Benfey Lab

The quiescent center (QC) is a structure that has garnered a great deal of interest from plant biologists, ever since its discovery in the middle of the last century. The QC is made up of "central cells" in the root meristem, which are surrounded by the stem cell progenitors (initials) that give rise to each tissue type in the root (see root anatomy).
Characterized by very slow division rates, this population can nevertheless proliferate rapidly in response to wounding, or to pattern an entire nascent root upon surgical excision. Exceptional work in the laboratory of Ben Scheres, University of Utrecht, has shown that the QC is responsible for emitting a signal to surrounding initial cells which prevents their premature differentiation (van den Berg et al., 1997). We are interested in understanding more about QC function at the molecular and genetic levels.
By enhancer trap screen, we have identified a transcription factor that is expressed exclusively in the QC.
Preliminary analysis reveals that a mutation in this gene results in a subtle disorganization of the root tip, primarily involving the QC and surrounding initials. Fusion of the promoter sequences with GFP (fig. 1) have resulted in a useful marker for QC cells.

Fig. 1 A promoter-GFP fusion transgene highlights quiescent center cells in roots counterstained with propidium iodide and visualized with a laserscanning confocal microscope.

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