In this research, three isoforms for SOD and only one isoform for CAT weredetected. Figures 2 and 3 are examples for banding patterns of SOD and CATenzymes in borage from primed and unprimed seeds under different irrigationintervalsResults of analysis of variance showed that relative activities of SOD1and SOD3 were significantly influenced by irrigation treatments (p? 0.01), but the effect of seed priming on these isoforms were not significant(p > 0.
05). In contract, water deficit and also seed priming had nosignificant effect on SOD2 activity (p > 0.05). Theinteraction of irrigation × priming was not significant for SOD isoforms (p> 0.05). A decrease was observed in SOD1 and SOD3activities under mild water deficit (I2) in comparison with the wellwatering (14% and 8.1%, respectively).
However, relative activity of SOD1and SOD3 were severely increased with reducing water availability.The activity of SOD1 was 41.5% and 29.
1% higher in the plantsirrigated with intervals of 120 mm (I3) and 150 mm evaporation (I4)compared to well watering, respectively. Moderate (I3) and severewater deficit (I4) also led to a 52.7% and 48% increase in therelative activity of SOD3, respectively (Figure 4). Although, SOD2activity was not significantly changed in leaves under different levels ofirrigation (p > 0.05), moderate (I3) and severe waterdeficit (I4) increased relative activity of SOD2.Relative activity of CAT was significantly affected by irrigation intervals(p ? 0.
01), but the effect of seed priming on this enzyme was notsignificant (p > 0.05). CAT activity of plants from primed andunprimed seeds was similar in response to drought stress (p > 0.05).All plants from primed and unprimed seeds showed the highest CAT activity underwell watering (I1), but all limited irrigation treatmentssignificantly and almost similarly decreased relative activity of CAT, comparedwith well irrigation (Figure 5).