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Morphophysiological responses and programmed cell death induced by cadmium in Genipa americana L. (Rubiaceae).
Souza, Vânia L; de Almeida, Alex-Alan F; Lima, Stella G C; de M Cascardo, Júlio C; da C Silva, Delmira; Mangabeira, Pedro A O; Gomes, Fábio P.
Afiliação
  • Souza VL; Laboratório de Genômica e Expressão Gênica, DCB/UESC, Rod. BR 415, Km 16, Ilheus, BA 45662-000, Brazil.
Biometals ; 24(1): 59-71, 2011 Feb.
Article em En | MEDLINE | ID: mdl-20838856
Cadmium (Cd) originating from atmospheric deposits, from industrial residues and from the application of phosphate fertilizers may accumulate in high concentrations in soil, water and food, thus becoming highly toxic to plants, animals and human beings. Once accumulated in an organism, Cd discharges and sets off a sequence of biochemical reactions and morphophysiological changes which may cause cell death in several tissues and organs. In order to test the hypothesis that Cd interferes in the metabolism of G. americana, a greenhouse experiment was conducted to measure eventual morphophysiological responses and cell death induced by Cd in this species. The plants were exposed to Cd concentrations ranging from 0 to 16 mg l(-1), in a nutritive solution. In TUNEL reaction, it was shown that Cd caused morphological changes in the cell nucleus of root tip and leaf tissues, which are typical for apoptosis. Cadmium induced anatomical changes in roots and leaves, such as the lignification of cell walls in root tissues and leaf main vein. In addition, the leaf mesophyll showed increase of the intercellular spaces. On the other hand, Cd caused reductions in the net photosynthetic rate, stomatal conductance and leaf transpiration, while the maximum potential quantum efficiency of PS2 (Fv/Fm) was unchanged. Cadmium accumulated in the root system in high concentrations, with low translocation for the shoot, and promoted an increase of Ca and Zn levels in the roots and a decrease of K level in the leaves. High concentrations of Cd promoted morphophysiological changes and caused cell death in roots and leaves tissues of G. americana.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Cádmio / Raízes de Plantas / Folhas de Planta / Rubiaceae Idioma: En Revista: Biometals Assunto da revista: BIOQUIMICA Ano de publicação: 2011 Tipo de documento: Article País de afiliação: Brasil País de publicação: Holanda

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Cádmio / Raízes de Plantas / Folhas de Planta / Rubiaceae Idioma: En Revista: Biometals Assunto da revista: BIOQUIMICA Ano de publicação: 2011 Tipo de documento: Article País de afiliação: Brasil País de publicação: Holanda