Cauliflower fractal forms arise from perturbations of floral gene networks

Abstract

Throughout development, plant meristems regularly produce organs in defined spiral, opposite, or whorl patterns. Cauliflowers present an unusual organ arrangement with a multitude of spirals nested over a wide range of scales. How such a fractal, self-similar organization emerges from developmental mechanisms has remained elusive. Combining experimental analyses in an Arabidopsis thaliana cauliflower-like mutant with modeling, we found that curd self-similarity arises because the meristems fail to form flowers but keep the "memory" of their transient passage in a floral state. Additional mutations affecting meristem growth can induce the production of conical structures reminiscent of the conspicuous fractal Romanesco shape. This study reveals how fractal-like forms may emerge from the combination of key, defined perturbations of floral developmental programs and growth dynamics.

Additional Information

© 2021 American Association for the Advancement of Science. This is an article distributed under the terms of the Science Journals Default License. Received 15 January 2021; accepted 3 June 2021. We thank A.-M. Chèvre, R. Immink, R. Simon, L. Ostergaard, and M. Benitez for advice; T. Vernoux, C. Zubieta, and H. Chahtane for proofreading and useful feedback on the manuscript; D. Tardy, E. Giraud, R. Dumas, and V. Martin (OBS, France) for providing cauliflower samples; L. Bousset Vaslin for images and branch counting; F. Boudon for help with L-Py; R. Immink (Wageningen, Netherlands), C. Ferrándiz (IBMCP; Spain), G. Coupland (MPIPZ, Germany), M. Ángel Blázquez (IBMCP, Spain), R. Amasino (UWM, USA), and the European Arabidopsis Stock Centre for providing seeds; V. Berger (CEA/DRF) for financing the Keyence microscope; and C. Lancelon-Pin (Plateau de microscopie électronique - ICMG. CERMAV-CNRS) for help with SEM experiments. This work was supported by the INRAE Caulimodel project (to F.P. and C.Go.); Inria Project Lab Morphogenetics (to C.Go., E.A., and F.P.); the ANR BBSRC Flower model project (to F.P. and C.Go.); the GRAL LabEX (ANR-10-LABX-49-01) within the framework of the CBH-EUR-GS (ANR-17-EURE-0003) (to F.P., G.T., M.L.M., and J.L.); the EU H2020 773875 ROMI project (to C.Go.); and the Spanish Ministerio de Ciencia Innovación and FEDER (grant no. PGC2018-099232-B-I00 to F.M.). Author contributions: C.Go. and F.P. conceived the study. C.Go., E.A., and E.F. performed the modeling. A.S.-M., C.Gi., D.B., F.M., F.P., G.T., M.M.K., M.L.M., and V.G. designed and performed the plant experiments. N.P. performed the confocal imaging experiment. J.L. analyzed the RNA-seq and genomic data. C.Go., F.P., and E.A. wrote the paper with contributions from all authors. The authors declare no competing interests. Data and materials availability: All data are available in the main paper or the supplementary materials. All plant materials are available upon request. Raw and processed RNA-seq data are available at GEO under accession no. GSE150627. All source codes to run the simulations are available as a supplementary archive file (descriptions of installation and execution are available as README.txt).

Attached Files

Accepted Version - Azpeitia_et_al_main_final.pdf

Supplemental Material - abg5999-Azpeitia-SM-Archive.zip

Supplemental Material - abg5999-Azpeitia-SM-Movie-S1.mov

Supplemental Material - abg5999-Azpeitia-SM-Movie-S2.mov

Supplemental Material - abg5999-Azpeitia-SM-Movie-S3.mov

Supplemental Material - abg5999-Azpeitia-SM-Reproducibility-Checklist.pdf

Supplemental Material - abg5999-Azpeitia-SM.pdf

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