PiP Elicitor and Suppressor from Phytophthora infestans Regulate Ca~(2+)-Dependent Protein Kinase (CDPK) in the Plasma Membranes of Potato

摘要

The relationship between the effect of Ca~(2+)-dependent protein kinase (CDPK) domain-Ill peptide-antibodies (Abs) raised against CDPK from Arabidopsis thaliana on the hypersensitive response of plant cells was investigated. The effect of peptide elicitor (PiP) and suppressor glucans from Phytophthora infestans on the kinase activity of membrane protein (MP) from potato (R_1 gene) was investigated. Stimulation of the kinase activity of the MP with CDPK-Abs but not with pre-immune sera was assumed tobe caused by the interaction with CDPK suggesting the presence of the kinase in the MP. It was assumed that the interaction of kinase domain-Ill peptide-Abs with CDPK in MP might have disengaged the active site of CDPK resulting in an increase in the kinase activity of MP. The PiP and suppressor from P. infestans inhibited the kinase activity of MP, which contained CDPK-Abs. It was suggested that PiP and suppressor might have interacted with the active site resulting in the inhibition of the CDPK activity of MP. We suggest that PiP and suppressor may interact with CDPK of MP initiating the signal, which, in the case of PiP, leads to the occurrence and/or inhibition of HR.