Regulation of Polyphosphoinositide Metabolism in Pea Plasma Membranes by Elicitor and Suppressor from a Pea Pathogen, Mycosphaerella pinodes

Effects of the elicitor and the suppressor from a pea pathogen,Mycosphaerella pinodes, on polyphosphoinositide metabolism inpea plasma membranes were examined in vitro. Lipid phosphorylationin the isolated pea plasma membrane was drastically stimulatedby the elicitor, but markedly inhibited by the suppressor. Asimilar inhibitory effect was observed by the treatment withorthovanadate or K-252a that blocked pisatin production inducedby the elicitor. Neomycin, an aminoglycoside antibiotic thatinteracts with the polyphosphoinositide metabolism, also affectedthe lipid phosphorylation in vitro and blocked the elicitor-inducedaccumulation of pisatin in vivo. These results suggest thatrapid changes of polyphosphoinositide metabolism in pea plasmamembranes is one of indispensable processes during the elicitationof defense responses. (Received January 22, 1992; Accepted March 23, 1992)