Modulation of osmotic adjustment and enzymatic antioxidant profling in Apera intermedia exposed to salt stress

Abstract

Abstract: Te efects of salinity on growth, osmotic adjustment, and antioxidative responses were evaluated in Apera intermedia . Forthis purpose, 30-day-old plants were irrigated every other day with Hoagland nutrient solution containing 0, 150, 300, or 600 mMNaCl for 7 and 14 days. Te results showed inhibition of growth, relative growth rate, relative water content, and osmotic potential withincreasing NaCl concentration. Increased Na +, Clˉ, and Na+/K+ ratio and decreased K+ and Ca2+ were determined with increasing NaClconcentrations. Te activities of superoxide dismutase and ascorbate peroxidase were conspicuously enhanced at 150 mM NaCl, butactivities of catalase, peroxidase, and NADPH oxidase were reduced in a concentration/time-dependent manner. Te highest proline,choline, and glycine betaine accumulation assisted higher osmotic adjustment and maintenance of water status at 150 mM. However, thedestructive efects of 300 600 mM were more severe in comparison to lower salinity, depending on the increase of hydrogen peroxideand thiobarbituric acid reactive substances for 14 days. Afer exposure to 300 and 600 mM, only ascorbate peroxidase and glutathionereductase were induced, but they were not sufcient to scavenge H O .