Loosening of a preprophase band of microtubules in onion (Allium cepa L.) root tip cells by kinase inhibitors.

Effects of kinase inhibitors on the preprophase band of microtubules in onion (Allium cepa L.) root tip cells were examined. Bundled microtubules in preprophase bands were dispersed on the cell cortex when onion seedlings were incubated with 2.5-5.0 mM 6-dimethylaminopurine. Fifteen min was enough for the bundled microtubules to disappear. Although many preprophase bands remained when the seedlings were incubated with 60 microM staurosporin, these preprophase band microtubules were loosened and the width of the band became broad. These results sugget that some kinases are involved in the microtubule bundling in the preprophase band development.