Changes in the Activity of Antioxidant and Glyoxylate Cycle Enzymes of Hydro-Primed Calendula officinalis (L.) Seeds after Re-Drying Temperature Stress

In order to study the effect of re-drying temperatures on the enzymatic activation of hydro-primed Calendula officinalis (L.) seeds, a completely randomized design with three replications was conducted. Treatments were six different re-drying temperatures including control (without drying), 20, 30, 40, 50, and 60°C applied after hydro-priming. Results showed that rapid drying at high temperatures (40-60°C) caused a significant difference comparing control. The best re-drying temperature considering many studied traits was 20-30°C. At 60°C, activity of antioxidant enzymes such as superoxide dismutase, catalase and peroxidase decreased 65.5, 75, and 62%, respectively over control. Re-drying had not significant effect on the activity of malate synthase and isocitrate lyase in comparison with control and 20-30°C that demonstrates no negative and reductive effect of re-drying with these temperatures on seed germination. It seems that seeds are more desiccation tolerant at these temperatures. In conclusion, we can dry hydro-primed seeds slowly at 20 and 30 °C and store them until utilization.