Halophytic Species Research Articles

Lithium in the Environment and its Effects on Higher Plants

Summary Lithium (Li) is present in low concentrations in all parts of the biosphere, including living organisms. It reaches the terrestrial environment primarily through natural processes to which parent substrate was subjected during pedogenesis, and due to anthropogenic activities. Individual soil types differ regarding Li content; for example saline and loamy soils have higher Li content. It is found in low concentrations primarily in ionic form in aquatic environments in surface and groundwater. It is mobile in the soil and thus soil contamination with Li can lead to its higher concentration in groundwater. In the environment, Li reaches the atmosphere from Li-emitting sources. It is widely used in many industries, lately in the Li-ion batteries in electronic goods, due to which it may be a potential risk for the environment. Terrestrial plants take up Li largely via roots from the soil, but also via shoots from the atmosphere. In the soil, Li is mostly bound by clay fraction and organic matter. During the uptake, transport and distribution in plants it behaves like an alkaline earth ion, not like an alkali ion. The fact that Li is immobile in the phloem supports this claim. Its ascendent transport mainly depends upon the transpiration intensity. More Li is taken up by plants from acid soils than from alkaline soils. Li is non-essential for plant growth and development. In low concentrations it can be stimulative and affect chemical composition and organic production of plants. Li plays an important role in the metabolism of halophyte species. It is increasingly regarded as an essential trace element for animals and humans, and used in human medication to treat dementia, suicidal ideation, aggression and violence. High levels of Li are toxic to all plants, but uptake and sensitivity to Li are species-dependent. Some representatives of the Ranunculaceae, Solanaceae and Asteraceae families are characterized by increased Li accumulation, while Poaceae, Liliaceae, Brassicaceae, Caprifoliaceae show low accumulation. High concentrations of Li have adverse effects on many physiological and biochemical processes in plants (DNA, RNA and protein pathways, water relations, content of photosynthetic pigments, photosynthesis, production of reactive oxygen species, lipid peroxidation of the cell membranes etc.), which is further manifested as stunted growth, developmental disorder, visual symptoms, interveinal necrosis and necrosis along the leaf margins. Hyperaccumulator plants extract significant amounts of Li and are therefore used in phytoremediation. Better understanding of the effects of beneficial and phytotoxic concentrations of Li on metabolism and plant growth and development remains vital for the improvement of the knowledge about biological activity of Li in higher plants.

Diverse responses of halophyte and glycophyte Lepidium species to the salt-mediated amelioration of nickel toxicity and accumulation.

Tolerance mechanisms employed by plants under environmental stresses can protect them against other co-occurring stresses. In this study, the effect of pre-exposure and simultaneous salt treatment on nickel (Ni) toxicity tolerance in one halophyte (L. sativum) and one glycophyte (L. latifolium) Lepidium species in hydroponics was investigated. In order to compare the species independent from their salt and Ni tolerance level, the glycophyte was subjected to lower salt and Ni concentrations and for a shorter period of time than the halophyte. Salt (NaCl) was applied at 50 and 100mM concentrations and Ni was provided at an equal free Ni2+ activity by adding 100 and 200µM Ni as single stresses, but 130 and 300µM Ni for the treatment of its combination with salt in the glycophyte and halophyte, respectively. Temporal analyses of signaling molecules revealed that the halophyte is characteristically different from the glycophyte in that it exhibits a higher constitutive level of nitric oxide and hydrogen peroxide, a longer duration of response to Ni, and its augmentation by salt. In addition to higher biomass and less Ni accumulation in salt-treated plants, the concentrations of free thiol groups, leaf pigments, proline, free and cell wall-bound phenolics contents, and the activity of phenolic metabolizing enzymes were higher in L. latifolium under the combined salt and Ni treatments than under the single Ni stress. In contrast, the biomass and most biochemical parameters of Ni-stressed L. sativum plants were not enhanced by salt treatment but rather decreased. Our findings shed light on cross-tolerance mechanisms in halophytes and uncovered halophyte survival strategies under multiple stresses.

Effects of salinity, temperature, and immersion conditions on seed germination of invasive Spartina alterniflora Loisel (smooth cordgrass) in Japan

Spartina alterniflora is a halophytic perennial grass species that has invaded coastal wetlands worldwide, including tidal flats in Japan. Rapid removal or eradication of invasive plants is desirable because of their severe ecological impact on local ecosystems. Seed germination is the main cause of its distribution and invasion. Understanding germination characteristics of S. alterniflora is critical for the prediction and early detection of its populations in new environments. Therefore, we aimed to investigate the effects of salinity (0, 10 20, 30, and 40 g/L artificial seawater), temperature (15, 20, 25 °C for constant, and 15/25 °C for alternating), and seed immersion (5 ml and 40 ml medium) based on laboratory experiments to evaluate the physicochemical environmental factors that facilitate the germination of S. alterniflora seeds. The cumulative germination rate and mean germination time were significantly affected by temperature and salinity but not by immersion. Increased salinity gradually reduced the cumulative germination rate in all temperature and immersion conditions. The mean germination time tended to be prolonged with the salinity level. A constant temperature of 25 °C promoted higher seed germination compared to constant temperatures of 15 and 20 °C. Notably, alternating temperature between 15 and 25 °C induced a higher seed germination compared to other constant temperatures. In addition, alternating temperatures varied the mean germination time to facilitate sensitivity to salinity, indicating that temperature fluctuation is a key factor that stimulates seed germination of S. alterniflora. These results suggest that S. alterniflora seeds prefer gaps in vegetation canopies and a low depth of burial in soil. Further studies are needed to analyze prevention strategies for the eradication of this invasive species in Japan.

Antioxidant and antimicrobial activity of Tamarix ramosissima halophyte and its application in the food industry

Tamarix ramosissima is a halophytic species with diuretic, diaphoretic, astringent, analgesic and hemostatic effects. Decoctions and infusions used for various diseases are prepared from it. Infusion of flowers is useful for stomach inflammation, decoction of branches is effective for rheumatism, infusion of leaves and bark is prescribed for diarrhea, bleeding and diseases of the spleen. Tamarix twigs are brewed like tea. In the past, a decoction of the fruits of the plant was used in the Caucasus against infertility, and a decoction of branches treated syphilis. In this work, we investigated the antioxidant and antimicrobial activity of Tamarix ramosissima inflorescence extracts as an additive in the food industry. The results showed that the inflorescences exhibit high antioxidant activity, the degree of inhibition at 20 µl of the studied material is 9 times greater. compared with ascorbic acid and 3 times compared with emoxypine. In addition, tamarisk extracts have shown noticeable antibacterial properties against the Staphylococcus aureus strain. The strongest activity was recorded in 70% of the water-alcohol extract of inflorescences at a minimum concentration of 1 to 10. These data indicate that tamarix can be considered as an interesting source of antioxidants for the therapeutic or nutraceutical industry and for food production. These indicators characterize tamarisk extracts as an object for further study, and without a doubt are promising and little-studied raw materials for the food industry

Nutritional anti-nutritional chemical composition and antioxidant activities of the leaves of the sea cliff dwelling species Limonium spathulatum (Desf.) Kuntze.

This work explored the nutritional and antioxidant properties of the leaves of the halophytic species Limonium spathulatum (Desf.) Kuntze from Tunisian sea cliffs. Furthermore, the analysis of the total phenolics and flavonoids contents and their individual compounds using high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS/MS) were also studied. L. spathulatum leaves had high levels of moisture, ash, neutral detergent fiber, and acid detergent fiber, but low concentrations of crude protein, crude fat and acid detergent lignin. It contained low carbohydrates levels, and low energetic values. The most abundant macroelements were Cl, Na and Ca while the microelements detected in the highest levels were Fe and Zn. No relevant α-amylase inhibition was observed, and no toxic metals (Pb and Cd) and phytic acid were detected. The ethanol and the hydroethanolic extracts had the highest capacity to scavenge free radicals, to chelate iron and copper and to inhibit lipid peroxidation. The same samples were also the most active towards oxidative haemolysis. These extracts contained high total phenolic and flavonoid contents. HPLC analysis, performed on ethanolic extracts identified 58 individual compounds known for their high antioxidant actvitiy including hydroxybenzoic acids (gallic, syringic acids), hydroxycinnamic acids (caffeic, coumaric, ferulic acids) and flavonoids (catechin, epigallocatechin gallate and naringin).In conclusion, the leaves of Tunisian accession of L. spathulatum were good source of minerals and fibers useful in the human diet for attaining nutritional sufficiency. The high in vitro and ex vitro antioxidant activities associated with high favonoids contents and compounds suggest the possibility to use the extracts of L. spathulatum in herbal products with the aim of improving general health and well-being, and/or as food additives for preventing lipid oxidation of lipid-rich foods.

Guard Cell Transcriptome Reveals Membrane Transport, Stomatal Development and Cell Wall Modifications as Key Traits Involved in Salinity Tolerance in Halophytic Chenopodium quinoa.

A comparative investigation was conducted to evaluate transcriptional changes in guard cells (GCs) of closely related halophytic (Chenopodium quinoa) and glycophytic (Spinacia oleracea) species. Plants were exposed to 3 weeks of 250 mM sodium chloride treatment, and GC-enriched epidermal fragments were mechanically prepared. In both species, salt-responsive genes were mainly related to categories of protein metabolism, secondary metabolites, signal transduction and transport systems. Genes related to abscisic acid (ABA) signaling and ABA biosynthesis were strongly induced in quinoa but not in spinach GCs. Also, expression of the genes encoding transporters of amino acids, proline, sugars, sucrose and potassium increased in quinoa GCs under salinity stress. Analysis of cell-wall-related genes suggests that genes involved in lignin synthesis (e.g. lignin biosynthesis LACCASE 4) were highly upregulated by salt in spinach GCs. In contrast, transcripts related to cell wall plasticity Pectin methylesterase3 (PME3) were highly induced in quinoa. Faster stomatal response to light and dark measured by observing kinetics of changes in stomatal conductance in quinoa might be associated with higher plasticity of the cell wall regulated by PME3 Furthermore, genes involved in the inhibition of stomatal development and differentiation were highly expressed by salt in quinoa, but not in spinach. These changes correlated with reduced stomatal density and index in quinoa, thus improving its water use efficiency. The fine modulation of transporters, cell wall modification and controlling stomatal development in GCs of quinoa may have resulted in high K+/Na+ ratio, lower stomatal conductance and higher stomatal speed for better adaptation to salinity stress in quinoa.

Halophyte Plants as Potential Sources of Anticancer Agents: A Comprehensive Review.

Salt-tolerant plants (halophytes) are widely distributed worldwide in several environments such as coastal salt marshes, sand dunes, and inland deserts. To cope with the harsh conditions that characterize those habitats, which include high salinity and radiation levels, such plants have developed morphological and physiological traits, the latter including the synthesis and accumulation of important secondary metabolites such as alkaloids and polyphenols. While essential in maintaining plant homeostasis, these compounds are highly valued in the medical field for the treatment of several human diseases, including cancer. Cancer is one of the most life-threatening disorders worldwide, which accentuates the need to improve current cancer therapies and minimize potential adverse secondary side-effects. In this context, the pharmacological evaluation of natural compounds has attracted growing interest since nature has already provided some important anti-cancer drugs. This review compiles, for the first time, research regarding the anticancer activity of halophytes from different families, including, whenever possible, the bioactive molecules involved in such therapeutical properties along with possible mechanisms of action. The introduction section provides some pertinent information regarding cancer and a summary of the most important characteristics of halophytes. The next section gives information regarding the in vitro and in vivo cytotoxic properties of several halophyte species, grouped by families, including contents in bioactive metabolites and proposed modes of action, if possible. Lastly, the conclusion presents the most relevant metabolites and/or promising species and extracts that could be further explored in anticancer drug research.

Cd Phytoextraction Potential in Halophyte Salicornia fruticosa: Salinity Impact.

The phytoextraction potential of halophytes has been broadly recognized. Nevertheless, the impact of salt on the accumulation proprieties of cadmium (Cd) in different halophytic species, likely linked to their salt tolerance, remains unclear. A hydroponic culture was used to investigate the impact of salinity on Cd tolerance as well as accumulation in the distinct halophyte Salicornia fruticosa (S. fruticosa). The plant was subjected to 0, 25, and 50 μg L−1 Cd (0-Cd, L-Cd, and H-Cd, respectively), with or without 50, 100, and 200 mM NaCl in the nutrient solution. Data demonstrated that Cd individually induced depletion in biomass accumulation. NaCl amplified the Cd tolerance induced by enhanced biomass gaining and root length, which was associated with adequate transpiration, leaf succulence, elevated levels of ascorbic acid (ASA), reduced glutathione (GSH), phytochelatins (PCs), and proline as well as antioxidant enzymatic capacity via upregulation of peroxidases (PO), glutathione peroxidase, ascorbate peroxidase, and superoxide dismutase. All Cd treatments decreased the uptake of calcium (Ca) as well as potassium (K) and transport to the shoots; however, sodium (Na) accumulation in the shoots was not influenced by Cd. Consequently, S. fruticosa retained its halophytic properties. Based on the low transfer efficiency and high enrichment coefficient at 0–50 mM NaCl, an examination of Cd accumulation characteristics revealed that phytostabilization was the selected phytoremediation strategy. At 100–200 mM NaCl, the high aboveground Cd-translocation and high absorption efficiency encourage phytoremediation via phytoextraction. The results revealed that S. fruticosa might be also potentially utilized to renovate saline soils tainted with heavy metals (HMs) because of its maximized capacity for Cd tolerance magnified by NaCl. Cd accumulation in S. fruticosa is mainly depending on the NaCl concentration. Future studies may be established for other heavy metal pollutants screening, to detect which could be extracted and/or stabilized by the S. fruticosa plant; moreover, other substrates presenting high electrical conductivity should be identified for reclamation.

Transcriptome analysis reveals molecular mechanisms underlying salt tolerance in halophyte Sesuvium portulacastrum.

Soil salinity is an important environmental problem that seriously affects plant growth and crop productivity. Phytoremediation is a cost-effective solution for reducing soil salinity and potentially converting the soils for crop production. Sesuvium portulacastrum is a typical halophyte which can grow at high salt concentrations. In order to explore the salt tolerance mechanism of S. portulacastrum, rooted cuttings were grown in a hydroponic culture containing ½ Hoagland solution with or without addition of 400 mM Na for 21 days. Root and leaf samples were taken 1 h and 21 days after Na treatment, and RNA-Seq was used to analyze transcript differences in roots and leaves of the Na-treated and control plants. A large number of differentially expressed genes (DEGs) were identified in the roots and leaves of plants grown under salt stress. Several key pathways related to salt tolerance were identified through KEGG analysis. Combined with physiological data and expression analysis, it appeared that cyclic nucleotide gated channels (CNGCs) were implicated in Na uptake and Na+/H+ exchangers (NHXs) were responsible for the extrusion and sequestration of Na, which facilitated a balance between Na+ and K+ in S. portulacastrum under salt stress. Soluble sugar and proline were identified as important osmoprotectant in salt-stressed S. portulacastrum plants. Glutathione metabolism played an important role in scavenging reactive oxygen species. Results from this study show that S. portulacastrum as a halophytic species possesses a suite of mechanisms for accumulating and tolerating a high level of Na; thus, it could be a valuable plant species used for phytoremediation of saline soils.

The effects of hydrological connectivity blocking on Suaeda salsa development in the Yellow River Delta, China

Blocking of hydrological connectivity could greatly impact the sediment deposition process and change water and salinity conditions, which in turn affect plant germination, growth, and development in delta wetlands. A 2-year experiment, which included the effects of soil burial, water, and salinity on germination, growth, and production, was conducted to examine the function of hydrological connectivity blocking on the development of Suaeda salsa, a halophyte species. The results demonstrated that soil burial, water, and salinity all had significant effects on seed germination, plant growth, and production (p < 0.05). Seed germination decreased as soil buried depth increased (< 4 cm), and seeds did not germinate successfully when the buried depth was > 4 cm. Seed germination was the highest at 0 cm burial. However, moderate burial was beneficial for seedling emergence; therefore, the survival rate was the lowest when seeds were distributed at the surface (0 cm). Water and salinity both significantly affected the germination, growth, and productivity of S. salsa. Moderate salinity (10–20 g/kg) and fluctuating water (0–10 cm water depth) were suitable for seed germination and plant growth. Low salinity (< 10 g/kg), High salinity (>20 g/kg), drought, and high water levels (long-term flooding with water depth > 10 cm) were not conducive to the growth of S. salsa, and biomass and seed yield were also reduced. As a halophyte, salinity that is too low or too high is unsuitable for S. salsa population. Water and salinity also significantly affected S. salsa population (p < 0.05). In particular, water can offset the hazards of high salt concentrations. Blocking of hydrological connectivity can influence seed germination, yield, and vitality. In this case, S. salsa may have died out from the coastal wetland due to the lack of hydrological connectivity restoration.

Effect of Salinity on Leaf Functional Traits and Chloroplast Lipids Composition in Two C3 and C4 Chenopodiaceae Halophytes.

Salt stress is one of the most common abiotic kinds of stress. Understanding the key mechanisms of salt tolerance in plants involves the study of halophytes. The effect of salinity was studied in two halophytic annuals of Chenopodiaceae Salicornia perennans Willd. and Climacoptera crassa (Bied.) Botsch. These species are plants with C3 and C4-metabolism, respectively. We performed a comprehensive analysis of the photosynthetic apparatus of these halophyte species at different levels of integration. The C3 species S. perennans showed larger variation in leaf functional traits—both at the level of cell morphology and membrane system (chloroplast envelope and thylakoid). S. perennans also had larger photosynthetic cells, by 10–15 times, and more effective mechanisms of osmoregulation and protecting cells against the toxic effect of Na+. Salinity caused changes in photosynthetic tissues of C. crassa such as an increase of the mesophyll cell surface, the expansion of the interface area between mesophyll and bundle sheath cells, and an increase of the volume of the latter. These functional changes compensated for scarce CO2 supply when salinity increased. Overall, we concluded that these C3 and C4 Chenopodiaceae species demonstrated different responses to salinity, both at the cellular and subcellular levels.

The mechanistic basis of sodium exclusion in Puccinellia tenuiflora under conditions of salinity and potassium deprivation.

Soil salinity is a significant threat to global agriculture. Understanding salt exclusion mechanisms in halophyte species may be instrumental in improving salt tolerance in crops. Puccinellia tenuiflora is a typical salt-excluding halophytic grass often found in potassium-deprived saline soils. Our previous work showed that P. tenuiflora possesses stronger selectivity for K+ than for Na+ ; however, the mechanistic basis of this phenomenon remained elusive. Here, P. tenuiflora PutHKT1;5 was cloned and the functions of PutHKT1;5 and PutSOS1 were characterized using heterologous expression systems. Yeast assays showed that PutHKT1;5 possessed Na+ transporting capacity and was highly selective for Na+ over K+ . PutSOS1 was located at the plasma membrane and operated as a Na+ /K+ exchanger, with much stronger Na+ extrusion capacity than its homolog from Arabidopsis. PutHKT2;1 mediated high-affinity K+ and Na+ uptake and its expression levels were upregulated by mild salinity and K+ deprivation. Salinity-induced changes of root PutHKT1;5 and PutHKT1;4 transcript levels matched the expression pattern of root PutSOS1, which was consistent with root Na+ efflux. The transcript levels of root PutHKT2;1 and PutAKT1 were downregulated by salinity. Taken together, these findings demonstrate that the functional activity of PutHKT1;5 and PutSOS1 in P. tenuiflora roots is fine-tuned under saline conditions as well as by operation of other ion transporters/channel (PutHKT1;4, PutHKT2;1, and PutAKT1). This leads to the coordination of radial Na+ and K+ transport processes, their loading to the xylem, or Na+ retrieval and extrusion under conditions of mild salinity and/or K+ deprivation.

Mineral nutrient analysis of three halophytic grasses under sodic and saline stress conditions

Present study was carried out to assess the effects of soil salinity/sodicity on mineral nutrient status of Urochondra setulosa, Leptochloa fusca and Sporobolus marginatus at ICAR- Central Soil Salinity Research Institute, Karnal, Haryana during 2016–19. Treatments of salinity/sodicity (pH ~ 9.5, pH ~ 10, ECe ~ 30 dS/m, ECe ~ 40 dS/m and ECe ~ 50 dS/m) were created in microplots (2.5 m × 1.5 m × 0.5 m) using saline/sodic water. Na+ and Cl– content (% DW) significantly increased with increasing sodicity/salinity stress condition in all three grass halophytes, whereas K+ content decreased. These grass halophytic species showed relatively less reduction in Ca, Mg and Fe contents up to sodic stress of pH ~ 9.5 and salinity level of ECe ~ 40 dS/m. Zn, Cu and Mn content decreased with increasing stress conditions but higher decrease was observed under sodic stress. The Na+/K+ and Na+/Ca2+ ratio was considered as indicators for measuring salt tolerance in plants. Na+/K+ ratio increased with increasing stress condition in all the three grasses but Leptachloa maintained their Na+/K+ near pH 1.0 under sodic stress condition and also maintained their Na+/Ca2+ below 1.0 up to pH ~ 9.5 and ECe ~ 40 dS/m. Higher sodic stress of pH~10.0 caused significant increase in Na+/Ca2+ in Urochondra and Sporobolus, whereas under highest salinity level, Leptachloa showed highest value for Na+/Ca2+. Changes in the accumulation patterns of nutrient in response to salinity is an important aspect and study showed highest positive correlation between Ca - Mg & Zn and negative between Na - Ca and K.

Petrochemical attributes of glazed architectural elements from Middle-Elamite to Achaemenid excavation sites in Iran

Glazed decoration in Iran from the Middle Elamite to the Achaemenid periods includes world art milestones. With the exception of Hasanlu IVB, for most sites, comprehensive chemical and mineralogical data are lacking, owing to the generally profound alteration of the vitreous material. To bridge the information gap, and to enable to reconstruct operation production chains in a diachronic fashion, thirty-six glazed artefacts from Qalaichi, Rabat, Hasanlu, Ziwiye, Chogha Zanbil, Susa and Persepolis are studied. The microstructural make-up and alteration phenomena of glazes are characterized by petrographic microscopy, back-scattered electron (BSE) imaging and electron probe microanalysis (WDS-EPMA) on high-quality polished thin sections. Pristine glaze domains at all sites show plant ash soda-lime glass compositions and indicate the use of regionally specific halophyte species for soda production. A distinct feature in the composition of white and turquoise glazes from Qalaichi, Ziwiye and Achaemenid Susa is the employment of sodium-antimonate as white colourant and opacifier. Inter-diffusion and dissolution-precipitation are identified as regionally and temporally contrasting alteration processes.

Antimicrobial activity of endophytic fungi associated with halophytic species Salsola vermiculata

Antimicrobial activity of endophytic fungi associated with halophytic species Salsola vermiculata

Improvement of salt tolerance of Arabidopsis thaliana seedlings inoculated with endophytic Bacillus cereus KP120

ABSTRACT In our previous reports, an endophytic bacterium, Bacillus cereus KP120 was isolated from the halophyte species Kosteletzkya virginica. In this study, the effect of KP120 colonization on Arabidopsis thaliana seedlings was investigated. Our results showed that inoculation with KP120 could promote the growth of A. thaliana seedlings plants under salt-stress conditions, compared with uninoculated controls. After salt treatment, chlorophyll, proline, the activity of antioxidant enzymes, Indole-3-acetic acid and 1-aminocyclopropane-1-carboxylate-deaminase in plants inoculated were increased significantly but malondialdehyde content was decreased compared with the plants under salt stress lonely. Similarly, under non-salt stress, physiological indices above except for MDA in plants inoculated with KP120 were increased compared with control. B. cereus also induced the up-regulation of key genes involved in IAA biosynthesis, responses, transport, down-regulated expression of genes related with ethylene synthesis and response. Our work principally demonstrates that Bacillus cereus KP120 significantly enhances plant growth and increases plant tolerance to salt stress.

Halophytes as Medicinal Plants against Human Infectious Diseases

Halophytes have long been used for medicinal purposes. However, for many decades, their use was entirely empirical, with virtually no knowledge of the bioactive compounds underlying the different applications. In recent decades, the growing problem of antibiotic resistance triggered the research on alternative antimicrobial approaches, and halophytes, along with other medicinal plants, regained attention as an underexplored pharmacological vein. Furthermore, the high nutritional/nutraceutical/pharmacological value of some halophytic species may represent added value to the emerging activity of saline agriculture and targeted modification of the rhizosphere, with plant-growth-promoting bacteria being attempted to be used as a tool to modulate the plant metabolome and enhance the expression of interesting metabolites. The objective of this review is to highlight the potential of halophytes as a valuable, and still unexplored, source of antimicrobial compounds for clinical applications. For that, we provide a critical perspective on the empirical use of halophytes in traditional medicine and a state-or-the-art overview of the most relevant plant species and metabolites related with antiviral, antifungal and antibacterial activities.

The Content of Certain Groups of Phenolic Compounds and the Biological Activity of Extracts of Various Halophyte Parts of Spergularia marina (L.) Griseb. and Glaux maritima L. at Different Levels of Soil Salinization.

Halophyte plants are known for their resistance to harsh environmental conditions associated with excess salts in their habitats. Their resistance to salinization is due, among other things, to their high ability to detoxify free radicals, owing to the relatively high content of antioxidants. On the coast of the Baltic Sea and in the lagoons, there are several rare halophyte species included in the Red Book of the Kaliningrad Region (Russia) and the Baltic region, such as Spergularia marina (L.) Griseb. and Glaux maritima L. The aim of the research was to study the accumulation of certain groups of phenolic compounds in different parts of S. marina and G. maritima plants under conditions of weak and strong soil salinity, as well as to analyze the antioxidant, antibacterial, and fungicidal activity of extracts of the studied plant species. The present study showed an increase in total phenolic content in the roots and shoots of S. marina, and the shoots of G. maritima, in response to increased soil salinity. At the same time, the total content of flavonoids in all the studied parts of the two plant species remained unchanged. However, the content of individual flavonoids (hesperetin, epicatechin, apigenin derivative, luteolin derivative) in S. marina increased, for G. maritima there was a tendency to reduce the content of flavonoids in roots and shoots with an increase in soil salinity. There was an increase in the total content of hydroxycinnamic acids in the roots of Glaux maritima, as well as an increase in the content of protocatechuic acid in the roots and shoots of Spergularia marina. A positive relationship was established between the antioxidant activity of S. marina root extracts and the total content of phenolic compounds, as well as G. maritima shoots extracts and the total content of phenolic compounds. Extracts of S. marina showed no antibacterial activity against Escherichia coli and Bacillus subtilis, and weak fungicidal activity of stem extracts and inflorescences grown on soils, with high levels of salinities, was detected against Candida albicans. The extracts of roots and shoots from G. maritima showed weak antimicrobial and fungicidal activity.

Population Dynamic of the Annual Halophyte Salicornia ramosissima in Salt Pans: Towards a Sustainable Exploitation of Its Wild Populations.

Halophyte species growing under stressful conditions, such as the annual species of the Salicornia genus, have been recognized as a source of metabolites of pharmacological and nutraceutical interest. Therefore, planning the extraction of individual plants from wild populations in a sustainable way is especially important in the case of annual species. We studied the environmental matrix and population dynamic of four Salicornia ramosissima populations growing at two elevations in salt pans under a Mediterranean climate. In elevated areas, S. ramosissima populations presented maximum plant densities of between 628–6288 plants m−2 that remained almost constant until fruiting. In contrast, populations in depressed zones presented five-times greater soil-seed-bank densities and maximum plant densities than populations in elevated zones. In this context, populations in depressed zones lost c. 60% of their maximum plant densities from the end of spring and through summer. In whatever way the environmental matrix seemed to control the population dynamic of S. ramosissima in depressed zones, the effects of a stressful environment would interact with plant densities. In this sense, we recorded the density-dependent mortality for the densest population (max. 51,558 plants m−2). Our results are useful for planning a sustainable harvesting of natural populations of S. ramosissima.

Multi-omics Analysis of Young Portulaca oleracea L. Plants' Responses to High NaCl Doses Reveals Insights into Pathways and Genes Responsive to Salinity Stress in this Halophyte Species.

The online version contains supplementary material available at 10.1007/s43657-022-00061-2.