Manipulation of Plant Signaling by Bacterial Effector Proteins

Ohio State University Research Foundation -Do Not Use, Columbus OH

Investigators

Abstract

Whether plants are resistant to pathogens depends on the genetic make-up of both organisms. Pathogens produce effector proteins that manipulate the plant for the pathogen's benefit. Plants produce resistance or R-proteins that recognize effectors and induce defenses that restrict pathogen growth. Recent cloning of genes encoding effectors and R-proteins enables mechanistic study of their interactions by molecular and biochemical methods. This research focuses on Arabidopsis thaliana plants and their bacterial pathogen Pseudomonas syringae. These model organisms offer a wealth of tools useful in answering fundamental biological questions, such as: How do pathogens more successfully parasitize plants by using effectors to manipulate them? How do R-proteins enable plants to restrict pathogen growth by recognizing effectors and inducing defense responses? Specifically, this research focuses on a protein of the plant (RIN4) that is targeted by multiple bacterial effectors. One major focus is to determine how targeting of RIN4 by bacterial effectors enhances the virulence (or pathogenicity) of the bacteria. RIN4 also regulates the function of R-proteins that respond to those effectors. A second major focus is to determine how manipulation of RIN4, induced by effector proteins, elicits the activity of R-proteins. This project is important because little is currently known about the interactions between pathogenic effectors and their targets in plants. Fundamental understanding of these interactions will advance understanding of how pathogens cause disease in plants and of how plants resist pathogens. This information will ultimately contribute to the rational design of superior crops by classical breeding efforts or by introduction of transgenes. Understanding these processes at the molecular level will also enable rational design of new chemicals to manage disease in crops. The significance of this research extends beyond the interaction of pathogens with plants. Pathogen encoded effectors similarly manipulate targets in animal hosts, and advances in understanding of effector action in plants will lead to a better fundamental understanding this process in all organisms. Students will be trained to conduct research in this field.