Salinity-Induced Changes in the Antioxidant Status of Common Basil Plants (Ocimum basilicum L.) Grown under Controlled Conditions

Abstract

Studies were performed to determine the influence of salinity on the antioxidant status of basil plants, var. Sweet Green. The experiments were conducted in a growth chamber under controlled conditions (photoperiod—14/10 h, photosynthetic photon density (PPFD)—250–300 µmol m−2 s−1, temperature—24 ± 1 °C/16 ± 1 °C, humidity—65–70%). The plants were grown on ½ Hoagland’s nutrient solution, with the addition of elevated concentrations of sodium chloride (0, 80, 160 mM). In addition, increased content of macro- and micronutrients in the solution was applied (4/2 Hoagland’s nutrient solution and 0 mM NaCl). The activity of the antioxidant enzyme guaiacol peroxidase, content of malondialdehyde and total polyphenolic compounds, concentration of free proline, and antiradical activity were characterized. The results demonstrate that the salinity of Hoagland’s solution with 160 mM NaCl induced considerable changes concerning enzymatic and non-enzymatic elements of the plant defense and antioxidant systems. Enhancing the concentration of macro- and microelements in the nutrient solution (4/2 of Hoagland and 0 mM NaCl) in terms of biochemical parameters presented a similar trend to the variant with an additional lower concentration of sodium chloride (80 mM).