Fig. 4.

H₂O₂ is required for the BR-induced expression of ZmMAP65-1a in maize. (A, B) Expression analysis of ZmMAP65-1a in maize leaves (A) or mesophyll protoplasts (B) exposed to H₂O₂ treatment. The seedlings or protoplasts were treated with 10mM H₂O₂ (A) or 1mM H₂O₂ (B) for various times as indicated. Seedlings treated with distilled water and protoplasts treated with culture medium, under the same conditions during the whole period served as controls. The relative expression level of the ZmMAP65-1a gene was analysed by real-time qRT-PCR. (C) Effects of pre-treatments with ROS manipulators DMTU, DPI, and CAT on the expression of ZmMAP65-1a in response to BR treatment. The detached plants were pre-treated with 5mM DMTU, 100 μM DPI, or 200U CAT for 4h, and then exposed to 10nM BR treatment for 0.5h. Plants treated with distilled water under the same conditions served as a control. After treatment, the relative expression level of the ZmMAP65-1a gene was analysed by real-time qRT-PCR. Values are means ±SE of three different experiments. Means denoted by the same letter did not differ significantly at P <0.05 according to Duncan’s multiple range test.