A signaling network controls stomatal development
The formation and distribution of stomata – epidermal pores facilitating gas exchange – is tightly regulated by intrinsic and environmental signals, thereby representing an excellent system to study the fundamental mechanisms that control cell fate and patterning. In Arabidopsis (Arabidopsis thaliana), stomata originate from protodermal cells that undergo asymmetric divisions and thereby enter the stomatal lineage. The smaller daughter cell of such a division, the meristemoid, can further divide asymmetrically before it differentiates into a guard mother cell (GMC), which then divides once symmetrically to form the two guard cells of a stoma ( Figure 1) 1 and 2.