(A) Vascular systems of cleared specimens of Col-0, bud1, mpk3, mpk3bud1, mpk6, and mpk6bud1 plants. The seedlings grown on MS plates for 12 d were taken with the same magnification. The upper panel refers to the vascular system of cotyledon and the lower to leaves. (B) The filament elongation of Col-0, bud1, mpk3, mpk3bud1, mpk6, and mpk6bud1 flowers grown under long day conditions. (C) Gravitropic responses of dark-grown seedlings. Seedlings were grown in the dark for 4 d. The plates were reoriented by 90° and photographed after 18 h of gravistimulation. Bars, 0.5 cm. (D) Kinetic analysis of hypocotyl gravitropism. Seedlings were grown in the dark for 3 d on 0.5 × MS plates and reoriented by 90°. The gravitropic curvatures were measured at the time as indicated. Values are means ± SE (n = 20). (E) Statistical analysis of lateral root number. Lateral root numbers were counted at 12 d after germination. The values are means ± SE (n = 19). According to Turkey’s honest significant difference (HSD) test (p < 0.05), means of lateral root number do not differ if they are indicated with the same letter.