Figure 3.

Depolymerizing microtubules decreases the rigidity of Arabidopsis protoplasts. (A) Typical viscoeleastic moduli ($\left|G^{\ast }\right|\left(f\right)=\sqrt{G^{\prime }{\left(f\right)}^2+G^{\prime \prime }{\left(f\right)}^2}$) measured for an untreated protoplast (circles), a protoplast treated with 2 μM of cytochalasin D (squares), and a protoplast treated with 20 μM of oryzalin (triangles). Dotted lines represent power law fits of the data. (B) Diagram comparing the effects of 2 μM of actin depolymerizing drug cytochalasin D (left, n = 13) and 20 μM of microtubule depolymerizing drug oryzalin (right, n = 11) on the values of the elastic (dark gray) and loss (light gray) moduli of protoplasts. The mean values of elastic and loss moduli of treated cells are respectively normalized by the mean value of elastic and loss moduli measured for untreated cells. Error bars are normalized standard errors of the mean, ^∗P value < 0.05, ^∗∗P < 0.01, ^∗∗∗P < 0.001, Student’s t-test.