CIPYP   05508
CENTRO DE INVESTIGACIONES SOBRE PORFIRINAS Y PORFIRIAS
Unidad Ejecutora - UE
artículos
Título:
Inhibition of root growth and polyamine metabolism in sunflower (Helianthus annuus) seedlings under cadmium and copper stress
Autor/es:
GROPPA, MARÍA D.; ZAWOZNIK, MYRIAM S.; TOMARO, MARÍA L.; BENAVIDES, MARÍA P.
Revista:
Biological Trace Element Research
Referencias:
Año: 2008 vol. 126 p. 246 - 256
Resumen:
Although sunflower is usually regarded as a highly tolerant crop, impairment of root
growth at initial stages of plant development may result in poor crop establishment and higher
susceptibility to pathogen attack. In order to evaluate if Cd2+ and Cu2+ may impact on
sunflower germination and initial root development, a pot experiment under controlled
conditions was carried out. Possible involvement of polyamine metabolism in sunflower
response to these stressors was also investigated. Although Cd2+ and Cu2+ treatments affect
neither seed germination nor radicle emergence, sunflower seedlings grown in the presence of
these heavy metals showed significant inhibition of root growth, being this inhibition greater
for Cd2+. Both metals caused significant increases in proline contents at the highest
concentrations tested (0.5 and 1 mM), and these increments were more pronounced for Cd2+2+ and Cu2+ may impact on
sunflower germination and initial root development, a pot experiment under controlled
conditions was carried out. Possible involvement of polyamine metabolism in sunflower
response to these stressors was also investigated. Although Cd2+ and Cu2+ treatments affect
neither seed germination nor radicle emergence, sunflower seedlings grown in the presence of
these heavy metals showed significant inhibition of root growth, being this inhibition greater
for Cd2+. Both metals caused significant increases in proline contents at the highest
concentrations tested (0.5 and 1 mM), and these increments were more pronounced for Cd2+2+ and Cu2+ treatments affect
neither seed germination nor radicle emergence, sunflower seedlings grown in the presence of
these heavy metals showed significant inhibition of root growth, being this inhibition greater
for Cd2+. Both metals caused significant increases in proline contents at the highest
concentrations tested (0.5 and 1 mM), and these increments were more pronounced for Cd2+2+. Both metals caused significant increases in proline contents at the highest
concentrations tested (0.5 and 1 mM), and these increments were more pronounced for Cd2+2+
treatments, especially between days 3 and 10. Metals also increased putrescine (Put) contents
at all concentrations assayed from the seventh day onward, causing no variations on this
polyamine time-course pattern. Spermine and spermidine contents, however, were increased
only by 1 mM Cd2+. Arginine decarboxylase seems to have been the enzyme responsible for
Put increases under both metal treatments. This work demonstrates that initial root growth of
sunflower seedlings may be significantly impaired in Cd2+ or Cu2+ contaminated soils. It also
shows that polyamines are key biological compounds, which are probably involved in
signaling pathways triggered under stress environmental conditions.2+. Arginine decarboxylase seems to have been the enzyme responsible for
Put increases under both metal treatments. This work demonstrates that initial root growth of
sunflower seedlings may be significantly impaired in Cd2+ or Cu2+ contaminated soils. It also
shows that polyamines are key biological compounds, which are probably involved in
signaling pathways triggered under stress environmental conditions.2+ or Cu2+ contaminated soils. It also
shows that polyamines are key biological compounds, which are probably involved in
signaling pathways triggered under stress environmental conditions.
..