Increasing model robustness for stem cell regulation in plant shoots

Abstract: The transcription factor WUSCHEL and the peptide CLAVATA3 have key roles to plat in the regulatory network effecting the differentiation of the stem cells at the shoot apical meristem of Arabidopsis. The signal pathway of this network has been under investigation for several years and models utilizing the already identified parts of the network have been developed. Such models have however so far been unable to explain a buffering ability of WUSCHEL against certain perturbations made experimentally to the promoter strength of CLAVATA3. For this thesis several alternative models have been proposed and investigated. All of them have a basis in a previously published model and adds or replaces different connections in order to be able to produce the experimentally observed dynamics. These in silico experiments have yielded several new models that are able to explain the buffering capabilities of WUSCHEL. They also show that many types of self-activation of WUSCHEL can produce not only the WUSCHEL buffering dynamics, but also the dynamics of the additional six mutant experiments that were used as a basis for the previous model.