title: The redox state of Ipomoea nil 'Scarlet O'Hara' growing under ozone in a subtropical area.
abstract: The occurrence of visible leaf injury caused by ozone in Ipomoea nil 'Scarlet O'Hara' may be regulated by their redox state, affecting its bioindicator efficiency. Thus, this study aimed to determine whether the redox state of I. nil plants in a subtropical area (São Paulo, SE-Brazil) contaminated by ozone oscillates, and to identify the environmental factors behind these variations. We comparatively evaluated indicators of redox state (ascorbic acid, glutathione, superoxide dismutase, ascorbate peroxidase, glutathione reductase) and leaf injury during nine field experiments of 28 days each. The variations in the redox indicators were explained by the combined effects of chronic levels of ozone and meteorological variables (mainly global solar radiation and air temperature) 3-6 days prior to the sampling days. The ascorbic acid and glutathione were crucial for increasing plant tolerance to ozone. Weak visible injury was observed in all experiments and occurred in leaves with low levels of ascorbic and dehydroascorbic acids.
authors: Instituto de Botânica, Caixa Postal 68041, 04045-972 São Paulo, SP, Brazil.
authors: Marcelle
authors: M
authors: Dafré-Martinelli
authors: Ricardo K
authors: RK
authors: Nakazato
authors: Ana P L
authors: AP
authors: Dias
authors: Mirian C S
authors: MC
authors: Rinaldi
authors: Marisa
authors: M
authors: Domingos
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D001205:Ascorbic Acid / Q000378:metabolism; D001938:Brazil; D003683:Dehydroascorbic Acid / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D049915:Ipomoea nil / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010126:Ozone / Q000633:toxicity*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D013696:Temperature
chemical_list: D000393:Air Pollutants; D010126:Ozone; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005978:Glutathione; D001205:Ascorbic Acid; D003683:Dehydroascorbic Acid