In the shoot apical meristem stem cells are maintained throughout the life of the plant, cells at the periphery starts to differentiate into more specialized cell types, and new organs are initiated in spectacularly symmetric patterns. It is known that the dynamics and maintenance of the meristem is determined by gene regulatory networks, hormone signaling and mechanical forces. Our aim is to understand how these modules are integrated, acting on a cellular level, and producing a very organized tissular regulation of a coordinated differentiation and morphogenesis. To address this we employ the method of Computational Morphodynamics, where live-imaging of the complete shoot is combined with mathematical modeling for iteratively improving the understanding of growth and differentiation. In this talk I will discuss several aspects of the dynamics. In particular, I will focus on how a radial patterning within the meristem can robustly result from a gene regulatory network as well as from a purely mechanical model.  I will continue to discuss how the phytohormones auxin and cytokinin can be involved in setting up the radial patterning, how this relates to early organ initiation, and how meristem shape can play an essential role in the differentiation process.

References

[1] Bozorg, B, Krupinski, P, Jönsson, H (2014) Stress and Strain provide positional and directional cues in development. Plos Comp Biol 10:e1003410.

[2] Yadav, RK, Perales, M, Gruel, J, Ohno, C, Heisler, M, Girke, T, Jönsson, H*, Reddy, GV* (2013) Plant stem cell maintenance involves direct transcriptional repression of differentiation program. Mol Sys Biol 9:654.