title: Salt stress mitigation by seed priming with UV-C in lettuce plants: growth, antioxidant activity and phenolic compounds.
abstract: Seeds of Lactuca sativa L. 'Romaine' were subjected to priming treatments with UV-C radiation at 0.85 or 3.42 kJ m(-2). Seedlings obtained from both primed (Pr) and non-primed (NPr) seeds were grown in an hydroponic culture system supplemented with 0 (control) or 100 mM NaCl. After 21 days of NaCl treatment, root and leaf biomass, root lengths, leaf numbers, and leaf surface area were measured. Ions (Na(+) and K(+)) accumulation was determined in roots and leaves. Total phenolic compound and flavonoid concentrations, as well as antioxidant and antiradical activities were measured in L. sativa leaves. Salt stress resulted in a lower increase in fresh weight of roots and leaves, which was more pronounced in roots than in leaves, due to reduced root elongation, leaf number and leaf expansion, as well as leaf thickness. The lower increase in fresh weight was accompanied by a restriction in tissue hydration and K(+) ion uptake, as well as an increase in Na(+) ion concentrations in all organs. These effects were mitigated in plants from the UV-C primed seeds. The mitigating effect of UV-C was more pronounced at 0.85 than at 3.42 kJ m(-2). Salt stress also resulted in an increase in total phenolic compounds and flavonoid concentrations and in the total antioxidant capacity in leaves. The highest diphenylpicrylhydrazyl radical (DPPH) scavenging activity was found in the leaves of plants from both Pr seeds. Our results suggest that plants grown from seed primed by exposure to moderate UV-C radiation exhibited a higher tolerance to salinity stress.
authors.affiliation: Unité de Physiologie et Biochimie de la réponse des plantes aux contraintes abiotiques, Département de Biologie, FST, Université Tunis El Manar, 1068 Tunis, Tunisia; Laboratoire Physiologie des Fruits et Légumes (EA 4279), Université d'Avignon et des Pays du Vaucluse, Campus Agroparc, 301 Rue Baruch de Spinoza, 84916 Avignon, France. Electronic address: chayma.ouhibi@gmail.com.
authors.forename: Chayma
authors.initials: C
authors.lastname: Ouhibi
authors.affiliation: Unité de Physiologie et Biochimie de la réponse des plantes aux contraintes abiotiques, Département de Biologie, FST, Université Tunis El Manar, 1068 Tunis, Tunisia.
authors.forename: Houneida
authors.initials: H
authors.lastname: Attia
authors.affiliation: Unité de Physiologie et Biochimie de la réponse des plantes aux contraintes abiotiques, Département de Biologie, FST, Université Tunis El Manar, 1068 Tunis, Tunisia.
authors.forename: Fedia
authors.initials: F
authors.lastname: Rebah
authors.affiliation: Unité de Physiologie et Biochimie de la réponse des plantes aux contraintes abiotiques, Département de Biologie, FST, Université Tunis El Manar, 1068 Tunis, Tunisia.
authors.forename: Najoua
authors.initials: N
authors.lastname: Msilini
authors.affiliation: Unité de Physiologie et Biochimie de la réponse des plantes aux contraintes abiotiques, Département de Biologie, FST, Université Tunis El Manar, 1068 Tunis, Tunisia.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Chebbi
authors.affiliation: Laboratoire Physiologie des Fruits et Légumes (EA 4279), Université d'Avignon et des Pays du Vaucluse, Campus Agroparc, 301 Rue Baruch de Spinoza, 84916 Avignon, France.
authors.forename: Jawad
authors.initials: J
authors.lastname: Aarrouf
authors.affiliation: Laboratoire Physiologie des Fruits et Légumes (EA 4279), Université d'Avignon et des Pays du Vaucluse, Campus Agroparc, 301 Rue Baruch de Spinoza, 84916 Avignon, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Urban
authors.affiliation: Unité de Physiologie et Biochimie de la réponse des plantes aux contraintes abiotiques, Département de Biologie, FST, Université Tunis El Manar, 1068 Tunis, Tunisia.
authors.forename: Mokhtar
authors.initials: M
authors.lastname: Lachaal
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D018545:Lactuca / Q000235:genetics / Q000378:metabolism*; D010636:Phenols / Q000378:metabolism*; D012965:Sodium Chloride / Q000008:administration & dosage*; D013312:Stress, Physiological; D014466:Ultraviolet Rays
chemical_list: D000975:Antioxidants; D010636:Phenols; D012965:Sodium Chloride
keywords: Lactuca sativa L; Phenolic compounds; Salinity; UV-C priming