Plants and some animals have a profound capacity to regenerate organs from adult tissues. Molecular mechanisms for regeneration have, however, been largely unexplored. Here we investigate a local regeneration response in Arabidopsis roots. Laser-induced wounding disrupts the flow of auxin—a cell-fate–instructive plant hormone—in root tips, and we demonstrate that resulting cell-fate changes require the PLETHORA, SHORTROOT, and SCARECROW transcription factors. These transcription factors regulate the expression and polar position of PIN auxin efflux–facilitating membrane proteins to reconstitute auxin transport in renewed root tips. Thus, a regeneration mechanism using embryonic root stem-cell patterning factors first responds to and subsequently stabilizes a new hormone distribution.