Figure 4.
Tropic responses of Arabidopsis inflorescence stems. (A, E, I, and M) Wild type (WT), (B, F, J, and N) mpG12, (C, G, K, and O) mpBS1354 and (D, H, L, and P) mp nph4 MP-GR plants are depicted. (A-D) Inflorescence stem gravitropic responses. Potted plants (with initially upright inflorescence stems) were turned 90° onto their sides and placed in the dark for 24 h. Images depict plants at the conclusion of the assay, with the gravity vector downward. (E-P) Unilateral auxin application. Lanolin paste (pink) containing 0, 1 or 10 mM indole-3-acetic acid was applied near the apices of inflorescence stems. Inflorescence stem bending was assessed 24 h after application. Ratios indicate the fraction of treated inflorescence stems resembling the depicted image with respect to degree of bending. Bars: (A-D) 2 cm; (E-P) 5 mm.