title: Elastic domains regulate growth and organogenesis in the plant shoot apical meristem.
abstract: Although genetic control of morphogenesis is well established, elaboration of complex shapes requires changes in the mechanical properties of cells. In plants, the first visible sign of leaf formation is a bulge on the flank of the shoot apical meristem. Bulging results from local relaxation of cell walls, which causes them to yield to internal hydrostatic pressure. By manipulation of tissue tension in combination with quantitative live imaging and finite-element modeling, we found that the slow-growing area at the shoot tip is substantially strain-stiffened compared with surrounding fast-growing tissue. We propose that strain stiffening limits growth, restricts organ bulging, and contributes to the meristem's functional zonation. Thus, mechanical signals are not just passive readouts of gene action but feed back on morphogenesis.
authors.affiliation: Institute of Plant Sciences, University of Bern, Bern, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Kierzkowski
authors.forename: Naomi
authors.initials: N
authors.lastname: Nakayama
authors.forename: Anne-Lise
authors.initials: AL
authors.lastname: Routier-Kierzkowska
authors.forename: Alain
authors.initials: A
authors.lastname: Weber
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Bayer
authors.forename: Martine
authors.initials: M
authors.lastname: Schorderet
authors.forename: Didier
authors.initials: D
authors.lastname: Reinhardt
authors.forename: Cris
authors.initials: C
authors.lastname: Kuhlemeier
authors.forename: Richard S
authors.initials: RS
authors.lastname: Smith
mesh_terms: D002473:Cell Wall / Q000502:physiology / Q000648:ultrastructure; D004548:Elasticity; D006874:Hydrostatic Pressure; D018551:Solanum lycopersicum / Q000166:cytology / Q000254:growth & development*; D018519:Meristem / Q000166:cytology / Q000254:growth & development*; D008954:Models, Biological; D009024:Morphogenesis; D009994:Osmolar Concentration; D009997:Osmotic Pressure; D018520:Plant Shoots / Q000166:cytology / Q000254:growth & development*