Fig. 4

Onion epidermal peel deformation in extensometer experiments can be accurately measured using cell junctions. A,B Longitudinally stretched cell in a relaxed state (A) and under 10% strain (B). Yellow line highlights cell junctions where distances were measured from. C Corresponding force–displacement curve for longitudinally stretched sample. D,E Transversely stretched cell in a relaxed state (D) and under 10% strain (E). Yellow line highlights cell junctions where distances were measured from. F Corresponding force–displacement curve for transversely stretched sample. The red lines in C and F mark the onset of plastic deformation, as determined based on cell junction displacements. Scale bars: 20 µm