Salicornia europaea L. Maintains its Physiological Integrity under High Salinity Stress in Retreated Sections of the Urmia Lake, Iran

Arid lands and inland water bodies, such as Urmia Lake in Iran, have become vulnerable to increased salinity stress because of rising temperature as a result of global warming. High salinity enhances plants photorespiration and affects its physiology, but Salicornia europaea L. in Urmia Lake has adapted to grow, propagate and occupy increasingly exposed saline habitats. Plant and soil samples were collected in triplicate plots from different sites of retreated beds of Urmia Lake in fall, 2015. Salinity stress physiology of S.europaea L. populations were investigated in Urmia Lake through determining: (a) leaf cell membrane lipid peroxidation (Malondialdehyde production, MDA); (b) antioxidant enzymes activities (peroxidase, catalase and Phenylalanine Ammonia Lyase (PAL) and (3) changes in contents of non-enzymatic antioxidants (flavonoid and anthocyanin). Analysis of variance (ANOVA), Duncan Post-hoc tests and correlation tests were performed using the SPSS.21 statistical program when significant differences occurred at 5% level. Results showed that peroxidase activity reduced and MDA content remained constant which indicates intact integrity of leaf cell membrane and the ability of cells to scavenge Reactive Oxygen Species (ROS). Increase in catalase activity and anthocyanin and total flavonoid contents correlated strongly with increased salinity at all stations located along the exposed and drying bed of the Urmia Lake. It is concluded that S.europaea tolerates salinity stress and subsequent ill-effects of ROSs produced through, (1) regulating vacuolar water exchanges, (2) managing peroxisome activity and (3) developing a complex system of antioxidants. Therefore, S.europaea can be cultivated in retreated Urmia Lake bed for animal feed or other uses.