Proteins frequently interact with other proteins to execute specific biological processes. Identifying protein-protein interactions (PPIs) is essential for understanding the molecular pathways underlying various physiological functions. Proximity labeling (PL), particularly the TurboID-based PL approach, has been widely utilized to identify PPIs across different organisms in recent years. For the first time, we applied the TurboID-based PL method to detect PPIs in plants. We recently demonstrated that the TurboID complementation approach, referred to as split-TurboID, can be used to screen for binding partners of defined protein complexes in planta. Here, we provide a detailed protocol for performing split-TurboID-based PL assays in Nicotiana benthamiana plants.