PROTECTIVE EFFECT OF EXOGENOUS POLYAMINES AGAINST ATRAZINE IN PEA-PLANTS

The effect of exogenously applied polyamines in reversing the effect of atrazine stress on pea seedlings (Pisum sativum L., cv. Koray) was investigated. The plants treated with combinations of atrazine (14 mM) + spermidine (1 mM) and atrazine (14 mM) + spermine (1 mM) possessed improved growth (30-35% increase of leaf area and 10-20% increase of fresh weight 10 days after treatment) and chlorophyll content (50-60% increase) in comparison with atrazine- (14 mM) treated plants. Spermine and spermidine also diminished the inhibitory effect of atrazine on gas exchange and photosystem II function. This fact supports the hypothesis of Yordanov and Goltsev (1990, Plant Physiol 4:42-51) that the interaction of polyamines with the thylakoid membrane surface led to their stacking, to separation of the photosystems, and to the association of light-harvesting complex II with the photosystem II core complex.