title: Involvement of phospholipase D and NADPH-oxidase in salicylic acid signaling cascade.
abstract: Salicylic acid is associated with the primary defense responses to biotic stress and formation of systemic acquired resistance. However, molecular mechanisms of early cell reactions to phytohormone application are currently undisclosed. The present study investigates the participation of phospholipase D and NADPH-oxidase in salicylic acid signal transduction cascade. The activation of lipid signaling enzymes within 15 min of salicylic acid application was shown in Arabidopsis thaliana plants by measuring the phosphatidic acid accumulation. Adding of primary alcohol (1-butanol) to the incubation medium led to phosphatidylbutanol accumulation as a result of phospholipase D (PLD) action in wild-type and NADPH-oxidase RbohD deficient plants. Salicylic acid induced rapid increase in NADPH-oxidase activity in histochemical assay with nitroblue tetrazolium but the reaction was not observed in presence of 1-butanol and NADPH-oxidase inhibitor diphenylene iodide (DPI). The further physiological effect of salicylic acid and inhibitory analysis of the signaling cascade were made in the guard cell model. Stomatal closure induced by salicylic acid was inhibited by 1-butanol and DPI treatment. rbohD transgenic plants showed impaired stomatal reaction upon phytohormone effect, while the reaction to H2O2 did not differ from that of wild-type plants. Thus a key role of NADPH-oxidase D-isoform in the process of stomatal closure in response to salicylic acid has been postulated. It has enabled to predict a cascade implication of PLD and NADPH oxidase to salicylic acid signaling pathway.
authors.affiliation: Institute of Bioorganic Chemistry and Petrochemistry, National Academy of Science of Ukraine, Kyiv 02094, Ukraine. kalachova@bpci.kiev.ua
authors.forename: Tetiana
authors.initials: T
authors.lastname: Kalachova
authors.forename: Oksana
authors.initials: O
authors.lastname: Iakovenko
authors.forename: Sergii
authors.initials: S
authors.lastname: Kretinin
authors.forename: Volodymyr
authors.initials: V
authors.lastname: Kravets
mesh_terms: D020001:1-Butanol / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects* / Q000201:enzymology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media / Q000378:metabolism; D004789:Enzyme Activation; D020404:Glycerophospholipids / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism*; D009580:Nitroblue Tetrazolium / Q000378:metabolism; D010712:Phosphatidic Acids / Q000378:metabolism; D010739:Phospholipase D / Q000235:genetics / Q000378:metabolism*; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology; D054046:Plant Stomata / Q000187:drug effects / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000201:enzymology; D017382:Reactive Oxygen Species / Q000378:metabolism; D020156:Salicylic Acid / Q000494:pharmacology*; D015398:Signal Transduction; D013997:Time Factors
chemical_list: D029681:Arabidopsis Proteins; D003470:Culture Media; D020404:Glycerophospholipids; D007527:Isoenzymes; D010712:Phosphatidic Acids; D017382:Reactive Oxygen Species; C068564:phosphatidylbutanol; D009580:Nitroblue Tetrazolium; D020001:1-Butanol; D006861:Hydrogen Peroxide; C568857:AT5G47910 protein, Arabidopsis; D019255:NADPH Oxidases; D010739:Phospholipase D; D020156:Salicylic Acid