Figure 2

Effect of altered auxin signaling and transport capacity on cellular auxin homeostasis. (A,B) Graphs represent the relative average mean gray values (MGV) of the DR5rev:mRFP signal intensity. Error bars represent standard error (n = 60). Statistical significance was evaluated with the unpaired student T-test (* P < 0.05, ** P < 0.01, *** P < 0.0001). (A) Coexpression of DR5rev:mRFP and the stabilized version of IAA17 fused to a VP16 activator domain (35S:VP16-IAA17mImII), causing constitutive auxin signaling, significantly increased the relative average MGV compared to the 35S:HDEL-GFP-expressing control cells. (B) NPA treatment leads to an increased MGV/DR5 signaling compared to transformants maintained in standard cultivation medium. (C) 10 representative pictures are shown for the control cells (left panel) and the cells overexpressing VP16-IAA17-mImII (right panel). (D) 10 representative pictures are shown for the untreated control cells (left panel) and the cells treated with NPA (right panel). (E,F) Graphs depict the changes in relative number of transformed cells displaying a low (-), medium (+), high (++), and very high (+++) DR5rev:mRFP signal between the two samples addressing VP16-IAA17-mImII expression or NPA treatment (for detailed description of the quantification, see Additional file 1: Figure S2). Error bars represent standard error (n = 3 repetitions with at least 50 counted cells). Statistical significance was evaluated with the ANOVA test; the P-value is indicated.