Poster: Cytoskeleton: Structure & Function
Abs #
1108: The spatial and temporal organization of microtubules and cytokinesis during Arabidopsis stomatal development
The role of microtubules (MT) in shaping guard cells has been extensively studied, but arrays present earlier during dicot stomatal development are not well characterized. Living Arabidopsis stomatal precursor cells from plants harboring a 35S alpha tubulin-GFP construct were analyzed to characterize specific stages of development. Arabidopsis stomata originate through one or more asymmetric divisions followed by the symmetric division of a guard mother cell. The progress and polarization of cytokinesis differed in asymmetric and symmetric divisions. In the former, the placement of the division site and the process of cytokinesis were polarized in four dimensions. In contrast, guard mother cell divisions were not polarized at either stage. Here the division site is marked by wall thickenings whose presence coincides with longitudinally aligned MTs that eventually constrict into a wide preprophase band. After both types of divisions a series of novel nucleo-cortical arrays are present. The characterization of stage-specific MT arrays provides a foundation for analyzing the functions of genes involved in stomatal patterning. For example, developing stomatal clusters in the four lips mutant contain inappropriate arrays indicating a disruption in the transition to terminal differentiation.
