Download Division Plane Orientation in Plant Cells

Invited talk
Division Plane Orientation in Plant Cells
Carolyn G. Rasmussen*1, Pablo Martinez2, Christopher Hoyt3, Jordan Hayes4,Kenneth
Brakke5 and Lindy Allsman1
1
Center for Plant Cell Biology, Department of Botany and Plant Sciences, University of
California, Riverside, CA, USA.
2
Biochemistry and Molecular Biology Graduate Program, University of California,
Riverside, CA, USA
3
NSF-REU-CEPCEB Harvey Mudd College, CA, USA
4
Biocluster Systems Administrator, University of California, Riverside, CA, USA
5
Susquehanna University, Pennsylvania, PA, USA
*E-mail: [email protected]
Keywords: cell division, live-cell imaging, separated by comma, maximum five.
Cell division is essential for the growth of any organism. One aspect of cell division that plays
a critical role in proliferation and development in multicellular organisms is the location of
the division axis. Proper establishment of the division axis or plane significantly contributes
to the plant body organization. In order to determine how much cell geometry alone predicts
division plane orientation, we used a mathematical modeling approach. Probabilistic division
plane predictions of cells were made based on century-old observations of symmetric plant
division: the daughter cells will have equal volume, and the dividing cell wall is a local
surface area minimum. Many land plant cells form a preprophase band (PPB) composed of
microtubules and other proteins that accurately predicts the future location of the new cell
wall. We directly compared the mathematically predicted divisions to the location of the PPB.
The PPB mostly overlapped with one of the possible types of purely geometrically predicted
divisions. Discrepancies in PPB location compared to the predicted division occurred when
the neighboring cell had a cell wall or PPB directly adjacent to the division site. The PPB
location shifted to avoid creating a “four-way-junction”. Avoidance of four-way-junctions, in
which nearby cell edges do not align at right angles, is a long recognized structural feature in
overall patterning of plant cells. Finally, we use the predicted divisions to determine the
relative contribution that cell geometry has in regulating specific division plane choices
during maize leaf development. At a population level, the division predictions based only on
cell geometry are not sufficient to describe the actual divisions observed during certain stages
of maize leaf development suggesting other factors, such as mechanical signals might play an
important role in division plane orientation.
SCANDEM 2017, Reykjavik, Iceland