A human gene that Japanese researchers have inserted into rice enables the plant to break down a portfolio of chemicals now used on farms to kill weeds. The unusual breadth of that herbicide resistance could circumvent a major shortcoming of existing genetically engineered crops and also open new avenues for cleaning up contaminated soils.
Some scientists, however, are concerned that weeds growing with the rice could eventually acquire the human gene and become herbicide-resistant superweeds.
The herbicide resistance of many crops, including much of U.S. soy and cotton, results from genetic elements that scientists have transferred from other species. These engineered plants can tolerate powerful weed-control chemicals. To date, most plants tweaked this way are resistant to only one type of chemical, so farmers must use both the herbicide-resistant crop and the matching herbicide to keep weeds at bay without killing the plants they want to harvest.