INVESTIGADORES
BENAVIDES Maria Patricia
congresos y reuniones científicas
Título:
Antioxidative response of Helianthus annuus L. against copper toxicity
Autor/es:
GROPPA, MD, TOMARO ML AND BENAVIDES MP
Lugar:
Buenos Aires, Argentina
Reunión:
Congreso; XII Biennial Meeting of the Society for Free Radical Research International; 2004
Resumen:
Copper is essential for normal plant growth, though is phytotoxic at
high concentrations. To study copper toxicity in sunflower, we evaluated some
antioxidant enzymes, polyamines and proline during the first 16 days of growth,
under 0.1 and 1 mM CuCl2.
Plant growth was significantly reduced by the
highest copper concentration from the seventh day of treatment. Ascorbate
peroxidase, superoxide dismutase, glutathione and proline showed a significant
increase, in shoots and roots, under 1 mM CuCl2 from day 10.
Putrescine increased in shoots and roots from the 7th day, while
spermidine and spermine increased in shoots only by day 16. Guayacol peroxidase
increased in roots while glutathione reductase showed an irregular pattern
under 1 mM Cu2+. Catalase was not detected in roots, while in shoots
it decreased from day 16 under both copper concentrations. Thiobarbituric acid
reactive substances (TBARS) increased in roots and shoots only with 1 mM CuCl2.
Although some antioxidant enzymes, polyamines and proline (postulated as
antioxidants), raised under 1 mM Cu2+, this increase was not enough
to avoid growth inhibition and to protect sunflower plants against the
oxidative damage produced by 1 mM Cu2+. The precise role of enzymes
and antioxidant compounds against copper-induced oxidative damage is discussed.