Figure 5.

DN-rop3 and rop3 Mutants Display Reduced Responses to Auxin.

(A) Time course of curvature in root gravitropic response tests. Root gravitropic responses of 35S_pro:DN-rop3 transgenic lines (L2 and L3) and rop3 knockout mutants (rop3-1 and rop3-2) are compared with the wild-type controls. Curvatures were measured at different time as indicated after reorientation. Data are means ± sd (n = 30 to 50). Asterisks indicate significant differences from the wild type by Student’s t test (*P < 0.05; **P < 0.01).

(B) Measurement of relative root elongation of seedlings grown on medium supplemented with different concentrations of NAA compared the sensitivity to auxin of 35S_pro:DN-rop3 transgenic lines (L2 and L3), rop3 knockout mutants (rop3-1 and rop3-2), and wild-type control. Primary root lengths of untreated plants were set as 100%. Data are means ± sd (n = 30 to 50). Asterisks indicate significant differences from the wild type by Student ’s t test (*P < 0.05; **P < 0.01).

(C) Hypocotyl lengths of 7-d-old seedlings grown at 22 and 29°C were measured for 35S_pro:DN-rop3 transgenic lines (L2 and L3), rop3 knockout mutants (rop3-1 and rop3-2), and wild-type control. Data are means ± sd (n = 30 to 50). Asterisks indicate significant differences from the wild type by Student's t test (*P < 0.05; **P < 0.01).