RESUMO
ABSTRACT This study aimed to evaluate the radiosensitivity of castor bean seeds after applications of different doses of Cobalt60 gamma radiation. Seeds were pre-soaked for 24 hours in distilled water and then irradiated with 50, 100, 150, and 200 Gy, except the control. Sowing was performed in trays, which contained soil as substrate and were maintained in a greenhouse. The electrical conductivity, emergence, emergence speed index, growth parameters and activities of antioxidant enzymes (superoxide dismutase, ascorbate peroxidase, and catalase) were evaluated in the leaves and roots of castor bean seedlings. Gamma radiation did not affect the electrical conductivity of the seeds; however, at a dose of 200 Gy, the emergence and emergence speed index of the seedlings was negatively affected. An analysis of the morphophysiological parameters revealed a reduction in seedling size as the radiation dose increased. There was a significant increase in superoxide dismutase and ascorbate peroxidase activities at higher radiation doses in the leaves, but not in roots. Thus, the analysis of all the variables suggests a response pattern as to the morphophysiological and biochemical changes of castor bean seedlings due to the increase of gamma radiation, which may serve as a tool for generating greater genetic variability.
Assuntos
Ricinus/efeitos da radiação , Sementes/efeitos da radiação , Radioisótopos de Cobalto , Germinação/efeitos da radiação , Raios gama , Ricinus/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Relação Dose-Resposta à RadiaçãoRESUMO
This study aimed to evaluate the radiosensitivity of castor bean seeds after applications of different doses of Cobalt60 gamma radiation. Seeds were pre-soaked for 24 hours in distilled water and then irradiated with 50, 100, 150, and 200 Gy, except the control. Sowing was performed in trays, which contained soil as substrate and were maintained in a greenhouse. The electrical conductivity, emergence, emergence speed index, growth parameters and activities of antioxidant enzymes (superoxide dismutase, ascorbate peroxidase, and catalase) were evaluated in the leaves and roots of castor bean seedlings. Gamma radiation did not affect the electrical conductivity of the seeds; however, at a dose of 200 Gy, the emergence and emergence speed index of the seedlings was negatively affected. An analysis of the morphophysiological parameters revealed a reduction in seedling size as the radiation dose increased. There was a significant increase in superoxide dismutase and ascorbate peroxidase activities at higher radiation doses in the leaves, but not in roots. Thus, the analysis of all the variables suggests a response pattern as to the morphophysiological and biochemical changes of castor bean seedlings due to the increase of gamma radiation, which may serve as a tool for generating greater genetic variability.
Assuntos
Radioisótopos de Cobalto , Raios gama , Germinação/efeitos da radiação , Ricinus/efeitos da radiação , Sementes/efeitos da radiação , Relação Dose-Resposta à Radiação , Ricinus/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimentoRESUMO
Pereskia aculeata is a Cactaceae plant with valuable nutritional properties, including terrific amounts of protein, minerals, vitamins, and fiber. However, P. aculeata is reported to contain antinutrients and alkaloids in its leaves. In addition, in a study on growth and development, Wistar rats fed with P. aculeata and casein as protein source grew less than the control group (fed with casein only). Therefore, in this study, we evaluated, for the first time, the oral acute toxicity of P. aculeata in rats and also the cytotoxicity behavior of the plant on lettuce seeds. The acute toxicity research was carried out using dried P. aculeata ethanolic extract, in three different doses, administered by gavage to 24 female Wistar rats. The rats were then examined for signs of toxicity, food intake, body weight, and fecal excretion fluctuations, as well as histopathological alterations, using eight different body tissues. The acute toxicity study did not show any difference among the groups in either clinical evaluation or histopathological analyses. For the cytotoxicity study, dried P. aculeata ethanolic extract was applied on lettuce seeds in five different concentrations. These seeds were evaluated for germination, root and shoot length, and mitotic index. The results show that P. aculeata extract affects lettuce root and shoot growth, but not germination or mitotic index. In conclusion, the acute toxicity on rats and the cytogenotoxicity on lettuce of P. aculeata are neglectable, validating the potential of this plant to be used as a functional food.