Scientists discover why cauliflowers have their unique structure
Have you ever wondered how cauliflowers develop their strange shape? The mystery of how these peculiarly shaped vegetables form has now been solved by a team from the University of Nottingham. Mathematicians and plant scientists worked with an international team led by CNRS* and Inria on the study. The findings have been published in Science.
Cauliflowers, especially Romanescos, have buds designed to become flowers but never reach their goal. Instead of flowering, cauliflowers develop into stems, which in turn continue trying to produce flowers. The curd is born from this chain reaction, resulting in a succession of stems upon stems.
This brief incursion of buds into a flowering state allows them, unlike normal stems, to grow without leaves and to multiply almost infinitely. The atypical shape of the Romanesco occurs because its stems produce buds more and more rapidly. This acceleration gives each floret a pyramidal, fractal appearance. The study highlights domestication and how our selection of plants has changed their shape, sometimes drastically.
How cauliflowers develop – a decade of work
University of Nottingham mathematician Assistant Professor Etienne Farcot helped to start the project. He said: “After over a decade of collaborative work from a multidisciplinary and international team of researchers, this emergent process can finally be explained.
“Most plants present a geometric organisation in spirals along main and secondary axes (phyllotaxis). Cauliflowers present an unusual phyllotaxis with a multitude of spirals, nested over a wide range of scales. How such a fractal self-similar organisation emerges from developmental mechanisms has, until now, remained elusive.
“Combining experimental analyses in Arabidopsis thaliana cauliflower-like mutant with mathematical modelling, we found that curd self-similarity arises because growing plant tissues fail to form flowers but keep the “memory” of their transient passage in a floral state. Understanding this genetic mutation could help plant scientists optimise the growth of related plants.”
For more information, visit www.sciencemag.org.
*Scientists from the laboratoire de physiologie cellulaire et végétale (CNRS/CEA/INRAE/Université Grenoble Alpes) and the laboratoire de reproduction et développement des plantes (CNRS/ENS Lyon/INRAE) took part. Other universities involved are the Polytechnic University of Valencia, the University of Milan, the University of California and the National Autonomous University of Mexico.
