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Background: The in vitro propagation of halophytes is innovative perspective for sustainable agriculture, conservation of natural plants and essential raw materials for industry due to increasing soil salinization and decreasing freshwater availability. Sarcocornia fruticosa, a halophytic plant, may hold promise for biosaline production systems and achieve bioactive products. Understanding the salt tolerance mechanisms of halophytes through elicitors can enhance the production of secondary metabolites, such as phenolics and flavonoids, under saline environment. This study aimed to evaluate the effects of NaCl salinity (700 mM and 1000 mM) on Sarcocornia fruticosa shoot cultures and assess the influence of different elicitors-Enterobacter cloacae extract (BE), selenium nanoparticles (SeNPs) and methyl jasmonate (MeJA) -on the plants growth, physiological and biochemical responses, and isorhamnetin production. Methodology: Shoot cultures were grown under controlled conditions with two concentrations of NaCl, alone and in combination with BE (0.5%), SeNPs (100 ppm), or MeJA (50 µM). Growth parameters, photosynthetic pigments, ion accumulation, osmolyte content, oxidative stress marker, enzyme activity, phenolic compound levels, and isorhamnetin production were analyzed to determine the impact of salinity and elicitor treatments on S. fruticosa for 14 days. Results: Sarcorcocnia fruticosa exhibited better tolerance up to 700 mM than 1000 mM NaCl, as evidenced by higher dry weights, chlorophyll a/b ratios, and enhanced osmolyte and antioxidant contents. Elicitation both saline cultures with BE and SeNPs improved growth mostly by increasing biomass, pigment contents, K+/Na+ ratios, and reducing lipid peroxidation, however, MeJA reduced the biomass mainly by increasing MDA and Na+ ion accumulation. In contrast, application of all elicitors stimulated the production of phenolic compounds and isorhamnetin, as well as BE can contribute for increasing resistance of S. fruticosa to stressful conditions. Conclusion: This study demonstrated that PTC techniques and appropriate elicitors can optimize halophyte propagation and secondary metabolite production under saline conditions. The findings suggest that BE and SeNPs significantly enhanced the growth and biochemical resilience of S. fruticosa under salinity stress, with a notable increase in isorhamnetin production. MEJA. [ABSTRACT FROM AUTHOR]

Purpose: Hypersaline environments are extremely vulnerable and important ecological niches. Because much knowledge has focused on the distribution of heavy metals in these areas, the detailed behavior of key major elements in hypersaline environments has not been elucidated in detail. This research aims to define the distribution, translocation pathways, and mobility patterns of the major elements in hypersaline sediments and halophytes. Materials and methods: Samples of Sarcocornia fruticosa plants were collected from evaporation (ES) and crystallization (CA) sites in the Sečovlje Salina area (Republic of Slovenia). The major element contents were measured by digestion in HNO3 then aqua regia and analyzed by ICP-MS for ultra-low detection limits. Rhizo-sediments from EA and CA were processed using sequential extraction analysis to determine the precise fractionation of Al, Ca, Fe, K, Mg, Mn, and Na. To determine the translocation patterns of individual major elements in S. fruticosa, two indices were calculated: bioconcentration (BCF) and translocation factor (TF). Differences and similarities between samples and elements were highlighted using Statistica VII and Grapher 8 statistical software and Ward's method, respectively. Results and discussion: The obtained results confirmed that halophyte plants take up large amounts of the essential micronutrient Na due to high salinity, and that macronutrients (Ca, Mg, P, and S) are intensively translocated from the roots to the upper parts of the plant. The overall trend in translocation signature for major elements, distinguished by BCF and TF factor calculations, emphasizes that root tissues accumulate a significant amount of major elements and that accumulation depends on individual major elements. It also showed that the major elements Ca, Mg, Na, P, and S are highly translocated within plants, while the mobility of Al, Fe, and K is limited. Conclusions: Our results suggest that the major elements are vital macronutrients for halophytes, but their accumulation in the roots and further translocation within the plant depend on individual elements and their dynamics. The translocation pattern of the major elements can be justified as follows: Ca is an essential element for plant growth, maintenance, and membrane integrity; Mg is a specific component of chlorophyll; Na is present because of the hypersaline environment; P is a key component of plant metabolic processes; S represents an important component of enzymes and other key proteins; Al and Fe are preferentially accumulated in roots; and plant leaves are generally undersupplied with K. The presented results are of great importance for the general knowledge and use/application of halophytes in agriculture and biotechnology. [ABSTRACT FROM AUTHOR]

This work aims to boost the sustainable valorization of the edible halophyte Sarcocornia fruticosa (L.) A.J. Scott (Amaranthaceae) from Southern Tunisia by assessing its potential as a source of bioactive components. To achieve this, hydroethanolic extracts of S. fruticosa , collected from two distinct Tunisian biomes (Zarzis: SFZ and Djerba: SFDJ), were profiled for total phenolic, flavonoid, and condensed tannin contents, as well as for individual phenolic composition by HPLC-ESI-MS. Then, the extracts were evaluated for in vitro antioxidant properties via complementary methods and for in vitro inhibition of enzymes related to Alzheimer's disease (acetylcholinesterase: AChE, and butyrylcholinesterase: BuChE), type 2 diabetes (α-glucosidase and α-amylase), and hyperpigmentation and food oxidation (tyrosinase). Finally, they were assessed for acute in vitro toxicity. Our findings identified thirteen phenolic compounds, with rutin being the predominant compound and its content being nearly twice as high in SFZ than in SFDJ (1224.51 and 643.61 mg/kg DW, respectively). Salvianolic acid B was also reported for the first time in Sarcocornia genus. The extracts exhibited notable ferric reducing antioxidant power (FRAP), with SFZ displaying an effective median concentration (EC 50) value of 0.97 mg/mL. They also showed promising inhibitory effects on acetylcholinesterase (>40%) and tyrosinase (>50%), without any cytotoxicity. The Zarzis ecotype in particular displayed superior bioactive properties, making it an excellent candidate for future cultivation trials under saline conditions, with potentially valuable economic outcomes for the region. These findings highlight the potential of S. fruticosa as a source of functional ingredients with nutraceutical and therapeutic applications. • Rutin is the predominant compound in Sarcocornia fruticosa from Southern Tunisia. • Salvianolic acid B is reported for the first time in Sarcocornia genus. • The enzymatic inhibitory potential of S. fruticosa is disclosed for the first time. • S. fruticosa is a source of antioxidant, anti-AChE and anti-tyrosinase compounds. • Potential uses of S. fruticosa in nutraceuticals, pharmaceuticals and cosmetics. [ABSTRACT FROM AUTHOR]

Current agricultural problems, such as the decline of freshwater and fertile land, foster saline agriculture development. Salicornia and Sarcocornia species, with a long history of human consumption, are ideal models for developing halophyte crops. A greenhouse experiment was set up to compare the response of the perennial Sarcocornia fruticosa and the two annual Salicornia europaea and S. veneta to 30 days of salt stress (watering with 700 mM NaCl) and water deficit (complete withholding of irrigation) separate treatments, followed by 15 days of recovery. The three species showed high tolerance to salt stress, based on the accumulation of ions (Na+, Cl−, Ca2+) in the shoots and the synthesis of organic osmolytes. These defence mechanisms were partly constitutive, as active ion transport to the shoots and high levels of glycine betaine were also observed in non-stressed plants. The three halophytes were sensitive to water stress, albeit S. fruticosa to a lesser extent. In fact, S. fruticosa showed a lower reduction in shoot fresh weight than S. europaea or S. veneta, no degradation of photosynthetic pigments, a significant increase in glycine betaine contents, and full recovery after the water stress treatment. The observed differences could be due to a better adaptation of S. fruticosa to a drier natural habitat, as compared to the two Salicornia species. However, a more gradual stress-induced senescence in the perennial S. fruticosa may contribute to greater drought tolerance in this species. [ABSTRACT FROM AUTHOR]

Coexistence impact of pollutants of different nature on halophytes tolerance to metal excess has not been thoroughly examined, and plant functional responses described so far do not follow a clear pattern. Using the Cu-tolerant halophyte Sarcocornia fruticosa as a model species, we conducted a greenhouse experiment to evaluate the impact of two concentration of copper (0 and 12 mM CuSO 4) in combination with three nitrate levels (2, 14 and 50 mM KNO 3) on plant growth, photosynthetic apparatus performance and ROS-scavenging enzymes system. The results revealed that S. fruticosa was able to grow adequately even when exposed to high concentrations of copper and nitrate. This response was linked to the plant capacity to uptake and retain a large amount of copper in its roots (up to 1500 mg kg−1 Cu), preventing its transport to aerial parts. This control of translocation was further magnified with nitrate concentration increment. Likewise, although Cu excess impaired S. fruticosa carbon assimilation capacity, the plant was able to downregulate its light-harvesting complexes function, as indicated its lowers ETR values, especially at 12 mM Cu + 50 mM NO 3. This downregulation would contribute to avoid excess energy absorption and transformation. In addition, this strategy of avoiding excess energy was accompanied by the upregulation of all ROS-scavenging enzymes, a response that was further enhanced by the increase in nitrate concentration. Therefore, we conclude that the coexistence of nitrate would favor S. fruticosa tolerance to copper excess, and this effect is mediated by the combined activation of several tolerance mechanisms. • Role of nitrate on the Cu tolerance of the halophytic S. fruticosa remain unknown. • Nitrate reduces Cu excess impact on photosynthetic apparatus yield under Cu stress. • Nitrate had a positive effect on photosystem light harvest energy efficiency. • Nitrate contribute to maintain plant water use efficiency. • Enzyme oxidative machinery was modulated by nitrate presence. [ABSTRACT FROM AUTHOR]

Current agricultural problems, such as the decline of freshwater and fertile land, foster saline agriculture development. Salicornia and Sarcocornia species, with a long history of human consumption, are ideal models for developing halophyte crops. A greenhouse experiment was set up to compare the response of the perennial Sarcocornia fruticosa and the two annual Salicornia europaea and S. veneta to 30 days of salt stress (watering with 700 mM NaCl) and water deficit (complete withholding of irrigation) separate treatments, followed by 15 days of recovery. The three species showed high tolerance to salt stress, based on the accumulation of ions (Na+, Cl−, Ca2+) in the shoots and the synthesis of organic osmolytes. These defence mechanisms were partly constitutive, as active ion transport to the shoots and high levels of glycine betaine were also observed in non-stressed plants. The three halophytes were sensitive to water stress, albeit S. fruticosa to a lesser extent. In fact, S. fruticosa showed a lower reduction in shoot fresh weight than S. europaea or S. veneta, no degradation of photosynthetic pigments, a significant increase in glycine betaine contents, and full recovery after the water stress treatment. The observed differences could be due to a better adaptation of S. fruticosa to a drier natural habitat, as compared to the two Salicornia species. However, a more gradual stress-induced senescence in the perennial S. fruticosa may contribute to greater drought tolerance in this species.

A new flavonol triglycoside, rhamnazin 3-O-2G-rhamnorutinoside or rhamnazin 3-O-(2″,6″-O-α-di-rhamnosyl)-β-glucoside (1) was isolated along with known flavonols, rhamnazin 3-O-rutinoside (2), rhamnazin 3-O-(6″-O-α-rhamnosyl)-β-galactoside (3), isorhamnetin 3-O-(6″-O-α-rhamnosyl)-β-galactoside (4), isorhamnetin 3-O-(2″,6″-O-α-di-rhamnosyl)-β-galactoside (5), and isorhamnetin (6), and allantoin (7) from the aqueous methanol extract of Sarcocornia fruticosa leaves. Spectral analyses (UV, MS, and NMR) and acid hydrolysis were used to determine the structures. These compounds in this study except 6 were reported for the first time from the genus Sarcocornia. The extract and flavonol glycosides (1–5) were evaluated for antioxidant and inhibition of HCV protease enzyme. Rhamnazin triglycoside (1) was shown to have a potent HCV protease inhibitor with IC50 value 8.9 μM, while isorhamnetin di- and triglycosides (4 and 5) were effectively scavenged DPPH radicals with IC50 values 3.8 and 4.3 μM, respectively. [ABSTRACT FROM AUTHOR]

Ria Formosa lagoon is a coastal system in the south of Portugal, characterized by sediments contaminated from urban and industrial pollution emissions. In this study, sediments from two contrasted metal contamination level sites, colonized by Sarcocornia fruticosa were used in an on-site experimentation. The heavy metal removal efficiencies of S. fruticosa with and without bioaugmentation using autochthonous metal resistant isolated yeast (Saccharomyces cerevisiae) were compared. After 15 days of incubation, the total amount of metal concentration (Cd, Pb, Ni, Cr, and Cu) in sediments and plant matter were compared. We found a striking difference between heavily contaminated site and less contaminated site. Metal reductions in heavily contaminated site were generated more by S. fruticosa which was inoculated with S. cerevisiae. In the less contaminated sediments, the higher percentage reductions were achieved with S. fruticosa alone. Our results indicate that despite the phytoremediation potential of S. fruticosa , the addition of S. cerevisiae , increases the plant phytoremediation capacity. [ABSTRACT FROM AUTHOR]

Platinum is one of the least abundant elements in the earth crust with an average concentration of 0.51 ng g − 1 , but its use in several human activities (mainly automobile catalytic converters) is leading its enrichment in surface sediments. Whereas, previous studies have assessed the Pt behavior in soils from urban areas, natural systems are still poorly studied. Accordingly, this study is aimed to characterize the behavior of the Pt released to coastal environments in sediments, ascertain the role of vegetation on the biogeochemistry of this element and assess the transference of Pt into the biological compartments. Several sediment cores were sampled in salt marshes (in unvegetated and vegetated areas) of the Tagus Estuary under different traffic pressure. Platinum concentration was analyzed in solid sediment, interstitial water and roots, leaves and stems of Sarcocornia fruticosa , a typical plant in south European salt marshes. In addition, interpretative parameters (e.g. redox potential, dissolved oxygen, pH, total reduced sulfur species, salinity and dissolved Fe and Mn in interstitial waters) were determined to better understand the biogeochemical cycle of Pt in salt marsh sediments. Although surface enrichment of Pt exists in the sediments at Low Traffic Station (2.8 ng g − 1 ), the highest enrichment was found at High Traffic Station where concentration was, in some cases, up to 40 ng g − 1 , linked to traffic emissions. However, dissolved Pt in interstitial waters (from 0.14 to 0.70 ng L − 1 ) did not show this superficial maximum. This dissimilarity points out the unreactivity of traffic-borne Pt and the dissolution/precipitation cycle of natural Pt linked to Mn and O 2 cycle, depending on the redox conditions, highly controlled by the vegetation. Platinum concentration in roots (0.9 ± 0.6 ng g − 1 ) is reflecting the Pt concentration in the interstitial waters in each moment, even though at the two peaks of dissolved Pt (up to 2.5 ng L − 1 ) found at deeper layers, reflecting a low bioaccumulation. However, results pointed that a different Pt species (with different bioavailability) may exist in both stations. Besides, Pt mean value in stems and leaves (0.04 ± 0.05 ng g − 1 ) indicates a low translocation of Pt from the roots to aerial parts. Therefore, the role of vegetation is fundamental on the geochemical behavior of Pt in sediments, due to the control of the redox conditions by roots in the surrounding sediments (between the O 2 release and the organic matter degradation) and leading to Pt species of varying bioavailability. [ABSTRACT FROM AUTHOR]

Salt marshes provide environmental conditions that are known to affect metal speciation in sediments. The elevational gradient along the marsh and consequent differential flooding are some of the major factors influencing halophytic species distribution and coverage due to their differential tolerance to salinity and submersion. Different species, in turn, also have distinct influences on the sediment's metal speciation, and its metal accumulation abilities. The present work aimed to evaluate how different halophyte species in two different salt marshes could influence metal partitioning in the sediment at root depth and how that could differ from bare sediments. Metal speciation in sediments around the roots (rhizosediments) of Halimione portulacoides , Sarcocornia fruticosa and Spartina maritima was determined by sequentially extracting operationally defined fractions with solutions of increasing strength and acidity. Rosário salt marsh generally showed higher concentrations of all metals in the rhizosediments. Metal partitioning was primarily related to the type of metal, with the elements' chemistry overriding the environment's influence on fractionation schemes. The most mobile elements were Cd and Zn, with greater availability being found in non-vegetated sediments. Immobilization in rhizosediments was predominantly influenced by the presence of Fe and Mn oxides, as well as organic complexes. In the more mature of both salt marshes, the differences between vegetated and non-vegetated sediments were more evident regarding S. fruticosa , while in the younger system all halophytes presented significantly different metal partitioning when compared to that of mudflats. [ABSTRACT FROM AUTHOR]

Wetlands are highly effective systems in removing large amounts of N from waters, preventing eutrophication processes. However, when wetlands are polluted by metal-mine wastes their capacity to act as green filters may be diminished. The objective of this study was to evaluate the effect of liming and plants (Sarcocornia fruticosa and Phragmites australis) on the removal of NO3 − from eutrophic water in slightly acidic, wetland soils polluted by metal-mine wastes. Simulated soil profiles were constructed and six treatments were assayed: (1) no liming + no plant, (2) no liming + S. fruticosa, (3) no liming + P. australis, (4) liming + no plant, (5) liming + S. fruticosa and (6) liming + P. australis. Three horizons were differentiated: A (never under water), C1 (alternating flooding-drying conditions) and C2 (always under water). The eutrophic water used to flood the soil profiles was enriched in N and organic carbon (pH ∼ 7.5, electrical conductivity ∼ 11 dS m−1, NO3 − ∼ 234 mg L−1 and dissolved organic carbon ∼ 106 mg L−1). The pH, Eh and concentrations of dissolved organic carbon (DOC), N–NO3 − and N–NH4 + were measured regularly for 18 weeks. Liming stimulated the growth of plants, especially for S. fruticosa (20-fold more plant biomass than without liming), increased the soil pH and favoured the decline of the Eh values, enhancing the removal of NO3 − via denitrification. Of all the treatments assayed, liming + S. fruticosa was the only treatment that removed almost completely the high concentration of NO3 − from the eutrophic flooding water, reaching ∼1 mg L−1 N–NO3 − at the end of the experiment, at all depths. The higher content of DOC in the pore water of this treatment could explain this behaviour, since more labile carbon was available to the soil microorganisms in the rhizosphere, favouring NO3 − removal through denitrification processes. However, the treatment liming + P. australis (2-fold more plant biomass that without liming) did not remove completely the high concentrations of NO3 − from the eutrophic water, except in the C2 horizon – which was permanently under water. Hence, our results show that the effectiveness of liming, regarding the removal of NO3 − from eutrophic flooding water in wetland soils polluted by metal-mine wastes, depends on the presence of plants, their growth and the production of organic compounds in the rhizospheric environment. [Copyright &y& Elsevier]

Abstract: The aim of this study was to evaluate the effects of liming and vegetation on the dynamic of Fe in eutrophic wetland soils affected by mine wastes, under different flooding regimes. Simulated soil profiles were constructed with two types of wastes (pH∼3.1 and ∼6.4) collected from polluted salt marshes and four treatments were assayed: without liming+without plant, without liming+with plant, with liming+without plant, and with liming+with plant. The plant species was the halophyte Sarcocornia fruticosa. Three horizons were differentiated in the profiles: A horizons (never underwater), C1 (alternating flooding–drying conditions), and C2 (always underwater). The pH, Eh, salinity, and the concentrations of DOC and soluble Fe were measured regularly at each horizon for 18 weeks. Liming decreased Fe solubility, mainly in the acidic waste (maximum average concentrations ∼18mgL−1 without liming and ∼6mgL−1 with liming). However, liming also facilitated a drop in Eh, increasing soluble Fe content. Plant rhizosphere re-distributed this Fe, which was accumulated in the upper horizons of the treatments with liming+with plant, particularly in the acidic waste (average concentrations ∼10mgL−1 in the A horizon and ∼5mgL−1 in the C1 and C2 horizons). Therefore, we conclude that the combined use of liming and vegetation enhance the mobilization of Fe in eutrophic wetland soils polluted by mine wastes under alternating flooding–drying conditions. This should be considered for the environmental management of these sites due to the role of Fe-minerals as sink for potentially-harmful compounds. [Copyright &y& Elsevier]

Abstract: The aim of this study was to identify the effectiveness of liming in combination with vegetation for the recovery of slightly acidic, saline soils of eutrophic wetlands affected by mine wastes, under fluctuating flooding conditions. Simulated soil profiles were constructed and four treatments were assayed under greenhouse conditions: control, only plant, only liming, and liming and plant. The plant species was the halophyte Sarcocornia fruticosa. Three horizons were differentiated: A (never under water), C1 (alternating flooding-drying conditions), and C2 (always under water). The pH, Eh, salinity, and the concentrations of dissolved organic carbon and soluble metals were measured regularly for 18 weeks. Liming favoured the growth of S. fruticosa, an increase in pH and a fall in Eh. The amendment was effective for reducing Mn, Zn, and Cd in pore water of bare soils, but not Cu and Pb. In the treatment with liming and plant, the growth of S. fruticosa counteracted the effect of the amendment, strongly increasing the concentrations of metals in pore water and distributing them along the soil profile. Hence, the combined use of liming and plants may increase the risk of metals mobilisation. [Copyright &y& Elsevier]

Purpose: The aim of this study was to evaluate the behaviour of P in saline Spolic Technosols flooded with eutrophic water, with and without plant rhizosphere, in order to assess the role of these soils as sinks or sources of this nutrient. Materials and methods: Samples were taken from basic (pH ~7.8), carbonated and acidic (pH ~6.2), de-carbonated soils of salt marshes polluted by mine wastes. Three treatments were assayed: pots with Sarcocornia fruticosa, pots with Phragmites australis and pots without plants (bare soil). The pots were flooded for 15 weeks with eutrophic water (PO ~6.92 mg L) and pH, Eh and water-soluble organic carbon and PO concentrations were monitored in the soil solution. A soil P fractionation was applied before and after the flooding period. Results and discussion: The PO concentration in the soil solution decreased rapidly in both soils, with and without plant, being diminished by 80-90 % after 3 h of flooding. The Fe/Mn/Al oxides and the Ca/Mg compounds played an important role in soil P retention. In pots with S. fruticosa, the reductive conditions due to flooding induced P release from metal oxides and P retention to Ca/Mg compounds. In turn, P. australis may have favoured the release of P from carbonates, which was transferred to Fe/Mn/Al compounds. Conclusions: The retention of P by the soil was the main mechanism involved in the removal of PO from the eutrophic flooding water but to evaluate the capacity of these systems as long-term P sinks, the combined effect of metals, Ca/Mg compounds and specific plant species should be considered. [ABSTRACT FROM AUTHOR]

The toxicity of high salinity tannery wastewater produced after an activated sludge secondary treatment on the germination and seedling growth of Trifolium pratense, a species used as indicator in toxicity tests, was evaluated. Growth was inhibited by wastewater concentrations >25% and undiluted effluent caused a complete germination inhibition. Constructed wetlands (CWs) with Arundo donax or Sarcocornia fruticosa were envisaged to further polish this wastewater. Selection of plant species to use in CWs for industrial wastewater treatment is an important issue, since for a successful establishment they have to tolerate the often harsh wastewater composition. For that, the effects of this wastewater on the growth of Arundo and Sarcocornia were assessed in pot assays. Plants were subject to different wastewater contents (0/50/100%), and both were resilient to the imposed conditions. Arundo had higher growth rates and biomass than Sarcocornia and may therefore be the preferred species for use in CWs treating tannery wastewater. CWs planted with the above mentioned plants significantly decreased the toxicity of the wastewater, as effluent from the CWs outlet stimulated the growth of Trifolium at concentrations <50%, and seed germination and growth even occurred in undiluted effluent. [ABSTRACT FROM AUTHOR]

Abstract: Salt marshes near urban, industrial and mining areas are often affected both by heavy metals and by eutrophic water. The aim of this study was to assess and evaluate the main processes involved in the decrease of nitrate concentration in pore water of mine wastes flooded with eutrophic water, considering the presence or absence of plant rhizhosphere. Basic (pH∼7.8) carbonated loam mine wastes and free-carbonated acidic (pH∼6.2) sandy-loam mine wastes were collected from polluted coastal salt marshes of SE Spain which regularly receive nutrient-enriched water. The wastes were put in pots and flooded for 15 weeks with eutrophic water (dissolved organic carbon ∼26mgL−1, PO4 3− ∼23mgL−1, NO3 − ∼180mgL−1). Three treatments were assayed for each type of waste: pots with Sarcocornia fruticosa, pots with Phragmites australis and unvegetated pots. Soluble organic carbon, nitrate, soluble Cd, Pb and Zn, pH and Eh were monitored. But the 2nd day of flooding, nitrate concentrations had decreased between 70% and 90% (equivalent to 1.01–1.12gN-NO3 − m−2 day−1) with respect to the content in the water used for flooding, except in unvegetated pots with acidic wastes. Denitrification was the main mechanism associated with the removal of nitrate. The role of vegetation in improving the rhizospheric environment was relevant in the acidic wastes because higher sand content, lower pH and higher soluble metal concentrations might strongly hinder microbial activity Hence, revegetation of salt marshes polluted by acidic sandy mining wastes might improve the capacity of this type of environment to act as a green filter against excessive nitrate contents flowing through them. [Copyright &y& Elsevier]

Abstract: The aim of this study was to evaluate the combined effects of liming and behaviour of Sarcocornia fruticosa as a strategy of phytomanagement of metal polluted salt marsh soils. Soils were taken from two polluted salt marshes (one with fine texture and pH∼6.4 and the other one with sandy texture and pH∼3.1). A lime amendment derived from the marble industry was added to each soil at a rate of 20gkg−1, giving four treatments: neutral soil with/without liming and acidic soil with/without liming. Cuttings of S. fruticosa were planted in pots filled with these substrates and grown for 10 months. The pots were irrigated with eutrophicated water. As expected, lime amendment decreased the soluble metal concentrations. In both soils, liming favoured the growth of S. fruticosa and enhanced the capacity of the plants to phytostabilise metals in roots. [Copyright &y& Elsevier]

Salt marshes show a characteristic zonation of species distribution, which is correlated with marsh elevation. Radiation intensity and photoperiod change throughout the tidal frame. Photosynthetic response to light regime, 90-2450 μmol/(m s), was determined in the laboratory for four closely related halophytic taxa of the genus Sarcocornia (Chenopodiaceae), which inhabit different positions in the tidal frame. Sarcocornia fruticosa, which germinates below vegetation cover and is found at high levels in the tidal frame, had the lowest maximum net photosynthetic rate and stomata conductance values. The two S. perennis subspecies demonstrated intermediate maximum net photosynthetic rates but S. perennis ssp. alpini reached light saturation point at higher light intensities. S. perennis ssp. perennis, found in the lowest elevations of the marshes, spends a significant proportion of its time submerged and therefore needs to take full advantage of available light. S. perennis ssp. alpini is exposed to very high light intensities in open salt pans at high elevations. The hybrid, S. perennis x fruticosa, which is currently found at intermediate elevations with less frequent inundation, had the highest net photosynthetic rate and chlorophyll a content. The ability to cope with high light levels may help to explain one of the environmental parameters, which affects distribution of four taxa throughout the tidal frame and also raise intriguing questions about the future role of the hybrid in the successive development of these marsh systems. [ABSTRACT FROM AUTHOR]

Abstract: Laboratory experiments were conduced to assess the synergic effect of chilling and light on photosystem II photochemistry of the halophyte, Sarcocornia fruticosa, grown at different salinity concentrations (0, 170, 340, 510 and 1030mM). Chlorophyll fluorescence was measured after chilling (at 5°C in darkness) and light-chilling (at 5°C and 700μmolm−2 s−1) treatments, and after 24h of recovery (at 20°C and 75μmolm−2 s−1). At 5°C and 700μmolm−2 s−1, plants grown with 0 and 170mM NaCl showed the lowest F v/F m values, whereas quantum efficiency of PSII (Φ PSII) was higher for plants grown at 170 and 340mM NaCl, these results being consistent after two exposures to chilling treatments. Susceptibility to photoinhibition decreases when low temperature and high light are combined with high salinity. Therefore, populations of S. fruticosa that occur in arid environments with salinities c. 340mM could show a higher tolerance to light-chilling. [Copyright &y& Elsevier]

The article examines the generality of mechanisms generating zonation of plant across intertidal stress gradients in the salt marsh system in Chile. According to researchers, the low-lying clonal succulent called Sarcocornia fruticosa dominates the flooded flow marsh, while Spartina densiflora dominated the intermediate elevations. They also found out that transplant studies of all four plant species revealed the mechanisms driving the striking patters in plant segregation. Based on the results, the researchers concluded that mechanisms driving community organization across environmental stress gradients cannot be directly extrapolated to unstudied systems.

Seed germination and seedling establishment are very sensitive plant stages to metal pollution. Many halophyte species colonizing salt marshes are able to germinate and establish in highly contaminated habitats and low marsh halophyte species seem to show higher tolerance to metals than high marsh species. We analyzed the effects of copper, zinc and nickel in concentrations up to 2000 μM on seed germination and seedling growth in two closely related species of Sarcocornia , S. perennis , a low marsh species, and S. fruticosa , a high marsh species. Germination of both halophytes was not affected by any metal concentration, and their seedling growth, mainly radicle length, was reduced by increasing metal concentrations. Seedlings of S. perennis showed higher tolerance to the three metals than those of S. fruticosa. Our results are useful for designing ecotoxicological bioassays and planning phytoremediation projects in salt marshes. • Germination of S. perennis and S. fruticosa was not affected by any metal concentration. • Seedling growth, mainly radicle length, was reduced by increasing metal concentrations. • Seedlings of S. perennis showed higher tolerance to metals than those of S. fruticosa. [ABSTRACT FROM AUTHOR]

Sixteen PAH compounds (containing three to six rings) were quantified in sediments from the Rosário and Mitrena salt marshes in the Tagus and Sado estuaries, respectively, colonized by Sarcocornia fruticosa, and in belowground and aboveground plant tissues. Sediments from Rosário presented higher PAH concentrations (0.83-8.71 μg g-1) than those from Mitrena (0.22-1.63 μg g-1). Levels in belowground plant tissues showed a pronounced contrast between the two marshes: 84-165 and 0.15-0.43 μg g-1, respectively. Belowground material in contaminated layers contained 9-55 times more PAHs than sediments, while ratios lower than one were obtained in lower contaminated layers. Five- and six-ring compounds predominated (60-75%) in sediments and belowground plant material from both sites. Aboveground plant tissues presented no differences in PAH concentrations (0.17-0.18 ng g-1) and composition in both marshes, only three- and four-ring compounds being detected. This narrow concentration range appears to indicate that atmospheric deposition is the predominant pathway of PAH accumulation in aerial plant tissues. [ABSTRACT FROM AUTHOR]

Abstract: Depth concentration profiles of PAHs, organic carbon and dissolved oxygen in non-colonised sediments and sediments colonised by Sarcocornia fruticosa from Mitrena salt marsh (Sado, Portugal) were determined in November 2004 and April 2005. Belowground biomass and PAH levels in below and aboveground material were also determined. In both periods, colonised sediments were oxygenated until 15-cm, rich in organic carbon (max 4.4%) and presented much higher PAH concentrations (max. 7.1μgg−1) than non-colonised sediments (max. 0.55μgg−1). Rooting sediments contained the highest PAH concentrations. The five- and six-ring compounds accounted to 50–75% of the total PAHs in colonised sediments, while only to 30% in non-colonised sediments. The elevated concentrations of PAHs in colonised sediments may be attributed to the transfer of dissolved PAH compounds towards the roots as plant uptake water and subsequent sequestration onto organically rich particles. A phase-partitioning mechanism probably explains the higher retention of the heavier PAHs. In addition oxygenated conditions of the rooting sediments favour the degradation of the lighter PAHs and explain the elevated proportion of the heavier compounds. Below and aboveground materials presented lower PAH concentrations (0.18–0.38μgg−1) than colonised sediments. Only 3- and 4-PAHs were quantified in aboveground material, reflecting either preferential translocation of lighter compounds from roots or atmospheric deposition. [Copyright &y& Elsevier]

We analysed the responses of seeds of three closely related halophytic taxa of the genus Sarcocornia in contrasted habitats, Sarcocornia perennis (low marsh), Sarcocornia fruticosa (high marsh) and S. perennis × fruticosa (middle marsh), to different salinity concentrations (0, 2, 4 and 6%) and light regime (light/dark and dark). Germination reflected their position in the tidal gradient, showing higher percentages at hypersalinity those taxa colonising upper positions (c. 40%). S. fruticosa showed germination in darkness and it accelerated its germination after prolonged salinity exposure. S. perennis × fruticosa presented intermediate responses, sharing the capacity of germinating in hypersaline conditions with S. fruticosa and the absence of germination in darkness and the absence of acceleration of germination with S. perennis. Finally, we recorded common germination behaviours for the three taxa: short germination periods, reduction of final germination percentage, enforcing of seed dormancy and reduction of seed viability by increasing salinity.Germination responses to salinity of the three Sarcocornia seem likely to influence their colonisation capacities down the tidal gradient and hence may be important in the maintenance of taxa zonation in salt marshes. [Copyright &y& Elsevier]

The hydrocarbon fraction of leaf waxes of three halophytes of the Chenopodiaceae common to Mediterranean salt marshes (Suaeda vera, Sarcocornia fruticosa and Halimione portulacoides) revealed the presence of a minor series of odd and even chains 1-chloro-n-alkanes ranging from C19 to C29. The identification of these new chlorinated plant constituents was based on a combination of mass spectrometry data with selective chlorine detection (CPG-AED) and was confirmed by comparison with authentic standards. The qualitative and quantitative distributions of these 1-chloro-n-alkanes varied inter-specifically. Homologues with an odd carbon-chain were predominant in all species but maximised at C25 and C27 in S. vera and S. fruticosa, and at C27 and C29 in H. portulacoides. Remarkably, 1-chloro-nonacosane was an abundant homologue only in this latter species. Leaves of S. vera contained 4 to 7 times more of total chloroalkanes than leaves of the other two species. These compounds accounted for 10, 4 and 1% of the hydrocarbon fraction of leaf waxes of S. vera, S. fruticosa and H. portulacoides, respectively. Attempts to link the occurrence of these chloroalkanes with other classes of leaf waxes (n-alkenes, n-aldehydes and n-alcohols) did not allowed a clear precursor–product relationship to be established. The biological functions as well as the mode of synthesis of alkylchlorides in (halophyte) plants remain unknown but undoubtedly deserve further attention. [Copyright &y& Elsevier]

Seeds of four halophytes from southeastern Spain (the perennials Halocnemum strobilaceum,Arthrocnemum macrostachyum and Sarcocornia fruticosa, and the annual Salicornia ramosissima) were exposed to iso-osmotic stress with NaCl, MgCl2, MgSO4and Na2SO4. The osmotic potential that enforced dormancy in the majority of seeds was determined. The percentage of ungerminated seeds that recovered when they were transferred to distilled water did not differ significantly from the percentage germination of seeds in distilled water controls, irrespective of the salt used to impose the stress. Therefore, the factor responsible for the dormancy of seeds seems to be the decrease in osmotic potential. Such osmotic pretreatments promoted an increase in the rate of recovery germination which, inArthrocnemum macrostachyum and Sarcocornia fruticosa, doubled their rates of germination compared to distilled water controls. The osmotic potentials of the soils where the four species occur naturally were more negative than those allowing seeds to germinate after osmotic stress. Copyright 2000 Annals of Botany Company [ABSTRACT FROM AUTHOR]

Fluorescence microscopy and physiological examination revealed the presence of an inner cylinder of active photosynthetic cells located below the endodermis-like layer in stems of four of the six taxa of the tribe Salicornieae (Chenopodiaceae). [ABSTRACT FROM AUTHOR]

This study aimed to assess the effectiveness of biochar from sewage sludge -BSS- and from pruning trees -BPT- (addition dose of 6% d.w.) to immobilise metals in acidic (pH ∼ 4.7) and basic (pH ∼ 7.4) mine soils under variable flooding conditions, and to determine biochar influence on plant (Sarcocornia fruticosa -Sf-) growth and metal uptake. BSS had lower pH (∼8.2 vs. ∼ 9.8), CaCO 3 (∼71 vs. ∼ 85 g kg -1 ), total organic carbon (∼354 vs. ∼ 656 g kg -1 ) and higher water soluble organic carbon (WSOC ∼ 0.15 vs ∼ 0.06 mg kg -1 ) than BPT. PVC columns (15 × 30 cm) were prepared with the following treatments (n = 4): 1) no Biochar-no Sf; 2) no Biochar-Sf; 3) BSS-no Sf; 4) BSS-Sf; 5) BPT-no Sf; 6) BPT-Sf. Changes in water table level (WL) were simulated for 303 days with tap water (upper 0-15 cm alternating flooding-drying conditions, lower 15-30 cm always underwater). The pH, redox potential (Eh), temperature and porewater WSOC, Zn, Cd and Pb concentrations were regularly measured, and plants were removed at the end and length, fresh weight and metal concentrations in tissues measured. In the basic soil, there were no consistent evidences that BSS and BPT were effective decreasing porewater metal concentrations and reducing metal uptake in plants. Sf contributed to mobilise Zn, and in less extent Cd, in the upper soil layer, regardless of the type of biochar, and this effect increased with aging. In the acidic soil, BSS and BPT were effective increasing the pH and decreasing porewater metals. BSS increased its efficiency with aging, which can be mainly attributable to the more reduced conditions that induced (lower Eh values) due to its higher WSOC content. Biochar was effective hindering metal mobilisation by Sf and reducing plant's metal uptake (e.g. reduction in roots: ∼7 fold for Zn, ∼19-fold for Cd and ∼ 2-fold for Pb). BSS was more effective promoting Sf growth (fresh weight) than BPT. Therefore, in relation with the use of biochar from sewage sludge and from pruning trees as soil amendments under flooding-non flooding conditions, we can conclude that it can be a useful option in acidic mine soils for decreasing water soluble metals and improving plant growth. However, in basic mine soils, we have no evidences to support the advantages of using these two types of biochar as amendments. Hence, the use of biochar in metal-polluted wetlands has environmental implications that must be planned for each specific case in order to optimize the positive aspects (wetland as sinks of pollutants) and reduce the drawbacks (wetland as source of pollutants)., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In their natural habitats, different mechanisms may contribute to the tolerance of halophytes to high soil salinity and other abiotic stresses, but their relative contribution and ecological relevance, for a given species, remain largely unknown. We studied the responses to changing environmental conditions of five halophytes (Sarcocornia fruticosa, Inula crithmoides, Plantago crassifolia, Juncus maritimus and J. acutus) in a Mediterranean salt marsh, from summer 2009 to autumn 2010. A principal component analysis was used to correlate soil and climatic data with changes in the plants' contents of chemical markers associated with stress responses: ions, osmolytes, malondialdehyde (MDA, a marker of oxidative stress) and antioxidant systems. Stress tolerance in S. fruticosa, I. crithmoides and P. crassifolia (all succulent dicots) seemed to depend mostly on the transport of ions to aerial parts and the biosynthesis of specific osmolytes, whereas both Juncus species (monocots) were able to avoid accumulation of toxic ions, maintaining relatively high K(+)/Na(+) ratios. For the most salt-tolerant taxa (S. fruticosa and I. crithmoides), seasonal variations of Na(+), Cl(-), K(+) and glycine betaine, their major osmolyte, did not correlate with environmental parameters associated with salt or water stress, suggesting that their tolerance mechanisms are constitutive and relatively independent of external conditions, although they could be mediated by changes in the subcellular compartmentalization of ions and compatible osmolytes. Proline levels were too low in all the species to possibly have any effect on osmotic adjustment. However-except for P. crassifolia-proline may play a role in stress tolerance based on its 'osmoprotectant' functions. No correlation was observed between the degree of environmental stress and the levels of MDA or enzymatic and non-enzymatic antioxidants, indicating that the investigated halophytes are not subjected to oxidative stress under natural conditions and do not, therefore, need to activate antioxidant defence mechanisms., (Published by Oxford University Press on behalf of the Annals of Botany Company.)