Ozone treatment rapidly activates MAP kinase signalling in plants.
Brief exposure to ozone, a potent cross-inducer of plant stress responses, leads within minutes to activation of an ERK-type MAP kinase (approximately 46 kDa) in tobacco. This activation process is calcium-dependent and can be blocked both by free radical quenchers and by a specific inhibitor of MEK-1 (MAPKK). Hydrogen peroxide and superoxide anion radicals can substitute for ozone as the activation stimulus, which does not appear to require salicylate as an intermediary. The properties of the ozone-induced MAPK suggest that it may be SIPK (salicylate-induced protein kinase), a tobacco MAPK that is activated by a variety of stress treatments. The ability of ozone to activate SIPK indicates that this protein kinase acts as a very early transducer of redox stress signals in plant cells.
Samuel
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MA
Biotechnology Laboratory/Agricultural Sciences, University of British Columbia, 2357 Main Mall, Vancouver, British Columbia, Canada V6T 1Z4.
Miles
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GP
Ellis
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D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D004789:Enzyme Activation; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010126:Ozone / Q000494:pharmacology*; D010944:Plants / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D017382:Reactive Oxygen Species; D020156:Salicylic Acid / Q000378:metabolism
D017382:Reactive Oxygen Species; D010126:Ozone; D020928:Mitogen-Activated Protein Kinases; D020156:Salicylic Acid; D002118:Calcium