Fig. 4.

The expression of ZmCCaMK and the activities of ZmCCaMK and antioxidant enzymes in the protoplasts with transiently silenced ZmCCaMK. (A) The expression of ZmCCaMK. Protoplasts were transfected with dsRNA against ZmCCaMK (RNAi) or with water (Control) and incubated for 24h. Silencing of ZmCCaMK was analysed by RT-PCR, and was normalized to GAPDH transcript levels. Experiments were repeated at least three times with similar results. (B) ABA-induced activation of ZmCCaMK. The protoplasts were treated with 10 µM ABA for 5min. Protein extracts from ABA-treated or untreated protoplasts were immunoprecipitated with ZmCCaMK antibody and then subjected to an in-gel kinase assay. Experiments were repeated at least three times with similar results. (C) ABA-induced gene expression of ZmCCaMK. Protoplasts were treated with 10 µM ABA for 15min, and the expression of ZmCCaMK was analysed by RT-PCR. Experiments were repeated three times with similar results. (D, E) ABA increased the activities of SOD (D) and APX (E). Protoplasts were treated with 10 µM ABA for 15min, and the activities of SOD and APX were measured as described in the Materials and methods. 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.