INVESTIGADORES
BENAVIDES Maria patricia
artículos
Título:
Reactive oxygen species formation and cell death in catalase-deficient tobacco leaf disks exposed to cadmium
Autor/es:
IANNONE M.F; ROSALES E.P; GROPPA M.D., ; BENAVIDES M.P
Revista:
PROTOPLASMA
Editorial:
SPRINGER WIEN
Referencias:
Año: 2010 vol. 245 p. 15 - 27
ISSN:
0033-183X
Resumen:
The physiological responses of tobacco (Nicotiana
tabacum L.) to oxidative stress induced by cadmium were
examined with respect to reactive oxygen species (ROS)
formation, antioxidant enzymes activities, and cell death
appearance in wild-type SR1 and catalase-deficient CAT1AS
plants. Leaf disks treated with 100 or 500 μM CdCl2
increased Evans blue staining and leakage of electrolytes in
SR1 or CAT1AS plants, more pronouncedly in the transgenic
cultivar, but without evidence of lipid peroxidation in
any of the cultivars compared to controls. Cadmium
significantly reduced the NADPH oxidase-dependent O2
−
formation in a dose dependent manner in SR1 very strongly
at 500 μM (to 5% of the activity in the nontreated SR1 leaf
disks). In CAT1AS, the NADPH oxidase activity was
constitutively reduced at 50% with respect to that of SR1,
but the magnitude of the decay was less prominent in this
cultivar, reaching an average of 64% of the C at 21 h, for
both Cd concentrations. Hydrogen peroxide formation was
only slightly increased in SR1 or CAT1AS leaf disks at 21 h
of exposure compared to the respective controls. Cd
increased superoxide dismutase activity more than six times
at 21 h in CAT1AS, but not in SR1 and reduced catalase
activity by 59% at 21 h of treatment only in SR1 plants.
Despite that catalase expression was constitutively lower in
CATAS1 compared to SR1 nontreated leaf disks, 500 μM
CdCl2 almost doubled it only in CAT1AS at 21 h. The
mechanisms underlying Cd-induced cell death were possibly
not related exclusively to ROS formation or detoxification in
tobacco SR1 or CAT1AS plants