Abstract
Cortical microtubules (CMTs) anchor to the plasma membrane with cross-bridge structures whose components have not been identified yet. Dhonukshe et al (2003) reported that n-butanol induced dissociation of CMTs from the plasma membrane, resulting in CMT disorganization and proposed that phospholipase D (PLD) might act as a cross-bridges between CMTs and the plasma membrane. Here we will report on the reexamination of the effect of n-butanol on CMTs. When tobacco BY-2 cells were treated with n-butanol, CMTs were fragmented, but they are normal upon treatment with t-butanol. Similar result was obtained with protoplasts. Fragmented CMTs were observed on the membrane ghost which had been prepared from protoplasts treated with n-butanol.Taxol canceled the effect of n-butanol on CMTs. Fragmentation of CMTs did not occur, when membrane ghosts were directly treated with n-butanol. These results suggested that metabolism of phospholipids by PLD is involved in regulation of CMT dynamics.
