Actin-depolymerizing protein. Stimulates F-actin depolymerization. Involved in plant development, cell organ expansion and flowering by controlling breakdown of thick actin cables (PubMed:11402164). Severs actin filaments or bundles and promotes actin cytoskeleton disassembly (PubMed:21570971). Binds monomeric actin (G-actin) with a marked preference for the ADP-loaded form and inhibits the rate of nucleotide exchange on G-actin (PubMed:17538023). Interacts with the 14-3-3-like protein GRF6/AFT1. A number of isoforms are produced. According to EST sequences. Expressed in vascular tissues of all organs. Phosphorylation at Ser-6 by CPK3/CDPK6 inhibits actin-depolimerizing activity. Increased length of hypocotyls under dark-grown conditions. Belongs to the actin-binding proteins ADF family.