Abstract
Potassium channels play essential roles in plant growth and development, however, the role of K+ channels during plant cell-cycle progression is unclear. In this study, we show that K+ uptake through K+ channels is necessary for proper cell cycle progression from G1 to S phase in tobacco BY-2 cells. Molecular cloning of the K+ channels identified 4 tobacco Shaker-like K+ channel genes. Gene expression analysis showed that one of the tobacco K+ channel genes, NKT1, was induced in G1 phase. Antisense analysis of NKT1 showed a reduced K+ uptake and delayed cell cycle progression of the BY-2 cells. Our data indicate that inwardly rectifying K+ channels mediate K+ uptake to progress the plant cell cycle and a Shaker-like inward rectifier NKT1 is involved in this process.
