Secondary growth regulation by strains induced by wind: from stem structure to gene expression

Mechanical signals are important factors controlling plants growth and development. External mechanical loadings, such as wind, lead to a decrease of primary growth, an increase of secondary growth, modifications of stem mechanical properties and biomass reallocation to roots (Telewski, 2006, Badel et al., 2015). Integrative approaches combining physical/modeling/kinematics at plant and organ levels demonstrated that strain-sensing (deformation) are involved in the process of mechanoperception (Moulia et al., 2011; Coutand et al., 2009). These results allowed the development of an integrative biomechanical model called S3m which postulates that mechanoperception is proportional to local strain and volume of the considered tissue (Moulia et al., 2011). In this study, we tested this biomechanical model at tissue level by studying the relation between local strain intensity, secondary growth and genes expression.