Abstract

Plant form is controlled by post-embryonic organ formation. Organs initiate from the shoot apical meristem, an undifferentiated structure that contains a population of self-renewing stem cells. During organ initiation, founder cells on the periphery of the meristem are recruited into the forming organ primordium where they undergo dramatic changes in gene expression, cell division, and hormone signaling. Initiating organs are separated from the shoot apical meristem by a boundary region that is characterized by small, slowly-dividing cells. The boundary serves to isolate the primordium from the meristem and is critical for coordination of organogenesis and meristem maintenance. We study several boundary-specific transcription factors in Arabidopsis thaliana. These transcription factors function to specify boundary identity and to limit cellular growth. Our progress in understanding the networks regulated by boundary transcription factors will be presented.