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1

Salt-imposed restrictions on the uptake of macroelements by roots of Arabidopsis thaliana

100%
Attia H., Karray N., Rabhi M., Lachaal M.
Acta Physiologiae Plantarum
|
2008
|
tom 30
|
nr 5
The aim of this investigation was to identify the growth limiting factors in Arabidopsis thaliana subjected to a mild salt stress. Two natural accessions (Col and N1438) were compared. In spite of their morphological and developmental similarity, they have been previously shown to differ in the response of their superoxide dismutase genes to salt stress (Physiol Plant 132:293–305, 2008). Thirty-day-old seedlings were grown for 15 days using a split-root configuration in which the root system was divided into two equal parts: the first was immersed in a complete nutrient solution with 50 mM NaCl added, while the second part was immersed in either complete or incomplete K-, Ca-, or N-free medium. Using this approach, we demonstrated that K+ and Ca2+ uptake was impaired in the roots subjected to NaCl. There was no indication of the salt-induced inhibition of N uptake. If K+ or Ca2+ were available from salt-free medium, plants were able to grow at normal rate and accumulate large amounts of Na+ in the shoots. These results indicate that the sensitivity of Arabidopsis growth to mild salinity was probably due to an inhibition of K+ or Ca2+ root transport by salt rather than due to salt accumulation in shoots. Furthermore, the salt sensitivity of ion transport in roots seemed to depend on the genotype, since K+ was limiting for Col growth, in contrast to N1438, the growth of which was limited by Ca2+.
2

Sodium transport in basil

88%
Attia H., Karray N., Ellili A., Msilini N., Lachaal M.
Acta Physiologiae Plantarum
|
2009
|
tom 31
|
nr 5
In order to diversify the production of plants with pharmacological interest, it is important to understand the mechanisms involved in their tolerance to environmental constraints, such as salinity. Basil (Ocimum basilicum), known for its therapeutic uses, has been claimed to be salt tolerant, but physiological aspects of this behavior remain unknown. Since salt tolerance is known to be associated with several characteristics concerning Na⁺ transport to leaves, we studied this function in hydroponically grown basil. We analyzed the response of 30-day-old seedlings to 25–50 mM NaCl applied for 15 days. Growth was poorly affected, indicating that these concentrations corresponded to the tolerated salinity range. Leaves accumulated Na⁺ at relatively high concentration, without dehydrating. Potassium concentration in leaf tissues was maintained close to control level, indicating that K⁺ was 15- to 25-fold preferred over Na⁺ for ion transport and deposition. Collection of xylem sap on detopped plants revealed that this preference was only 10-fold for ion introduction into root xylem sap. Short-term (24 h) changes in Na⁺ distribution between organs after stem (steam) girdling suggested that Na⁺ downward recirculation by phloem occurred. Although modest, this transport might have augmented K⁺ selectivity of ion deposition in leaves.
3
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Arabidopsis thaliana tolerates iron deficiency more than Thellungiella salsuginea by inducing metabolic changes at the root level

88%
Msilini N., Ferhi J., Chebbi M., Lachaal M., Ouerghi Z.
Acta Biologica Cracoviensia. Series Botanica
|
2015
|
tom 57
|
nr 1
Several studies have used A. thaliana as a model to identify the physiological and molecular mechanisms underlying iron deficiency tolerance in plants. Here, Arabidopsis thaliana and Thellungiella salsuginea were used to investigate the differential responses to iron deficiency of these two species. Plants were cultivated in hydroponic medium containing 5 or 0 μM Fe, for 10 days. Results showed that rosette biomass was more reduced in T. salsuginea than in A. thaliana when grown on Fe-deficient medium. As a marker for iron deficiency tolerance, the induction of ferric chelate reductase (FCR) and phosphoenolpyruvate carboxylase (PEPC) activities was observed only in A. thaliana roots. In addition, we found that the accumulation of phenolic acids in roots of N1438 ecotype of A. thaliana was stimulated by Fe deficiency. Furthermore, an increase of flavonoids content in the root and exudates was observed under Fe-deficiency in this ecotype. Unlike other abiotic stresses, it appears that iron deficiency effects were more pronounced in Thellungiella than in Arabidopsis. The higher tolerance of the Arabidopsis plant to iron deficiency may be due to the metabolic changes occurring in the roots.
4

Effect of salinity on germination, phytase activity and phytate content in lettuce seedling

88%
Nasri N., Kaddour R., Rabhi M., Plassard C., Lachaal M.
Acta Physiologiae Plantarum
|
2011
|
tom 33
|
nr 3
Seeds of four lettuce (Lactuca sativa L.) varieties (Romaine, Augusta, Vista and Verte) differing in their salt sensitivity were sown at 0 (Control), 50, 100 and 150 mM NaCl. The final germination percentage decreased with the increasing salinity and was annulated at the highest salt concentration in Vista and Verte, the most sensitive varieties. However, in the less sensitive ones, Romaine and Augusta, it was slightly modified at 50 and 100 mM NaCl and then decreased by 50% compared with the control, at 150 mM. The effects of NaCl 100 mM on seedling growth, phytase activities, phytate and inorganic phosphorus contents were studied in Romaine and Vista showing different behaviours towards salinity. Radicle and hypocotyl length and fresh and dry weights were reduced by salt treatment in both varieties. In addition, radicle phytase activity exhibited an increase in Romaine (less sensitive) and a decrease in Vista (more sensitive). In hypocotyl, this activity showed no difference with the control in the two varieties. However, in cotyledons, and during early hours after germination, salinity decreased phytase activity in both varieties whereas in the later hours (72–96 h) this activity reached the value of the control in Romaine. The enhancement of phytase activity was concomitant with an increase in orthophosphate content and a decrease in phytate reserve. These results suggest that salt presence in the medium delays Pi remobilization from phytate stock, but stimulates assimilation of phosphorus more than its accumulation in the organs of the two lettuce varieties.
5

Salt effects on the growth, mineral nutrition, essential oil yield and composition of marjoram (Origanum majorana)

88%
Baatour O., Kaddour R., Wannes W. A., Lachaal M., Marzouk B.
Acta Physiologiae Plantarum
|
2010
|
tom 32
|
nr 1
The aim of this work was to investigate the growth, mineral nutrition and essential oil composition of marjoram aerial part. Seedlings were cultivated for 20 days on nutrient solution, and then transferred to hydroponic solution with different NaCl concentrations (0, 50, 100, 150 mM). Plants were harvested after 17 days of treatment. Mineral nutrition and essential oil composition of shoots were determined. Results showed that growth, water content and development of the different organs of marjoram plant were affected just at the highest NaCl concentration (150 mM). Furthermore, salt did not seem to affect leaf area and root length but reduced the number of leaves. An increase in the total leaf surface and its thickness was observed at different NaCl concentrations. At 50 mM NaCl, sodium was primarily accumulated in roots but at 150 mM, it was strongly accumulated in leaves. However, Cl⁻ accumulation was lower at higher NaCl concentrations. Essential oil yield of marjoram shoots was 0.12% in the control and 0.10% at 50 mM but an important decrease was observed at 100 mM (0.05%). Thirty-three components were identified belonging to different chemical classes. In the control, the essential oil was found to be rich in trans-sabinene hydrate (47.67%), terpinen-4-ol (20.82%) and cis-sabinene hydrate (7.23%). The proportions of these main compounds were differently affected by salt.
6

Physiological and antioxidant responses of Mentha pulegium (Pennyroyal) to salt stress

76%
Oueslati S., Karray-Bouraoui N., Attia H., Rabhi M., Ksouri R., Lachaal M.
Acta Physiologiae Plantarum
|
2010
|
tom 32
|
nr 2
Mentha pulegium L. is a medicinal and aromatic plant belonging to the Labiatae family present in the humid to the arid bioclimatic regions of Tunisia. We studied the effect of different salt concentrations on plant growth, mineral composition and antioxidant responses. Physiological and biochemical parameters were assessed in the plant organs after 2 weeks of salt treatment with 25, 50, 75 and 100 mM NaCl. Results showed that, growth was reduced even by 25 mM, and salt effect was more pronounced in shoots (leaves and stems) than in roots. This growth decrease was accompanied by a restriction in tissue hydration and K⁺ uptake, as well as an increase in Na⁺ levels in all organs. Considering the response of antioxidant enzymes to salt, leaves and roots reacted differently to saline conditions. Leaf and root guaiacol peroxidase activity showed an increase by different concentration of NaCl, but superoxide dismutase activity in the same organs showed a slight modification in NaCl-treated leaves and roots. Moreover, polyphenol contents and antioxidant activity were analysed in M. pulegium leaves and roots under salt constraint. The analysis showed an increase of total polyphenol content (2.41–8.17 mg gallic acid equivalent g⁻¹ dry weight) in leaves. However, methanol extract of leaves at 100 mM NaCl displayed the highest DPPH scavenging ability with the lowest IC₅₀ value (0.27 µg ml⁻¹) in comparison with control which exhibited IC₅₀ equal to 0.79 µg ml⁻¹ .
7

Effects of two sodium salts on fatty acid and essential oil composition of basil (Ocimum basilicum L.) leaves

76%
Tarchoune I., Baatour O., Harrathi J., Hamdaoui G., Lachaal M., Ouerghi Z., Marzouk B.
Acta Physiologiae Plantarum
|
2013
|
tom 35
|
nr 08
The effects of two sodium salts on growth, fatty acids, and essential oil compositions were investigated in a medicinal and aromatic plant, Ocimum basilicum cultivated in hydroponic medium. Plants were subjected to an equimolar concentration of Na2SO4 (25 mM) and NaCl (50 mM) for 15 days. Our results showed that leaf growth rate was more depressed by 25 mM Na2SO4 than by 50 mM NaCl. The total fatty acid contents did not show any change in plants. a-Linolenic, palmitic, and linoleic acids were the major fatty acids. The identification of basil leaf fatty acids has not been previously studied and this work revealed the predominance of polyunsaturated fatty acids. Under both salts, leaf fatty acid composition remained unchanged. Regarding the essential oil yield, it decreased significantly by 28 % under 25 mM Na2SO4 and showed an increase by 27 % under 50 mM NaCl. The major volatile compound in leaves was linalool with 34.3 % of total essential oil constituents, followed by eugenol (19.8 %), 1.8-cineole (14.4 %) and methyl eugenol (5.2 %). Further, levels of eugenol and methyl eugenol were most modulated by salt, and the negative correlation between these two compounds reflects the stimulation of O-methyltransferase activity under both salts.
8

Distribution of phenolic compounds and antioxidant activity between young and old leaves of Carthamus tinctorius L. and their induction by salt stress

76%
Abdallah S. B., Rabhi M., Harbaoui F., Zar-kalai F., Lachaal M., Karray-Bouraoui N.
Acta Physiologiae Plantarum
|
2013
|
tom 35
|
nr 04
In the present work, we investigated the effect of salt stress on the distribution of safflower (Carthamus tinctorius L.) antioxidant system in relation to leaf age. The study was carried out under growth chamber conditions using seedlings of three cultivars which were subjected to 0 and 50 mM NaCl for 3 weeks. Leaf growth, water content, lipid peroxidation, and phenolic compound (total polyphenols, total flavonoids, and proanthocyanidins) concentration were measured at two leaf stages (young and old leaves). Leaf growth was affected by salinity only in Kairouan cultivar that also showed a significant decrease in old leaf water content. By contrast, Gabes and Tazarka cultivars maintained their old leaf water content constant and showed a reduction in that of young leaves. This could be attributed to a higher aptitude of the latter two cultivars to use absorbed sodium and chloride for osmotic adjustment in old leaves, keeping potassium for specific functions. Salt-induced lipid peroxidation was observed only in old leaves, whereas the accumulation of the major phenolic compounds under saline conditions was higher in young leaves, except in Gabes cultivar where no significant difference was found between the two leaf stages. A significant variability was also found between the three cultivars. The better behavior of salt-challenged leaves of Gabes and Tazarka cultivars compared to that of Kairouan cultivar may be related to their higher water content and the accumulation of polyphenols, in particular flavonoids that were shown to be efficiently involved in the restriction of salt-induced oxidative damages.
9

Responses of Arabidopsis thaliana to bicarbonate-induced iron deficiency

76%
Msilini N., Attia H., Bouraoui N., M'rah S., Kosouri R., Lachaal M., Ouerghi Z.
Acta Physiologiae Plantarum
|
2009
|
tom 31
|
nr 4
Morpho-physiological and biochemical responses of Arabidopsis thaliana (accession N1438) to bicarbonate-induced iron deficiency were investigated. Plants were grown in cabinet under controlled conditions, in a nutrient solution containing 5 µM Fe, added or not with 10 mM NaHCO₃. After 30 days, bicarbonate-treated plants displayed significantly lower biomass, leaf number and leaf surface area as compared to control plants, and slight yellowing of their younger leaves was observed. Potassium (K⁺) content was not modified by bicarbonate treatment in roots, whereas it was significantly diminished in shoots. Their content in ferrous iron (Fe²⁺) and in leaf total chlorophylls was noticeably lower than in control plants. Root Fe(III)-chelate reductase and phosphoenolpyruvate carboxylase (PEPC) activities were significantly enhanced, but leaf ribulose 1.5-bisphosphate carboxylase (Rubisco) activity was decreased.
10

Analysis of salinity effects on basil leaf surface area, photosynthetic activity, and growth

76%
Attia H., Ouhibi C., Ellili A., Msilini N., Bouzaien G., Karray N., Lachaal M.
Acta Physiologiae Plantarum
|
2011
|
tom 33
|
nr 3
Basil (Ocimum basilicum L.) seedlings were cultured on liquid medium in controlled conditions. Two varieties differing in leaf size were compared. When plants were 30 days old, the medium was supplemented with 50 mM NaCl. After 15 days of treatment, root, stemand leaf biomass, leaf number, and leaf surface area were measured. Ion accumulation was determined in roots, stems, and leaves. Photosynthetic parameters (CO₂ fixation rate, internal CO₂ concentration, stomatal conductance) as well as transpiration rate were determined on separate leaves. Electrolyte leakage and malondialdehyde content were used to estimate damage to membranes and lipid peroxidation, respectively. Several antioxidant enzymatic activities were used as proxies of oxidative stress. High Na⁺ concentration was reached in leaf tissues. Salt restricted whole plant biomass deposition rate by diminishing leaf number and leaf expansion, as well as photosynthetic activity were estimated from whole plant biomass production per unit leaf surface area. Diminished stomatal conductance restricted CO₂ fixation rate, and decrease in chlorophyll content presumably limited photosynthetic activity. Lipid peroxidation revealed damages to membranes. The magnitude of these responses differed between the two varieties, indicating that an intraspecific variability in salt response exists in basil.
11

Salt stress (NaCl) affects plant growth and branch pathways of carotenoid and flavonoid biosyntheses in Solanum nigrum

76%
Abdallah S. B., Aung B., Amyot L., Lalin I., Lachaal M., Karray-Bouraoui N., Hannoufa A.
Acta Physiologiae Plantarum
|
2016
|
tom 38
|
nr 03
12

Physiological and molecular characterization of salt response of Arabidopsis thaliana NOK2 ecotype

76%
Kaddour R., M`rah S., Karray-Bouraoui N., Lambert C., Berthomieu P., Lachaal M.
Acta Physiologiae Plantarum
|
2010
|
tom 32
|
nr 3
Arabidopsis thaliana is a glycophyte capable to tolerate mild salinity. Although salt sensitivity of this species, a variability of this characteristic was revealed between different ecotypes. This study presents the physiological and molecular characteristics of salt response of two ecotypes, NOK2 and Columbia (Col). Seedlings were cultivated in hydroponics in the presence of 0 or 50 mM NaCl during 25 days. Rosette leaf samples were collected after 19, 22, and 25 days for determination of physiological parameters, and after 18 days for study of DNA polymorphism. Salt treatment decreased rosette dry matter, leaf number, leaf hydration, and leaf surface area. All these effects were significantly more visible in Col than in NOK2. Moreover, the NOK2 leaves accumulated less Na⁺ and more K⁺ than those of Col. DNA polymorphism between the two ecotypes was analyzed with codominant molecular markers based on PCR amplification, namely, microsatellites, cleaved amplified polymorphism sequence (CAPS), and single nucleotide polymorphism markers (SNP). Among the 35 tested markers, 17 showed a clear polymorphism and were distributed on the five Arabidopsis chromosomes ending with a genetic map construction. These results could play an important role in the future establishment of cartography of candidate gene controlling the K⁺/Na⁺ selectivity of ion transport in leaves, a component of plant salt tolerance.
13

Changes in the antioxidative systems of Ocimum basilicum L. (cv. Fine) under different sodium salts

76%
Tarchoune I., Sgherri C., Izzo R., Lachaal M., Navari-Izzo F., Ouerghi Z.
Acta Physiologiae Plantarum
|
2012
|
tom 34
|
nr 5
The effects of different sodium salts on some physiological parameters and antioxidant responses were investigated in a medicinal and aromatic plant, Ocimum basilicum L. (cultivar Fine). Plants were subjected to an equimolar concentration of Na₂SO₄ (25 mM) and NaCl (50 mM) for 15 and 30 days. Growth, oxidative stress parameters [electrolyte leakage, peroxidation, and hydrogen peroxide (H₂O₂) concentration], antioxidant enzyme activities [ascorbate peroxidase (APX, EC 1.11.1.11), glutathione reductase (GR, EC 1.6.4.2), and peroxidases (POD, EC 1.11.1.7)], as well as antioxidant molecules [ascorbate and glutathione] were determined. The two salts affected leaf growth rates to the same extent, after 15 or 30 days of treatment, indicating a similar effect of Na₂SO₄ and NaCl salinity on growth, even if different (enzymatic and non-enzymatic) antioxidant mechanisms were involved in H₂O₂ detoxification. However, under both salts, the efficiency of the antioxidant metabolism seemed to be sufficient to avoid the deleterious effects of reactive oxygen species (ROS). Indeed, both ion leakage and peroxidation did not change under either Na₂SO₄ or NaCl salinity. As a whole, these data suggest that a cooperative process between the antioxidant systems is important for the tolerance of Ocimum basilicum L., cv. Fine to Na₂SO₄ and NaCl salinity.
14

Effect of salt stress on growth, fatty acids and essential oils in safflower (Carthamus tinctorius L.)

76%
Harrathi J., Hosni K., Karray-Bouraoui N., Attia H., Marzouk B., Magne C., Lachaal M.
Acta Physiologiae Plantarum
|
2012
|
tom 34
|
nr 1
This study examined the influence of salt treatment on the growth parameters (fresh and dry weights), the mineral content (K⁺ and Na⁺), total lipid contents, fatty acid composition, yields and chemical composition of the essential oil of safflower (Carthamus tinctorius L.) grown in hydroponics for 2 weeks. Results showed that the application of 50 mM NaCl reduced the fresh weight of aerial parts (shoots and leaves) while it enhanced those of the roots. The reduction of dry weight was found to be more pronounced in the aerial parts. Salt treatment increased markedly the concentrations of Na⁺ in both plant parts while it reduced those of K⁺ which resulted in a sharp reduction of K⁺/Na⁺ ratio. In response to salt treatment, total lipids contents decreased in both plant parts and great qualitative changes in the fatty acids profiles were observed. Whatever the plant parts analysed, a redirection of the lipidic metabolism towards synthesis of unsaturated fatty acids as revealed by the increase of double bond index and linoleic desaturation ratio was pointed out. The increased unsaturation index was found to be more important in roots than in aerial parts. Such treatment also reduced the essential oil yields and induced marked quantitative changes in the chemical composition of the essential oils from both plant parts. Of all the identified components, oxygenated components display a prominent salt-induced synthesis and/or accumulation in both roots and aerial parts.
15

Antioxidant pool optimization in Carthamus tinctorius L. leaves under different NaCl levels and treatment durations

76%
Zaoui S., Gautier H., Bancel D., Chaabani G., Wasli H., Lachaal M., Karray-Bouraoui N.
Acta Physiologiae Plantarum
|
2016
|
tom 38
|
nr 08
16

Salt tolerance analysis of Arabidopsis thaliana NOK2 accession under saline conditions and potassium supply

76%
Kaddour R., Baatour O., Mahmoudi H., Nasri N., Zaghdoudi M., Lachaal M.
Acta Physiologiae Plantarum
|
2011
|
tom 33
|
nr 6
The response to salt treatment and K⁺ provision of two Arabidopsis thaliana accessions grown for 17 days in the presence of 50 mM NaCl was investigated. Leaf and root dry weight deposition was restricted by salt, more in Col accession than in NOK2 accession. In both accessions, the growth inhibition induced by salinity was associated with a decrease in total leaf surface area, which resulted from diminished leaf number, but not from restriction of individual leaf surface area. Comparing the effects of salt on dry matter production and total leaf surface area revealed large difference between Col and NOK2 for net assimilation rate (the amount of whole plant biomass produced per unit leaf surface area), which was augmented by salt and K⁺ in NOK2 but not in Col. This result, which suggested a better capacity of NOK2 to preserve its photosynthetic machinery against salt stress, was in agreement with the effect of NaCl on photosynthetic pigments. Indeed, salt significantly reduced chlorophyll and carotenoid content in Col leaves but had no impact on NOK2 leaf pigment content. Since K⁺ provision had only marginal effects on these responses to salt stress, leaf mineral unbalance was unlikely. Guaiacol peroxidase activity was augmented by salt treatment in leaves and roots of both accessions. Salinity decreased the catalase activity in Col leaves and in roots, and increased this activity in NOK2 organs. In conclusion, when aggressed by salt, NOK2 was able (1) to produce more leaves than Col, and (2) to efficiently protect its photosynthetic apparatus, perhaps by developing more efficient antioxidative defense through increased catalase and peroxidase activities. Consequently, the overall photosynthetic activity was higher and more robust to salt aggression in NOK2 than in Col.
17

Effects of NaCl or Na2SO4 salinity on plant growth, ion content and photosynthetic activity in Ocimum basilicum L.

76%
Tarchoune I., Degl'Innocenti E., Kaddour R., Guidi L., Lachaal M., Navari-Izzo F., Ouerghi Z.
Acta Physiologiae Plantarum
|
2012
|
tom 34
|
nr 2
Basil (Ocimum basilicum L., cultivar Genovese) plants were grown in Hoagland solution with or without 50 mM NaCl or 25 mM Na₂SO₄. After 15 days of treatment, Na₂SO₄ slowed growth of plants as indicated by root, stem and leaf dry weight, root length, shoot height and leaf area, and the effects were major of those induced by NaCl. Photosynthetic response was decreased more by chloride salinity than by sulphate. No effects in both treatments on leaf chlorophyll content, maximal efficiency of PSII photochemistry (Fv/Fm) and electron transport rate (ETR) were recorded. Therefore, an excess of energy following the limitation to CO₂ photoassimilation and a down regulation of PSII photochemistry was monitored under NaCl, which displays mechanisms that play a role in avoiding PSII photodamage able to dissipate this excess energy. Ionic composition (Na⁺, K⁺, Ca²⁺, and Mg²⁺) was affected to the same extent under both types of salinity, thus together with an increase in leaves Cl-, and roots SO₄²⁻ in NaCl and Na₂SO₄-treated plants, respectively, may have resulted in the observed growth retardation (for Na₂SO₄ treatment) and photosynthesis activity inhibition (for NaCl treatment), suggesting that those effects seem to have been due to the anionic component of the salts.
18

Different antioxidant responses to salt stress in two different provenances of Carthamus tinctorius L.

64%
Karray-Bouraoui N., Harbaoui F., Rabhi M., Jallali I., Ksouri R., Attia H., Msilini N., Lachaal M.
Acta Physiologiae Plantarum
|
2011
|
tom 33
|
nr 4
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 (saltsensitive) 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.
19

Effect of salt stress on the antimicrobial activity of Ruta chalepensis essential oils

64%
Amdouni T., Abdallah S. B., Msilini N., Merck F., Chebbi M., Lachaal M., Karray-Boruaoui N., Ouerghi Z., Fernandez X.
Acta Physiologiae Plantarum
|
2016
|
tom 38
|
nr 06
20

Varied tolerance to NaCl salinity is related to biochemical changes in two contrasting lettuce genotypes

64%
Mahmoudi H., Kaddour R., Huang J., Nasri N., Olfa B., M'Rah S., Hannoufa A., Lachaal M., Ouerghi Z.
Acta Physiologiae Plantarum
|
2011
|
tom 33
|
nr 5
Salt stress perturbs a multitude of physiological processes such as photosynthesis and growth. To understand the biochemical changes associated with physiological and cellular adaptations to salinity, two lettuce varieties (Verte and Romaine) were grown in a hydroponics culture system supplemented with 0, 100 or 200 mM NaCl. Verte displayed better growth under 100 mM NaCl compared to Romaine, but both genotypes registered relatively similar reductions in growth under 200 mM NaCl treatment. Both varieties showed differences in net photosynthetic activity in the absence of salt and 8 days after salt treatment. These differences diminished subsequently under prolonged salt stress (14 days). Verte showed enhanced leaf proline and restricted total cations especially Na⁺, lesser malondialdehyde (MDA) formation and lignification in the roots under 100 mM NaCl salinity. Membrane damage estimated by electrolyte leakage increased with elevated salt concentrations in roots of both varieties, but Verte had significantly lower electrolyte leakage relative to Romaine under 100 mM NaCl. Moreover, Verte also accumulated greater levels of carotenoids under increasing NaCl concentrations compared to Romaine. Taken together, these findings suggest that the greater tolerance of Verte to 100 mM NaCl is related to the more restricted accumulation of total cations and toxic Na⁺ in the roots and enhanced levels of antioxidative metabolites in root and leaf tissue.
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