Physiological effects of NaCl application on Oenothera biennis L.

Salinity is one of the most important environmental factors that limit plant growth and development. The aim of the present study is to evaluate the physiological effects of different NaCl concentrations (0, 25, 50 and 100 mM) on Oenothera biennis (evening primrose), which were grown in a climate chamber as hydroponically. The seeds of the plant were germinated in a controlled climate chamber in perlite. The seedlings were then transferred to vessels containing 10% nutrient solution. At the end of the acclimatization period, different concentrations of NaCl were applied to the seedlings during 10 days. Root and shoot weights of the seedlings were decreased by NaCl concentrations. Photosynthetic pigment contents were decreased with the increase in NaCl concentrations. Similarly, the protein contents of roots and shoots were decreased due to NaCl concentrations. Total carbohydrate content decreased in the roots of seedling, but increased in shoots. Non-protein SH groups of the roots and shoots were reduced by NaCl concentrations. Increases in the amount of hydrogen peroxide and malondialdehyde in seedlings and shoots were found. This may indicate the presence of oxidative stress due to NaCl toxicity.