Researchers at the University of Missouri, including Scott Peck, recently identified a mechanism in plants that cues bacteria to attack the plants' cells with harmful proteins. Finding ways to suppress this mechanism can lead to plants that are more resistant to infection and have natural defenses that could render bacteria harmless.

Knowing that bacteria can attack plants once they've recognized the plant cells as potential hosts, researchers at the University of Missouri recently identified and replicated this recognition process: a discovery that could lead to natural anti-infective treatments that enhance resistance to harmful bacteria in the field.

"When potential pathogens enter host plants, a race ensues to deploy their respective disease and defense mechanisms," said Scott Peck, associate professor of biochemistry and a researcher in the Bond Life Sciences Center at the university. "Scientists have paid a lot of attention to how plants and other organisms recognize and respond to invading microbes, but little attention has been paid to how the signals transmitted by the organisms that are being attacked play a role in the process. Our work focuses on suppressing the signals from the plant that cue the bacteria to attack."

Peck and fellow researchers, including Jeffrey Anderson and Ying Wan, post-doctoral fellows at the university's department of biochemistry, found that plants, in this case tomatoes, produce a molecular signal that invites an attack from a pathogen.

The signaling system in the plant triggers a structure in bacteria similar in shape to a syringe, which is used to inject the bacteria's harmful proteins into its target. The research team found a group of five acids from plants that trigger the bacteria.

"We know that microbes can disguise themselves by altering the proteins or molecules that the plant uses to recognize the bacteria, as a strategy for evading detection," Peck said. "Our results show that the plant can disguise itself from pathogen recognition by removing the signals needed by the pathogen to become fully virulent."

The findings may help scientists grow plants that are more resistant to infection and create natural defenses for plants that could render bacteria harmless.

The findings come from a collaboration of scientists led by Peck and researchers from the Biological Sciences Division at Pacific Northwest National Laboratory, and the Environmental Molecular Sciences Laboratory and the Department of Energy's Environmental Molecular Sciences Laboratory. The study was published in the Proceedings of the National Academy of Sciences and was funded by the National Science Foundation.