title: The role of antioxidant responses on the tolerance range of extreme halophyte Salsola crassa grown under toxic salt concentrations.
abstract: Salsola crassa (Amaranthaceae) is an annual halophytic species and naturally grows in arid soils that are toxic to most plants. In order to study the effects of salinity on their antioxidant system and to determine the tolerance range against salt stress, S. crassa seeds were grown with different concentrations of NaCl (0, 250, 500, 750, 1000, 1250 and 1500mM) for short (15d) and long-term (30d). Results showed that growth (RGR), water content (RWC) and osmotic potential (ΨΠ) decreased and, proline content (Pro) increased at prolonged salt treatment. Unlike K(+) and Ca(2+) contents, S. crassa highly accumulated Na(+) and Cl(-) contents. Chlorophyll fluorescence (Fv/Fm) only decreased in response to 1500mM NaCl at 30d. No salt stimulation of superoxide anion radical (O2(•-)) content was observed in plants treated with the range of 0-500mM NaCl during the experimental period. NaCl increased superoxide dismutase (SOD) activity depending on intensities of Mn-SOD and Fe-SOD isozymes except in 1500mM NaCl-treated plants at 30d. In contrast to catalase (CAT), peroxidase (POX) activity increased throughout the experiment. Also, salinity caused an increase in glutathione reductase (GR) and glutathione peroxidase (GPX) and decreased in ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR) at 15d. Both total ascorbate (tAsA) and glutathione (tGlut) contents significantly increased in treated plants with 1000-1500mM NaCl at 15d. After 0-1000mM NaCl stress, H2O2 and TBARS contents were similar to control groups at 15d, which were consistent with the increased antioxidant activity (POX, GR and GPX). However, H2O2 content was more pronounced at 30d. Therefore, S. crassa exhibited inductions in lipid peroxidation (TBARS content) in response to extreme salt concentrations. These results suggest that S. crassa is tolerant to salt-induced damage at short-term treatments as well as extreme salt concentrations.
authors.affiliation: Selcuk University, Faculty of Science, Department of Biology, 42250 Konya, Turkey. Electronic address: eytugay@selcuk.edu.tr.
authors.forename: Evren
authors.initials: E
authors.lastname: Yildiztugay
authors.affiliation: Necmettin Erbakan University, Faculty of Science, Department of Molecular Biology and Genetics, 42090 Konya, Turkey. Electronic address: cozfidan@konya.edu.tr.
authors.forename: Ceyda
authors.initials: C
authors.lastname: Ozfidan-Konakci
authors.affiliation: Selcuk University, Faculty of Science, Department of Biology, 42250 Konya, Turkey. Electronic address: mkucukoduk@selcuk.edu.tr.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Kucukoduk
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D060387:Ascorbate Peroxidases / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D011392:Proline / Q000378:metabolism; D054712:Salinity; D031248:Salsola / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D055051:Salt-Tolerant Plants / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D012965:Sodium Chloride / Q000633:toxicity; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism
chemical_list: D000975:Antioxidants; D013481:Superoxides; D012965:Sodium Chloride; D011392:Proline; D006861:Hydrogen Peroxide; D060387:Ascorbate Peroxidases; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005978:Glutathione; D001205:Ascorbic Acid
keywords: Antioxidant enzyme system; Halopyhte; Reactive oxygen species; Salsola crassa; Salt stress