**3. Conclusions**

The functional organization of eukaryotic cells requires the exchange of proteins, lipids, and polysaccharides between membrane compartments through transport intermediates. Transport from one compartment of this pathway to another is mediated by vesicular carriers, which are formed by the controlled assembly of coat protein complexes (COPs) on donor organelles. The plant endomembrane system is mostly conserved among eukaryotes but shows complex features. The structural organization of the endomembrane system is important for correct membrane trafficking and plant physiology. The trans-Golgi network (TGN) is a unique subcellular structure, which is a sorting center that integrates upstream cargoes

from secretory vesicles, the plasma membrane, and other organelles. The TGN functions as an early endosome compartment, adding to the complexity of sorting mechanisms in plant cells. Protein sorting at the ER-Golgi interface is important for the protein defects. However, the specificity and quantity of cargo sorting control mechanisms between endosome compartments are not completely clarified. More comprehensive studies on endomembrane trafficking will be necessary for the illumination of development, disease responses, hormone signaling (ABA and auxin), and plant immune system via sRNAs in exosomes in plant cells.
