Ricerc@Sapienza

In the Arabidopsis thaliana root, stem cells divide in the apical stem cell niche of the meristem and originate daughter cells that divide until they reach a distal boundary denominated transition zone where they start differentiating. At the end of root meristem development, a balance between cell division and cell differentiation is reached to maintain indeterminate root growth. The transition zone is early established during meristem development due to a drop of PLETHORA 2 gene levels in the distal part of the meristem. At later stage of root development, once the transition zone is established, an auxin minimum sets the position of this boundary, determining the size of the meristem and the rate of root growth. Nevertheless, how the PLETHORA 2 drop acts to establish the transition zone first and how the auxin minimum acts to stabilize the transition zone at later stage of root development is still unknown. Aim of this project is to unveil these molecular mechanisms by using both a molecular and a genetic approach.