Actin in plants

It has been known for some time that actin exists in lower plants, the most familiar examples being provided by certain algae in which actin constitutes the cytoplasmic cables along which particles and organelles stream. The choice of material was an important part of determining the identity of the filaments because these giant filamentous cells were capable of being broken open to expose cytoplasmic strands, which could then be decorated with heavy meromyosin (HMM) (reviewed by Williamson, 1986).