The SAM is a curved structure and its geometry can be approximated either by a spherical cap or by a paraboloid. In this paper we focus on the stem cell dynamics in the shoot apical meristem (SAM) that is responsible for formation of all above ground structures. In case of agricultural plants, meristem dynamics are linked to the crop yield, therefore, a better understanding meristem regulations is of practical importance. These vital functions require meristems to be robust with respect to perturbations such as injuries or environmental fluctuations. Stem cell proliferation and fate choice have a direct impact on the architecture of the plant and its reproductive fitness. The accessibility of meristems to live-imaging and the repetitive formation of identical organs, such as leaves, make plants an attractive system to study the regulatory cues underlying cell production and fate transition. The plant stem cells are located in specialized tissues, referred to as meristems. For this purpose they maintain pools of stem cells which remain active during the whole life of the plant. Plants continuously generate new organs such as leaves, roots and flowers. Perturbations of the underlying control mechanisms may reduce the ability of the organism to adapt to changing environmental conditions. To establish, maintain and regenerate tissues, cell production and fate specification have to be orchestrated in a robust and well-defined manner. Tissue function is an effect of the cooperation of multiple specialized cell types. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Д¬ompeting interests: The authors have declared that no competing interests exist. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Дata Availability: All experimental data used to validate the model has been previously published and corresponding references are given in the text.ДЇunding: This work was supported by research funding from the German Research Foundation DFG (Collaborative Research Center SFB 873, Maintenance and Differentiation of Stem Cells in Development and Disease). Received: OctoAccepted: JPublished: July 20, 2020Д¬opyright: В© 2020 Klawe et al. Based on the model we study the specific role of the transcription factor HECATE and provide new insights in its action on cell dynamics and in its interrelation with other known transcription factors in the meristem.Д¬itation: Klawe FZ, Stiehl T, Bastian P, Gaillochet C, Lohmann JU, Marciniak-Czochra A (2020) Mathematical modeling of plant cell fate transitions controlled by hormonal signals. The model allows simulating different hypotheses about signal effects. We test the model by simulating perturbations of meristem signals and comparing them to experimental data. This allows studying how the non-linear interaction of multiple transcription factors is linked to cell division and fate-transition. The model describes the meristem as a two-dimensional disk that can grow and shrink over time, depending on the concentrations of the signalling factors in its interior. To better understand this regulation, we develop a computational model of the shoot meristem. Plant architecture and crop yield crucially depend on the regulation of meristem dynamics. Dividing stem cells give rise to offspring that, during a process referred to as cell fate transition, become more specialized and give rise to organs. This process is driven by stem cells which are located in specialized regions, so-called meristems. The model provides new insights on how the transcription factor HECATE is integrated in the regulatory network that governs stem cell differentiation. The model is tested by simulating perturbations in the level of key transcription factors that maintain SAM homeostasis. Coupling growth and hormonal signaling results in a nonlinear system of reaction-diffusion equations on a growing domain with the growth rate depending on the model components. The model is based on a simplified two-dimensional disc geometry of the SAM and accounts for a continuous displacement towards the periphery of cells produced in the central zone. We designed a mathematical model to elucidate the impact of hormonal signaling on the fate transition rates between different zones corresponding to slowly dividing stem cells and fast dividing transit amplifying cells. In this paper, we analysed the stem cell dynamics at the shoot apical meristem (SAM) that is one of the plant stem cells locations. Coordination of fate transition and cell division is crucial to maintain the plant architecture and to achieve efficient production of plant organs.

Models of plant cells