Figure 4.

Effect of Mg²⁺, Ca²⁺, CaM, and W7 on the in vitro phosphorylation of swCDPK in the soluble protein extracts of torpedo-stage somatic embryos (20 μg of protein assayed in the absence of exogenous substrate prior to electrophoresis). Assays were performed with various concentrations of MgCl₂ (A), Ca²⁺ (B), CaM (C), and CaM antagonist W7 (D). Experiments B, C, and D were performed in the presence of 10 mm Mg²⁺, and experiments A, C, and D were performed in the absence or presence of 0.2 mm Ca²⁺.