The role of Dornröschen-like in early floral organogenesis.

Positional signals that specify founder cells and determine where lateral organs initiate and how these signals are perceived by cells that transition to the periphery of the meristem is a challenging problem. We recently showed that expression of the AP2 ERF transcription factor Dornröschen-like (DRNL) marks all floral organ founder cells and pre-patterns lateral stamen and petal, or medial stamen founder cells by two regions of expression that we propose represent morphogenetic fields, that subsequently resolve into discrete foci. The spatio-temporal expression pattern of DRNL allows speculation concerning evolutionary aspects of plant developmental biology and the control of the floral plant body. It further paves the way to use DRNL as a tool to address fundamental questions of cell type specification.