title: Spread of oxidative damage and antioxidative response through cell layers of tobacco callus after UV-C treatment.
abstract: Tobacco (Nicotiana tabacum L. cv. Petit Havana) callus cultures were exposed to UV-C high dose pulse-treatment (254 nm, 50 kJ m(-2), 1 h-treatment). After 6, 24 and 48 h from the end of the treatment, calli were cut transversally in two layers and oxidative damage (malondialdehyde [MDA] and hydrogen peroxide), non-enzymatic (radical scavenging antioxidants [RSA] and polyamines) and enzymatic antioxidants (ascorbate peroxidase [APX, EC 1.11.1.11], glutathione reductase [GR, EC 1.6.4.2], catalase [CAT, EC 1.11.1.6] and guaiacol peroxidase [GPX, EC 1.11.1.7]) were evaluated. At each time-point data referred to UV-C treated calli were compared to data of untreated ones (control). Despite of a strong increase of H2O2 content, a slight cellular damage was observed in both upper and lower layers 24 and 48 h after UV-C treatment. An activation first of non-enzymatic antioxidants and then of enzymatic antioxidants was detected in UV-C treated calli. In particular, RSA and putrescine (PUT) accumulated 6 h after UV-C treatment while APX, GR and GPX enzyme activities increased 24 h after UV-C irradiation. Catalase activity did not change. UV-C-induced oxidative stress and antioxidative response were observed also in cell layers not directly exposed to UV irradiation, indicating that a stress signal was transmitted to the whole mass of callus.
authors.affiliation: Istituto di Biologia Agroambientale e Forestale, Consiglio Nazionale delle Ricerche, Via Salaria km 29.300, 00016 Monterotondo Scalo (Roma), Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Zacchini
authors.forename: Marina
authors.initials: M
authors.lastname: de Agazio
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D060387:Ascorbate Peroxidases; D002374:Catalase / Q000494:pharmacology; D005609:Free Radicals; D005980:Glutathione Reductase / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology; D015227:Lipid Peroxidation; D008054:Lipid Peroxides / Q000737:chemistry; D008315:Malondialdehyde / Q000494:pharmacology; D018384:Oxidative Stress; D009195:Peroxidase / Q000494:pharmacology; D010544:Peroxidases / Q000494:pharmacology; D011073:Polyamines / Q000737:chemistry; D011700:Putrescine / Q000494:pharmacology; D013997:Time Factors; D014026:Nicotiana / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D008054:Lipid Peroxides; D011073:Polyamines; D008315:Malondialdehyde; D006861:Hydrogen Peroxide; D010544:Peroxidases; C121048:guaiacol peroxidase; D060387:Ascorbate Peroxidases; D002374:Catalase; D009195:Peroxidase; D005980:Glutathione Reductase; D011700:Putrescine