2012 Annual Report 1a.Objectives (from AD-416): Develop methods for targeting and investigating interactions between soybean pathogen proteins and plant proteins involved in disease resistance or other important signaling pathways necessary for optimal plant productivity. 1b.Approach (from AD-416): Genes from plants and pathogens will be modified to encode a recognizable protein sequence tag. The modified gene will be expressed in plants. The expressed tagged-protein from the transgene will be purified based on tag recognition methodology and approaches will be designed to isolate the tagged protein and it’s potential interacting protein partners. These protein complexes or aggregates will be analyzed by mass spectrometry, which will resolve the individual protein components and thus reveal which proteins are interacting with the tagged protein. 3.Progress Report: The goal is to develop methods for investigating molecular interactions between proteins. Genes from plants were modified to encode a sequence tag and were expressed in plants. Tagged proteins were isolated from plants and identified. Results suggested that a tagged protein was phosphorylated. Phosphorylation is a chemical modification of proteins. Cells phosphorylate proteins to regulate protein function. Experiments are being conducted to evaluate how phosphorylation changes the function of the tagged protein to alter flowering and stress tolerance.