PROTEIN-KINASES AND P34(CDC2)-LIKE PROTEIN IN ROOT-MERISTEMS OF PISUM-SATIVUM DURING GERMINATION

Protein kinase activity was detected in a 0.5-M NaCl soluble protein extract obtained from nuclei purified after 24 h of germination from pea root meristematic tissue. Permeation chromatography of this extract resolved several different protein kinase activities. One was Ca2+-dependent and was able to phosphorylate histone and casein as exogenous substrates to the incubation mixture. Another one was stimulated by the presence of Mg2+ under Ca2+-free condition. Two proteins (of 33.1 and 34.6 kDa) present in this extract were specifically recognised by the EGV antibody (an antibody raised against a conserved region of the p34cdc2protein kinase). It is proposed that part of the Ca2+-independent protein kinase activity solubilised from plant nuclei is contributed by a p34cdc2-like protein kinase and the possible functions of nuclear p34cdc2-like proteins during germination are discussed.