Establishing the redox potential of Tibouchina pulchra (Cham.) Cogn., a native tree species from the Atlantic Rain Forest, in the vicinity of an oil refinery in SE Brazil

Autor(es)

Esposito, Marisia Pannia ^[1] ; Domingos, Marisa ^[1]

Afiliação do(s) autor(es)

^[1] Inst Bot, Nucleo Pesquisa Ecol, BR-04045972 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Environmental Science and Pollution Research; v. 21, n. 8, p. 5484-5495, APR 2014.
• Citações Web of Science: 8

Resumo

The present study aimed to establish the seasonal variations in the redox potential ranges of young Tibouchina pulchra plants growing in the Cubato region (SE Brazil) under varying levels of oxidative stress caused by air pollutants. The plants were exposed to filtered air (FA) and non-filtered air (NFA) in open-top chambers installed next to an oil refinery in Cubato during six exposure periods of 90 days each, which included the winter and summer seasons. After exposure, several analyses were performed, including the foliar concentrations of ascorbic acid and glutathione in its reduced (AsA and GSH), total (totAA and totG) and oxidized forms (DHA and GSSG); their ratios (AsA/totAA and GSH/totG); the enzymatic activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and glutathione reductase (GR); and the content of malondialdehyde (MDA). The range of antioxidant responses in T. pulchra plants varied seasonally and was stimulated by high or low air pollutant concentrations and/or air temperatures. Glutathione and APX were primarily responsible for increasing plant tolerance to oxidative stress originating from air pollution in the region. The high or low air temperatures mainly affected enzymatic activity. The content of MDA increased in response to increasing ozone concentration, thus indicating that the pro-oxidant/antioxidant balance may not have been reached. (AU)

• Processo FAPESP: 08/58682-1 - Capacidade de oxirredução de plantas jovens de Tibouchina pulchra (Cham.) Cogn.: resposta indicadora de mudanças na qualidade do ar no entorno de uma refinaria de petróleo na região de Cubatão, SP
• Beneficiário: Marisia Pannia Esposito
• Modalidade de apoio: Bolsas no Brasil - Doutorado