WSU ecologist says defense by plants to disease may leave them vulnerable to insect attack

Some of the defenses plants use to fight off disease leave them more susceptible to attack by insects, according to a Don Cipollini, Ph.D., a chemical ecologist at Wright State University.

Cipollini, an assistant professor of biological sciences, will present a research paper on this topic at the annual meeting of the Ecological Society of America in Savannah, Ga., on Tuesday, Aug. 5. Some 3,000 national and international scientists are expected to attend the meeting.

“Plant Resistance and Susceptibility” is the title of the session in which Cipollini will present his paper. “My research shows that induction of a particular plant response to pathogens that results in enhanced resistance to disease (termed systemic acquired resistance) can nullify the induction of resistance to feeding by some insects,” he explained. “This interaction can result in the unfortunate tradeoff where plants become resistant to some diseases, but more susceptible to some insects. This phenomenon represents an ecological cost of resistance.”

His study, done in collaboration with researchers at the University of Chicago, illustrates the effects of salicylate, a natural plant chemical, on resistance of the plant species Arabidopsis thaliana to the beet armyworm larvae (Spodoptera exigua). Salicylate is chemically similar to the aspirin that humans take, and it functions in nature to heighten plant defenses to pathogens, or disease-causing microbes. When applied to plants, salicylate can interfere with the induction of resistance to some insects, however, leaving them more susceptible to insect feeding damage.

Cipollini’s research, which has funding support from the U.S. Department of Agriculture, has implications for crop plants in which salicylate-mediated defenses have been either genetically engineered or chemically manipulated. It also illustrates natural constraints on the evolution of plant resistance.

A major research interest of the Wright State scientist is how plants cope with insects and diseases. This includes examining biochemical mechanisms of resistance, as well as the ecological costs and benefits of plant responses to pests.

Cipollini, who received a WSU Presidential Award for Faculty Excellence Early Career Achievement earlier this year, has been invited to present his induced defense research at international symposia in Australia and Canada next year.

For more information on his research, contact Cipollini at 937-775-3805 or don.cipollini@wright.edu. The Web page for Ecological Society of America is http://www.esa.org and Cipollini’s research Web page is http://www.wright.edu/~don.cipollini.