Micro-Mechanical Approaches to Characterize Tip Growth: Insights Into Root Hair Elasto-Viscoplastic Properties

The study introduces two innovative mechanical setups to characterize the mechanical properties of single growing root hairs in Arabidopsis thaliana. The first setup involves root hairs growing against an elastic obstacle until buckling, allowing the determination of the surface modulus and estimation of the Young’s modulus of the cell wall. The second setup uses a cantilever with variable stiffness to independently estimate the root hair’s axial stiffness. Both methods confirm that the axial stiffness, which reflects the root hair's elastic resistance to compression, is primarily influenced by tip compression and depends mainly on turgor pressure within the low deformation regime.