Abstract
In higher plant cells, it is well known hypotheses that cortical microtubules regulate direction of cellulose microfibril deposition in cell wall, and that the direction of cellulose microfibrils forms and maintains cell shape, however, mechanisms how cortical microtubules regulate the cellulose microfibril deposition are still unclear. We have previously identified a novel inhibitor, designated cobtorin, which perturbed the parallel alignment between cortical microtubules and cellulose microfibrils by chemical genetics approach on tobacco BY-2 suspension cells. In this study, we investigated the effect of cobtorin on Arabidopsis plant. Cobtorin inhibited cell elongation and induced cell swelling phenotype both in hypocotyl and root. Although hypocotyl showed severe morphological changes by cobtorin treatment, root exhibited mild phenotype even at higher concentration, indicating the difference of sensitivity to cobtorin between hypocotyl and root. These data may indicate the difference in expression, function or structure of putative cobtorin target protein between tissues.
