title: Differential speed of activation in antioxidant system in three oat genotypes.
abstract: The objective of this study was to evaluate whether the oxidative stress caused by aluminum (Al) toxicity is a symptom that can trigger root growth inhibition in oat genotype seedlings. Oat seedlings were grown in a nutrient solution (pH 4.0) with 0 and 370 μM Al. At 12, 24, and 36 h after Al addition, growth (root length) and biochemical parameters (catalase - CAT, ascorbate peroxidase - APX, and superoxide dismutase - SOD activities, lipid peroxidation, ascorbic acid (ASA) and non-protein thiol group (NPSH) concentration) were determined. The aluminum content was measured in oat seedlings. Regardless of the exposure time, root of the tolerant genotype grew normally with any Al treatments. Al supply caused lipid peroxidation only in the Al-sensitive genotype in roots and shoots (at 12, 24, and 36 h). In sensitive genotype seedlings, CAT, APX, and SOD were activated only at 24 or 36 h. In tolerant and intermediate genotypes, CAT, APX, and SOD were activated at 12, 24, and 36 h. Data for root growth and lipid peroxidation suggested that lipid peroxidation in the sensitive genotype may be an effect of Al toxicity on root growth. Therefore, the tolerant, intermediate, and sensitive genotypes differ in the expression of the amount, type of antioxidants, and speed of activation of antioxidant system, suggesting a varying capacity of these genotypes to deal with oxidative stress, which resulted in varying sensitivity and tolerance to Al.
authors.affiliation: Federal University of Santa Maria, Graduate Program in Toxicology Biochemistry, Santa Maria, Brazil. Electronic address: lubiors@yahoo.com.br.
authors.forename: Luciane Belmonte
authors.initials: LB
authors.lastname: Pereira
authors.forename: Denise
authors.initials: D
authors.lastname: Cargnelutti
authors.forename: Liana Verônica
authors.initials: LV
authors.lastname: Rossato
authors.forename: Jamile Fabbrin
authors.initials: JF
authors.lastname: Gonçalves
authors.forename: Luciane Almeri
authors.initials: LA
authors.lastname: Tabaldi
authors.forename: Roberta
authors.initials: R
authors.lastname: Schmatz
authors.forename: Juliano Marchi
authors.initials: JM
authors.lastname: Vieira
authors.forename: Valderi
authors.initials: V
authors.lastname: Dressler
authors.forename: Fernando Teixeira
authors.initials: FT
authors.lastname: Nicoloso
authors.forename: Luiz Carlos
authors.initials: LC
authors.lastname: Federizzi
authors.forename: Vera M
authors.initials: VM
authors.lastname: Morsch
authors.forename: Maria R C
authors.initials: MR
authors.lastname: Schetinger
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics; D000535:Aluminum / Q000633:toxicity; D000975:Antioxidants / Q000378:metabolism*; D060387:Ascorbate Peroxidases / Q000378:metabolism; D018554:Avena / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005838:Genotype; D015227:Lipid Peroxidation / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors
chemical_list: D000975:Antioxidants; D000535:Aluminum; D060387:Ascorbate Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase
keywords: Aluminum; Antioxidant system; Avena sativa; Genotypes; Lipid peroxidation