Molecular motors in higher plants

Until recently, it was difficult to investigate how plants generated intracellular motility. However, the identification and characterization of molecular motors has improved our understanding of the underlying mechanisms involved, and should facilitate new experimental approaches. Cytoplasmic streaming - the most prominent form of intracellular movement in nondividing plant cells - can be explained by the activity of an actin-based motor first purified from lily pollen tubes. Mitosis and cytokinesis involve microtubule- based movement, and experiments now implicate various microtubule-based motors (kinesin-like proteins) in aspects of cell division. Some of these plant motors have unique features and forms of regulation not seen before in other eukaryotes.