Early effects of salt stress on the physiological and oxidative status of Cakile maritima (halophyte) and Arabidopsis thaliana (glycophyte)

Abstract

Early changes in physiological and oxidative status induced by salt stress were monitored in two Brassicaceae plants differing in their tolerance to salinity, Cakile maritima (halophyte) and Arabidopsis thaliana (glycophyte). Growth response and antioxidant defense of C. maritima under 400 mM NaCl were compared with those of A. thaliana exposed to 100 mM NaCl. Salinity induced early growth reduction that is less pronounced in C. maritima than in A. thaliana. Maximum hydrogen peroxide (H₂O₂) level occurred in the leaves of both species 4 h after the onset of salt treatment. A rapid decline in H₂O₂ concentration was observed thereafter in C. maritima, whereas it remained high in A. thaliana. Correlatively, superoxide dismutase, catalase and peroxidase activities increased at 4 h of treatment in C. maritima and decreased thereafter. However, the activity of these enzymes remained higher in treated plants than that in controls, regardless of the duration of treatment, in A. thaliana. The concentrations of malondialdehyde (MDA) reached maximum values at 24 h of salt stress in both species. Again, MDA levels decreased later in C. maritima, but remained high in A. thaliana. The contents of α-tocopherol remained constant during salt stress in C. maritima and decreased during the first 24 h of salt stress and then remained low in A. thaliana. The results clearly showed that C. maritima, in contrast to A. thaliana, can rapidly evolve physiological and antioxidant mechanisms to adapt to salt and manage the oxidative stress. This may explain, at least partially, the difference in salt tolerance between halophytes and glycophytes.

Comparison of an antioxidant system in tolerant and susceptible wheat seedlings in response to salt stress

“…6). The correlation between salinity tolerance and the increase of SOD activity has been demonstrated in many works (Hernández et al, 2001;Sreenivasulu et al, 2000;Ben Amor et al, 2005;Mandhania et al, 2006;Koca et al, 2007;Ellouzi et al, 2011). Increased SOD activity in the cv.…”

Modulation of superoxide dismutase (SOD) isozymes by organ development and high long-term salinity in the halophyte Cakile maritima

“…The composition of the nutrient solution was as follows: 2.5 mM Ca(NO 3 ) 2 · 4H 2 O, 2.5 mM KNO 3 , 0.5 mM KH 2 PO 4 , and 1 mM MgSO 4 ·7H 2 O for the macronutrients and 23.2 μM H 3 BO 3 , 4.6 μM MnCl 2 · 4H 2 O, 1.2 μM ZnSO 4 · 7H 2 O, 0.185 μM CuSO 4 · 5H 2 O, and 0.06 μM Na 2 MoO 4 ·2H 2 O for the micronutrients. The plantlets were then divided into two lots: control (C) plants kept in the Hoagland nutrient solution and salt-stressed plants exposed to 400 mM NaCl, with 50 mM NaCl being added daily to reach this final concentration (Ellouzi et al 2011). After 22 days, the plants were harvested and separated into roots, stems, leaves, and flowers and stored at −80°C for biochemical analysis.…”

“…In addition to the culinary uses of all parts of C. maritima, it is of fundamental importance as Debez et al (2012) recently deemed it to be an excellent model for understanding biochemical and physiological mechanisms of salinity tolerance in halophytes and is a C 3 halophyte closely related to other model plants such as Arabidopsis thaliana. The response of several components of the antioxidant system to salt-induced oxidative stress in C. maritima has been analyzed in a certain number of studies (Ben Amor et al 2006Ksouri et al 2007;Ellouzi et al 2011Ellouzi et al , 2013Debez et al 2012). However, to our knowledge, no information exists on the type and number of SODs in the halophyte C. maritima.…”

Growth, sodium uptake and antioxidant responses of coastal plants differing in their ecological status under increasing salinity

“…H2O2 quantification is based on the formation of a titanium peroxide complex (Ellouzi et al 2011). The dry leaf samples were homogenized in cold acetone (1:6, w/v).…”