Figure 2. Deviations from the shortest symmetric path.

(A) Schematic representations of different cell divisions: shortest path symmetric, longitudinal symmetric, and shortest path asymmetric. (B) Drawing of Arabidopsis thaliana with highlights of some locations where deviations from the shortest path are found. (C) Illustration of the Shoot Apical Meristem (SAM) where differential growth associated with organogenesis generate compressive forces (red arrows) (based on results from [22,86]). (D) Confocal image of the region of the SAM under compression exhibiting longitudinal divisions (as in (c), red arrows represents compressive forces). (E) Confocal image of a cotyledon. (F) Close up of the cotyledon in (E) showing asymmetric divisions in the stomatal lineage (highlighted in red). (G) BASL polar distribution (in green) is required to make the divisions asymmetric. In a basl mutant divisions of the stomatal lineage are symmetric and lead to the formation of stomatal clusters (Based on results from [68,71,87]). (H) Arabidopsis thaliana seed. (I) In wild type embryos the presence of an auxin response is associated with asymmetric divisions. In transgenic lines expressing a negative regulator of auxin signaling (pRPS5A::bdl), these embryonic divisions become symmetric and are reminiscent of the conformation adopted by soap film in quadrant (based on result from [5,30]). (J) Schematic representation of the spontaneous formation of soap film in a quadrant (based on results from [5]). (K) Glandular trichome of Pilea glaucophylla exhibiting a division pattern similar to (J) and pRPS5A::bdl.