The Perils of GM Rice

The perils of GM rice

The International Year of Rice ended last December, but the debate over genetically modified (GM) rice looks set to escalate, especially with the latest discovery of unauthorised GM rice in China.

Chee Yoke Heong

THE recent discovery of GM rice, unapproved for human consumption, in Hubei province in China by environmental group Greenpeace brought out the worst fears of critics that contamination of the food chain has occurred.

Based on a tip-off, a Greenpeace team was dispatched to investigate and found the presence of GM rice in samples of rice seed and unmilled and milled rice taken from seed companies, agriculture extension stations, farmers, rice millers, wholesalers and retailers. Among the samples were two that tested positive for Bt rice (which contains a Bacillus thuringiensis endotoxin gene that allows the rice to be resistant to the yellow stem borer).

The Chinese government has not authorised GM rice for commercial planting, and has to date permitted only field testing. Large-scale field trials with Bt rice have been conducted by scientists of the Huazhong Agriculture University in Wuhan, the provincial capital of Hubei. But it appears that the GM rice has entered the food chain in China for the past two years.

GM rice is not commercially cultivated anywhere in the world though one trait – tolerance to the herbicide glufosinate – has been approved in the US.
According to Greenpeace, the GM Bt rice could potentially cause allergenic reactions in humans. Citing studies, it says that the protein produced in the Bt rice (called Cry1Ac) may have induced allergenic-type responses in mice.

Centre of origin

The illegal release of GM rice into the food chain prior to approval underscores the weakness of the regulatory system. This is a cause for concern as China, the world’s top producer and consumer of rice, is under tremendous pressure to release GM rice to boost domestic grain production and farmer income. With its regulatory oversight system still weak, it is questionable whether it is ready to release GM rice without cross-pollinating other non-GM rice varieties.

The safety of GM rice for human consumption is also not determined yet.

What worries some scientists and critics about the introduction of GM rice in Asia, which is the centre of origin for rice, is the danger of GM rice contamination of indigenous varieties and the threat that this poses to food security. Crop genetic diversity is important for food security. If a disease sweeps through the rice population worldwide, locally bred traditional varieties that are currently abundant can be relied upon to provide varieties that are resistant to the disease. However, if GM rice is introduced, it is likely to cross-breed with local varieties, causing the erosion and perhaps even extinction of local crops in the long term.

The contamination by GM maize in Mexico is a case in point and signals what would happen to rice in Asia. In 2001, it was found that local varieties of maize in Mexico were contaminated by GM maize even though the country has a ban on commercial cultivation. Just as Mexico is the centre of origin and diversity for maize, so is Asia for rice.

Other known contamination cases include the admittance by GM giant Syngenta in March this year that they mistakenly sold hundreds of tonnes of unapproved (thus illegal) GM maize in the US and elsewhere over the past four years. Another GM contamination case in the US in 2001 resulted in a US$1 billion product recall amid concerns of potential allergenic reactions after GM maize (Starlink) unapproved for human consumption entered the human food chain.

Asia produces over 90% of the world’s rice supply. An estimated 140,000 different varieties of rice have been created by small farmers in Asia. It is therefore of great importance that contamination is avoided in the region in order to protect food security and crop diversity.

Different modifications

The types of GM rice that are likely to be available for commercial use in the short term are herbicide-tolerant varieties, Bt rice and rice that is resistant to bacterial leaf blight. Other varieties of GM rice in various stages of development include biofortified rice (beta-carotene, iron and zinc), and rice resistant to other major pests (such as brown planthopper), pathogens (bacterial blight, rice blast) and abiotic stresses (drought, salinity, submergence). Researchers are also pyramiding (or stacking) multiple GM genes into rice, trying to make GM rice resistant to multiple insects or both disease- and insect-resistant.

In many parts of the developing world, vitamin A and iron deficiency is a serious problem. A lack of these nutrients can cause anaemia, vision loss or a weakened immune system, and is one reason for the high rate of mortality and illness among women and children in many developing countries.

Proponents of ‘Golden Rice’ – a GM variant that has been biofortified to produce pro-vitamin A – argue that it holds the solution to the widespread vitamin A deficiency problem in the developing world. Critics, however, say there are many alternatives and cheaper ways to solve this problem as vitamin A can also be obtained from green vegetables and unpolished rice, which are rich in other essential vitamins and minerals as well [see ‘The return of “Golden Rice”‘ in this issue].

Other traits of GM rice are also under close scrutiny. Many GM varieties of rice under development confer resistance to some type of plant pest or pathogen, whether insects, weeds, fungi, viruses or bacteria. According to Greenpeace, pests can evolve to overcome these insect-resistant crops. Citing studies, it says that past experience in chemical control of organisms would indicate that insects, weeds, or pathogens will also eventually develop resistance to GM varieties of rice. Loss of control because of the evolution of resistance is likely to increase the use of insecticides, which is more harmful to the environment or human health.

Using the experience in the US as a guide, critics believe that use of herbicides is likely to increase, rather than decrease, as the proponents of GM rice claim. In the nine years of commercial growing of GM crops in the US, herbicide use, while having dropped in the early years, increased later. Though the reasons are varied, the increase in herbicide usage is primarily due to several weeds becoming tolerant to herbicide used with herbicide-tolerant crops. Therefore, claims by proponents that herbicide use will fall and farmers will save costs and the environment will benefit sound hollow.

‘Pharma’ rice

Concerns are also voiced by some scientists and organisations over the planting of rice crops that are genetically engineered to produce pharmaceutical proteins. Their concerns include the threats posed by these crops to food safety, the environment and the rice industry should contamination take place.
According to the Union of Concerned Scientists, US federal oversight of crops genetically engineered to produce medications in their seeds and leaves is inadequate to prevent unwanted contamination of food crops.

Such crops are being field tested in the rice-growing Central Valley in California but attempts to begin commercial production were stalled by California and federal authorities. But this does not stop companies trying to increase field testing elsewhere in the country despite setbacks.

Biotechnology company Ventria Biosciences in April declared that its plan to grow pharmaceutical rice still holds even though its original plan to do so in Missouri by May had to be shelved. The company has been facing opposition from farmers and a beer producer who are worried of contamination. It is now searching for alternative sites.

Another worry that plagues critics is that the introduction of GM rice heralds the arrival of corporate dominance of rice by a small number of large seed and agriculture companies such as Monsanto, Bayer and Syngenta, the main developers of GM rice. According to an ActionAid (an aid and policy advocacy organisation) study, as of 2001, there are 250 patents on rice, 61% are controlled by just six seed companies, three of them also the world’s largest pesticide corporations. There is concern that through patents and contractual agreements, seed companies will seek to prohibit farmers from sharing or saving seed, control what herbicides and pesticides are used and even assert ownership rights over the harvest.

Proponents of biotechnology insist the aim of GM organisms is not to create monopolies or to introduce new farming techniques, but to try to improve nutrition and health in developing countries. However, critics point to the successful alternatives to genetic engineering that are less costly and controversial. Plant breeders at the International Rice Research Institute, for example, have identified rice varieties in its collection of germplasm that are naturally high in iron. They found that aromatic grains were usually higher in iron concentration and often also higher in zinc, compared to non-aromatic varieties. At the same time, they also experimented in growing, by conventional breeding, new varieties that could thrive in poor soils and cold temperature, and found that one variety that was designed to tolerate low temperatures was also rich in iron and zinc.

With mounting evidence on why the GM road is full of peril, coupled with uncertainties over the benefits of GM rice, there are justifications for farmers and governments in Asia and other rice-growing regions in the world to tread very cautiously and continue to search for less costly, more durable and safer alternatives.

Chee Yoke Heong is a researcher with the Third World Network.

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