Effects of NaCl on some physiological and biochemical responses in two cultivars of L. usitatissimum

Linum usitatissimum L. is one of the economically important oilseed crops and salt stress is one of the major environmental challenges affecting several physiological processes in plants. The present investigation was carried out to study the effects of NaCl on some physiological and biochemical responses in two cultivars of L. usitatissimum. Three week-old plants were exposed to salt stress (0 and 150 mM) for 21 days. Results showed that salinity enhanced proline and flavonoid contents and total antioxidant capacity in flax cultivars. Exposure to NaCl (150 mM) did not alter levels of oxidative stress parameters, such as Malondialdehyde (MDA) and other aldehydes, content of phenol and POD enzyme activity in TN-97-28 cultivar while increased these parameters in TN-97-106 cultivar. On the other hand, there was no change in the soluble protein and K+ contents in TN-97-28 cultivar in response to salt stress whereas these contents decreased in TN-97-106 cultivar under salinity. Contents of Na+ and Cl- were increased in NaCl-treated flax plants. Antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) were declined and increased in TN-97-28 and TN-97-106 cultivars, respectively. It might be concluded that various cultivars have different mechanisms to diminish negative impacts of salinity stress.