Figure 5.

swCDPK activity and protein in various stages of somatic embryogenesis. A, Ca²⁺-dependent phosphorylation of the in vitro substrate histone III-S by soluble proteins of somatic embryogenic stages of sandalwood, PEMs, globular (Gl), torpedo (Torp), and cotyledonary (Cot) stages. The mean value of five replicates has been plotted. Black bars, 0.0 mm CaCl₂; white bars, 0.2 mm CaCl₂. B, Autoradiogram of 10% (w/v) SDS-polyacrylamide gel showing proteins (10 μg) assayed for in vitro phosphorylation of swCDPK protein in the absence of exogenous substrate prior to electrophoresis. Phosphorylation of the 45-kD protein was observed from the torpedo stage onwards. C, Western-blot analysis of 50-μg protein extracts using polyclonal anti-soybean CDPK. The samples were: lanes 1, regenerated plantlet; lanes 2, torpedo/cotyledonary stage somatic embryos; lanes 3, globular-stage somatic embryos; and lanes 4, PEMs.