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

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.

Ellouzi H ，Hamed KB ，Cela J ，Munné-Bosch S ，Abdelly C ... -  《-》

Differential responses of antioxidative enzymes and lipid peroxidation to salt stress in salt-tolerant Plantago maritima and salt-sensitive Plantago media.

Sekmen AH ，Türkan I ，Takio S 《-》

Comparison of NaCl-induced programmed cell death in the obligate halophyte Cakile maritima and the glycophyte Arabidopsis thaliana.

Salinity represents one of the most important constraints that adversely affect plants growth and productivity. In this study, we aimed at determining possible differences between salt tolerant and salt sensitive species in early salt stress response. To this purpose, we subjected suspension-cultured cells from the halophyte Cakile maritima and the glycophyte Arabidopsis thaliana, two Brassicaceae, to salt stress and compared their behavior. In both species we could observe a time and dose dependent programmed cell death requiring an active metabolism, a dysfunction of mitochondria and caspase-like activation although C. maritima cells appeared less sensitive than A. thaliana cells. This capacity to mitigate salt stress could be due to a higher ascorbate pool that could allow C. maritima reducing the oxidative stress generated in response to NaCl. It further appeared that a higher number of C. maritima cultured cells when compared to A. thaliana could efficiently manage the Na(+) accumulation into the cytoplasm through non selective cation channels allowing also reducing the ROS generation and the subsequent cell death.

Ben Hamed-Laouti I ，Arbelet-Bonnin D ，De Bont L ，Biligui B ，Gakière B ，Abdelly C ，Ben Hamed K ，Bouteau F ... -  《-》

Differential transcript regulation in Arabidopsis thaliana and the halotolerant Lobularia maritima indicates genes with potential function in plant salt adaptation.

Popova OV ，Yang O ，Dietz KJ ，Golldack D ... -  《GENE》

H(2)O(2) seed priming improves tolerance to salinity; drought and their combined effect more than mannitol in Cakile maritima when compared to Eutrema salsugineum.

The effect of H2O2 and mannitol seed priming was investigated on plant growth, oxidative stress biomarkers and activities of antioxidant enzymes in leaves of Cakile maritima and Eutrema salsugineum, when exposed to drought and salt stress, either separately applied or combined. Under unprimed conditions, drought severely restricted growth (40% as compared to the control) and redox balance of C. maritima seedlings, whereas E. salsugineum showed these drastic effects under individual salinity (33% as compared to the control). Combined salinity and drought maintained and even stimulated the antioxidant defense of both plants from unprimed seeds. Both priming agents (mannitol and H2O2) significantly ameliorated growth and antioxidant defense of both species grown under salinity, drought and their combined effect. However, H2O2 priming appeared to be more beneficial in C. maritima seedlings. Indeed, oxidative injuries were significantly reduced, together with significantly higher concentrations of ascorbic acid (36%), glutathione (2-fold) and proline production (2-fold), leading to a greater redox balance that was closely associated with enhanced antioxidant enzyme activities, specifically under salt stress. Overall, our results indicate that it is very likely that H2O2 priming, due to its signal role, improves C. maritima tolerance to both osmotic stresses and enables the plant to memorize and to decode early signals that are rapidly activated when plants are later exposed to stress.

Ellouzi H ，Sghayar S ，Abdelly C 《-》