Henrik Jönsson, Bruce E. Shapiro, Elliot M. Meyerowitz and Eric Mjolsness Modeling Plant Development with Gene Regulation Networks Including Signaling and Cell Division in Bioinformatics of Genome Regulation and Structure, N. Kolchanov, R. Hofestaedt (eds.), Kluwer Academic Publishers, Boston, (2004). (ISBN 1-4020-7735-1) Abstract: The shoot apical meristem of Arabidopsis thaliana is an example of a developmental system which can be modeled at genetic and mechanical levels provided that suitable mathematical and computational tools are available to represent intercellular signaling, cell cycling, mechanical stresses, and a changing topology of neighborhood relationships between compartments. In this paper we present a simplified dynamical 2-dimensional model of a growing plant. Cells in the shoot grow and proliferate, while the number of stem cells at the apex stays constant due to differentiation into tissue cells. Cell types are defined by protein concentrations within the cells, and the dynamics of the differentiation follows from a gene regulation network which includes intercellular signals. LU TP 03-29