These Genes Might Let You Grow Pesticide-Free Veggies

By Hank Becker
September 30, 1999

Commercial vegetable producers and home gardeners may one day have fewer problems with caterpillars eating up their corn, broccoli, cauliflower and other vegetables, thanks to new genes that command plant cells to produce a worm-killing protein.

Scientists with the Agricultural Research Service and Mississippi State University were the first to find and isolate the protein in insect-resistant corn. The scientists, ARS plant geneticist W. Paul Williams and MSU biochemist and molecular biologist Dawn Luthe, believe the protein helps keep tiny fall armyworm larvae from developing into fat caterpillars that eat corn and other crops.

Seminis, the world's largest vegetable seed company, has signed an agreement to investigate the potential use of the gene for controlling a variety of caterpillars in commercially grown broccoli, cauliflower and other vegetables. Seminis is based in Saticoy, Calif.

The technology could benefit commercial vegetable producers by lowering the cost of pesticide inputs, according to Williams. He works at the ARS Corn Host Plant Resistance Research Unit at Mississippi State, Miss. Williams and Luthe isolated the protein, a cysteine proteinase, from cultured tissue of resistant corn plants. Last November, MSU and ARS received a patent for the gene sequence that encodes the protein. ARS is the chief scientific agency of the U.S. Department of Agriculture.

The fall armyworm is a serious pest of corn, especially late-planted corn in the South. Drought-stricken Texas was particularly hit with high populations of this pest last year. Estimates of losses to the pest in some years have exceeded $200 million.

Williams and co-workers have already collaborated with DeKalb Genetics Corp. of DeKalb, Ill., in evaluating corn hybrids that possess both natural and bioengineered sources of resistance to fall armyworms. In lab and field tests, the ARS researchers evaluated corn hybrids that DeKalb developed using germplasm created and released by ARS as a source of natural resistance.

Scientific contact: W. Paul Williams, ARS Crop Science Research Laboratory, Mississippi State, Miss., phone (601) 325-2735, fax (601) 325-2735, pwilliams@dorman.msstate.edu.