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.

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Publisher Full Text

Publisher Full Text

Authors

Kierzkowski D, Nakayama N, Routier-Kierzkowska AL, Weber A, Bayer E, Schorderet M, Reinhardt D, Kuhlemeier C, Smith RS

Institution

Institute of Plant Sciences, University of Bern, Bern, Switzerland.

Source

Science (New York, N.Y.) 335:6072 2012 Mar 2 pg 1096-9

MeSH

Cell Wall
Elasticity
Hydrostatic Pressure
Lycopersicon esculentum
Meristem
Models, Biological
Morphogenesis
Osmolar Concentration
Osmotic Pressure
Plant Shoots

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22383847