Identifying the transcription factors (TFs) and associated networks involved in stem cell regulation is essential for understanding the initiation and growth of plant tissues and organs. Although many TFs have been shown to have a role in the Arabidopsis root stem cells, a comprehensive view of the transcriptional signature of the stem cells is lacking. In this work, we used spatial and temporal transcriptomic data to predict interactions among the genes involved in stem cell regulation. To accomplish this, we transcriptionally profiled several stem cell populations and developed a gene regulatory network inference algorithm that combines clustering with dynamic Bayesian network inference. We leveraged the topology of our networks to infer potential major regulators. Specifically, through mathematical modeling and experimental validation, we identified PERIANTHIA (PAN) as an important molecular regulator of quiescent center function. The results presented in this work show that our combination of molecular biology, computational biology, and mathematical modeling is an efficient approach to identify candidate factors that function in the stem cells.root stem cell | root development | cell-type expression profile | gene regulatory network | modeling I dentifying the transcriptional signature underlying stem cell regulation is fundamental to understanding the initiation and growth of plant tissues and organs. The Arabidopsis thaliana root provides a tractable system to study stem cells since they are spatially confined at the tip of the root, in the stem cell niche (SCN), and are anatomically well characterized. The SCN contains several stem cell populations that include the cortexendodermis initials (CEIs), vascular initials [including phloem and xylem (XYL)], columella initials, and epidermal/lateral root cap initials. These stem cell populations divide asymmetrically to replenish the stem cell and produce a daughter cell that later differentiates into the different tissues of the root. In the center of all of these stem cell populations is the quiescent center (QC), which acts as the organizing center and maintains the surrounding stem cells in an undifferentiated state (1). Major players in stemcell regulation have been previously identified, such as BABY BOOM (BBM) and PLETHORA1-3 (PLT1, PLT2, PLT3/AIL6), which are important for proper root formation and maintenance (2). Additionally in the QC, the homeodomain transcription factor WUSCHEL-RELATED HOMEOBOX 5 acts noncell autonomously to maintain the columella stem cells (3-5). In the endodermal and cortical layers, the GRAS family transcription factors SHORTROOT (SHR) and SCARECROW (SCR) activate the transcription of the cell-cycle gene CYCLIN D6 (CYCD6) to trigger the asymmetric cell division of the CEI (6, 7). Additional TFs, such as REVOLUTA (REV) and PHABULOSA (PHB), have been shown to regulate tissue specification and differentiation in the vascular stem cells (8-11). Despite these findings, a transcriptional signature within and across each of these diff...