ARS Scientists Present Findings at Society MeetingBy Jan Suszkiw
August 11, 2003
Protecting corn crops with "flower power" is Eric Johnson's focus as one of about 20 Agricultural Research Service scientists who will discuss their work and latest findings Aug. 9-13 at the Phytochemical Society of North America's (PSNA) annual meeting in Peoria, Ill.
A research associate at ARS' National Center for Agricultural Utilization Research in Peoria, Johnson is conducting studies aimed at developing corn plants that carry genes for making anthocyanins. These are pigments that, depending on pH conditions, impart red and purple color to many kinds of flowers, fruits (visualize blueberries) and vegetables.
Johnson's anthocyanin interests aren't of the aesthetic kind, however.
Rather, he is following up on prior research suggesting large amounts of anthocyanins can deter some insects from feeding. Specifically, Johnson set his sights on the fall armyworm and corn earworm. As a caterpillar, the latter insect costs U.S. corn growers $1 billion annually in crop losses and chemical control expenses. At the ARS center's Crop Bioprotection Research Unit, Johnson is feeding the caterpillars a diet they'd normally benefit from, except for one secret ingredient: a 1,000-parts-per-million dose of delphinidin. It's one of several anthocyanins available commercially.
During the PSNA's "Art Niesh Young Investigator Mini Symposium" on Monday, Aug. 11, Johnson will report his observations to date. These include a 60 percent decrease in the weight of armyworms fed a diet containing delphinidin, compared to a control group. Chemical insecticide is now used to fight this pest, as well as the corn earworm. But Johnson's work could eventually lead to new corn hybrids whose silks mass-produce the anthocyanin pigments as a built-in defense against the caterpillars before they chew their way to the kernels. ARS entomologist Pat Dowd, the lead scientist on the work, is especially interested in stopping the pests from spreading fungi that can sometimes contaminate corn kernels with toxins such as aflatoxin and fumonisins, which are harmful to humans and livestock.
ARS is the U.S. Department of Agriculture's chief scientific research agency.