Essential protein required during embryogenesis and all plant development stages, probably through a chromatin-mediated regulation of gene expression. Localized in the nucleus during the interphase, but is released into the cytoplasm during the mitotic phase (PubMed:12609034). Mostly expressed in flowers, and, to a lower extent, in roots, seedlings, leaves and siliques (at protein level). Before cytokinesis. Belongs to the actin family. Plant ARP7 subfamily.