Trans-Golgi network/early endosome: a central sorting station for cargo proteins in plant immunity

- Vesicular trafficking pathways converge at the trans-Golgi network/early endosome.
- Distinct TGN/EE vesicle components traffic specific immune-related cargoes.
- Cargo sorting at the TGN/EE is specific and more complex than 'bulk-flow' sorting.
- Identifying immune-related cargoes helps shed light into TGN/EE's role in immunity.
- Pathogen effectors target TGN/EE components to suppress host immune responses.

In plants, the trans-Golgi network (TGN) functionally overlaps with the early endosome (EE), serving as a central sorting hub to direct newly synthesized and endocytosed cargo to the cell surface or vacuole. Here, we focus on the emerging role of the TGN/EE in sorting of immune cargo proteins for effective plant immunity against pathogenic bacteria and fungi. Specific vesicle coat and regulatory components at the TGN/EE ensure that immune cargoes are correctly sorted and transported to the location of their cellular functions. Our understanding of the identity of immune cargoes and the underlying cellular mechanisms regulating their sorting are still rudimentary, but this knowledge is essential to understanding the physiological contribution of the TGN/EE to effective immune responses.