Fig. 4

CBIs and auxin decrease cell wall stiffness. Atomic force microscopy (AFM) was used to measure cell wall stiffness profiles of Arabidopsis suspension-cultured cells treated with: a methanol (control), b thaxtomin A (TA; 1 μM), c 2,4-dichlorophenoxyacetic acid (2,4-D; 50 μM), d 2,4-D and TA, e isoxaben (IXB; 1 μM), f IAA (1 μM), g IAA and IXB for 24 h. Force curves were recorded at the surface of 3 cells per condition in order to extract Young’s modulus (MPa) values (see Material and Methods). Each histogram bar represents the relative proportion of Young’s modulus values measured on the cell surface in each condition. Because of the low proportion of values measured above 1 MPa, a scale change was used after 1 MPa. h Average median values of Young’s modulus were calculated for each condition from 3 different experiments (3 to 4 cells per experiment). Error bars represent SD