Root Stem Cell Niche networks: It's complexed! A review on gene networks regulating the Arabidopsis root stem cell niche.

The presence of two meristematic cell populations in the root and shoot apex allow plants to grow indefinitely. Due to its simple and predictable tissue organisation, the Arabidopsis root apical meristem remains an ideal model to study mechanisms such as stem cell specification, asymmetric cell division and differentiation in plants. The root stem cell niche consists of a quiescent organizing center surrounded by mitotically active stem cells, that originate all root tissues. The transcription factors PLETHORA, SCARECROW and WOX5 form the signaling hubs that integrate multiple inputs from an increasing number of proteins implicated in the regulation of the stem cell niche function. Recently, locally produced auxin was added to the list of important mobile factors in stem cell niche. In addition, protein-protein interaction data elegantly demonstrated how parallel pathways can meet into a common objective. Here we discuss in a comprehensive way how multiple networks converge to specify and maintain the root stem cell niche.