Physiological Responses of Paneer-Booti (Withania coagulans Dunal) to NaCl Stress Under Tissue Culture Conditions

Salinity is one of the major abiotic stresses, which affects physiological traits and reduces plant productivity. Paneer-booti (Withania coagulans Dunal) is a medicinal and aromatic plant belonging to the Solanaceae family, which is an endemic plant in the Middle East. In this study, the effect of different salt concentrations (0, 50, 100, 150, 200, and 250 mM NaCl) on antioxidant enzymes activity such as catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX), proline, phenols, and flavonoids contents, relative water content (RWC), electrolyte leakage, Na+ and K+ concentrations, and chlorophyll fluorescence of Paneer-booti were studied. Results indicated that the effect of NaCl stress was significant on all traits. By increasing NaCl, to 250 mM levels, enhance activity of CAT (76.75%), POD (56.49%), and APX (44.77%), proline (79.56%), phenols (56.15%), electrolyte leakage (76.74%), Na+ (54.70%), and minimum fluorescence (Fo) (44.94%) was observed while decreased RWC (11.33%), K+ concentration (50.8%), K+/Na+ ratio (77.77%), and Fv/Fm ratio ( 67.5%) compared to the control treatment was noted. By increasing electrolyte leakage enhance in the rate of antioxidant enzymes activity (CAT, POD, and APX), proline, phenols, and flavonoids contents, and Na+ concentration was observed. The rate of K+/Na+ ratio is very important under salinity condition, so, the trait had a negative correlation with antioxidant enzyme activities, proline, phenols, and flavonoids contents. Our results revealed that Paneer-booti plantlet had a high tolerant to the NaCl stress due to the fact high level of the enzymatic and non-enzymatic antioxidant activities under higher levels of salinity.