Perda da tolerância à dessecação em sementes de tento-carolina (Adenanthera pavonina L.) durante a germinação

• Autor(a) principal: Soares, Giuliana Cristina Mourão
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4335
• topic: Dessecação; Ciclo celular; Enzimas antioxidantes; Desiccation; Cell cycle; Antioxidant enzymes; CNPQ::CIENCIAS BIOLOGICAS::BOTANICA::FISIOLOGIA VEGETAL

On germination, orthodox seeds become intolerant of desiccation. In this condition, these seeds may be a useful model for studies of recalcitrance, in order to elucidate structural and biochemical attributes associated with desiccation sensitivity. Here, we evaluated the loss of desiccation tolerance (DT) in Adenathera pavonina germinating seeds, by following the ability of seeds to germinate after desiccation following various periods of preimbibition. DT was progressively lost during germination, and seeds with radicle length of 1 mm did not withstand drying up to 13% of moisture content. By the rates of electrolyte leakage, it was observed that membrane system was damaged when 60-hour imbibed seeds were dried. It was also observed that dehydration decreased the activity of superoxide dismutase, however catalase, peroxidase and ascorbate peroxidase activities remained unchanged. Three groups of heat shock proteins were detected in fresh seeds, but with the progress of germination the number and intensity of its bands declined. Relative DNA content assessment was done by flow citometry. These analyses showed that the resumption of cell cycle coincided with the complete los of DT.