Abstract
Microtubules (MTs) are major cytoskeleton in plant cells and organize their structures by interaction with actin microfilaments (MFs). To investigate the role of MFs in microtubular-structure organization, we prepared MT-MF double-visualized tobacco BY-2 cell lines by using the MT plus-end binding protein, EB1 and the fimbrin actin-binding domain as markers for MTs and MFs, respectively. At the cell surface, both MTs and MFs were localized near the cell cortex but these structures were not observed to be interacted. In the preprophase band (PPB), MFs were not localized in the MT PPB structure but rather surrounding the PPB. At the growing edge of the phragmoplast, MTs seemed to elongate by the guidance of the MFs These observations suggested that in cytoplasm MTs elongate and organized their structures by interaction with MFs but in cell cortex MTs organized their structures without the help of MFs.
