Plant Cell Monogr (9)
D.P.S. Verma and Z. Hong: Cell Division Control in Plants
DOI 10.1007/7089_2007_131/Published online: 31 July 2007
©Springer-Verlag Berlin Heidelberg 2007
Plant Cytokinesis – Insights Gained
from Electron Tomography Studies
José M. Seguí-Simarro^1 ()·MarisaS.Otegui^2 ·JothamR.AustinII^3 ·
L. Andrew Staehelin^4
(^1) Instituto para la Conservación y Mejora de la Agrodiversidad Valenciana (COMAV),
Universidad Politécnica de Valencia, Camino de Vera s/n, edificio 9B, 46022 Valencia,
Spain
[email protected]
(^2) Department of Botany, University of Wisconsin, 430 Lincoln Drive, Madison, WI 53706,
USA
(^3) MLK 007D, University of Chicago, 910 E. 58th st, Chicago, IL 60637, USA
(^4) MCD Biology, University of Colorado, UCB 347, Boulder, CO 80309-0347, USA
AbstractCytokinesis 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 contri-
bution of dual-axis electron tomography of cells cryopreserved by high-pressure freezing
and freeze-substitution (HPF-FS) to the understanding of the mechanisms underlying cy-
tokinesis 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 func-
tional properties of the recently characterized Cell Plate Assembly Matrix (CPAM), and
the relationship between the CPAM and phragmoplast microtubule dynamics.
1
Introduction
Plant cytokinesis is the final event in the plant cell division cycle that yields
two daughter nuclei separated by a new cell wall. During this process, the
plant cell divides its whole cell mass, including its genetic material and its or-
ganelles, into two daughter cells. Typically, cytokinesis (the separation of the
daughter cytoplasms) is initiated once the partition and segregation of the
nuclear components (caryokinesis) is completed and the daughter nuclei are
being rebuilt. When caryokinesis and cytokinesis are temporally and mecha-
nistically coupled, the process is known as somatic-type cytokinesis, whereas
the term syncytial-type cytokinesis is used to denote systems where caryo-