Can we think more complex than plant root systems?

Plant root systems combine several features that make them extremely complex. Their structure grows dynamically in time and space, in response to several layers of signals (e.g. environment, hormones) acting simultaneously, under the control of several scales of organization. This complexity is probably a payload for ensuring optimality of the multiple, potentially antagonistic functions of root systems, while ensuring their persistence throughout plant life. As a result, several formalisms have been introduced to describe root systems and analyse their functioning. Functional structural plant models provide new opportunities to describe root systems as dynamic structures. We believe these will be important to face new phenotyping challenges (e.g. model assisted phenotyping) but also to discover new formalisms to handle root system functions and optimization.