Protein Phosphorylation Is Induced in Tobacco Cells by the Elicitor Cryptogein.
Changes in plasmalemma ion fluxes were observed when tobacco (Nicotiana tabacum) cells were treated with cryptogein, a proteinaceous elicitor from Phytophthora cryptogea. A strong alkalization of the culture medium, accompanied by a leakage of potassium, was induced within a few minutes of treatment. These effects reached a maximum after 30 to 40 min and lasted for several hours. This treatment also resulted in a rapid, but transient, production of activated oxygen species. All these physiological responses were fully sensitive to staurosporine, a known protein kinase inhibitor. Furthermore, a study of protein phosphorylation showed that cryptogein induced a staurosporine-sensitive phosphorylation of several polypeptides. These data suggest that phosphorylated proteins may be essential for the transduction of elicitor signals.
Viard
M. P.
MP
Institut National de la Recherche Agronomique, Universite de Bourgogne, Laboratoire de Phytopharmacie Phytobiologie Cellulaire, BV 1540 21034 Dijon Cedex, France (M.-P.V., F.M., A.P.J.-P.B.).
Martin
F.
F
Pugin
A.
A
Ricci
P.
P
Blein
J. P.
JP