Salt-stress induced alterations in protein profile and protease activity in the mangrove Bruguiera parviflora

Two-month-old seedlings of Bruguiera parvifora were treated with varying levels of NaCl (100, 200 and 400 mM) under hydroponic culture. Total proteins were extracted from leaves of control and NaCl treated plants after 7, 14, 30 and 45 d of treatment and analysed by SDS-PAGE. As visualized from SDS-PAGE, the intensity of several protein bands of molecular weight 17, 23, 32, 33 and 34 kDa decreased as a result of NaCl treatment. The degree of decrease of these protein bands seemed to be roughly proportional to the external NaCl concentration. The most obvious change concerned a 23 kDa-polypeptide (SSP-23), which disappeared after 45 d treatment in 400 mM NaCl. Moreover, the SSP-23 protein, which disappeared in B. parviflora under salinity stress, reappeared when these salinized seedlings were desalinized. These observations suggest the possible involvement of these polypeptides for osmotic adjustment under salt stress. NaCl stress also caused an increase in the activity of both acid and alkaline protease. The increasing activity of proteases functions as a signal of salt stress in B. parviflora, which induces the reduction of protein level.     

Effects of salicylic acid and salinity on apoplastic antioxidant enzymes in two wheat cultivars differing in salt tolerance

The effects of salicylic acid (SA) and salinity on the activity of apoplastic antioxidant enzymes were studied in the leaves of two wheat (Triticum aestivam L.) cultivars: salt-tolerant (Gerek-79) and salt-sensitive (Bezostaya). The leaves of 10-d-old seedlings grown at nutrient solution with 0 (control), 250 or 500 mM NaCl were sprayed with 0.01 or 0.1 mM SA. Then, the activities of catalase (CAT), peroxidase (POX) and superoxide dismutase (SOD) were determined in the fresh leaves obtained from 15-d-old seedlings. The NaCl applications increased CAT and SOD activities in both cultivars, compared to those of untreated control plants. In addition, the NaCl increased POX activity in the salt-tolerant while decreased in the salt-sensitive cultivar. In control plants of the both cultivars, 0.1 mM SA increased CAT activity, while 0.01 mM SA slightly decreased it. SA treatments also stimulated SOD and POX activity in the salt-tolerant cultivar but significantly decreased POX activity and had no effect on SOD activity in the saltsensitive cultivar. Under salinity, the SA treatments significantly inhibited CAT activity, whereas increased POX activity. The increases in POX activity caused by SA were more pronounced in the salt-tolerant than in the salt-sensitive cultivar. SOD activity was increased by 0.01 mM SA in the salt-tolerant while increased by 0.1 mM SA treatment in the salt-sensitive cultivar.     

NaCl-Dependent growth, ion content and regeneration of calluses initiated from the mangrove plant,Bruguiera sexangula

Calluses initiated from leaves and seedlings of the mangrove,Bruguiera sexangula, were isolated from the original tissues and subcultured. Effects of NaCl on growth and ion content of each callus were measured. The growth rate of calluses derived from leaves (leaf callus) gradually decreased as the NaCl concentration in the medium increased, while that of calluses derived from seedlings (seedling callus) was highest in the medium containing 100 mM NaCl. Concentrations of Na and Cl in both calluses increased with increasing the NaCl concentration in the culture medium. The concentration of K of leaf calluses greatly decreased at 300 mM NaCl, while the K concentration of seedling calluses decreased only slightly and remained relatively high even in the presence of 300 mM NaCl. Transient treatment of leaf calluses with media containing high concentrations of NaCl frequently induced regeneration of adventitious tissues.     

The role of cotyledons in the establishment of Suaeda physophora seedlings

The role of cotyledons in seedling establishment of the euhalophyte Suaeda physophora under non-saline and saline conditions (addition of 1 mM or 400 mM NaCl) was investigated. Survival and fresh and dry weights were greater for seedlings grown in the light (12-h light/12-h dark) than in the dark (24-h dark). The shading of cotyledons tended to decrease shoot height, shoot organic dry weight, number of leaves, and survival of seedlings regardless of NaCl treatment, but the effect of cotyledon shading was greater with 400 mM NaCl. Concentrations of Na⁺ were higher in cotyledons than in leaves, regardless of NaCl treatment. The K⁺/Na⁺ ratio was lower in cotyledons than in leaves for seedlings treated with 1 mM NaCl but not for seedlings treated with 400 mM NaCl. Addition of 400 mM NaCl decreased oxygen production in cotyledons but especially in leaves. These results are consistent with the hypothesis that, by generating oxygen via photosynthesis and by compartmentalizing Na⁺, cotyledons are crucial for the establishment of S. physophora seedlings in saline environments.     

Growth and ion uptake in <Emphasis Type="Italic">Annona muricata</Emphasis> and <Emphasis Type="Italic">A. squamosa</Emphasis> subjected to salt stress

The effects of treatment with NaCl (3, 100 and 300 mM) for 1, 2, 3 and 7 d on plant growth and ion accumulation were analyzed in 2-week and 8-week-old Annona muricata and A. squamosa plants. Fresh mass and root growth inhibition were directly related to the increase in salinity, particularly for A. squamosa. Two-weeks old seedlings were sensitive to 100 and 300 mM NaCl particularly after 7 d, whereas 8-week-old plants were shown to be more resistant to NaCl even at 300 mM NaCl. Na⁺ and Cl^– mostly accumulated in young leaves. Our results suggest that A. squamosa is more sensitive than A. muricata to salt stress and that older seedlings of both species are more tolerant than younger seedlings.     

Expression,tissue distribution and subcellular localization of dehydrin TAS14 in salt-stressed tomato plants

We previously isolated and characterized TAS14, an mRNA that is induced in tomato upon osmotic stress or abscisic acid (ABA) treatment and that shares expression and sequence characteristics with other dehydrin genes in different species. Affinity-purified antibodies against TAS14 protein were used to study the expression of TAS14 protein, both in seedlings and mature plants, its tissue distribution and its subcellular localization. TAS14 protein was not detected in 4-day-old seedlings but accumulated after ABA, NaCl or mannitol treatments. In NaCl-treated seedlings, some protein was detectable after 6 h of treatment and reached maximal levels between 24 and 48 h. Concentrations ranging from 5 to 12.5 g/l NaCl induced the protein to similar levels. In salt-stressed mature plants, TAS14 was expressed abundantly and continuously in aerial parts, but only slightly and transiently in roots. Immunocytochemical analysis of salt-treated plants showed TAS14 accumulated in adventitious root primordia and associated to the provascular and vascular tissues in stems and leaves. Immunogold electron microscopy localized TAS14 protein both in the cytosol and in the nucleus, associated to the nucleolus and euchromatin. Since TAS14 is a phosphoprotein in vivo, the classes of protein kinases potentially responsible for its in vivo phosphorylation were tested in in vitro phosphorylation assays. TAS14 protein was phosphorylated in vitro by both casein kinase II and cAMP-dependent protein kinase.The first two authors contributed equally to this paper.     

Effects of salt on growth,ion accumulation,photosynthesis and leaf anatomy of the mangrove,<Emphasis Type="Italic"> Bruguiera parviflora</Emphasis>

The effects of a range of salinity (0, 100, 200 and 400 mM NaCl) on growth, ion accumulation, photosynthesis and anatomical changes of leaves were studied in the mangrove, Bruguiera parviflora of the family Rhizophoraceae under hydroponically cultured conditions. The growth rates measured in terms of plant height, fresh and dry weight and leaf area were maximal in culture treated with 100 mM NaCl and decreased at higher concentrations. A significant increase of Na⁺ content of leaves from 46.01 mmol m^-2 in the absence of NaCl to 140.55 mmol m^-2 in plants treated with 400 mM NaCl was recorded. The corresponding Cl^- contents were 26.92 mmol m^-2 and 97.89 mmol m^-2. There was no significant alteration of the endogenous level of K⁺ and Fe²⁺ in leaves. A drop of Ca²⁺ and Mg²⁺ content of leaves upon salt accumulation suggests increasing membrane stability and decreased chlorophyll content respectively. Total chlorophyll content decreased from 83.44 g cm^-2 in untreated plants to 46.56 g cm^-2 in plants treated with 400 mM NaCl, suggesting that NaCl has a limiting effect on photochemistry that ultimately affects photosynthesis by inhibiting chlorophyll synthesis (ca. 50% loss in chlorophyll). Light-saturated rates of photosynthesis decreased by 22% in plants treated with 400 mM NaCl compared with untreated plants. Both mesophyll and stomatal conductance by CO₂ diffusion decreased linearly in leaves with increasing salt concentration. Stomatal and mesophyll conductance decreased by 49% and 52% respectively after 45 days in 400 mM NaCl compared with conductance in the absence of NaCl. Scanning electron microscope study revealed a decreased stomatal pore area (63%) in plants treated with 400 mM NaCl compared with untreated plants, which might be responsible for decreased stomatal conductance. Epidermal and mesophyll thickness and intercellular spaces decreased significantly in leaves after treatment with 400 mM NaCl compared with untreated leaves. These changes in mesophyll anatomy might have accounted for the decreased mesophyll conductance. We conclude that high salinity reduces photosynthesis in leaves of B. parviflora, primarily by reducing diffusion of CO₂ to the chloroplast, both by stomatal closure and by changes in mesophyll structure, which decreased the conductance to CO₂ within the leaf, as well as by affecting the photochemistry of the leaves.     

Effects of 24-epibrassinolide on seed germination, seedling growth, lipid peroxidation, proline content and antioxidative system of rice (Oryza sativa L.) under salinity stress

The effects of 24-epibrassinolide (24-epiBL) on seedling growth, antioxidative system, lipid peroxidation, proline and soluble protein content were investigated in seedlings of the salt-sensitive rice cultivar IR-28. Seedling growth of rice plants was improved by 24-epiBL treatment under salt stress conditions. When seedlings treated with 24-epiBL were subjected to 120 mM NaCl stress, the activities of superoxide dismutase (EC 1.15.1.1), catalase (EC 1.11.1.6) and glutathione reductase (EC 1.6.4.2) did not show significant difference, whereas the activity of ascorbate peroxidase (EC 1.11.1.11) significantly increased. Increased activity of peroxidase (EC 1.11.1.7) under NaCl stress showed remarkable decrease in the 24-epiBL+NaCl-applied group. Lipid peroxidation level significantly increased under salt stress but decreased with 24-epiBL application revealing that less oxidative damage occurred in this group (24-epiBL+NaCl). In addition, increased proline content in the NaCl-applied group was decreased by 24-epiBL application in the 24-epiBL+NaCl-applied group. Soluble protein content was increased by 24-epiBL application even under NaCl stress, being also higher than control conditions (no 24-epiBL or NaCl treatment). 24-epiBL treatment considerably alleviated oxidative damage that occurred under NaCl-stressed conditions and improved seedling growth in part under salt stress in sensitive IR-28 seedlings.     

Effect of NaCl on biomass, protein and proline contents, and antioxidant enzymes in seedlings and calli of two Trigonella species

The effects of NaCl on growth, contents of proteins and proline, and activities of catalase, peroxidase and polyphenol oxidase were investigated in seedlings and calli of Trigonella foenum-graecum L. and T. aphanoneura Rech. f. Seeds and hypocotyl explants were cultured on Murashige and Skoog medium supplemented with 0, 50, 100, 150 and 200 mM NaCl. Seed germination and the fresh and dry mass of the seedlings decreased significantly under salinity. In both species significant increases in protein content of seedlings over that of control were observed at 150 and 200 mM NaCl. Protein content in calli decreased at 200 mM NaCl over that of control. Protein content was higher in seedlings than in calli at all NaCl concentrations. Conversely, proline content was lower in seedlings than in calli at all the tested NaCl concentrations. NaCl caused changes in the activities of peroxidase, catalase and polyphenol oxidase in seedlings and calli.     

Different antioxidant responses to salt stress in two different provenances of <Emphasis Type="Italic">Carthamus tinctorius</Emphasis> L.

Seedlings of two Tunisian Carthamus tinctorius L. provenances (Kairouan and Tazarka) differing in salt sensitivity were hydroponically grown at 0 and 50 mM NaCl over 21 days. Leaves of Kairouan (salt-sensitive) showed a 48% restriction in their growth at 50 mM NaCl although they accumulated less sodium than those of Tazarka (less salt-sensitive) that maintained an unchanged growth. Salt treatment induced oxidative stress in C. tinctorius and the effect was more pronounced in the leaves of the more salt sensitive provenance, Kairouan. Both provenances exhibited a stimulation of antioxidant enzyme activities with higher catalase (CAT) and superoxide dismutase (SOD) activities in Tazarka and higher peroxidase (POD) activity in Kairouan. But, it seems that antioxidant activities were more correlated with polyphenol content. Actually, leaves of Tazarka experienced higher polyphenol and antioxidant activity than Kairouan at 50 mM NaCl. Hence, moderate salinity (3 g NaCl L⁻¹) enhanced bioactive molecule yield in the less salt sensitive provenance, Tazarka. In addition, C. tinctorius was found rich in ascorbic acid, but the moderate salt stress enhanced its production only in the sensitive provenance.     

Effect of NaCl salinity on growth and mineral partitioning in Quercus robur L., a rhythmically growing species

 Sodium salt sensitivity of common oak (Quercus robur L.) was evaluated in hydroponic culture using INRA-Morizet solution. Addition of NaCl to the nutrient solution reduced only length and weight of roots and first flush stems. In contrast, the second flush was properly expanded even in the presence of 40 mM of NaCl in culture medium. Both leaf number and leaf area were not affected by increasing salt concentration in medium culture while this increase induced significant leaf damage especially in first flush leaves. Stem starch storage was reduced only at 40 mM NaCl treatment. Common oak seedlings seemed to be able to better compartmentalize sodium than chloride when the NaCl concentration increased in the medium culture. Chloride presented a lower uptake than sodium. Sodium was preferentially accumulated in roots and this accumulation occurred at the expense of potassium uptake. The decrease of ATP content in leaves of common oak seedlings submitted to NaCl treatments could indicate that it was used for sodium exclusion out of the leaves, especially in second flush leaves. Relationships between growth responses, starch and mineral element distribution in common oak seedlings will be discussed. Received: 20 November 1997 / Accepted: 3 March 1998     

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

The changes in plant growth, relative water content (RWC), stomatal conductance, lipid peroxidation and antioxidant system in relation to the tolerance to salt stress were investigated in salt-tolerant Plantago maritima and salt-sensitive Plantago media. The 60 days old P. maritima and P. media seedlings were subjected to 0, 100 and 200 mM NaCl for 7 days. Reduction in shoot length was higher in P. media than in P. maritima after exposure to 200 mM NaCl, but 100 mM NaCl treatment did not show any effect on shoot length of P. maritima. Shoot dry weight decreased in P. media and did not change in P. maritima. Two hundred millimolar NaCl treatment had no effect on leaf RWC in P. maritima, but it was reduced in P. media. Salt stress caused reduction in stomatal conductance being more pronounced in P. media than in P. maritima. Activities of superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC 1.11.1.6), glutathione reductase (GR; EC 1.6.4.2) decreased in P. media with increasing salinity. Ascorbate peroxidase (APX; EC 1.11.1.11) activity in leaves of P. media was increased and showed no change under 100 and 200 mM NaCl, respectively. However, activities of CAT, APX and GR increased under 200 mM NaCl while their activities did not change under 100 mM NaCl in P. maritima. SOD activity in leaves of P. maritima increased with increasing salinity. Concomitant with this, four SOD activity bands were identified in leaves of P. maritima, two bands only were observed in P. media. Peroxidase (POX; EC 1.11.1.7) activity increased under both salt concentrations in P. maritima, but only under 200 mM NaCl in P. media. Confirming this, five POX activity bands were identified in leaves of P. maritima, but only two bands were determined in P. media. Malondialdehyde levels in the leaves increased under salt stress in P. media but showed no change and decreased in P. maritima at 100 and 200 mM NaCl, respectively. These results suggest that the salt-tolerant P. maritima showed a better protection mechanism against oxidative damage caused by salt stress by its higher induced activities of antioxidant enzymes than the salt-sensitive P. media.     

The effects of NaCl on antioxidant enzyme activities in callus tissue of salt-tolerant and salt-sensitive cotton cultivars (Gossypium hirsutum L.)

Summary To determine NaCl effects on callus growth and antioxidant activity, callus of a salt-tolerant and a salt-sensitive cultivar of cotton was grown on media amended with 0, 75, and 150 mM NaCl. Callus of the salt-tolerant cultivar, Acala 1517-8 8, grown at 150 mM NaCl, showed significant increases in superoxide dismutase, catalase, ascorbate peroxidase, peroxidase and glutathione reductase activities compared to callus tissue grown at 0 mM NaCl. In contrast, callus tissue of the salt-sensitive cultivar, Deltapine 50, grown at 0, 75, and 150 mM NaCl, showed no difference in the activities of these enzymes. At the 150 mM NaCl treatment, peroxidase was the only antioxidant enzyme from Deltapine 50 with an activity as high as that observed in Acala 1517-88. The NaCl-induced increase in the activity of these enzymes in Acala 1517-88 indicates that callus tissue from the more salt-tolerant cultivar has a higher capacity for scavenging and dismutating superoxide, an increased ability to decompose H₂O₂, and a more active ascorbate-glutathione cycle when grown on media amended with NaCl.     

Effect of NaCl and Proline on Bean Seedlings Cultured in vitro

Effects of NaCl (150 mM), proline (10 mM) and their combination on growth and contents of chlorophyll, proline and protein of bean (Phaseolus vulgaris cv. Kizilhaç) seedlings in vitro were investigated. NaCl decreased seedling growth. Proline added to control seedlings did not change seedling growth but decreased chlorophyll and increased protein contents. When proline added to NaCl-treated seedlings growth was increased in comparison with NaCl-treated only. Thus, proline alleviated salinity stress in bean seedlings.     

Expression of a carbonic anhydrase gene is induced by environmental stresses in Rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.)

Expression of the gene (OsCA1) coding for carbonic anhydrase (CA) in leaves and roots of rice was induced by environmental stresses from salts (NaCl, NaHCO₃ and Na₂CO₃), and osmotic stress (10%, w/v, PEG 6000). CA activity of rice seedlings more than doubled under some of these stresses. Transgenic Arabidopsis over-expressing OsCA1 had a greater salt tolerance at the seedling stage than wild-type plants in 1/2 MS medium with 5 mM NaHCO₃, 50 mM NaCl, on 100 mM NaCl. Thus CA expression responds to environmental stresses and is related to stress tolerance in rice.     

Effect of salinity on osmotic adjustment characteristics of <Emphasis Type="Italic">Kandelia candel</Emphasis>

To elucidate the osmotic adjustment characteristics of mangrove plants, inorganic ion and organic solute contents of intermediate leaves were investigated in 3-month-old Kandelia candel (L.) Druce seedlings during 45 days of NaCl treatments (0, 200, and 500 mM NaCl). The contents of Na⁺, Cl⁻, total free amino acids, proline, total soluble sugars, pinitol and mannitol increased to different degree by salinity, whereas, K⁺ content decreased by salinity compared with control. NaCl treatment induced an increase of inorganic ion contribution while a decrease of organic solute contribution. It was concluded that accumulating a large amount of inorganic ions was used as the main osmotic adjustment mechanism under salinity treatment. However, accumulation of organic osmolytes might be considered to play much more important role in osmoregulation under severe salinity (500 mM NaCl) than under moderate salinity (200 mM NaCl), thus the damage caused by high toxic ions (Na⁺ and Cl⁻) concentration in K. candel leaves could be avoided.     

NaCl pre-treatment at the seedling stage enhances fruit yield of tomato plants irrigated with salt water

Although salt-adaptation seems to be a widespread property of plants, the adaptive response has been rarely differentiated to the tolerance response. We report on the adaptive response of tomato plants to growing under saline conditions following a 15 day pre-treatment with a lower NaCl concentration (half) than that used during the plant growth. After 20 days of salt treatment (100 mM NaCl), the biomass of the adapted plants increased significantly with respect to that of the unadapted plants when the pre-treatment was applied to five leaf seedlings, but not at the two leaf stage. The long-term adaptive response was determined in two tomato genotypes with different tolerance to moderate salt levels. At 70 mM NaCl, the adapted-plants of the more salt-sensitive genotype produced up to 29% more fruit yield than did the unadapted plants. However, no positive effect was observed to long-term in the adapted-plants of the more salt-tolerant genotype, which suggests that the stress level necessary to trigger the adaptive response is related to the tolerance degree of genotype. The physiological response of the plants showing a positive response to the adaptation was also modified to long-term. Thus, K⁺ concentrations increased in the young leaves of the adapted plants, with respect to unadapted plants, and moreover these differences increased with the salinization period. These results indicate that the changes in growth and physiological responses induced by NaCl pre-treatment at the seedling stage are maintained throughout plant life cycle and this is, therefore, an interesting strategy for increasing the salt tolerance in tomato plants.     

Salt tolerance in the halophyte Suaeda maritima L. Dum.

Osmotic potentials and individual epidermal cell turgor pressures were measured in the leaves of seedlings of Suaeda maritima growing over a range of salinities. Leaf osmotic potentials were lower (more negative) the higher the salt concentration of the solution and were lowest in the youngest leaves and stem apices, producing a gradient of osmotic potential towards the apex of the plant. Epidermal cell turgor pressures were of the order of 0.25 to 0.3 MPa in the youngest leaves measured, decreasing to under 0.05 MPa for the oldest leaves. This pattern of turgor pressure was largely unaffected by external salinity. Calculation of leaf water potential indicated that the gradient between young leaves and the external medium was not altered by salinity, but with older leaves, however, this gradient diminished from being the same as that for young leaves in the absence of NaCl, to under 30% of this value at 400 mM NaCl. These results are discussed in relation to the growth response of S. maritima.     

Interaction of NaCl and Cd stress on compartmentation pattern of cations,antioxidant enzymes and proteins in leaves of two wheat genotypes differing in salt tolerance

Physiological mechanisms of salinity–Cd interactions were investigated in inter- and intracellular leaf compartments of salt-tolerant wheat × Lophopyrum elongatum (Host) A. Löve (syn. Agropyron elongatum) amphiploid and its salt-sensitive wheat parent (Triticum aestivum L. cv Chinese Spring). In comparison with the intracellular fluid, only very low Na⁺ concentrations (up to about 4 mM) were found in the intercellular leaf compartment of wheat after a 75 mM supply of NaCl. NaCl salinity led to a higher Cd concentration in leaves of the salt-sensitive genotype. Cd in the intercellular leaf compartment was not detectable. Higher K⁺ concentrations in the intercellular leaf compartment of the salt-sensitive genotype suggest a higher plasma membrane permeability caused by NaCl + Cd stress. Ascorbate peroxidase (APX) activity was increased in leaves of the salt-sensitive genotype under the combined NaCl and Cd stress. The highest non-specific peroxidase activities were detected under the combined stresses. It is suggested that NaCl and Cd stress in combination enhance the production of oxygen radicals and H₂O₂, especially in leaves of the salt-sensitive genotype. As a consequence, disturbed membrane function may cause elevated Cd concentrations in the intracellular leaf compartment under salinity. Cd did not change protein concentration and pattern in leaves. The protein content in inter-and intracellular leaf compartments of both genotypes was increased under salinity. A different protein pattern was obtained in inter- and intracellular leaf compartments. Thus, several physiological interactions between NaCl stress and Cd were found in the two wheat genotypes.     

Sea fennel (<Emphasis Type="Italic">Crithmum maritimum</Emphasis> L.) under salinity conditions: a comparison of leaf and root antioxidant responses

The present study was carried out to compare the effect of NaCl on growth, cell membrane damage, and antioxidant defences in the halophyte Crithmum maritimum L. (sea fennel). Physiological and biochemical changes were investigated under control (0 mM NaCl) and saline conditions (100 and 300 mM NaCl). Biomass and growth of roots were more sensitive to NaCl than leaves. Roots were distinguished from leaves by increased electrolyte leakage and high malondialdehyde (MDA) concentration. Superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activities, ascorbic acid (AA) and glutathione (GSH) concentrations were lower in the roots than in the leaves of control plants. The different activity patterns of antioxidant enzymes in response to 100 and 300 mM NaCl indicated that leaves and roots reacted differently to salt stress. Leaf CAT, APX and glutathione reductase (GR) activities were lowest at 300 mM NaCl, but they were unaffected by 100 mM NaCl. Only SOD activity was reduced in the latter treatment. Root SOD activity was significantly decreased in response to 300 mM NaCl and root APX activity was significantly higher in plants treated with 100 and 300 mM compared to the controls. The other activities in roots were insensitive to salt. The concentration of AA decreased in leaves at 100 and 300 mM NaCl, and in roots at 300 mM NaCl, when compared to control plants. The concentrations of GSH in NaCl-treated leaves and roots were not significantly different from the controls. In both organs, AA and GSH were predominating in the total pool in ascorbic acid and glutathione, under control or saline conditions.