ABSTRACT
Introduction Plant development is largely post-embryonic, and relies on the proliferative activity of meristematic cells that can form new organs and tissues throughout the life cycle of the plant. Tight control of cell proliferation is therefore instrumental to shape the plant body. In the root meristem, the quiescent centre cells have a low division rate; they play a key role in the self-maintenance of the stem cell pool and function as a reservoir of stem cells that can divide to replace more actively dividing initials (Heyman et al. 2014). The shoot meristem, although less strictly organized than the root meristem, also contains a pool of slowly dividing cells at its centre. On the sides of the meristem, an increase in mitotic index precedes or at least accompanies primordium outgrowth to initiate leaf development (Laufs et al. 1998). Finally, cell proliferation gradually ceases from the tip of the developing leaf to its base as cells progressively differentiate (Andriankaja et al. 2012). This brief summary of the basic mechanisms underlying plant development perfectly illustrates that tight control of the cell cycle plays a central role in this process (Polyn et al. 2015).
