Abstract:

The content of an endogenous putrescine increased dramatically in four tree species of Robinia pseudocacia Linn., Liriodendron tulipifera Linn., Platanus acerifolia Willd and Gardenia jasminoides Ellis under acid stress, but the content of spermidine and spermine showed no change.The additional D-Arginine (an inhibitor of the putrescine biosynthetic enzymes) to acid medium could inhibited the level of putrescine.However a simultaneous additional D-Arginine and putrescine could reverse the inhibitory effects of D-Arginine.Under the acid stress, the balance of active oxygen metabolism was lost, the content of MDA was accumulated rapidly, the activies of SOD and CAT decreased.Applying exogenous putrescine to acid medium could regulate the balance of active oxygen metabolism, decrease the accumulation of MDA, while increase the activities of SOD and CAT.The results showed putrescine could protect plants from the acid stress.

Key words: Acid stress, Polyamine, Putrescine, Active oxy gen metabolism