Tethering factor involved in vesicle fusion at the trans-Golgi network (TGN) thus being required for efficient protein trafficking to the vacuole (PubMed:21521696). Implicated in resistance to salt and osmotic stresses (PubMed:21521696). Modulates the cell morphology (e.g. epidermal cell file rotation (CFR) and cell expansion) in mature regions of roots and the base of hypocotyls as well as root skewing, a process leading to root movement within the soil in order to maximize anchorage and nutrient acquisition, probably by regulating microtubule stabilization independently of their orientation (PubMed:28399805). Interacts with SYP41. Expressed ubiquitously in roots, leaves and flowers, and, to a lower extent, in stems. Highly expressed during germination, flower development, and silique maturation. Increased sensitivity to high concentrations of NaCl, KCl and LiCl, and also to mannitol-induced osmotic stress (PubMed:21521696). Altered localization of SYP61 and abnormal partial secretion of vacuolar proteins to the apoplast (PubMed:21521696). Enhanced root skewing and epidermal cell file rotation (CFR) probably due to microtubule destabilization, thus leading to abnormal cell morphology in mature regions of roots and the base of hypocotyls (PubMed:28399805).