Óxido nítrico e tolerância ao arsênio em aguapé

• Autor(a) principal: Andrade, Heloísa Monteiro de
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2331
• topic: Óxido nítrico; Macrófita aquática; Nitric oxide; Aquatic macrophyte; Toxicity; CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL

Water hyacinth (Eichhornia crassipes (Mart.) Solms) were subjected to toxic levels of arsenic (As) in order to induce oxidative stress and assess the role of nitric oxide (NO), provided by the sodium nitroprusside (SNP), as agent for mitigating this stress. The plants were treated with As 20 μM, with or without SNP at a concentration of 100 μM, added to the nutrient solution for 24 hours. The concentration of hydrogen peroxide (H2O2), superoxide anion (O2 .-) and malonaldehyde (MDA) were determined, as well as the activity of the enzymes superoxide dismutase (SOD), catalase (CAT), peroxidase (POX) and the internal concentration of As. The membrane integrity of the root was inferred by staining using Evans Blue solution. The presence of SNP with As, resulted in higher concentrations of this metalloid on the roots and increased translocation to the leaves. Nevertheless, the concentration of H2O2, O2.- and the MDA was lower in comparison with plants treated only with As, as well as the activity of SOD and POX. However, CAT was most active in the early stages of treatment. The protective role of NO decreased the oxidative damage induced by As, which was also evident from the staining for detection of plasma membrane integrity. Thus, the NO, provided by the SNP, alleviates toxicity induced in roots of water hyacinth by As.