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Accueil du site > Emplois et Stages > Sujets de Thèses > PhD Project : « The role of a ‘mechanical identity’ in growth and morphogenesis in Arabidopsis »

PhD Project : « The role of a ‘mechanical identity’ in growth and morphogenesis in Arabidopsis »

Institute :

Laboratoires Joliot-Curie and Reproduction et Développement des Plantes, ENS Lyon

PhD supervisor :


Email adress and phone number :

Arezki.Boudaoud(A)ens-lyon.fr, 04 72 72 88 75

Team members involved :

Olivier HAMANT and Arezki BOUDAOUD

Project description :

The emergence of shape in an organism involves changes in its structural elements — adding new materials and remodeling old materials. In this context, morphogenesis appears as a physical process controlled at the cellular level. Therefore the investigation of morphogenesis must also address the mechanical properties of the structural elements of the organism during its development. How do cells regulate their mechanical properties ? How do these properties guide morphogenesis ? Plants are perfectly suited for these questions, as their shape is mostly imposed by their stiff cell walls and by turgor. The main goal of the project is to establish three-dimensional maps of the mechanical properties of the plant tissues and to validate this map using pharmacological treatments and transgenic constructions. The principle is to use micromechanical manipulations and osmotic treatments to deform cells and to infer relative mechanical properties by quantifying deformations. Preliminary results obtained in the team indicate the feasibility of this approach and suggest a regional specification of mechanical properties. Wild type plants will be compared to plants with pharmacological treatments affecting cell walls, or to plants where cell wall synthesis or remodeling is locally modified using well-chosen promoters. In a first step, we will perform a comparative study of stem segments, hypocotyls and roots, and address the longstanding question of the relative role of epidermal and internal tissues in growth. Once this step is validated, the approach will be extended to the shoot apical meristem, considering either the maintenance of a stable dome, or the emergence of new organs. More generally, the PhD work will help building a new framework for morphogenesis, linking cellular behavior directly with shape.