Protein-protein interactions play important roles in many cellular processes, including the regulation of phytohormone signaling pathways. Identification of interacting partners of key proteins involved in the cellular signaling control can provide potentially unexpected insights into the molecular events occurring in any signaling pathway. Over the years, various techniques have been developed to examine protein-protein interactions, but, besides certain advantages, most of them have various pitfalls, such as yielding nonspecific interactions. Therefore, additional information obtained through different methods may be needed to substantiate protein-protein interaction data. One of these techniques involves the co-localization of proteins suspected to interact in the same subcellular compartment. In this chapter, we describe a method for co-expression of proteins associated with jasmonate signaling in Nicotiana benthamiana for studies such as co-localization.