because of the presence of toxin and not because the gene was “foreign”. Given that the DNA code is universal across all organisms and no genes have species-specific identifiers marking them as “plant”, “animal”, “bacterial” et cetera, this fear of the technology is misplaced.
One concern with growing GM canola is that herbicide-resistance genes will ‘contaminate’ non-GM canola crops via cross-pollination, since canola is an out-crossing species. In an Australian study, Rieger et al. (2002) found that canola pollen could be spread up to 3 kilometres away from source plants, but herbicide-resistance genes were present in an average of 0.03% of plants tested at those distances, suggesting that buffer zones could be successfully used where farmers want to grow non-GM canola without fear of contamination. This is especially applicable in the case of Tasmania. Under European standards for instance, “GM free” canola is permitted to contain up to 0.9% genetically modified material.
It is true that the organic sector could be affected by the commercial planting of GM canola, however ABARE currently estimates that organic canola accounts for less than 1% of the Australian canola crop. In any case, the economic debate is one which farmers will need to have and decide upon. This is not an environmental risk, but an economic one.
I believe that the adoption or otherwise of GM crops should be conducted where it is economically and environmentally prudent to do so. If a particular agricultural industry doesn’t want to grow GM crops because they feel their industry can gain higher prices with non-GM, then I support them wholehartedly. But if the environmental return (eg less use of herbicides, less water use etc) and the economic return is greater with GM crops, then as a society we should embrace the technology.
Of course there are risks. One risk is of GM crops hybridising with wild relatives in species where this is possible and wild relatives are present, causing a transfer of new traits (such as herbicide resistance) to these plants. However it is the job of the OGTR to evaluate and regulate new releases and to date, they’ve done an excellent job in risk assessment. Anyone who works in a PC2 laboratory would know how stringent the Gene Technology Act 2000 is.
It is up to affected farming groups, the OGTR, the Food Standards Authority and state governments to decide for each agricultural sector what is best for consumers, industry and the country. Consumers are entitled to stringent labelling regulations on all food, and the choice whether to purchase GM food products.
Genetic modification of crops offers Australia many opportunities and it would be foolish in the extreme to ignore the potential of this tried-and-tested technology and miss out on what it can offer the people of Australia and the world.
Bennett et al. (2004) Environmental and human health impacts of growing genetically modified herbicide-tolerant sugar beet: a life-cycle assessment. Plant Biotechnology Journal 2: 273–278
DallaPenna et al. (1986) Molecular cloning of tomato fruit polygalacturonase: Analysis of polygalacturonase mRNA levels during ripening. Proceedings of the National Academy of Science USA 83 (17): 6420-6424
Rieger et al. (2002) Pollen-Mediated movement of herbicide resistance between commercial canola fields. Science 296 (5577): 2386-2388