Phosphorylation of proteins in the cultured buckwheat cells differing in morphogenic abilities

Abstract

The level of Ca2+-and cAMP-dependent phosphorylation of intracellular and extracellular proteins in morphogenic calli of buckwheat (Fagopyrum tataricum (L.) Gaertn.) was higher than in nonmorphogenic calli. Using monoclonal (PY20) antibodies we showed that morphogenic and nonmorphogenic calli also differed in the number of proteins phosphorylated at tyrosine residues and by the extent of their phosphorylation. As compared with morphogenic calli, nonmorphogenic calli lacked phosphorylation at tyrosine in the protein with molecular weight of 21 kD and manifested reduced phosphorylation of proteins with molecular weights of 19, 22, and 29 kD. This evidence suggests that in the cultured cells incapable of regenerating plants, considerable changes occur in intracellular regulation and intercellular communications.