Abstract
In plant cell morphogenesis, it is believed that elongation axes are decided by cellulose microfibril orientation in cell wall and that orientation is controlled by cortical microtubules. Spirogyra is composed of tandem cylindrical cells, and the terminal cells differentiate to be rhizoid of rod or rosette shape. We had indicated that microtubules have an essential role in rhizoid morphogenesis. In the present study, we found that bulging occurred only at the tip region, when oryzalin was added after the start of differentiation. In the presence of DCB, a cellulose biosynthesis inhibitor, cell wall of tip region was burst. These results indicated that control of orientation and synthesis of cellulose at very tip region are essential for rhizoid differentiation. In addition, we tried to observe cellulose microfibrils during differentiation with FE-SEM. It will be discussed how cortical microtubules are involved in cellulose microfibril orientation during rhizoid differentiation in Spirogyra.
