Analysis of cell division patterns in the Arabidopsis shoot apical meristem

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 112; no. 15; pp. 4815 - 4820
• Main Authors: Shapiro, Bruce E, Tobin, Cory, Mjolsness, Eric, Meyerowitz, Elliot M
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 14-04-2015; National Acad Sciences; Proceedings of the National Academy of Sciences
• Subjects: Algorithms; Arabidopsis; Arabidopsis - cytology; Arabidopsis - metabolism; Arabidopsis thaliana; BASIC BIOLOGICAL SCIENCES; Biological Sciences; Cell Division; Cell Lineage; Cell Size; Cell Wall - metabolism; computer modeling; Computer Simulation; Cytoplasm; Flowers & plants; live imaging; Meristem - cytology; Meristem - metabolism; Microscopy, Confocal; Models, Biological; Plant Shoots - cytology; Plant Shoots - metabolism; Potential energy; Time-Lapse Imaging; live imaging; cell division; computer modeling; Arabidopsis
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1502588112

Significance Plant cells are incapable of sliding past each other, so generation of shape and structure in plant tissue is dependent on cells dividing and expanding in particular directions. Therefore, understanding how cells choose where to build new walls is critical in understanding how plant tissue is patterned. In the present study we expand on previous models of cell division to further understand what parameters of cell geometry and growth influence the position of new walls.
The stereotypic pattern of cell shapes in the Arabidopsis shoot apical meristem (SAM) suggests that strict rules govern the placement of new walls during cell division. When a cell in the SAM divides, a new wall is built that connects existing walls and divides the cytoplasm of the daughter cells. Because features that are determined by the placement of new walls such as cell size, shape, and number of neighbors are highly regular, rules must exist for maintaining such order. Here we present a quantitative model of these rules that incorporates different observed features of cell division. Each feature is incorporated into a “potential function” that contributes a single term to a total analog of potential energy. New cell walls are predicted to occur at locations where the potential function is minimized. Quantitative terms that represent the well-known historical rules of plant cell division, such as those given by Hofmeister, Errera, and Sachs are developed and evaluated against observed cell divisions in the epidermal layer (L1) of Arabidopsis thaliana SAM. The method is general enough to allow additional terms for nongeometric properties such as internal concentration gradients and mechanical tensile forces.