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. 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. Participates in polarized pectin delivery required for the polarized development of the mucilage-producing volcano cells of the seed coat. Involved in the recycling and localization of auxin efflux carriers PIN1 and PIN2, and thus in polar auxin transport regulation. Functions in vesicle trafficking in tracheary elements to regulate patterned secondary cell wall (SCW) thickening (PubMed:27801942). The exocyst complex is composed of SEC3, SEC5, SEC6, SEC8, SEC10, EXO70A1 and EXO84B. Interacts with SEC3A and EXO84B. Co-localizes with FPP3/VETH1, FPP2/VETH2 and COG2 in vesicle-like small motile compartments (PubMed:25541219). May interact with COG2 (PubMed:27801942). During cytokinesis, localizes to the nascent cell plate and later to the cell plate insertion site and along the post-cytokinetic wall (PubMed:20870962). Localized at vesicle-like small compartments at cortical microtubules, especially in the presence of FPP3/VETH1, FPP2/VETH2 and COG2 (PubMed:25541219). Confined to helical/annular plasma membrane (PM) domains in protoxylem of roots before the secondary cell wall (SCW) is deposited. After the induction of xylem differentiation, first associated with plasma membrane (PM) foci and later co-localizes with microtubules (MT) organized into regular bundles, especially at the cell cortex (PubMed:27801942). A number of isoforms are produced. According to EST sequences. Dwarf and sterile plants with decreased apical dominance. Branched inflorescences due to ectopic initiation of lateral inflorescences instead of flowers. Altered polar growth of root hairs and stigmatic papillae. Reduced cell expansion and aberrant xylem development. Aberrant deposition of xylem secondary cell wall (SCW) (PubMed:27801942). Belongs to the EXO70 family.