Phosphorylation of recombinant p26 by CPKs in vitro. A and B, Incorporation of 32P into p26 after in vitro kinase assays using recombinant AtCPK34, CKII, or PKA with recombinant p26a (A) and p26b (B). Top gels are autoradiographs showing 32P incorporation (total pmol), and bottom gels are western blots to show equal loading of protein. C and D, Incorporation of 32P into p26a (C) and p26b (D) during in vitro phosphorylation using PrCPK17/34, PrCPK14, PrCPK6/26, or AtCPK34. Values are means ± se (n = 3).