Caffeine inhibits callose deposition in the cell plate and the depolymerization of microtubules in the central region of the phragmoplast.
نویسنده
چکیده
Treatment of tobacco BY-2 cells with 10 mM caffeine that was started after the cells had entered the mitotic phase did not completely inhibit the deposition of callose in the cell plate and allowed the centrifugal redistribution of phragmoplast microtubules. On the other hand, when treatment with caffeine was started before the cells entered the mitotic phase, the deposition of callose was completely inhibited and the redistribution of phragmoplast microtubules was also inhibited. As the inhibition of redistribution of phragmoplast microtubules seems to be caused by the inhibition of depolymerization of microtubules at the central region of the phragmoplast, these results strongly suggest that the deposition of callose in the cell plate is tightly linked with the depolymerization of phragmoplast microtubules. Callose deposition was observed in phragmoplasts isolated from caffeine-treated cells as well as in those isolated from non-caffeine-treated cells, and caffeine did not inhibit callose synthesis in isolated phragmoplast, indicating that caffeine neither inhibits the accumulation of callose synthase at the equatorial regions of the phragmoplast nor arrests callose synthase itself.
منابع مشابه
Update on Vesicle Trafficking during Somatic Cytokinesis Vesicle Trafficking during Somatic Cytokinesis
Plant cytokinesis, the final event of cell division, generates two daughter cells by partitioning the cytoplasm of a mother cell. This depends on targeted secretion to generate a new plasma membrane (PM; Whaley and Mollenhauer, 1963; Samuels et al., 1995; Jurgens, 2005a, 2005b). Plant cells control cytokinesis by constructing a plant-specific cytoskeletal configuration, the phragmoplast (Zhang ...
متن کاملThe Arabidopsis HINKEL Gene Encodes a Kinesin-Related Protein Involved in Cytokinesis and Is Expressed in a Cell Cycle-Dependent Manner
Plant cytokinesis starts in the center of the division plane, with vesicle fusion generating a new membrane compartment, the cell plate, that subsequently expands laterally by continuous fusion of newly arriving vesicles to its margin. Targeted delivery of vesicles is assisted by the dynamic reorganization of a plant-specific cytoskeletal array, the phragmoplast, from a solid cylinder into an e...
متن کاملEndosidin 7 Specifically Arrests Late Cytokinesis and Inhibits Callose Biosynthesis, Revealing Distinct Trafficking Events during Cell Plate Maturation.
Although cytokinesis is vital for plant growth and development, our mechanistic understanding of the highly regulated membrane and cargo transport mechanisms in relation to polysaccharide deposition during this process is limited. Here, we present an in-depth characterization of the small molecule endosidin 7 (ES7) inhibiting callose synthase activity and arresting late cytokinesis both in vitr...
متن کاملElectron tomographic analysis of somatic cell plate formation in meristematic cells of Arabidopsis preserved by high-pressure freezing.
We have investigated the process of somatic-type cytokinesis in Arabidopsis (Arabidopsis thaliana) meristem cells with a three-dimensional resolution of approximately 7 nm by electron tomography of high-pressure frozen/freeze-substituted samples. Our data demonstrate that this process can be divided into four phases: phragmoplast initials, solid phragmoplast, transitional phragmoplast, and ring...
متن کاملCytokinesis in tobacco BY-2 and root tip cells: a new model of cell plate formation in higher plants
Cell plate formation in tobacco root tips and synchronized dividing suspension cultured tobacco BY-2 cells was examined using cryofixation and immunocytochemical methods. Due to the much improved preservation of the cells, many new structural intermediates have been resolved, which has led to a new model of cell plate formation in higher plants. Our electron micrographs demonstrate that cell pl...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Plant & cell physiology
دوره 46 7 شماره
صفحات -
تاریخ انتشار 2005