By Jane Qiu

China's recent roll-out of a a US$3.7 billion research programme to develop
genetically modified (GM) crops, particularly rice, has been hailed by
supporters as the means to feed the country's swelling population.
In a paddy field 30 kilometres south of Fuzhou, the capital of China's
Fujian province, Wang Feng is surveying a massive green and yellow
chessboard before him. Wang, a rice researcher at the Fujian Academy of
Agricultural Sciences, and his colleagues have been developing genetically
modified (GM) rice strains to resist pest infestation, and have been testing
in these plots for a decade. Two strains from Wang's team are now awaiting
regulatory approval by the agricultural ministry for commercial growth. It
could represent the largest commercialization of a GM foodcrop. Rice is a
staple for most of the country's 1.3 billion people and a primary source of
calories for more than half the world's population.

China's population is set to top 1.45 billion by 2020, and the country needs
to increase grain production by about 25%, a daunting task in the face of
increasing urbanization, industrialization, farmland reduction and the
efflux of rural workers to the cities. The Chinese government has latched on
to transgenic plants as a solution, rolling out a major research and
development initiative on GM crops for the next 12 years, including a
sizeable investment of 25 billion yuan (US$3.7 billion) from the central
government and additional matched funding from its provincial counterparts.

The bigger picture

Like GM initiatives elsewhere, such as in the United States, the move has
drawn its share of criticism, with concerns being raised about the
practicality and safety of such a push. Scientists warn that a single-minded
focus on genetic engineering to enhance pest resistance misses the bigger
picture of how to address agricultural production. China is the world's
largest rice producer, weighing in with nearly 200 million tonnes, and
several observers fear that introducing GM rice could endanger the food
supply and the environment. "The consequences would be unthinkable if
large-scale cultivation of GM rice were not properly regulated," says Xue
Dayuan, chief scientist on biodiversity at the Nanjing Institute of
Environmental Sciences. But in a country where policies are rarely a matter
of open debate, government officials warn that the scale of the impending
food shortage makes further delays an unaffordable luxury. "This is the only
way to meet the growing food demand in China," says Huang Dafang, former
director of the Biotechnology Research Institute of the Chinese Academy of
Agricultural Sciences (CAAS) in Beijing.

Wang is optimistic that his group's pest-resistant GM rice will help lead
the way. In April, the team planted alternating squares of conventional rice
crops and crops genetically modified to produce an insecticidal toxin made
by the bacterium Bacillus thuringiensis (Bt) gene and the cowpea trypsin
inhibitor (CpTI) gene. In the absence of chemical pesticides, Bt/_CpTI_ rice
thrived, whereas the conventional plants withered, resulting in the
chessboard pattern of alternating colours. Wang pulls the top from one of
the non-transgenic plants. Unrolling its leaves and splitting its stem, he
reveals the insecticides' primary target, the stem borer.

Wang says stem borers can affect 3.3 million hectares of rice fields,
resulting in a 5% loss in yields at a cost of 10 billion yuan a year.
According to Zhu Zhen, a geneticist at the Beijing-based Institute of
Genetics and Developmental Biology, Chinese Academy of Sciences (CAS), who
developed the rice strains with Bt and CpTI genes, there are no naturally
occurring strains that can confer such resistance. After ten years of field
testing at a dozen locations, the researchers are confident that farmers
would use less pesticide with GM rice strains1.

Plagued by pests

But David Andow, an entomologist at the University of Minnesota in St Paul,
says he is unconvinced. In the past few decades, the stem borer has been
overtaken by another pest, the brown planthopper (Nilaparvata lugens), which
wreaks havoc every spring and has become the main concern of farmers in
Asia. Bt and CpTI toxins have no effect on the insect.

Moreover, many simply see GM approaches as ham-fisted in the face of complex
ecologies. Kong Luen Heong, an entomologist at the International Rice
Research Institute in Los Ba?os, the Philippines, calls pest-resistant GM
crops a short-term fix for long-term problems caused by crop monoculture and
overuse of broad-spectrum pesticides. "Pests thrive where biodiversity is at
peril," says Heong. "Instead of genetic engineering, why don't we engineer
the ecology by increasing biodiversity?"

Indeed, such ecological engineering has proved beneficial. Zhu Youyong,
president of the Yunnan Agricultural University in Kunming, and his
colleagues have found that growing a mixture of rice varieties across
thousands of farms in China could greatly limit the development of rice
blast - a fungal rice disease - and boost the yield2. They have also tested
similar practices using different crops and found beneficial effects.

Although GM crops are, in principle, compatible with such an ecological
approach, it requires management that has proved hard to achieve within
China's agricultural system, which is based on small-scale cultivation, says
Xue. Although Bt cotton, the biggest GM crop produced in China to date, has
put the cotton bollworm (Helicoverpa armigera) under control, the population
of secondary pests, such as mirids, has risen since 2001. That has led to
increased pesticide use3,4, but still at levels lower than pre-1997, when
the cotton was introduced.

Safety concerns

Debates have also flared because of rice's central role in the Chinese diet.
One concern has been that antibiotic-resistance marker genes used in the
derivation of the transgenic plants could invariably be taken up by
naturally occurring gut bacteria and lead to resistant, pathogenic strains.
Both of Zhu Zhen's Bt/_CpTI_ rice lines and other Bt strains developed
elsewhere are free of such markers.

The GM plants must also be shown to be non-allergenic. Composition tests and
studies assessing toxicity in non-human animals allow the developers to
claim that the GM rice varieties are "substantially equivalent" to
unmodified counterparts apart from the target-gene expression. But for food
eaten three times a day by a billion people, short-term animal studies
aren't enough to measure equivalence. "If there were a health risk, we would
be heading for a major disaster," warns Liu Bing, an expert on science and
society in Tsinghua University in Beijing.

Another concern is the potential environmental consequences of transgenes
escaping from GM rice to its unmodified crop counterparts through
cross-pollination. Several escapes have occurred around the world, including
releases of unapproved GM crops such as rice and corn into human consumption
streams. For example, in 2006, the European Union halted imports of US rice
when an unapproved strain was found in the food supply. Trade resumed, but
the problem of accidental cross-pollination, which is thought to have caused
the contamination, is one that has not yet been solved. The consensus seems
to be that perfect prevention of such events is impossible5.

Lu Baorong, a biodiversity researcher at Fudan University in Shanghai, is
concerned about gene flow from GM rice to its wild or weedy relatives.
Wild-rice plants are undomesticated strains, whereas weedy rice, which is
characterized by its seed scattering and dormancy, is thought to originate
from rice crops as a result of mutations. Lu's team and another group have
shown that the rate of gene flow from GM strains to wild and weedy rice is
3?18% and 0.01?0.5%, respectively6,7.

"What is most worrying is that such gene flow is cumulative," says Lu.
Although rice crops are harvested at the end of the season, wild and weedy
rice carrying transgenes would continue to reproduce, allowing the genes to
spread, subject to selection.

This could threaten the biodiversity of wild rice, which provides a valuable
gene pool for rice breeders but is already at the brink of extinction in
China. In addition, weedy rice with pest-resistant or other fitness genes
could have a greater capacity to infest rice fields, causing yield loss.
However, Lu says that these are not inevitable consequences of large-scale
cultivation of GM rice. "Proper regulation is the key," he says.

A regulatory mess

But regulation, says Xue, is where the majority of problems lie. "Field
testing is one thing, but the reality is quite another." Although China has
had biosafety regulations for GM crops since 1996, their implementation has
proved uneven - a fact that most people approached by Nature acknowledged.
In some provinces, such as Xinjiang, farmers began large-scale cultivation
of Bt cotton long before approval was granted, says Xue. In several cases,
Bt cotton strains were grown without proper labelling, some of which were
experimental strains from research institutes.

Cross pollination and labelling slip-ups could be disastrous for China's
exports of rice and rice-related products. And proper regulation of GM crops
is crucial for delaying the emergence of resistant pests. Many crops, such
as cotton and rice, are grown as a monoculture in China, which would select
pests that are resistant to the toxins. One way to avoid this from happening
is to use seeds that produce high toxin levels; another way is to set aside
some land near GM-crop fields for its unmodified counterparts, which would
serve as a 'refuge' for insects.

This 'high-dose and refuge' strategy, which has been widely adopted in
countries that grow GM crops, is difficult to implement in China. Many
Chinese farmers exchange seeds with each other or buy cheap seeds from
illegal dealers, and end up growing cotton plants with low levels of Bt
toxin. In addition, as agricultural practices in China are based on
small-scale cultivation by individual families with limited resources, Bt
cotton plants are grown without refuge areas.

Fortunately, the cotton bollworm also attacks crops such as wheat, corn,
soya beans, peanuts and vegetables, which are grown next to the Bt-cotton
fields and offer a safety valve against resistance8,9. "This is unlikely to
happen with Bt/CpTI rice because the stem borer feeds only on rice," says
Heong. "Therefore, setting aside refuge areas is absolutely essential."

Behind closed doors

Worryingly, many of the stakeholders, including farmers, bioethicists and
environmental groups, aren't being involved in the biosafety evaluation
process as spearheaded by the agricultural ministry. The country hails GM
rice as a magic bullet for food-production problems and few dissenting
opinions are heard. "The whole process is rather opaque," says David Just,
an economist at Cornell University in Ithaca, New York. "China is trying
very hard to keep the lid on." Experts who express their concerns are often
sidelined. Xue, for example, has been repeatedly excluded from biosafety
committees that are assessing GM crops.

Despite these concerns, China does need to find a way to feed its swelling
population. Although it has instigated plans to prevent further reduction in
farmlands, boosting grain production remains the key to food security.
Still, the single-minded focus on genetic modification seems misguided to
many. "Genetic-modification technologies just treat the symptoms rather than
dealing with the causes," says Hans Herren, president of the Millennium
Institute in Arlington, Virginia, and a co-chair of the International
Assessment of Agricultural Knowledge, Science and Technology for Development
(IAASTD). According to a report released by the IAASTD in April, the main
challenges faced by agricultural development around the world are soil
fertility, water management and climate change10. "Life in the soil is gone
after decades of heavy use of pesticides, herbicides and chemical
fertilizers," says Manuela Giovannetti, a soil microbiologist at the
University of Pisa in Italy. Herren agrees: "Without a concerted global
effort to restore soil fertility, genetic modification would be futile."

Xue says he recognizes the potential of genetic modification, but is
concerned that huge investment in the technologies - as with China's new
initiative - would sap already dwindling attention from improving
traditional plant-breeding technologies and conventional farming practices.
However, GM strategies have a strong draw for keeping China competitive at
the cutting edge of agriculture. A report by the International Service for
the Acquisition of Agri-biotech Applications estimates that biotech rice
could deliver benefits of $4 billion per year for China11.

"What is behind all this might be about who controls germ plasm and who owns
intellectual-property rights," says Andow. The scale of the effect that
commercial GM rice could have on China and the rest of the world argues for
caution. Nevertheless, many interests within the country say that the time
to act is now. Huang puts it bluntly: "We cannot afford to think too far
ahead but must tackle the present issues."

References
1. Huang, J., Hu, R., Rozelle, S. & Pray, C. Science 308, 688?690 (2005).
2. Zhu, Y. et al. Nature 406, 718?722 (2000).
3. Wang, S., Just, D. & Pinstrup-Andersen, P. Int. J. Biotechnol. 10,
113?120 (2008).
4. Wang, Z. et al. Agric. Sci. China (in the press).
5. Ledford, H. Nature 445, 132?133 (2007).
6. Wang, F. et al. Plant Biotechnol. J. 4, 667?676 (2006).
7. Shivraina, V. K. et al. Crop Protection 26, 349?356 (2007).
8. Wu, K.-M., Lu, Y.-H., Feng, H.-Q., Jiang, Y.-Y. & Zhao, J.-Z. Science
321, 1676?1678 (2008).
9. Qiu, J. Nature doi:10.1038/news.2008.1118 (2008).
10. Beintema, N. et al. International Assessment of Agricultural Knowledge,
Science and Technology for Development: Global Summary for Decision Makers
(IAASTD, 2008); available at
[www.agassessment.org]
11. James, C. Global Status of Commercialized Biotech/GM Crops: 2007 ISAAA
Brief No. 37. (ISAAA, 2007); available at
[www.isaaa.org]

www.checkbiotech.org