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Desiccation tolerance of Rhamnidium elaeocarpum reissek
This study aimed to investigate the desiccation tolerance of Rhamnidium elaeocarpum Reissek seeds through physiological and biochemical alterations. Fruit were collected from the municipality of Jaupaci, Goias State, Brazil, when the water content of their seeds had a 37% wet basis (w.b.) and the se...
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| Published in: | Acta scientiarum. Agronomy 2015-04, p.181 |
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| Main Authors: | , , , , , |
| Format: | Article |
| Language: | Spanish |
| Online Access: | Get full text |
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| Summary: | This study aimed to investigate the desiccation tolerance of Rhamnidium elaeocarpum Reissek seeds through physiological and biochemical alterations. Fruit were collected from the municipality of Jaupaci, Goias State, Brazil, when the water content of their seeds had a 37% wet basis (w.b.) and the seeds were subsequently kept in a drying oven with air circulation at a temperature of 35°C until a water content was reached of 20 to 12% (w.b.). The following parameters were evaluated: germination, germination speed index, emergence, emergence speed index, electrical conductivity and respiration rate. Furthermore, the electrophoretic profile of the isoenzymes: catalase, peroxidase and esterase, the enzymatic activities of endo-β-mannanase and α-amylase and the electrophoretic analysis of heat-resistant proteins were performed. A higher germination speed and respiratory rate was obtained for seeds with a water content of 12% w.b., and the activity of catalase isoforms was more pronounced in seeds with a higher degree of dehydration, which was in contrast to peroxidase, showed decreased activity. The seeds contained heatresistant proteins of low molecular weight that ranged from 48.7 to 13.2 kDa. We found that the acquisition of drying tolerance in R. Elaeocarpum Reissek seeds is associated more with catalase than with esterase and peroxidase. Keywords: drying, germination, isoenzymes, respiration rate, heat-resistant proteins. O trabalho teve como objetivo investigar a tolerancia a dessecacao em sementes de Rhamnidium elaeocarpum Reissek por meio de alteracoes fisiologicas e bioquimicas. Os frutos foram coletados no municipio de Jaupaci, Estado de Goias, quando as sementes apresentavam teor de agua de 37% base umida (b.u.), sendo em seguida mantidas em estufa de secagem com circulacao de ar a temperatura de 35°C ate alcancarem os teores de agua de 20 e 12% (b.u.). Foram avaliados os seguintes parametros: germinacao; indice de velocidade de germinacao; emergencia; indice de velocidade de emergencia; condutividade eletrica; taxa respiratoria; perfil eletroforetico das isoenzimas: catalase, peroxidase e esterase; atividade enzimatica de endo-β-mananase e α-amilase e analise eletroforetica de proteinas resistentes ao calor. Maior velocidade de germinacao e taxa respiratoria foi obtida para sementes com teor de agua de 12% b.u. A atividade das isoformas de catalase foi mais pronunciada em sementes com maior grau de desidratacao em relacao a peroxidase que diminuiu su |
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| ISSN: | 1679-9275 1807-8621 |
| DOI: | 10.4025/actasciagron.v37i2.19425 |