In this project, the investigators will study the functions of a family of proteins called calmodulin binding protein 60 (CBP60) in plant defense signaling. Calmodulin is a small protein that binds calcium ion and regulates the functions of other proteins by binding to them. Preliminary work in the reference plant Arabidopsis thaliana revealed that two of these proteins, called CBP60g and CBP60h, play partially-redundant roles in plant defense signaling. Plants lacking both of these proteins produce greatly reduced amounts of the important signaling molecule, salicylic acid (SA), in response to pathogen attack. Consequently, they are more susceptible to a bacterial pathogen. The major goal of this project is to understand how the CBP60 proteins function to control activation of defense signaling. There are four main parts to the project. In the first part, the investigators will define the site of CBP60 protein action within the framework of the plant defense network. In the second part, altered versions of the CBP60g and CBP60h genes will be constructed and used to test hypotheses about why the two proteins have slightly different roles in different aspects of defense signaling. In the third part, proteins that physically interact with the CBP60g and h proteins will be identified. In the fourth part, the mechanisms by which calcium ion and calmodulin modulate CBP60g function will be investigated. Science education will be an important part of the work. Graduate and post-graduate students will receive training and mentoring to prepare them for careers in research and teaching. Undergraduate students will participate in various aspects of the project. They will be drawn from programs that encourage participation by members of under-represented groups, and from a network of teacher-scientists, faculty at nearby undergraduate institutions with whom the PI has established relationships.
