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Genetic control of plant cell division and regeneration

​Auxin mediates cell division frequency and orientation. We have separated cell division frequency regulation in roots into two distinct aspects. First, the competence to divide is set by PLETHORA transcription factors. These are transcriptionally controlled by auxin accumulation on a slow time scale. Second, a much faster effect of auxin on cell division frequencies operates independent and in parallel of PLETHORA input (Mähönen et al., 2014). Auxin also influences cell division plane orientation both in roots and in embryos (Yoshida et al., 2014). Recently, we have investigated the role of microtubule organization in cell division plane orientation in different developmental contexts and proposed a model for division plane orientation from first principles (Chakrabortty et al., 2017). Using this framework, we provide an explanation for the early division cycles in the Arabidopsis embryo, which replaces heuristic geometrical rules with mechanistic rules. I will also discuss extensions of this model into the root meristem context and its relation to the cell division orientation control mediated by the PLETHORA network. Finally, I will discuss recent data that reveal the involvement of Jasmonate signaling and the stem cell regulators SCARECROW and RETINOBLASTOMA-RELATED in control of quiescence, cell- and tissue regeneration.