Abstract
The continuous and rapid movement of organelles and endosomal vesicles, which is termed cytoplasmic streaming, is found within plant cells. We want to clarify the physiological roles of the cytoplasmic streaming which remains mysterious for more than 200 years. We found that one of the myosin double mutants showed hypersensitive responses to several environmental stimulus. In addition, cytoplasmic streaming of this double mutant was clearly defected in phloem. These results suggested that cytoplasmic streaming in phloem should regulate environmental responses, which may be one of the physiological roles of cytoplasmic streaming. In this presentation, we show the several experimental data in order to clarify which type of cells expresses these myosins and whether the myosins organize actin filament in the phloem cells like as in the epidermal cells (Ueda et al., 2010). Finally, we provide a hypothesis about the involvement of the intracellular functions and the expression patterns of the myosins in the mechanism of hypersensitive responses.
