Abstract
Potassium ion (K+) is one of a fundamental mineral nutrients for plant growth and development. It is also involved in cell elongation and cell division of tobacco BY-2 cells. Therefore, in this study, we compared the role of K+ and K+ channels between cell elongation and cell division. At first, when we examined K+ channel gene expression between cell elongation and cell division, gene expression of an inward K+ channel gene, NKT1, was induced both in cell elongation and cell division while an outward K+ channel gene, TORK1, was induced in the condition of cell division. Treatment of tetraetylammonium, which is known to inhibit outward K+ channels, reduced cell division but accelerated cell elongation. Furthermore, cell osmotic pressures measured by plasmolysis method was lower during cell division than during cell elongation. These results suggest that reduction of cell osmotic pressure by activation of outward K+ channel activity promotes cell division.
