Effect of polyamines pre-treatment on Cd- and Cu-changes in sunflower and wheat membrane fluidity

BENAVIDES, M. P.; GROPPA, M. D.; VERSTRAETEN, S. V.

Mar del Plata, Buenos Aires, Argentina

Congreso; XLIII Reunión Annual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2007

SAIB

physiological events. They bind to membrane phospholipids, nucleid acids and proteins. The objectives of this work were (a) to investigate whether Cd and/or Cu could alter plants membrane fluidity, and (b) whether these alterations could be prevented by PAs. Membrane fluidity was evaluated in leaves and roots of sunflower and wheat, watered for 15 days with 1 mM Cd2Cl or Cu2Cl. While Cd2+ decreased leaves and roots fluidity (evaluated with the fluorescent probe DPH), no significant effects were observed for Cu2+, although a small but significant fluidification was observed in wheat leaves. Next, plants were pre-treated with putrescine (Put), spermidine (Spd) or spermine (Spm) (0.1mM)for either 5 or 10 days, and then watered with the metals until day 15.A significant decrease in membrane fluidity was observed at days 5 and 10 of PAs pre-treatment, followed by a significant increase in the fluidity at day 15. Put did not prevent Cd-mediated decrease in membrane fluidity, while Spd and Spm partially or totally prevented the effects of this metal. Together, experimental results demonstrate that during plant development (a) Cd have noxious effects on plants membrane rheology that could be partially responsible of its toxicity, and (b) this deleterious effect could be partially or totally prevented by PAs pretreatment.