Figure 3.

Ethylene-Induced Adventitious Root Growth Is Dependent on ROS.

(A) Stem sections of rice cultivar PG56 were treated with or without 150 μM of ethephon (E) for up to 20 h. Isolated adventitious roots were stained with DAB to visualize H₂O₂. Adventitious root with H₂O₂ staining after 6 h with 150 μM of ethephon (Top). Asterisk indicates stained root tip. Percentage of H₂O₂ staining at the root tip after treatment with or without ethephon for the times indicated (Bottom). Data are means (n = 10 to 20).

(B) Stem sections were treated with or without 150 μM of ethephon for 48 h with or without 1 μM of DPI. The number of penetrated roots and root lengths were measured. Data are means ± se (n = 24 to 27). Asterisks indicate significantly different values (ANOVA; P < 0.001).

(C) Isolated adventitious root primordia were treated with 10 μM of ACC with or without 1 μM of DPI for 48 h.

(D) Isolated adventitious root primordia were treated with up to 100 μM of ACC, and the increase in length of each primordium was determined after 24 and 48 h. Increases in root lengths are means ± se (n = 20 to 41). Different letters indicate significantly different values (ANOVA; P < 0.001).

(E) Isolated adventitious roots were treated for 48 h with 10 μM of ACC, 1 μM of DPI, 10 or 100 μM of KI, or 50 mM of AT at the combinations indicated. ACC-induced root growth was set as 100, and all other values were calculated as a percentage of that. Data are means (n > 30).

Bars in (A) and (C) = 200 μm.