Anisocytic stomatal development in the succulent model Kalanchoë laxiflora

Xin Cheng, Lidia Hoffmann, Paola Ruiz Duarte, James Hartwell, Heike Lindner, Michael T Raissig
Institute of Plant Sciences, University of Bern, Altenbergrain 21, Bern, 3013, Switzerland

In the leaf epidermis, stomata are breathing pores that balance photosynthetic carbon dioxide uptake and water vapor loss. Stomatal arrangement and development are quite diverse among different species. In many succulent plants of the Crassulaceae family (e.g., Kalanchoë laxiflora), the kidney-shaped guard cells (GCs) are surrounded by three unequal-sized, putative subsidiary cells (SCs). Unlike in grasses, these “anisocytic” SCs stem from the same mother cell as the paired GCs and are generated by Arabidopsis-like, circular amplifying divisions of the stomatal lineage mother cell. Yet, how the stomata develop is completely unknown. We, therefore, established K. laxiflora as a genetically tractable model system for stomatal research. In addition, we also described stomatal development based on static imaging and manual time-lapse imaging.