Abstract
During development and growth, dynamic signals need to be translated into spatially precise and temporally stable gene expression states, which define cell fate. In the context of the apical plant stem cell system, local accumulation of the small, highly mobile phytohormone auxin triggers organ initiation. Here, we show that the WUSCHEL transcription factor locally protects stem cells from differentiation by controlling the auxin signaling and response pathway via regulation of histone acetylation. Conversely, low levels of signaling are required for stem cell maintenance, demonstrating that WUSCHEL acts as a rheostat on the auxin pathway. Our results reveal an important mechanism that allows cells to differentially translate a potent and highly mobile developmental signal into appropriate cell behavior with high spatial precision and temporal robustness.