How do leaf and floral primordia acquire distinct shape?

Both aerial organs initiate from an equivalent small population of stem cells, yet following successive days, the growth and morphogenesis patterns drastically diverge to create distinct organs. Leaf primordium keeps the initial bilateral symmetry, whereas floral primordium gradually loses it, acquiring radially symmetric shape. In this article by ’Dr. Wabnik group (@PlantDynamics), PhD student Daniel Alique worked together with Dr. Yuling Jiao’s lab (IGDB, Beijing) in the frame of the CEPEI international collaboration to determine the factors that drive the differential growth between these two primordia.

We used a computational framework developed by our research group to build a comparative model that realistically reproduces the morphogenesis of leaf and floral primordia starting from the same initial configurations. This spatial-temporal model brings together biomechanics and hormone transport properties to define organ growth with a single-cell resolution. By applying high-throughput simulations on computing cluster, we found that major differences between leaf and floral primordia morphogenesis can be explained by the interplay of three factors: 1) cell wall viscoelasticity, 2) cell anisotropy, and 3) auxin flux dynamics. Altogether, our results highlight the importance for integration of biomechanics and polar chemical transport for generating divergent organ shapes.