Can Gene-Altered Rice Rescue the Farm Belt?

Crops Engineered to Help Alleviate Hunger

Newspaper article

By: Alexei Barrionuevo

Date: August 16, 2005

Source: New York Times

About the Author: Alexei Barrionuevo is a contributor to the New York Times, a daily newspaper with a circulation of over one million readers worldwide.

INTRODUCTION

In theory, any organism—bacteria, plant, or animal—can be modified by genetic engineering. The technique involves the transfer of a gene of interest from one species to another, creating a combination of genes not found in nature. Since genes are the blueprints for proteins, the aim of a genetic engineering experiment is usually to have the modified host species manufacture a protein that belongs to another species. These proteins have many applications—in medicine, in the food industry, and in research. For example, bacteria modified with the human insulin gene can act as a host for the manufacture of this essential drug for diabetes treatment. Other medicines made in this way include human growth hormone, erthyropoietin (a treatment for anemia), and "clotbuster" drugs (used to treat strokes and heart attacks). Without genetic engineering, these proteins would only be available in tiny amounts or not at all.

Genetically modified (GM) crops such as soy, rice, and tobacco, are planted and used in many countries. The first examples were crop plants engineered to contain a toxin from the bacterium Bacillus thuringiensis (bt). Because the bt toxin attacks insects—by perforating their gut—such GM plants are more resistant to predators than non-modified plants and yields from these crop are higher. Such technology could, say its supporters, help feed the world. But GM plants have always been controversial. Critics fear that ingesting "foreign" genes might create a health hazard. There are also concerns, as described in the article below, that GM crops might contaminate the environment through gene transfer.

Despite the protests, which have included destruction of GM crops by environmental activists and bans on GM food by restaurants, research on plant genetic engineering has continued. The article reproduced below describes an application where genetic modification is used not to improve the plant—as in the bt example—but to create a kind of factory to manufacture proteins that could benefit human health by helping to alleviate world hunger.

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SIGNIFICANCE

The protein products being made by the Ventria GM rice "factories" include lactoferrin and lysozyme. Both are natural human proteins with many potential applications. Lactoferrin is found in tears, saliva, and breast milk. It has anti-viral, anti-fungal, and anti-bacterial properties and boosts the immune system. As such, it forms one of the body's natural defenses against infection. Given that there is a rise in resistance to many antibiotics, there is an urgent need for new drugs that can help fight infection—still the leading cause of death worldwide. Lactoferrin may be able to take on this role. Lysozyme has similar properties and, indeed, research has shown that it also can enhance the effects of lactoferrin.

Many other companies are using plants like rice, tobacco, or corn to make therapeutic proteins to treat a range of diseases. While some of these molecules, like insulin, can be made in genetically-modified bacteria or yeast, more complex molecules need more complex hosts. For instance, monoclonal antibodies, which are being used in the treatment of cancer and inflammatory diseases like rheumatoid arthritis, are usually made in cells derived from hamsters. These cell-based production systems involve fermenting cell cultures in giant stainless steel vessels under sterile conditions. One limitation of this approach is often the cost—these new drugs can be very expensive—and there is an ongoing search for cheaper and higher-yield production systems.

Using whole plants, like rice, tobacco, or corn, as production systems may provide a cost advantage and, as the article points out, it also provides the farmer with a useful alternative crop that can be sold. The use of genetically modified animals, such as pigs and rabbits, which secrete the therapeutic protein in their milk is another approach under development. So far, no drugs made in this way using genetically-modified plants or animals have reached the marketplace, although many are at the advanced clinical trial stage. GM plants have long been controversial. But if scientists can finally prove that their benefit to humanity outweighs the risk, then GM plants may make a valuable contribution.

FURTHER RESOURCES

Books

Pinstrup-Andersen, Per, and Ebbie Schioler. Seeds of Contention: World Hunger and the Global Controversy Over GM Crops. Washington, D.C.: International Food Policy Research Institute, 2001.

Periodicals

Giddings, Glynis, Gordon Allison, Douglas Brooks, and Adrian Carter. "Transgenic Plants as Factories for Biopharmaceuticals." Nature Biotechnology 18 (2000): 1151-1155.

Humphrey, Brooke D., Ning Huang, and Kirk D. Klasing. "Rice Expressing Lactoferrin and Lysozyme Has Antibiotic-like Properties When Fed to Chicks." Journal of Nutrition 132 (2002): 1214-1218.

Web sites

BBC News. "Study Finds Benefits in GM Crops." November 29, 2004. 〈http://news.bbc.co.uk/1/hi/sci/tech/4046427.stm〉 (accessed November 20, 2005).