A perspective of cell proliferation kinetics in the root apical meristem.

Organogenesis in plants is primarily postembryonic and relies in a strict balance between cell division and cell expansion. The root is a particularly well-suited model to study cell proliferation in detail since the two processes are spatially and temporally separated for all different tissues. In addition, the root is amenable for detailed microscopic analysis to identify cells progressing through the cell cycle. While it is clear that cell proliferation activity is restricted to the root apical meristem (RAM), the understanding of cell proliferation kinetics and identification of its parameters has been a long effort over the years. Here, we review the main concepts, experimental settings and findings aimed at obtaining a detailed knowledge of how cells proliferate within the RAM. The combination of novel tools, experimental strategies and mathematical models have contributed to our current view of cell proliferation in the RAM. Also, we discuss several lines of research that are needed to be explored in the future.