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Chedly Abdelly - One of the best experts on this subject based on the ideXlab platform.
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chloroplast implication in the tolerance to salinity of the halophyte Cakile Maritima
Russian Journal of Plant Physiology, 2020Co-Authors: Ben N Amor, Francisca Sevilla, Ana Jimenez, M Boudabbous, Chedly AbdellyAbstract:In this study, the response of the chloroplastic antioxidant system of the halophyte Cakile Maritima Scop. and its tolerance to NaCl stress have been studied using purified chloroplasts. Seedlings were grown in different salt concentrations (0, 100, 200 and 400 mmol/L NaCl) and plants were harvested after 40 days. Isolated chloroplasts were purified by centrifugation in density-gradients of Percoll. The evaluation of the oxidative stress was analysed measuring lipid peroxidation, carbonyl protein, $${\text{O}}_{2}^{ - }$$ and H2O2 contents and the antioxidant status by measurement of the activities of superoxide dismutase, catalase, peroxidase and enzymes of the ascorbate–glutathione cycle as well as the antioxidants ascorbate and glutathione, in the purified chloroplasts. Results revealed that the best growth response of C. Maritima under moderate salt stress was associated with a low oxidative stress, the highest activities of SOD, POD and APX and the highest glutathione content. The interaction between the water status of the plant and mineral nutrition seems to be strongly involved in the plant performance under salinity.
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Cakile Maritima a promising model for halophyte studies and a putative cash crop for saline agriculture
2019Co-Authors: Delphine Arbeletbonnin, Chedly Abdelly, Ibtissem Benhamedlouati, Patrick Laurenti, Karim Benhamed, Francois BouteauAbstract:Abstract Agricultural intensification necessary for global food security as well as changes in temperature and precipitation patterns expected from climate change are likely to cause further deterioration irrigated lands in various part of the world. Salinization is spreading particularly in arid and semi-arid regions and urban sprawl is forcing agricultural production into marginal areas. Many salted marginal areas could support biomass production if halophytes able to tolerate high salinity were used. This chapter presents general data on Cakile Maritima, a halophyte, concerning its ecological characteristics, diversity and distribution, adaptation to environment and its potential uses as medicinal plant, for oilseed production or phytoremediation. In a second part we present what have been uncovered in C. Maritima in term of mechanisms and physiological adaptations to salinity when compared to other plants. Cakile Maritima appears worthy of attention since it meets numerous criteria for being a good genetic model of halophyte. It has a small diploid genome, a short life cycle and produces large amount of seeds. Furthermore Cakile Maritima represents a promising species owing its large geographical and ecological amplitude, its economic potential because of its ability to produce numerous secondary compounds and as an oilseed and energy crop. This renders the cultivation of this plant on salted marginal soil of practical significance in the context of the necessary development of biosaline agriculture in the future.
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Effect of salinity on osmotic adjustment, proline accumulation and possible role of ornithine-δ-aminotransferase in proline biosynthesis in Cakile Maritima
Physiology and Molecular Biology of Plants, 2018Co-Authors: Dorsaf Hmidi, Chedly Abdelly, Habib-ur-rehman Athar, Muhammad Ashraf, Dorsaf MessediAbstract:The short time response to salt stress was studied in Cakile Maritima . Plants were exposed to different salt concentrations (0, 100, 200 and 400 mM NaCl) and harvested after 4, 24, 72 and 168 h of treatment. Before harvesting plants, tissue hydration, osmotic potential, inorganic and organic solute contents, and ornithine-δ-aminotransferase activity were measured. Plants of C. Maritima maintained turgor and tissue hydration at low osmotic potential mainly at 400 mM NaCl. The results showed that, in leaves and stems, Na^+ content increased significantly after the first 4 h of treatment. However, in roots, the increase of Na^+ content remained relatively unchanged with increasing salt. The K^+ content decreased sharply at 200 and 400 mM NaCl with treatment duration. This decrease was more pronounced in roots. The content of proline and amino acids increased with increasing salinity and treatment duration. These results indicated that the accumulation of inorganic and organic compounds was a central adaptive mechanism by which C. Maritima maintained intracellular ionic balance under saline conditions. However, their percentage contribution to total osmotic adjustment varies from organ to organ; for example, Na^+ accumulation mainly contributes in osmotic adjustment of stem tissue (60%). Proline contribution to osmotic adjustment reached 36% in roots. In all organs, proline as well as δ-OAT activity increased with salt concentration and treatment duration. Under normal growth conditions, δ-OAT is mainly involved in the mobilization of nitrogen required for plant growth. However, the highly significant positive correlation between proline and δ-OAT activity under salt-stress conditions suggests that ornithine pathway contributed to proline synthesis.
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high salinity impacts germination of the halophyte Cakile Maritima but primes seeds for rapid germination upon stress release
Physiologia Plantarum, 2018Co-Authors: Ahmed Debez, Chedly Abdelly, Andreas Pich, Wael Taamalli, Ikram Belghith, Hanspeter BraunAbstract:Seed germination recovery aptitude is an adaptive trait of overriding significance for the successful establishment and dispersal of extremophile plants in their native ecosystems. Cakile Maritima is an annual halophyte frequent on Mediterranean coasts, which produces transiently dormant seeds under high salinity, that germinate fast when soil salinity is lowered by rainfall. Here, we report ecophysiological and proteomic data about (1) the effect of high salt (200 mM NaCl) on the early developmental stages (germination and seedling) and (2) the seed germination recovery capacity of this species. Upon salt exposure, seed germination was severely inhibited and delayed and seedling length was restricted. Interestingly, non-germinated seeds remained viable, showing high germination percentage and faster germination than the control seeds after their transfer onto distilled water. The plant phenotypic plasticity during germination was better highlighted by the proteomic data. Salt exposure triggered (1) a marked slower degradation of seed storage reserves and (2) a significant lower abundance of proteins involved in several biological processes (primary metabolism, energy, stress-response, folding and stability). Yet, these proteins showed strong increased abundance early after stress release, thereby sustaining the faster seed storage proteins mobilization under recovery conditions compared to the control. Overall, as part of the plant survival strategy, C. Maritima seems to avoid germination and establishment under high salinity. However, this harsh condition may have a priming-like effect, boosting seed germination and vigor under post-stress conditions, sustained by active metabolic machinery.
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cellular mechanisms to survive salt in the halophyte Cakile Maritima
Plant Science, 2018Co-Authors: Delphine Arbeletbonnin, Chedly Abdelly, Patrick Laurenti, Karim Ben Hamed, Ibtissem Ben Hamedlaouti, Francois BouteauAbstract:We recently identified two behaviours in cultured cells of the salt accumulating halophyte Cakile Maritima: one related to a sustained depolarization due to Na+ influx through the non-selective cation channels leading to programmed cell death of these cells, a second one related to a transient depolarization allowing cells to survive (Ben Hamed-Laouti, 2016). In this study, we considered at the cellular level mechanisms that could participate to the exclusion of Na+ out of the cell and thus participate in the regulation of the internal contents of Na+ and cell survival. Upon addition of NaCl in the culture medium of suspension cells of C. Maritima, we observed a rapid influx of Na+ followed by an efflux dependent of the activity of plasma membrane H+-ATPases, in accordance with the functioning of a Na+/H+ antiporter and the ability of some cells to repolarize. The Na+ efflux was shown to be dependent on Na+-dependent on Ca2+ influx like the SOS1 Na+/H+ antiporter. We further could observe in response to salt addition, an early production of singlet oxygen (1O2) probably due to peroxidase activities. This early 1O2 production seemed to be a prerequisite to the Na+ efflux. Our findings suggest that in addition to the pathway leading to PCD (Ben Hamed-Laouti, 2016), a second pathway comprising an SOS-like system could participate to the survival of a part of the C. Maritima cultured cells challenged by salt stress.
Ahmed Debez - One of the best experts on this subject based on the ideXlab platform.
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comparative study of the effect of salt stress alternaria alternata attack or combined stress on the Cakile Maritima growth and physiological performance
Notulae Botanicae Horti Agrobotanici Cluj-napoca, 2021Co-Authors: Arbia Chalbi, Ahmed Debez, Besma Sghaierhammami, Narjes Baazaoui, Sofiene B M Hammami, Hatem Benjouira, Pedro Garciacaparros, Naceur Djebali, Imed Regaya, Jesus V JorrinnovoAbstract:DOI: 10.15835/nbha49312446 Cakile Maritima is a halophytic plant model that is well known by its ability to tolerate high salt concentrations. Salinity was reported to improve the tolerance of halophytes to several abiotic stresses; however, the involvement of salt in the tolerance to biotic stress is still scant. In the present work, the effect of salt on C. Maritima responses towards the pathogenic Alternaria alternata was investigated. For that, C. Maritima seeds were germinated for four weeks. Plants were then divided into four groups: i) Plants irrigated with salt (200mM NaCl); ii) Plants infested by fungus; iii) Plants irrigated with salt and infested by fungus and finally control plants (0mM NaCl, without inoculation). Our results showed that upon salt stress or fungal attack, plants reduced biomass production, hydration status and photosynthetic performance which were associated with a decrease in the gas exchange and chlorophyll fluorescence parameters, with a more pronounced effect upon fungal attack. However, under combined stress, a significant increase of these parameters was noticed, with a level close to that of control. Concerning nutrient contents, K, Zn, Fe, Cu and Mg decreased in the C. Maritima leaves exposed to both stresses applied individually. In contrast, all these nutrients were increased in plants grown under combined stress. Taken together, we can conclude that plants grown under combined stresses had better growth rate and physiological performance compared to all other treated plants, and that salt may be the key in improving the C. Maritima ability to tolerate fungal attack.
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stability of thylakoid protein complexes and preserving photosynthetic efficiency are crucial for the successful recovery of the halophyte Cakile Maritima from high salinity
Plant Physiology and Biochemistry, 2021Co-Authors: Nejia Farhat, Hanspeter Braun, Wafa Kouas, Ahmed DebezAbstract:Abstract Plants native to extreme habitats often face changes in environmental conditions such as salinity level and water availability. In response, plants have evolved efficient mechanisms allowing them to survive or recover. In the present work, effects of high salinity and salt-stress release were studied on the halophyte Cakile Maritima. Four week-old plants were either cultivated at 0 mM NaCl or 200 mM NaCl. After one month of treatment, plants were further irrigated at either 0 mM NaCl, 200 mM NaCl, or rewatered to 0 mM NaCl (stress release). Upon salt stress, C. Maritima plants exhibited reduced biomass production and shoot hydration which were associated with a decrease in the amount of chlorophyll a and b. However, under the same stressful conditions a significant increase of anthocyanin and malonyldialdehyde concentrations was noticed. Salt-stressed plants were able to maintain stable protein complexes of thylakoid membranes. Measurement of chlorophyll fluorescence and P700 redox state showed that PSI was more susceptible for damage by salinity than PSII. PSII machinery was significantly enhanced under saline conditions. All measured parameters were partially restored under salt-stress release conditions. Photoinhibition of PSI was also reversible and C. Maritima was able to successfully re-establish PSI machinery indicating the high contribution of chloroplasts in salt tolerance mechanisms of C. Maritima. Overall, to overcome high salinity stress, C. Maritima sets a cascade of physio-biochemical and molecular pathways. Chloroplasts seem to act as metabolic centers as part of this adaptive process enabling growth restoration in this halophyte following salt stress release.
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composition and stability of the oxidative phosphorylation system in the halophile plant Cakile Maritima
Frontiers in Plant Science, 2019Co-Authors: Nejia Farhat, Ahmed Debez, Sarra Hichri, Tatjana M Hildebrandt, Hanspeter BraunAbstract:Mitochondria play a central role in the energy metabolism of plants. At the same time, they provide energy for plant stress responses. We here report a first view on the mitochondrial Oxidative Phosphorylation (OXPHOS) system of the halophile (salt tolerant) plant Cakile Maritima. Mitochondria were purified from suspension cultures of C. Maritima and for comparison of Arabidopsis thaliana, a closely related glycophyte (salt sensitive) plant. Mitochondria were treated with digitonin and solubilized protein complexes were analyzed by 2D Blue native/SDS polyacrylamide gel electrophoresis. The OXPHOS systems of the two compared plants exhibit some distinct differences. C. Maritima mitochondria include a very abundant respiratory supercomplex composed of monomeric complex I and dimeric complex III. At the same time the complexes II and IV are of reduced abundance. The stability of the OXPHOS complexes was investigated by combined salt and temperature treatments of isolated mitochondria. ATP synthase (complex V) is of increased stability in C. Maritima. Also, the I + III2 supercomplex is present in high abundance during stress treatments. These results give insights into the mitochondrial contribution to the plant salt stress response.
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high salinity impacts germination of the halophyte Cakile Maritima but primes seeds for rapid germination upon stress release
Physiologia Plantarum, 2018Co-Authors: Ahmed Debez, Chedly Abdelly, Andreas Pich, Wael Taamalli, Ikram Belghith, Hanspeter BraunAbstract:Seed germination recovery aptitude is an adaptive trait of overriding significance for the successful establishment and dispersal of extremophile plants in their native ecosystems. Cakile Maritima is an annual halophyte frequent on Mediterranean coasts, which produces transiently dormant seeds under high salinity, that germinate fast when soil salinity is lowered by rainfall. Here, we report ecophysiological and proteomic data about (1) the effect of high salt (200 mM NaCl) on the early developmental stages (germination and seedling) and (2) the seed germination recovery capacity of this species. Upon salt exposure, seed germination was severely inhibited and delayed and seedling length was restricted. Interestingly, non-germinated seeds remained viable, showing high germination percentage and faster germination than the control seeds after their transfer onto distilled water. The plant phenotypic plasticity during germination was better highlighted by the proteomic data. Salt exposure triggered (1) a marked slower degradation of seed storage reserves and (2) a significant lower abundance of proteins involved in several biological processes (primary metabolism, energy, stress-response, folding and stability). Yet, these proteins showed strong increased abundance early after stress release, thereby sustaining the faster seed storage proteins mobilization under recovery conditions compared to the control. Overall, as part of the plant survival strategy, C. Maritima seems to avoid germination and establishment under high salinity. However, this harsh condition may have a priming-like effect, boosting seed germination and vigor under post-stress conditions, sustained by active metabolic machinery.
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comparative analysis of salt induced changes in the root proteome of two accessions of the halophyte Cakile Maritima
Plant Physiology and Biochemistry, 2018Co-Authors: Ikram Belghith, Chedly Abdelly, Tatjana M Hildebrandt, Hanspeter Braun, Jennifer Senkler, Ahmed DebezAbstract:Abstract NaCl stress is a major abiotic stress factor limiting the productivity and the geographical distribution of many plant species. Although halophytes are able to withstand and even to require salt in the rhizosphere, roots are the most sensitive organs to salinity. Here, we investigate the variability of salt tolerance in two Tunisian accessions of the halophyte Cakile Maritima (Raoued and Djerba, harvested from the semi-arid and arid Mediterranean bioclimatic stages, respectively) with a special emphasis on the proteomic changes in roots. Seedlings were hydroponically grown for one month under salt-free conditions and subsequently at three salinities (0, 100, and 300 mM NaCl). Physiological parameters (plant growth, water content, Na+, K+ contents) and root protein profiles were analyzed. Plant biomass was higher in Raoued than in Djerba but the latter was impacted to a lesser extent by salinity, notably due to lower sodium accumulation and higher selectivity for K+. 121 and 97 salt-responsive proteins were identified in Djerba and Raoued accessions, respectively. These proteins can be assigned to several different functional categories: protein metabolism, nucleotide metabolism, amino acid metabolism, glutathione metabolism, translation and ribosome biogenesis, carbohydrate and energy metabolism, and reactive oxygen species regulation and detoxification. The comparative proteome analysis revealed that 33 proteins were salt-responsive in both accessions, while 88 and 64 proteins were salt-responsive only in the Djerba or Raoued accessions, respectively. Our results give deeper insights into the plasticity of salt-stress response of C. Maritima in its native ecosystems.
Peter H Thrall - One of the best experts on this subject based on the ideXlab platform.
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Metapopulation Structure Predicts Population Dynamics in the Cakile Maritima-Alternaria brassicicola Host-Pathogen Interaction.
The American naturalist, 2020Co-Authors: Julien Papaïx, Luke G Barrett, Jeremy J. Burdon, Emily M. Walker, Peter H ThrallAbstract:AbstractIn symbiotic interactions, spatiotemporal variation in the distribution or population dynamics of one species represents spatial and temporal heterogeneity of the landscape for the other. S...
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expansion of genetic diversity in randomly mating founder populations of alternaria brassicicola infecting Cakile Maritima in australia
Applied and Environmental Microbiology, 2010Co-Authors: Celeste C Linde, Jennifer A Liles, Peter H ThrallAbstract:Founder populations of fungal plant pathogens are expected to have low levels of genetic diversity coupled with further genetic drift due to, e.g., limited host availability, which should result in additional population bottlenecks. This study used microsatellite markers in the interaction between Cakile Maritima and the fungal pathogen Alternaria brassicicola to explore genetic expectations associated with such situations. The host, C. Maritima, was introduced into Australia approximately 100 years ago, but it is unknown whether the pathogen was already present in Australia, as it has a wide occurrence, or whether it was introduced to Australia on brassicaceous hosts. Eleven A. brassicicola populations were studied, and all showed moderate levels of gene and genotypic diversity. Chi-square tests of the frequencies of mating type alleles, a large number of genotypes, and linkage equilibrium among microsatellite loci all suggest A. brassicicola reproduces sexually. Significant genetic differentiation was found among populations, but there was no evidence for isolation by distance effects. Bayesian analyses identified eight clusters where the inferred clusters did not represent geographical populations but instead consisted of individuals admixed from all populations. Further analysis indicated that fungal populations were more likely to have experienced a recent population expansion than a population bottleneck. It is suggested that A. brassicicola has been introduced into Australia multiple times, potentially increasing the diversity and size of any A. brassicola populations already present there. Combined with its ability to reproduce sexually, such processes appear to have increased the evolutionary potential of the pathogen through recent population expansions.
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variation in pathogen aggressiveness within a metapopulation of the Cakile Maritima alternaria brassicicola host pathogen association
Plant Pathology, 2005Co-Authors: Peter H Thrall, J J Burdon, Luke G Barrett, Helen M AlexanderAbstract:Variation in aggressiveness and its consequences for disease epidemiology were studied in the Cakile Maritima–Alternaria brassicicola host–pathogen association. Variability in pathogen growth rates and spore production in vitro, as well as disease severity and lesion growth rate on C. Maritima in glasshouse inoculation trials, were investigated. Substantial variation was found in growth rates among individual A. brassicicola isolates, as well as among pathogen populations. A significant trade-off also existed between growth and spore production, such that faster-growing isolates produced fewer spores per unit area. While there was little evidence for a link between growth in vitro and either disease severity or lesion development among fast- vs slow-growth isolate classes at the individual isolate level, the results suggest that variation in pathogen fitness components associated with aggressiveness may influence disease dynamics in nature. An analysis using an independent data set of disease prevalence in the associated host populations found a significant positive relationship between the average growth rate of pathogen populations in vitro and disease progress over the growing season in wild host populations. Trade-offs such as those demonstrated between growth rate and spore production may contribute to the maintenance of variation in quantitatively based host–pathogen interactions.
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short term epidemic dynamics in the Cakile Maritima alternaria brassicicola host pathogen association
Journal of Ecology, 2001Co-Authors: Peter H Thrall, J J Burdon, Clive H BockAbstract:Summary 1 Studies combining within- and among-population processes are crucial for understanding ecological and co-evolutionary dynamics in host‐pathogen interactions. We report on work over an 18-month period involving multiple beach populations of the plant Cakile Maritima and its fungal pathogen Alternaria brassicicola along the southeast coast of Australia. 2 Results from permanent transects replicated on several beaches show that disease incidence and prevalence vary significantly with plant age, class and distance from the sea, as well as time during the season. Plant density is also positively related to disease levels. 3 Results from three subregions indicate that disease persistence depends on survival of infected plants behind the foredunes of protected beaches. Population extinction was more likely on beaches with greater wind exposure and sea access, with the latter also related to colonization consistent with the dispersal of Cakile seeds via ocean currents. 4 Although disease dynamics during the epidemic were similar across subregions, the severity of the epidemic varied significantly among these areas, suggesting that largescale environmental factors may influence the timing and development of the epidemic. 5 Estimates of synchrony in disease dynamics indicated that populations within a subregion were significantly correlated with respect to epidemic development. There was, however, no evidence for spatial synchrony in disease dynamics based on amongpopulation covariances in disease prevalence and interbeach distances. Populations within a subregion were thus often at quite different phases of the epidemic at any given time.
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an analysis of mating structure in populations of the annual sea rocket Cakile Maritima brassicaceae
Australian Journal of Botany, 2000Co-Authors: Peter H Thrall, Andrew G Young, J J BurdonAbstract:Cakile Maritima is an introduced brassicaceous annual plant, now occurring widely along the Australian coastline. While variable, populations of C. Maritima often show high levels of infection by a fungal pathogen, Alternaria brassicicola. As part of a larger metapopulation study of host–pathogen dynamics in this system, an isozyme survey of seven populations of Cakile was carried out along the south coast of New South Wales to investigate mating structure. Given the possibility of self-incompatibility, a glasshouse crossing experiment was also carried out to investigate the potential for selfing. The results from the crossing study showed that C. Maritima is basically an obligate outcrosser, but that self-compatible individuals also occur at low frequency, providing some flexibility in the mating system. Similarly, analysis of the isozyme data showed a preponderance of cross fertilisation, but with significant low levels of selfing in two populations. There were no correlations between outcrossing rates and population size or density, although there was evidence of restricted mating at the individual level (low paternal diversity within seed from a given mother). However, this did not translate into biparental inbreeding, even in very small populations, most likely due to incompatibility leading to negative assortative mating.
Francois Bouteau - One of the best experts on this subject based on the ideXlab platform.
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Cakile Maritima a promising model for halophyte studies and a putative cash crop for saline agriculture
2019Co-Authors: Delphine Arbeletbonnin, Chedly Abdelly, Ibtissem Benhamedlouati, Patrick Laurenti, Karim Benhamed, Francois BouteauAbstract:Abstract Agricultural intensification necessary for global food security as well as changes in temperature and precipitation patterns expected from climate change are likely to cause further deterioration irrigated lands in various part of the world. Salinization is spreading particularly in arid and semi-arid regions and urban sprawl is forcing agricultural production into marginal areas. Many salted marginal areas could support biomass production if halophytes able to tolerate high salinity were used. This chapter presents general data on Cakile Maritima, a halophyte, concerning its ecological characteristics, diversity and distribution, adaptation to environment and its potential uses as medicinal plant, for oilseed production or phytoremediation. In a second part we present what have been uncovered in C. Maritima in term of mechanisms and physiological adaptations to salinity when compared to other plants. Cakile Maritima appears worthy of attention since it meets numerous criteria for being a good genetic model of halophyte. It has a small diploid genome, a short life cycle and produces large amount of seeds. Furthermore Cakile Maritima represents a promising species owing its large geographical and ecological amplitude, its economic potential because of its ability to produce numerous secondary compounds and as an oilseed and energy crop. This renders the cultivation of this plant on salted marginal soil of practical significance in the context of the necessary development of biosaline agriculture in the future.
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cellular mechanisms to survive salt in the halophyte Cakile Maritima
Plant Science, 2018Co-Authors: Delphine Arbeletbonnin, Chedly Abdelly, Patrick Laurenti, Karim Ben Hamed, Ibtissem Ben Hamedlaouti, Francois BouteauAbstract:We recently identified two behaviours in cultured cells of the salt accumulating halophyte Cakile Maritima: one related to a sustained depolarization due to Na+ influx through the non-selective cation channels leading to programmed cell death of these cells, a second one related to a transient depolarization allowing cells to survive (Ben Hamed-Laouti, 2016). In this study, we considered at the cellular level mechanisms that could participate to the exclusion of Na+ out of the cell and thus participate in the regulation of the internal contents of Na+ and cell survival. Upon addition of NaCl in the culture medium of suspension cells of C. Maritima, we observed a rapid influx of Na+ followed by an efflux dependent of the activity of plasma membrane H+-ATPases, in accordance with the functioning of a Na+/H+ antiporter and the ability of some cells to repolarize. The Na+ efflux was shown to be dependent on Na+-dependent on Ca2+ influx like the SOS1 Na+/H+ antiporter. We further could observe in response to salt addition, an early production of singlet oxygen (1O2) probably due to peroxidase activities. This early 1O2 production seemed to be a prerequisite to the Na+ efflux. Our findings suggest that in addition to the pathway leading to PCD (Ben Hamed-Laouti, 2016), a second pathway comprising an SOS-like system could participate to the survival of a part of the C. Maritima cultured cells challenged by salt stress.
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comparison of nacl induced programmed cell death in the obligate halophyte Cakile Maritima and the glycophyte arabidospis thaliana
Plant Science, 2016Co-Authors: Chedly Abdelly, Delphine Arbeletbonnin, Karim Ben Hamed, Bernadette Biligui, Bertrand Gakiere, Ibtissem Ben Hamedlaouti, Linda De Bont, Francois BouteauAbstract: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.
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insights into the ecology and the salt tolerance of the halophyte Cakile Maritima using multidisciplinary approaches
Halophytes for Food Security in Dry Lands, 2016Co-Authors: Karim Ben Hamed, Francois Bouteau, Ibtissem Ben Hamad, Chedly AbdellyAbstract:We review information on the halophyte Cakile Maritima, member of the Brassicaceae family and native of coastal ecosystems. The first investigations focused on the ecology of the species and demonstrated latitudinal range, dispersal and environmental adaptation that make Cakile an ideal model system in which to study phenological adaptation to climate. Cakile Maritima can be used as a model plant to learn about plant reactions that are not observed or experimentally reproduced in traditional glycophytic models. Ion homeostasis, osmotic adjustment, and antioxidant protection are the most studied mechanisms of salt tolerance in this species. By contrasting stress responses of C. Maritima to those of stress-sensitive models such as Arabidopsis, we are convinced that differences between both plant types lie mainly in the mechanisms that control how stress signals are perceived, transduced and how adaptive processes are controlled within the plant. The establishment of cell suspension culture in C. Maritima will help to evaluate salt tolerance at the cellular level. Preliminary results showed that cells exhibited similar growth and ion response to those of halophytes.
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establishment of a cell suspension culture of the halophyte Cakile Maritima
Advances in horticultural science, 2014Co-Authors: Ben I Hamed, Chedly Abdelly, Delphine Arbeletbonnin, Bernadette Biligui, Ben K Hamed, Francois BouteauAbstract:Cakile Maritima is a member of the Brassicaceae family also known as sea rocket. It is an annual succulent halophyte frequent in coastal dune vegetation in Mediterranean regions and Atlantic coasts from North Africa to the north of Europe. This halophyte presents a complex survival strategy at high salinity and its seeds contain up to 40% of an oil which could be suitable for biofuel production and other industrial applications. However, data concerning the cellular mechanisms allowing this plant to resist salinity are still lacking. Cell suspension cultures offer an in vitro system convenient for cell biology studies and biotechnological methods are still not developed for this putative crop. The present paper reports initiation of C. Maritima cell suspension cultures from callus obtained from aerial parts of seedlings. The establishment of a suspension culture which preserves its salt resistance provides an opportunity to gain insights into C. Maritima biology.
Karim Ben Hamed - One of the best experts on this subject based on the ideXlab platform.
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cellular mechanisms to survive salt in the halophyte Cakile Maritima
Plant Science, 2018Co-Authors: Delphine Arbeletbonnin, Chedly Abdelly, Patrick Laurenti, Karim Ben Hamed, Ibtissem Ben Hamedlaouti, Francois BouteauAbstract:We recently identified two behaviours in cultured cells of the salt accumulating halophyte Cakile Maritima: one related to a sustained depolarization due to Na+ influx through the non-selective cation channels leading to programmed cell death of these cells, a second one related to a transient depolarization allowing cells to survive (Ben Hamed-Laouti, 2016). In this study, we considered at the cellular level mechanisms that could participate to the exclusion of Na+ out of the cell and thus participate in the regulation of the internal contents of Na+ and cell survival. Upon addition of NaCl in the culture medium of suspension cells of C. Maritima, we observed a rapid influx of Na+ followed by an efflux dependent of the activity of plasma membrane H+-ATPases, in accordance with the functioning of a Na+/H+ antiporter and the ability of some cells to repolarize. The Na+ efflux was shown to be dependent on Na+-dependent on Ca2+ influx like the SOS1 Na+/H+ antiporter. We further could observe in response to salt addition, an early production of singlet oxygen (1O2) probably due to peroxidase activities. This early 1O2 production seemed to be a prerequisite to the Na+ efflux. Our findings suggest that in addition to the pathway leading to PCD (Ben Hamed-Laouti, 2016), a second pathway comprising an SOS-like system could participate to the survival of a part of the C. Maritima cultured cells challenged by salt stress.
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comparison of nacl induced programmed cell death in the obligate halophyte Cakile Maritima and the glycophyte arabidospis thaliana
Plant Science, 2016Co-Authors: Chedly Abdelly, Delphine Arbeletbonnin, Karim Ben Hamed, Bernadette Biligui, Bertrand Gakiere, Ibtissem Ben Hamedlaouti, Linda De Bont, Francois BouteauAbstract: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.
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insights into the ecology and the salt tolerance of the halophyte Cakile Maritima using multidisciplinary approaches
Halophytes for Food Security in Dry Lands, 2016Co-Authors: Karim Ben Hamed, Francois Bouteau, Ibtissem Ben Hamad, Chedly AbdellyAbstract:We review information on the halophyte Cakile Maritima, member of the Brassicaceae family and native of coastal ecosystems. The first investigations focused on the ecology of the species and demonstrated latitudinal range, dispersal and environmental adaptation that make Cakile an ideal model system in which to study phenological adaptation to climate. Cakile Maritima can be used as a model plant to learn about plant reactions that are not observed or experimentally reproduced in traditional glycophytic models. Ion homeostasis, osmotic adjustment, and antioxidant protection are the most studied mechanisms of salt tolerance in this species. By contrasting stress responses of C. Maritima to those of stress-sensitive models such as Arabidopsis, we are convinced that differences between both plant types lie mainly in the mechanisms that control how stress signals are perceived, transduced and how adaptive processes are controlled within the plant. The establishment of cell suspension culture in C. Maritima will help to evaluate salt tolerance at the cellular level. Preliminary results showed that cells exhibited similar growth and ion response to those of halophytes.
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ecophysiological and genomic analysis of salt tolerance of Cakile Maritima
Environmental and Experimental Botany, 2013Co-Authors: Ahmed Debez, Wided Megdiche, Karim Ben Hamed, Kilani Ben Rejeb, Mohamed Ali Ghars, Mohamed Gandour, Nader Ben Amor, Spencer Brown, Arnould Savoure, Chedly AbdellyAbstract:Arabidopsis thaliana L. (Brassicaceae) and its close relative Thellungiella salsuginea (Pallas) O.E. Schulz have been widely used as genetic models by researchers in their quest of understanding salt tolerance mechanisms in plants. Despite the fact that significant knowledge has been gained, both of these plants present some limitations mainly in relation to their response to salinity. Indeed, Arabidopsis is a glycophyte, whereas Thellungiella is a facultative halophyte. Among the Brassicaceae, Cakile Maritima Scop. is an annual succulent obligate halophyte with a small size genome (1C = 719 Mb) and short life cycle. With these attributes, C. Maritima presents a potential as a genetic model system to address salt stress adaptations at the molecular level in the quest to identify salt stress tolerance mechanisms. Beside their potential as promising model species, halophytes might also be valued for their potential as cash crops themselves. The present paper aims to highlight the main results gained on C. Maritima using multidisciplinary approaches in complement to those obtained on plant model species of the Brassicaceae family.
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early effects of salt stress on the physiological and oxidative status of Cakile Maritima halophyte and arabidopsis thaliana glycophyte
Physiologia Plantarum, 2011Co-Authors: Hasna Ellouzi, Karim Ben Hamed, Jana Cela, Sergi Munnebosch, Chedly AbdellyAbstract: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.
