A cytokinin-mediated, proliferation-based mechanism is involved in the generation and maintenance of cell-type specific tissue boundaries during vascular development in Arabidopsis roots. Specifically, the HANABA-TARANU transcription factor forms a feed-forward loop to cytokinin signaling, which in turn regulates the position and frequency of cell proliferation of proto-vascular cells such that mechanical stress of the surrounding tissues guides growth in an apical-oriented manor, maintaining cell patterning throughout the tissue section.