Discovered the mechanism by which these cauliflowers have buds programmed to become flowers, but only turn into stems.

Romanesco cauliflower with its fractal aspect.

The mystery of the peculiar shape romanesco cauliflower It has been resolved by an international team of scientists, in which the Institute of Molecular and Cellular Plant Biology (IBMCP, joint center of the Polytechnic University of Valencia and the CSIC) has participated.

The study, published this week in the journal Science, has been led by the National Center for Scientific Research of France (CNRS) and the National Institute for Research in Informatics and Automation (INRIA) of that country.

In the work, the researchers combined experiments in vivo with 3D computational models that reproduce the development of the inflorescence of plants. His goal was to discover the molecular foundations of the growth of cauliflowers in general, and Romanescos, in particular.

The team has verified that both are actually a proliferation of buds (meristems) programmed to turn into flowers but they never reach their goal. What they do is turn into stems that, in turn, continue to try to produce flowers. Cauliflower is born from the repetition of this process, which causes a succession of stems on stems.

Stems that do not become flowers

Thus, the atypical form of romanesco is explained by the increasingly rapid production of stems that fail in their attempt to become flowers, while this production rate is constant in other cauliflowers. As a result, the inflorescence of the romanesco acquires a pyramidal structure composed of smaller pyramids, causing the fractal aspect of it.

“The meristems of cauliflower do not manage to achieve the objective of forming flowers but they ‘remember’ that temporarily they did manage to acquire a floral state. The additional mutations that affect the growth and activity of meristems are those that cause the fractal forms characteristic of Romanesco ”, point out Francisco Madueño, Antonio Serrano and Carlos Giménez.

These three co-authors and researchers from the IBMCP have characterized the network of genes that determine the formation of a flower or a stem and whose activity is therefore altered in the meristems of cauliflower and romanesco.

Specifically, they observed how TFL1, an essential gene for the formation of stems, is activated by genes that promote the formation of flowers, an initially contradictory result but key to understanding the development of the inflorescence of plants and, specifically, the formation of such fascinating structures as the Romanesco fractal.