the effect of putrescine and spermine on drought tolerance of almond and peach

this study was performed to investigate the effect of putrescine and spermine on some physiological and biochemical characteristics and antioxidant enzymes activity of peach (prunus persica cv. alberta) and almond (prunus dulcis cv. rabi) seedlings under water deficit. the first factor was water regime at two levels (80% or 50% of soil available water), and the second factor was polyamine treatments (putrescine 0.1, putrescine 1, spermine 0.1, spermine 1 mm and control). water deficit led to increased electrolyte leakage percentage in peach leaves, compared to almond. under water deficit, polyamines reduced electrolyte leakage in both plants, spermine was more effective than putrescine under water deficit. leaf contents of soluble carbohydrates, proline and soluble proteins in almond more increased as compared to peach. spermine more effectively increased concentration of osmoregulants, compared to putrescine. under water deficit, the activities of catalase, guaiacol peroxidase and ascorbate peroxidase enzymes increased in both plants, higher enzyme activity was found in almond leaves in comparison with peach. the maximum antioxidant enzyme activity was found following spermine treatments. application of spermine and putrescine increased drought tolerance in almond and peach through reducing the electrolyte leakage, increasing compatibility osmolytes and antioxidant enzyme activity.