Effects of penconazole and water deficit stress on physiological and antioxidative responses in pennyroyal (Mentha pulegium L.)

The effects of penconazole (PEN) on physiological parameters and several antioxidative enzyme activities were investigated in pennyroyal (Mentha pulegium L.) under water deficit stress. Six weeks after sowing, plants were grown under soil moisture corresponding to 100, 75, 50, and 25% field capacity (FC) with or without PEN (15 mg l(-1)) for next 4 weeks. The exogenous application of PEN to drought-stressed plants increased some growth parameters, the relative water content (RWC), lipid peroxidation, electrolyte leakage, H2O2 content, activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), polyphenol oxidase (PPO), and the total phenol content. Native polyacrylamide gel electrophoresis (PAGE) indicated different isoform profiles under water deficit stress in non-PEN-treated and PEN-treated plants concerning antioxidant enzymes. A higher capacity for oxygen scavenging and phenolic content could possibly explain the ability of M. pulegium plants to grow at higher water stress under PEN treatment.