Threats to health reduced with Bt corn hybrids

October 17, 1999

St. Paul, MN (October 18, 1999) -- The recent approval and commercial release of genetically modified, insect-resistant corn hybrids (Bt corn) represents the culmination of decades of research. This innovative technology has a distinct health benefit of discouraging the build up of mycotoxins in corn, potentially dangerous human and animal toxins produced by fungi that cause plant disease.

Mycotoxin build up is directly related to certain fungal plant diseases, which can be increased by insect damage in crops. Insect larvae chew on stalks and kernels, creating wounds where fungal spores can enter the plant. Once established, these fungi often produce mycotoxins. Some mycotoxins such as fumonisin, can be fatal to horses and pigs, and are probable human carcinogens. "Lower mycotoxin concentrations in Bt corn hybrids clearly represent a benefit to consumers," says Gary Munkvold, plant pathologist at Iowa State University and American Phytopathological Society member. "Studies show Bt corn hybrids that control European corn borer damage to kernels usually have very little Fusarium ear rot, and consequently, lower fumonisin concentrations."

Bt corn hybrids control feeding by the European corn borer and to some extent closely related insects such as the corn earworm, common stalk borer, armyworm, and Southwestern corn borer. All of which cause mechanical damage to the corn which influences the development of several crop damaging diseases including ear rots, kernel rots and stalk rots.

Kernel rot caused by the fungus Aspergillus is also associated with insect damage to ears. Several species of this fungus produce the most notorious mycotoxins found in corn, the aflatoxins. "The economic impact of aflatoxins has been greater than that of other mycotoxins in corn because aflatoxins can be passed into milk if dairy cows consume contaminated grain," says Munkvold.

Bt corn hybrids can be an important tool in the integrated management of corn ear and stalk rots and a boon to the environment as well. "Using genetically modified hybrids to control insects and diseases offers an alternative that is much more effective, consistent, economic and environmentally sound than foliar insecticides. For example, non-Bt hybrid sweet corn can require 12 or more insecticide applications in a single season for the production of sweet corn for fresh market sales."

Controversy over production and use of genetically modified crop cultivars has focused a great deal of public attention on Bt corn. "Debate surrounding the use of genetically modified crops should be based on risk/benefit assessment, including environmental impacts, livestock impacts, and potential human health threats," says Munkvold. "Consumers and regulatory agencies should consider the food safety and environmental implications of Bt corn when making decisions about its use."
-end-
For more information about Bt corn, visit the APS October/November feature story at http://www.scisoc.org. The American Phytopathological Society (APS) is a professional scientific organization dedicated to the study and control of plant disease with 5,000 members worldwide. For more information on APS, contact APS Headquarters at 651-454-7250 or send an email to aps@scisoc.org.

American Phytopathological Society

Related Fungi Articles from Brightsurf:

Invisible fungi revealed by their genetic material
How can new life forms that we cannot see be discovered?

Producing leather-like materials from fungi
Leather is used as a durable and flexible material in many aspects of everyday life including furniture and clothing.

Breaking down wood decomposition by fungi
Through a combination of lab and field experiments, researchers have developed a better understanding of the factors accounting for different wood decomposition rates among fungi.

Impulse for research on fungi
For the first time, the cells of fungi can also be analysed using a relatively simple microscopic method.

Fungi as food source for plants
The number of plant species that extract organic nutrients from fungi could be much higher than previously assumed.

Bark beetles control pathogenic fungi
Pathogens can drive the evolution of social behaviour in insects.

Using fungi to search for medical drugs
An enormous library of products derived from more than 10,000 fungi could help us find new drugs.

Plants and fungi together could slow climate change
A new global assessment shows that human impacts have greatly reduced plant-fungus symbioses, which play a key role in sequestering carbon in soils.

Make fungi think they're starving to stop them having sex, say scientists
Tricking fungi into thinking they're starving could be the key to slowing down our evolutionary arms race with fungal pathogens, as hungry fungi don't want to have sex.

How plants react to fungi
Using special receptors, plants recognize when they are at risk of fungal infection.

Read More: Fungi News and Fungi Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.