Efeitos de extrato aquoso de folhas de Solanum lycocarpum St. Hil. no desenvolvimento inicial e na síntese protéica de plântulas de Sesamum indicum L.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Solanum lycocarpum St. Hil., the common wolf fruit, is a Cerrado shrub in which leaves and fruits present strong allelopathic potencial. It was previously shown that aqueous leaf extracts at 1% (w/v) inhibit root growth and root hair differentiation in sesame (Sesamum indicum L.) seedlings. Considering that the morphological changes observed in plants subjected to some treatment usually result from the primary effects of these treatments on plant metabolism, the main objectives of this study were: (1) to investigate the allelopathic effects of aqueous extracts of Solanum leaves on seedling growth, root differentiation and dry matter incorporation in sesame; (2) to verify whether the morphological changes observed in seedlings incubated in the extracts are reversible; (3) to investigate the effects of the aqueous extracts on protein synthesis during seedling growth. This study showed that: Aqueous leaf extracts of Solanum at 1 and 3% inhibited significantly the root growth of sesame seedlings in a dose-dependent manner, the roots were more affected than the shoots, and root tip necrosis were common at 3% concentration. Also, aqueous extracts at 3% inhibited lateral root and root hair differentiation. The water content of the seedlings were not significantly affected by the extracts. However, roots incubated in the extracts incorporated less dry matter than roots incubated in water. To investigate whether the allelopathic effects were reversible, seedlings incubated for two days in the extracts were transferred to water. After five days in water they resumed normal growth, the root tip necrosis disappeared, and lateral root and root hair differentiated. Seedlings incubated in the leaf extracts incorporated more 35S-methionine than those incubated in water. Also, the analysis of gels and fluorograms showed that seedlings incubated in the leaf extracts showed a higher protein synthesis, in comparison to seedlings incubated in water, and in both cases protein synthesis was higher in the roots than in the shoots

ASSUNTO(S)

allelopathy solanum lycocarpum sesamum indicum isotopic labeling sesamum indicum incorporação isotópica seedling growth cerrado alelopatia cerrado gergelim botanica desenvolvimento inicial proteína solanum lycocarpum sesame protein

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