Fig. 3.

Major distinguishing regulators defining the decision of a dividing cell to quiesce, differentiate or enter dormancy. Regulated proteolysis of transcription factors and other unknown targets by APC/C E3 ligase, activated by CCS52A2, operates in partnership with an oxidized cellular state (ROS), abscisic acid (ABA) signalling and cyclin-dependent kinase inhibitors (KRP) to define meristematic quiescence. In a similar way, regulated proteolysis by the APC/C, activated by CCS52A1, regulates the commitment to differentiation in partnership with the regulated balance of H₂O₂ and O₂^•− and cytokinin signalling. By contrast, dormancy is regulated at the level of chromatin accessibility, by the action of PcG-type histone modifications. Further details are given in the text.