Plant cytokinesis - Insights gained from electron tomography studies

Abstract

Cytokinesis is the final step of the cell division sequence. During cytokinesis, the plant cell completes its partition into two equal daughter cells by the transient formation of the cytokinetic apparatus, a complex structural scaffold that assists in the formation of a new cell wall. In the last few years, technical advances in sample processing and three-dimensional reconstruction and modeling have permitted the analysis of the dramatic structural changes undergone by the plant cell during cytokinesis at an unprecedented level of spatial resolution. The main purpose of this chapter is to summarize the contribution of dual-axis electron tomography of cells cryopreserved by high-pressure freezing and freeze-substitution (HPF-FS) to the understanding of the mechanisms underlying cytokinesis in angiosperms. We focus on the new structural and functional insights into the complex process of assembly of both somatic- and syncytial-type cell plates, the architecture of the different cell plate membrane intermediates, the structural and functional properties of the recently characterized Cell Plate Assembly Matrix (CPAM), and the relationship between the CPAM and phragmoplast microtubule dynamics. © 2008 Springer-Verlag Berlin Heidelberg.