Component of the exocyst complex involved in the docking of exocytic vesicles with fusion sites on the plasma membrane during regulated or polarized secretion. Involved in polarized cell growth and organ morphogenesis. During cytokinesis, involved in cell plate initiation, cell plate maturation and formation of new primary cell wall. The exocyst complex is composed of SEC3, SEC5, SEC6, SEC8, SEC10, EXO70A1 and EXO84B. Interacts with EXO84B. Binds to EXO70E2 (PubMed:24307681). Shuttles from the cytoplasm to the exocyst-positive organelle (EXPO) in the presence of EXO70E2. Expressed in seedlings, roots, leaves and flowers. No visible phenotype, due to the redundancy with SEC10a. Belongs to the SEC10 family. This locus, comprising the single gene At5g12370 in the original reference genome assembly, contains in fact two paralogous genes in tandem, SEC10a (At5g12370) and SEC10b (At5g12365), and a sequence segment of 7 kb in length is missing from the reference genome sequence.