100 Years of Bacillus thuringiensis (Bt)- A Colloquium One of the major issues in the public domain today is the controversy regarding the cultivation of modified plants. This issue is international in scope and involves farmers, consumers, pesticide manufacturers, environmentalists, and multinational corporations. Heated debates on the Internet and demonstrations on the streets outside meeting rooms have ensured that these issues receive daily press coverage.
Perhaps the single trait most vigorously discussed is the use of the toxin of the bacterium Bacillus thuringiensis (Bt). The gene for this toxin has been cloned and introduced into a wide variety of plants, including cotton, corn, and wheat. Previously, the toxin has been sprayed on crops- apparently without ill effects-protecting primarily against Lepidopteron insects.
A major controversy has not erupted with the demonstration that, under certain conditions, the toxin will kill monarch butterflies. The use of Bt to improve plants serves as the paradigm for all genetic engineering of plants.
The primary objective of the proposed colloquium is to consider all aspects of Bt, but focus on modified plants. We will analyze the scientific background of Bt and consider such questions as its mode of action, mechanism of insect resistance to the toxin, and its effect on nontarget organisms. Other questions that will be considered are questions of food safety of modified plants, threats to biodiversity from the use of Bt, and the effect on the use of chemical pesticides resulting from these modifications. We plan to convene this colloquium March 30-April 1, 2001, in Tucson, Arizona.
Although the toxic properties of Bt were discovered a century ago, this is the first far-ranging colloquium that has been held on this subject. The colloquium will bring together scientists with broad expertise to consider the science of an issue with broad political and social implications. Participants will have expertise in the following scientific disciplines: microbiology, entomology, ecology, population biology, risk assessment, and plants. Following the colloquium, a report will be developed-in both print and electronic formats-that will be analytical and comprehensive, yet offer practical recommendations.
