INVESTIGADORES
FABRA Adriana Isidora
artículos
Título:
Involvement of glutathione and enzymatic defense system
Autor/es:
BIANUCCI, E.; FABRA, ADRIANA; CASTRO,S.
Revista:
BIOMETALS
Editorial:
SPRINGER
Referencias:
Año: 2012 vol. 25 p. 23 - 32
ISSN:
0966-0844
Resumen:
In this study, the effects of cadmium (Cd)
on cell morphology and antioxidant enzyme activities
as well as the distribution of the metal in different cell
compartments in Bradyrhizobium sp. strains were
investigated. These strains were previously classified
as sensitive (Bradyrhizobium sp. SEMIA 6144) and
tolerant (Bradyrhizobium sp. NLH25) to Cd. Transmission
electron micrographs showed large electrontranslucent
inclusions in the sensitive strain and
electron-dense bodies in the tolerant strain, when
exposed to Cd. Analysis of Cd distribution revealed
that it was mainly bounded to cell wall in both
strains. Antioxidant enzyme activities were significantly
different in each strain. Only the tolerant strain
was able to maintain a glutathione/oxidized glutathione
(GSH/GSSG) ratio by an increase of GSH
reductase (GR) and GSH peroxidase (GPX) enzyme
activities. GSH S-transferase (GST) and catalase
(CAT) activities were drastically inhibited in both
strains while superoxide dismutase (SOD) showed a
significant decrease only in the sensitive strain. In conclusion, our findings suggest that GSH content
and its related enzymes are involved in the Bradyrhizobium
sp. tolerance to Cd contributing to the
cellular redox balance.