Cytoplasmic Streaming of a Plant Cell near the Freezing Point

Microscopic observations of the cooling process in plant leaf cells have been performed using a directional solidification stage in order to study on the optimum freezing condition of living tissues. Till date, several studies on the freezing or melting of cells have been conducted. However, few researchers have studied cells near the freezing point. In this study, a temperature-controlled stage was created in order to investigate the effect of cell temperature on cytoplasmic streaming, and the cells of an aquatic plant (Egeria densa) were used. The result showed that cytoplasmic streaming is greatly affected by ambient temperature and shift in temperature conditions. Moreover, the velocity of cytoplasmic streaming has a peak value at a particular temperature, and it does not recover soon after heating from a cold state.