Electrical Perception of "Death Message" in Chara: The Role of Turgor Pressure

Specimens consisting of two tandem internodal cells were prepared using Chara corallina in order to analyze the electrical response upon wounding. When one cell (victim cell) was killed by severing, another cell (receptor cell) generated a sharp spike followed by a long-lasting depolarization at the nodal end. It has been reported that K+ released from the victim cell is involved in generation of the long-lasting depolarization (Shim men 2006). In the present study, the trigger to induce the sharp spike was studied. When the turgor pressure of the victim cell was decreased by adding 1M methanol to the external medium, a sharp spike similar to that induced by wounding was generated at the nodal end of the receptor cell. It is suggested that the sudden disappearance of the turgor pressure of the victim cell due to severing is a trigger to induce the sharp spike of the receptor cell.