Vitoria, A. P. and Cunha, M. and Rodriguez, A. P. M. and Azevedo, R. A. and Lea, P. J. (2003) Structural changes in radish seedlings (Raphanus sativus) exposed to cadmium. Comparative Biochemistry and Physiology - Part A: Molecular and Integrative Physiology, 134 (Supple). S167. ISSN 1095-6433
Full text not available from this repository.Abstract
Radish (Raphanus sativus L. var. Redondo Vermelho) seedlings were analyzed by light and scanning electron microscopy to characterize the anatomical and morphological changes caused by the exposure to 0.5 or 1.0 mM CdCl2 for 24, 48 and 72 h. The analyses showed changes in the anatomical and morphological characteristics of roots, stems and leaves of two-week-old seedlings. In all tissues, loss of cell turgidity was observed. Premature death with disintegration of the epidermis and an increase in number of root hairs were observed in roots exposed to the heavy metal. The stems of seedlings exposed to cadmium exhibited an increased number of cells in the cambial layer. The main effects observed in leaves were stomatal closure, increase in chloroplast size and number, followed by a decrease in number of chloroplasts in response to the metal toxicity. This study suggests that the anatomical and morphological changes observed in seedlings treated with CdCl2 were mainly caused by a decrease in water absorption due to the presence of this heavy metal. (Financial support by FAPESP, Brazil, and the British Council).