title: Cross-talk between salicylic acid and NaCl-generated reactive oxygen species and nitric oxide in tomato during acclimation to high salinity.
abstract: Hydrogen peroxide (H₂O₂) and nitric oxide (NO) generated by salicylic acid (SA) are considered to be functional links of cross-tolerance to various stressors. SA-stimulated pre-adaptation state was beneficial in the acclimation to subsequent salt stress in tomato (Solanum lycopersicum cv. Rio Fuego). At the whole-plant level, SA-induced massive H₂O₂ accumulation only at high concentrations (10⁻³-10⁻² M), which later caused the death of plants. The excess accumulation of H₂O₂ as compared with plants exposed to 100 mM NaCl was not associated with salt stress response after SA pre-treatments. In the root tips, 10⁻³-10⁻² M SA triggered the production of reactive oxygen species (ROS) and NO with a concomitant decline in the cell viability. Sublethal concentrations of SA, however, decreased the effect of salt stress on ROS and NO production in the root apex. The attenuation of oxidative stress because of high salinity occurred not only in pre-adapted plants but also at cell level. When protoplasts prepared from control leaves were exposed to SA in the presence of 100 mM NaCl, the production of NO and ROS was much lower and the viability of the cells was higher than in salt-treated samples. This suggests that, the cross-talk of signalling pathways induced by SA and high salinity may occur at the level of ROS and NO production. Abscisic acid (ABA), polyamines and 1-aminocyclopropane-1-carboxylic acid, the compounds accumulating in pre-treated plants, enhanced the diphenylene iodonium-sensitive ROS and NO levels, but, in contrast to others, ABA and putrescine preserved the viability of protoplasts.
authors.affiliation: Department of Plant Biology, University of Szeged, PO Box 654, H-6701 Szeged, Hungary.
authors.forename: Katalin
authors.initials: K
authors.lastname: Gémes
authors.forename: Péter
authors.initials: P
authors.lastname: Poór
authors.forename: Edit
authors.initials: E
authors.lastname: Horváth
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Kolbert
authors.forename: Dóra
authors.initials: D
authors.lastname: Szopkó
authors.forename: Agnes
authors.initials: A
authors.lastname: Szepesi
authors.forename: Irma
authors.initials: I
authors.lastname: Tari
mesh_terms: D000064:Acclimatization; D002470:Cell Survival; D004305:Dose-Response Relationship, Drug; D006861:Hydrogen Peroxide / Q000032:analysis / Q000378:metabolism; D018551:Solanum lycopersicum / Q000187:drug effects* / Q000502:physiology*; D008856:Microscopy, Fluorescence; D009569:Nitric Oxide / Q000378:metabolism*; D018384:Oxidative Stress; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D011523:Protoplasts / Q000187:drug effects / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D020156:Salicylic Acid / Q000494:pharmacology*; D054712:Salinity; D015398:Signal Transduction; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological
chemical_list: D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D012965:Sodium Chloride; D006861:Hydrogen Peroxide; D020156:Salicylic Acid