A dynamic model of plant growth with interactions between development and functional mechanisms to study plant structural plasticity related to trophic competition.
OBJECTIVE
The strong influence of environment and functioning on plant organogenesis has been well documented by botanists but is poorly reproduced in most functional-structural models. In this context, a model of interactions is proposed between plant organogenesis and plant functional mechanisms.


METHODS
The GreenLab model derived from AMAP models was used. Organogenetic rules give the plant architecture, which defines an interconnected network of organs. The plant is considered as a collection of interacting 'sinks' that compete for the allocation of photosynthates coming from 'sources'. A single variable characteristic of the balance between sources and sinks during plant growth controls different events in plant development, such as the number of branches or the fruit load.


RESULTS
Variations in the environmental parameters related to light and density induce changes in plant morphogenesis. Architecture appears as the dynamic result of this balance, and plant plasticity expresses itself very simply at different levels: appearance of branches and reiteration, number of organs, fructification and adaptation of ecophysiological characteristics.


CONCLUSIONS
The modelling framework serves as a tool for theoretical botany to explore the emergence of specific morphological and architectural patterns and can help to understand plant phenotypic plasticity and its strategy in response to environmental changes.
Mathieu
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Ecole Centrale Paris, Laboratory of Applied Mathematics, Grande Voie des Vignes, 92295 Châtenay Malabry, France. amelie.mathieu@agroparistech.fr
Cournède
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Letort
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Barthélémy
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de Reffye
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D008954:Models, Biological; D063245:Plant Development