PROTECTIVE EFFECT OF EXOGENOUS POLYAMINES AGAINST ATRAZINE IN PEA-PLANTS

The effect of exogenously applied polyamines in reversing the effect o f atrazine stress on pea seedlings (Pisum sativum L., cv. Koray) was i nvestigated. The plants treated with combinations of atrazine (14 mM) + spermidine (1 mM) and atrazine (14 mM) + spermine (1 mM) possessed i mproved growth (30-35% increase of leaf area and 10-20% increase of fr esh weight 10 days after treatment) and chlorophyll content (50-60% in crease) in comparison with atrazine- (14 mM) treated plants. Spermine and spermidine also diminished the inhibitory effect of atrazine on ga s exchange and photosystem II function. This fact supports the hypothe sis of Yordanov and Goltsev (1990, Plant Physiol 4:42-51) that the int eraction of polyamines with the thylakoid membrane surface led to thei r stacking, to separation of the photosystems, and to the association of light-harvesting complex II with the photosystem II core complex.