Plant-specific EB1 subtype that functions preferentially at early stages of plant mitosis by regulating spindle positioning and chromosome segregation. Accumulates in the prophase nucleus and is required to maintain spindle bipolarity during premetaphase and/or metaphase and for efficient segregation of chromosomes at anaphase. May play a role in the dynamics of microtubule network in elongating pollen tubes. Homodimer. During mitosis, accumulates in the prophase nucleus, and after the nuclear envelope disintegration is associated with whole spindle microtubules, plus end of microtubules, phragmoplast and finally is actively recruited to the nucleus. Localizes in the microtubule network in elongating pollen tubes. Highly expressed in the root and shoot meristems, in guard cells of leaf stomata, pollen grains and pollen tubes. Composed of two functionally independent domains. The N-terminal domain forms a hydrophobic cleft involved in microtubule binding and the C-terminal is involved in protein binding. In Arabidopsis thaliana, EB1A and EB1B possess an acidic C-terminal tail that has autoinhibitory function, but EB1C has a tail region with patches of basic amino acid residues required for nuclear targeting. No visible phenotype under normal growth conditions, but seedlings show increased sensitivity to oryzalin, a microtubule-destabilizing agent. conditions. Plant microtubules behave differently from those of other eukaryotes in mitosis: they lack centrosomes and spindles are barrel-shaped with unfocused poles and no astral microtubules. Belongs to the MAPRE family.