A plausible model of phyllotaxis

Richard S. Smith1, Soazig Guyomarc'h2, Therese Mandel2, Didier Reinhardt2, Cris Kuhlemeier2, Przemyslaw Prusinkiewicz1.
1 Department of Computer Science, University of Calgary, 2500 University Drive N.W., Calgary, AB, Canada T2N 1N4
2Institute of Plant Sciences, University of Berne, CH-3013 Berne, Switzerland


A striking phenomenon unique to the kingdom of plants is the regular arrangement of lateral organs around a central axis, known as phyllotaxis. Recent molecular-genetic experiments indicate that active transport of the plant hormone auxin is the key process regulating phyllotaxis. A conceptual model based on these experiments, introduced by Reinhardt et al., provides an intuitively plausible interpretation of the data, but raises questions of whether the proposed mechanism is, in fact, capable of producing the observed temporal and spatial patterns, is robust, can start de novo, and can account for phyllotactic transitions, such as the frequently observed transition from decussate to spiral phyllotaxis. To answer these questions, we created a computer simulation model based on data described previously or in this paper and reasonable hypotheses. The model reproduces, within the standard error, the divergence angles measured in Arabidopsis seedlings and the effects of selected experimental manipulations. It also reproduces distichous, decussate, and tricussate patterns. The model thus offers a plausible link between molecular mechanisms of morphogenesis and the geometry of phyllotaxis.


R. S. Smith, S. Guyomarc'h, T. Mandel, D. Reinhardt, C. Kuhlemeier, P. Prusinkiewicz: A plausible model of phyllotaxis. Proceedings of the National Academy of Sciences 103 (5), pp. 1301-1306.

Download text and supplementary materials from the publisher's site, or download text from here (PDF, 770kb).

Supplementary materials: