title: Comparison of polyamine metabolism in tomato plants exposed to different concentrations of salicylic acid under light or dark conditions.
abstract: In this study the effect of exogenous 0.1 mM and 1 mM salicylic acid (SA) treatments were investigated on polyamine (PA) metabolism in tomato (Solanum lycopersicum L. cv. Ailsa Craig) leaves in illuminated or dark environments. The former proved to be sublethal and the latter lethal concentration for tomato leaf tissues. While PA biosynthetic genes, arginine- and ornitine decarboxylases or spermidine- and spermine synthases were highly up-regulated by 1 mM SA, the enzymes participating in PA catabolism, diamine- (DAOs, EC 1.4.3.6) and polyamine oxidases (PAOs, EC 1.5.3.3) displayed higher transcript abundance and enzyme activity at 0.1 mM SA. As a result, putrescine and spermine content but not that of spermidine increased after 1 mM SA application, which proved to be higher in the dark than in the light. H2O2content produced on the effect of 1 mM SA was significantly higher than at 0.1 mM SA in the light. Since there was no coincidence between H2O2accumulation and terminal PA catabolism, reactive oxygen species produced by photosynthesis and by other sources had more pronounced effect on H2O2generation at tissue level than DAOs and PAOs. Accordingly, H2O2in the absence of NO accumulation contributed to the initiation of defence reactions after 0.1 mM SA treatment, while high SA concentration generated simultaneous increase in H2O2and NO production in the light, which induced cell death within 24 h in illuminated leaves. However, the appearance of necrotic lesions was delayed in the absence of NO if these plants were kept in darkness.
authors.affiliation: Department of Plant Biology, University of Szeged, H-6726 Szeged, Közép Fasor 52., Hungary. Electronic address: takacszoltan8923@gmail.com.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Takács
authors.affiliation: Department of Plant Biology, University of Szeged, H-6726 Szeged, Közép Fasor 52., Hungary. Electronic address: poorpeti@bio.u-szeged.hu.
authors.forename: Péter
authors.initials: P
authors.lastname: Poór
authors.affiliation: Department of Plant Biology, University of Szeged, H-6726 Szeged, Közép Fasor 52., Hungary. Electronic address: tari@bio.u-szeged.hu.
authors.forename: Irma
authors.initials: I
authors.lastname: Tari
mesh_terms: D015317:Biogenic Polyamines / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects; D003624:Darkness; D004305:Dose-Response Relationship, Drug; D006861:Hydrogen Peroxide / Q000378:metabolism; D008027:Light; D018551:Solanum lycopersicum / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D020156:Salicylic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D000097667:Polyamine Oxidase
chemical_list: D015317:Biogenic Polyamines; D006861:Hydrogen Peroxide; D009569:Nitric Oxide; D000587:Oxidoreductases Acting on CH-NH Group Donors; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D020156:Salicylic Acid; D000097667:Polyamine Oxidase
keywords: Dark; Hydrogen peroxide; Light; Nitric oxide; Polyamine; Salicylic acid; Tomato