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Databases of genome sequences are growing exponentially, but, in some cases, assembly is incomplete and genes are poorly annotated. For evolutionary studies, it is important to identify all members of a given gene family in a genome. We developed a method for identifying most, if not all, members of a gene family from raw genomes in which assembly is of low quality, using the P-type ATPase superfamily as an example. The method is based on the translation of an entire genome in all six reading frames and the co-occurrence of two family-specific sequence motifs that are in close proximity to each other. To test the method’s usability, we first used it to identify P-type ATPase members in the high-quality annotated genome of barley (Hordeum vulgare). Subsequently, after suc- cessfully identifying plasma membrane H+ -ATPase family members (P3A ATPases) in various plant genomes of varying quality, we tested the hypothesis that the number of P3A ATPases correlates with the ability of the plant to tolerate saline conditions. In 19 genomes of glycophytes and halophytes, the total number of P3A ATPase genes was found to vary from 7 to 22, but no significant difference was found between the two groups. The method successfully iden- tified P-type ATPase family members in raw genomes that are poorly assembled., Databases of genome sequences are growing exponentially, but, in some cases, assembly is incomplete and genes are poorly annotated. For evolutionary studies, it is important to identify all members of a given gene family in a genome. We developed a method for identifying most, if not all, members of a gene family from raw genomes in which assembly is of low quality, using the P-type ATPase superfamily as an example. The method is based on the translation of an entire genome in all six reading frames and the co-occurrence of two family-specific sequence motifs that are in close proximity to each other. To test the method’s usability, we first used it to identify P-type ATPase members in the high-quality annotated genome of barley (Hordeum vulgare). Subsequently, after successfully identifying plasma membrane H+-ATPase family members (P3A ATPases) in various plant genomes of varying quality, we tested the hypothesis that the number of P3A ATPases correlates with the ability of the plant to tolerate saline conditions. In 19 genomes of glycophytes and halophytes, the total number of P3A ATPase genes was found to vary from 7 to 22, but no significant difference was found between the two groups. The method successfully identified P-type ATPase family members in raw genomes that are poorly assembled.

According to the EU, the global consumption of biomass, fossil fuels, metals, and minerals is expected to double by 2050, while waste will increase by 70%. In this context, the Circular Economy Action Plan (CEAP) intends to integrate development and sustainability. In this regard, tailored biofertilizers based on plant growth-promoting bacteria (PGPB) can improve plant yield with fewer inputs. In our project, an autochthonous halophyte of the Andalusian marshes, namely Mesembryanthemum crystallinum, was selected for its interest as a source of pharmaceuticals and nutraceuticals. The aim of this work was to use a culturomics approach for the isolation of specific PGPB and endophytes able to promote plant growth and, eventually, modulate the metabolome of the plant. For this purpose, a specific culture medium based on M. crystallinum biomass, called Mesem Agar (MA), was elaborated. Bacteria of three compartments (rhizosphere soil, root endophytes, and shoot endophytes) were isolated on standard tryptone soy agar (TSA) and MA in order to obtain two independent collections. A higher number of bacteria were isolated on TSA than in MA (47 vs. 37). All the bacteria were identified, and although some of them were isolated in both media (Pseudomonas, Bacillus, Priestia, Rosellomorea, etc.), either medium allowed the isolation of specific members of the M. crystallinum microbiome such as Leclercia, Curtobacterium, Pantoea, Lysinibacillus, Mesobacillus, Glutamicibacter, etc. Plant growth-promoting properties and extracellular degrading activities of all the strains were determined, and distinct patterns were found in both media. The three best bacteria of each collection were selected in order to produce two different consortia, whose effects on seed germination, root colonization, plant growth and physiology, and metabolomics were analyzed. Additionally, the results of the plant metabolome revealed a differential accumulation of several primary and secondary metabolites with

Plant-growth-promoting bacteria (PGPB) help plants thrive in polluted environments and increase crops yield using fewer inputs. Therefore, the design of tailored biofertilizers is of the utmost importance. The purpose of this work was to test two different bacterial synthetic communities (SynComs) from the microbiome of Mesembryanthemum crystallinum, a moderate halophyte with cosmetic, pharmaceutical, and nutraceutical applications. The SynComs were composed of specific metal-resistant plant-growth-promoting rhizobacteria and endophytes. In addition, the possibility of modulating the accumulation of nutraceutical substances by the synergetic effect of metal stress and inoculation with selected bacteria was tested. One of the SynComs was isolated on standard tryptone soy agar (TSA), whereas the other was isolated following a culturomics approach. For that, a culture medium based on M. crystallinum biomass, called Mesem Agar (MA), was elaborated. Bacteria of three compartments (rhizosphere soil, root endophytes, and shoot endophytes) were isolated on standard TSA and MA media, stablishing two independent collections. All bacteria were tested for PGP properties, secreted enzymatic activities, and resistance towards As, Cd, Cu, and Zn. The three best bacteria from each collection were selected in order to produce two different consortiums (denominated TSA- and MA-SynComs, respectively), whose effect on plant growth and physiology, metal accumulation, and metabolomics was evaluated. Both SynComs, particularly MA, improved plant growth and physiological parameters under stress by a mixture of As, Cd, Cu, and Zn. Regarding metal accumulation, the concentrations of all metals/metalloids in plant tissues were below the threshold for plant metal toxicity, indicating that this plant is able to thrive in polluted soils when assisted by metal/metalloid-resistant SynComs and could be safely used for pharmaceutical purposes. Initial metabolomics analyses depict changes in plant me

Background In New-Caledonia, at the end of each shrimp production cycle, earthen ponds are drained and dried to enhance microbial decomposition of nutrient-rich waste trapped in the sediment during the rearing. However, excessive ponds drying may not be suitable for the decomposition activities of microorganisms. Halophytes, salt tolerant plants, naturally grow at vicinity of shrimp ponds; due to their specificity, we explored whether halophytes cultivation during the pond drying period may be suitable for pond bioremediation. In addition, plants are closely associated with microorganisms, which may play a significant role in organic matter decomposition and therefore in bioremediation. Thus, in this study we aimed to determine the impact of 3 halophyte species (Suaeda australis, Sarcocornia quinqueflora and Atriplex jubata) on active sediment microbial communities and their implications on organic matter degradation. Results Drying significantly decreased the microbial diversity index compared to those of wet sediment or sediment with halophytes. Microbial profiles varied significantly over time and according to the experimental conditions (wet, dry sediment or sediment with halophyte species). Halophytes species seemed to promote putative microbial metabolism activities in the sediment. Taxa related to nitrogen removal, carbon mineralisation, sulphur reduction and sulphide oxidation were significant biomarkers in sediment harbouring halophytes and may be relevant for bioremediation. Whereas microbial communities of dry sediment were marked by soil limited-moisture taxa with no identification of microbial metabolic functions. Nitrogen reduction in sediments was evidenced in wet sediment and in sediments with halophytes cultures, along with putative microbial denitrification activities. The greatest nitrogen reduction was observed in halophytes culture. Conclusion The efficiency of sediment bioremediation by halophytes appears to be the result of both rhizosphere mi

Tamarix is native to Eurasia plus the northern and southern territories of Africa, with some species being introduced into America and Oceania. They are usually found in arid, desertic, or subdesertic areas, often on saline or subsaline soils, in Mediterranean, temperate, or subtropical climates. The genus is renowned for its complex taxonomy, which is usually based on rather variable or unstable characters, which leads to contrasting taxonomic treatments. As part of the taxonomic revision of Tamarix undertaken by the authors, ten names (i.e., T. africana, T. bounopoea, T. brachystylis var. fluminensis, T. malenconiana, T. muluyana, T. tenuifolia, T. tingitana, T. trabutii, T. valdesquamigera, and T. weyleri) published from material collected in the southwestern parts of the Mediterranean basin are taxonomically and nomenclaturally discussed after analysing their original material. Eight intended holotypes are corrected here to lectotypes; one epitype is designated for T. africana to warrant current use of the name; and one isotype, 30 isolectotypes, and 11 syntypes are also identified for the studied names. Further, the taxonomic identity of all names and their eventual synonymic placement are accordingly discussed.

Increased soil salinity has numerous negative effects on plant growth and poses a significant threat to agricultural productivity worldwide. The diversity of endophytic bacterial communities found in various indigenous halophytes such as Salicornia europaea, Suaeda maritima, and Camphorosma annua, may reveal beneficial bacteria with various plant growthpromoting (PGP) properties. Members of Halomonas, the largest genus of the family Halomonadaceae, are rod-shaped, gram-negative, moderately halophilic bacteria that have been increasingly isolated from various saline environments, including halophyte tissues. As part of the halophytic microbiota, halotolerant plant growth-promoting endophytic bacteria can contribute to plant host growth, productivity, and fitness under abiotic and biotic stresses. The use of halotolerant PGP bacteria represents a good alternative strategy to mitigate the effects of salt stress in crops and to recover saline soils. The aim of this study was to isolate halotolerant bacteria from halophyte roots, and evaluate their PGP ability and their effect on germination parameters of selected crops. The endophytic bacterial communities in the roots of halophytes from natural saline soil in Slano Kopovo (Serbia) were analyzed using culture-dependent techniques. The genus Halomonas was the predominant among the halotolerant root-associated bacteria of analyzed halophytes. We have isolated seven Halomonas sp. strains, six of which were closely related (>99,86% similarity) to Halomonas songnenensis, a moderately halophilic bacterium from saline and alkaline soils. Obtained isolates were tested at different sodium chloride concentrations for a range of PGP traits at different concentrations of sodium chloride. The selected strains were used to inoculate seeds iand monitor of the germination process of barley, sunflower, and wheat under conditions of elevated salinity. Most of the isolates tolerate the NaCl concentration up to 18% and showed multiple PGP

Plant-growth-promoting bacteria (PGPB) help plants thrive in polluted environments and increase crops yield using fewer inputs. Therefore, the design of tailored biofertilizers is of the utmost importance. The purpose of this work was to test two different bacterial synthetic communities (SynComs) from the microbiome of Mesembryanthemum crystallinum, a moderate halophyte with cosmetic, pharmaceutical, and nutraceutical applications. The SynComs were composed of specific metal-resistant plant-growth-promoting rhizobacteria and endophytes. In addition, the possibility of modulating the accumulation of nutraceutical substances by the synergetic effect of metal stress and inoculation with selected bacteria was tested. One of the SynComs was isolated on standard tryptone soy agar (TSA), whereas the other was isolated following a culturomics approach. For that, a culture medium based on M. crystallinum biomass, called Mesem Agar (MA), was elaborated. Bacteria of three compartments (rhizosphere soil, root endophytes, and shoot endophytes) were isolated on standard TSA and MA media, stablishing two independent collections. All bacteria were tested for PGP properties, secreted enzymatic activities, and resistance towards As, Cd, Cu, and Zn. The three best bacteria from each collection were selected in order to produce two different consortiums (denominated TSA- and MA-SynComs, respectively), whose effect on plant growth and physiology, metal accumulation, and metabolomics was evaluated. Both SynComs, particularly MA, improved plant growth and physiological parameters under stress by a mixture of As, Cd, Cu, and Zn. Regarding metal accumulation, the concentrations of all metals/metalloids in plant tissues were below the threshold for plant metal toxicity, indicating that this plant is able to thrive in polluted soils when assisted by metal/metalloid-resistant SynComs and could be safely used for pharmaceutical purposes. Initial metabolomics analyses depict changes in plant me

Background In New-Caledonia, at the end of each shrimp production cycle, earthen ponds are drained and dried to enhance microbial decomposition of nutrient-rich waste trapped in the sediment during the rearing. However, excessive ponds drying may not be suitable for the decomposition activities of microorganisms. Halophytes, salt tolerant plants, naturally grow at vicinity of shrimp ponds; due to their specificity, we explored whether halophytes cultivation during the pond drying period may be suitable for pond bioremediation. In addition, plants are closely associated with microorganisms, which may play a significant role in organic matter decomposition and therefore in bioremediation. Thus, in this study we aimed to determine the impact of 3 halophyte species (Suaeda australis, Sarcocornia quinqueflora and Atriplex jubata) on active sediment microbial communities and their implications on organic matter degradation. Results Drying significantly decreased the microbial diversity index compared to those of wet sediment or sediment with halophytes. Microbial profiles varied significantly over time and according to the experimental conditions (wet, dry sediment or sediment with halophyte species). Halophytes species seemed to promote putative microbial metabolism activities in the sediment. Taxa related to nitrogen removal, carbon mineralisation, sulphur reduction and sulphide oxidation were significant biomarkers in sediment harbouring halophytes and may be relevant for bioremediation. Whereas microbial communities of dry sediment were marked by soil limited-moisture taxa with no identification of microbial metabolic functions. Nitrogen reduction in sediments was evidenced in wet sediment and in sediments with halophytes cultures, along with putative microbial denitrification activities. The greatest nitrogen reduction was observed in halophytes culture. Conclusion The efficiency of sediment bioremediation by halophytes appears to be the result of both rhizosphere mi

Suaeda linearis is an edible halophyte crop with nutraceutical properties that is native to Florida. This study investigated how the biomass production and mineral content of aquacultured S. linearis was affected by harvest frequency during a 10-week period using four different harvest treatments. Under the first treatment (T1) plants received zero intermittent harvests, the second (T2) received harvests every five weeks, the third (T3) received harvests every 3.3 weeks, and the fourth (T4) received harvests every 2.5 weeks. The results indicate that biomass production and mineral content were both strongly affected by harvest treatment. Intermittent harvesting decreased biomass production and conversely, intermittent harvesting increased the quantities of certain desirable minerals in S. linearis. Early harvests of the study plants were small, suggesting that 13-15 weeks after germination is the earliest time a harvestable yield can be achieved from S. linearis., 2023, Includes bibliography., Degree granted: Thesis (MS)--Florida Atlantic University, 2023., Collection: FAU Electronic Theses and Dissertations Collection

According to the EU, the global consumption of biomass, fossil fuels, metals, and minerals is expected to double by 2050, while waste will increase by 70%. In this context, the Circular Economy Action Plan (CEAP) intends to integrate development and sustainability. In this regard, tailored biofertilizers based on plant growth-promoting bacteria (PGPB) can improve plant yield with fewer inputs. In our project, an autochthonous halophyte of the Andalusian marshes, namely Mesembryanthemum crystallinum, was selected for its interest as a source of pharmaceuticals and nutraceuticals. The aim of this work was to use a culturomics approach for the isolation of specific PGPB and endophytes able to promote plant growth and, eventually, modulate the metabolome of the plant. For this purpose, a specific culture medium based on M. crystallinum biomass, called Mesem Agar (MA), was elaborated. Bacteria of three compartments (rhizosphere soil, root endophytes, and shoot endophytes) were isolated on standard tryptone soy agar (TSA) and MA in order to obtain two independent collections. A higher number of bacteria were isolated on TSA than in MA (47 vs. 37). All the bacteria were identified, and although some of them were isolated in both media (Pseudomonas, Bacillus, Priestia, Rosellomorea, etc.), either medium allowed the isolation of specific members of the M. crystallinum microbiome such as Leclercia, Curtobacterium, Pantoea, Lysinibacillus, Mesobacillus, Glutamicibacter, etc. Plant growth-promoting properties and extracellular degrading activities of all the strains were determined, and distinct patterns were found in both media. The three best bacteria of each collection were selected in order to produce two different consortia, whose effects on seed germination, root colonization, plant growth and physiology, and metabolomics were analyzed. Additionally, the results of the plant metabolome revealed a differential accumulation of several primary and secondary metabolites with

soil salinity has numerous negative effects on plant growth and poses a significant threat to agricultural productivity worldwide. The diversity of endophytic bacterial communities found in various indigenous halophytes such as Salicornia europaea, Suaeda maritima, and Camphorosma annua, may reveal beneficial bacteria with various plant growthpromoting (PGP) properties. Members of Halomonas, the largest genus of the family Halomonadaceae, are rod-shaped, gram-negative, moderately halophilic bacteria that have been increasingly isolated from various saline environments, including halophyte tissues. As part of the halophytic microbiota, halotolerant plant growth-promoting endophytic bacteria can contribute to plant host growth, productivity, and fitness under abiotic and biotic stresses. The use of halotolerant PGP bacteria represents a good alternative strategy to mitigate the effects of salt stress in crops and to recover saline soils. The aim of this study was to isolate halotolerant bacteria from halophyte roots, and evaluate their PGP ability and their effect on germination parameters of selected crops. The endophytic bacterial communities in the roots of halophytes from natural saline soil in Slano Kopovo (Serbia) were analyzed using culture-dependent techniques. The genus Halomonas was the predominant among the halotolerant root-associated bacteria of analyzed halophytes. We have isolated seven Halomonas sp. strains, six of which were closely related (>99,86% similarity) to Halomonas songnenensis, a moderately halophilic bacterium from saline and alkaline soils. Obtained isolates were tested at different sodium chloride concentrations for a range of PGP traits at different concentrations of sodium chloride. The selected strains were used to inoculate seeds iand monitor of the germination process of barley, sunflower, and wheat under conditions of elevated salinity. Most of the isolates tolerate the NaCl concentration up to 18% and showed multiple PGP features w

Acclimation of root growth is vital for plants to survive salt stress. Halophytes are great examples of plants that thrive even under severe salinity, but their salt tolerance mechanisms, especially those mediated by root responses, are still largely unknown. We compared root growth responses of the halophyte Schrenkiella parvula with its glycophytic relative species Arabidopsis thaliana under salt stress and performed transcriptomic analysis of S. parvula roots to identify possible gene regulatory networks underlying their physiological responses. Schrenkiella parvula roots do not avoid salt and experience less growth inhibition under salt stress. Salt-induced abscisic acid levels were higher in S. parvula roots compared with Arabidopsis. Root transcriptomic analysis of S. parvula revealed the induction of sugar transporters and genes regulating cell expansion and suberization under salt stress. 14C-labeled carbon partitioning analyses showed that S. parvula continued allocating carbon to roots from shoots under salt stress while carbon barely allocated to Arabidopsis roots. Further physiological investigation revealed that S. parvula roots maintained root cell expansion and enhanced suberization under severe salt stress. In summary, roots of S. parvula deploy multiple physiological and developmental adjustments under salt stress to maintain growth, providing new avenues to improve salt tolerance of plants using root-specific strategies.

Sea fennel and seaside arrowgrass are two abundant but underutilized halophytes along the Atlantic and Mediterranean coasts. This study investigated the antioxidant capacity and the potential antihypertensive (Angiotensin Converting Enzyme I, ACE-I inhibition), hypoglycaemic (Dipeptidyl Peptidase IV, DPP-IV inhibition), and nootropic (Prolyl Endopeptidase, PEP inhibition) activity of their polyphenol extracts. They had a high phenol content (21–24 mEq GA/g), antioxidant capacity evaluated using the ABTS (17–2 mg ascorbic acid/g) and FRAP (170–270 mM Mohr’s salt/g) assays, and effective ACE-inhibiting properties (80–90% inhibiting activity at final concentration of 0.5 mg/mL). Additionally, the sea fennel extract displayed high DPP-IV inhibitory capacity (73% at 1 mg/mL), while the seaside arrowgrass extract exhibited potent Prolyl endopeptidase inhibitory capacity (75% at 1 mg/mL). Fractionation by HPLC concentrated the bioactive molecules in two fractions, for which the composition was analyzed by LC-MS/MS. Different chlorogenic acids seemed to play an important role in the bioactivity of sea fennel extract, and different flavonoids, mainly apigenin, luteolin and chrysoeriol, in the bioactivity of the seaside arrowgrass extract. Given their potential health benefits, these extracts could serve as valuable bioactive ingredients and could potentially encourage the cultivation of these species in regions where traditional crops face challenges in growth.

In the Alto Valle de Río Negro, excessive irrigation and poor drainage cause the water table to rise with dissolved salts that, combined with the texture of the soil, promote its salinization. Consequently, halophytes thrive, and both crop yields and the quality of the products decrease. This work aims to analyze the floristic diversity of halophytes in different crops and textural groups in the area. Vegetation surveys on salinized patches in different productive establishments were carried out. For each taxon, the importance value was calculated and was classified according to its geographical origin, habit, life form, and mechanism to resist salinity. The floristic comparison between environments was carried out using the ecological indices richness, diversity and evenness, and hierarchical grouping techniques. The floristic list presents 111 infrageneric taxa. The best-represented families are Poaceae, Asteraceae, and Chenopodiaceae. The 70.27 % of the taxa are pseudohalophytes, 17.11 % crinohalophytes, and 12.62 % euhalophytes. The “barda” and “media barda” soils have the highest ecological indices. The abandoned and forage crops present the highest values of diversity and equitability, while vine and abandoned crops, the highest values of specific richness. The floristic similarity values in the textural groups are low to medium, while in the crops, medium to high. The first floristic inventory of halophilic taxa in cultivated halomorphic soils for the region is presented, which provides useful information for adequate management of productive establishments., En el Alto Valle de Río Negro, el riego excesivo y drenaje deficiente ocasionan el ascenso de la capa freática con sales disueltas que, combinados con la textura del suelo, promueven su salinización. Consecuentemente, prosperan halófitos y merman los rendimientos de los cultivos y la calidad de los productos. El objetivo del presente trabajo es analizar la diversidad florística de halófitos en diferentes cultivos y grupos texturales en el área. Se realizaron relevamientos de vegetación sobre parches salinizados en diferentes establecimientos productivos. Para cada taxón se calculó el valor de importancia y se lo clasificó según su origen geográfico, hábito, forma de vida y mecanismo para resistir la salinidad. La comparación florística entre ambientes se realizó mediante los índices ecológicos riqueza, diversidad y equitatividad, y técnicas de agrupamiento jerárquico. El listado florístico presenta 111 taxones infragenéricos. Las familias mejor representadas son Poaceae, Asteraceae y Chenopodiaceae. El 70,27 % de los taxones son pseudohalófitos, el 17,11 % crinohalófitos y el 12,62 % euhalófitos. Los suelos de barda y media barda tienen los índices ecológicos más altos. Los cultivos abandonados y forrajeros presentan los mayores valores de diversidad y equitatividad, mientras que los de vid y abandonados, mayor riqueza específica. Los valores de similitud florística en los grupos texturales son bajos a medios, mientras que, en los cultivos, medios a altos. Se presenta el primer inventario florístico de taxones halófilos en suelos halomórficos cultivados para la región que provee información útil para una gestión adecuada de los establecimientos productivos.

In the Alto Valle de Río Negro, excessive irrigation and poor drainage cause the water table to rise with dissolved salts that, combined with the texture of the soil, promote its salinization. Consequently, halophytes thrive, and both crop yields and the quality of the products decrease. This work aims to analyze the floristic diversity of halophytes in different crops and textural groups in the area. Vegetation surveys on salinized patches in different productive establishments were carried out. For each taxon, the importance value was calculated and was classified according to its geographical origin, habit, life form, and mechanism to resist salinity. The floristic comparison between environments was carried out using the ecological indices richness, diversity and evenness, and hierarchical grouping techniques. The floristic list presents 111 infrageneric taxa. The best-represented families are Poaceae, Asteraceae, and Chenopodiaceae. The 70.27 % of the taxa are pseudohalophytes, 17.11 % crinohalophytes, and 12.62 % euhalophytes. The “barda” and “media barda” soils have the highest ecological indices. The abandoned and forage crops present the highest values of diversity and equitability, while vine and abandoned crops, the highest values of specific richness. The floristic similarity values in the textural groups are low to medium, while in the crops, medium to high. The first floristic inventory of halophilic taxa in cultivated halomorphic soils for the region is presented, which provides useful information for adequate management of productive establishments., En el Alto Valle de Río Negro, el riego excesivo y drenaje deficiente ocasionan el ascenso de la capa freática con sales disueltas que, combinados con la textura del suelo, promueven su salinización. Consecuentemente, prosperan halófitos y merman los rendimientos de los cultivos y la calidad de los productos. El objetivo del presente trabajo es analizar la diversidad florística de halófitos en diferentes cultivos y grupos texturales en el área. Se realizaron relevamientos de vegetación sobre parches salinizados en diferentes establecimientos productivos. Para cada taxón se calculó el valor de importancia y se lo clasificó según su origen geográfico, hábito, forma de vida y mecanismo para resistir la salinidad. La comparación florística entre ambientes se realizó mediante los índices ecológicos riqueza, diversidad y equitatividad, y técnicas de agrupamiento jerárquico. El listado florístico presenta 111 taxones infragenéricos. Las familias mejor representadas son Poaceae, Asteraceae y Chenopodiaceae. El 70,27 % de los taxones son pseudohalófitos, el 17,11 % crinohalófitos y el 12,62 % euhalófitos. Los suelos de barda y media barda tienen los índices ecológicos más altos. Los cultivos abandonados y forrajeros presentan los mayores valores de diversidad y equitatividad, mientras que los de vid y abandonados, mayor riqueza específica. Los valores de similitud florística en los grupos texturales son bajos a medios, mientras que, en los cultivos, medios a altos. Se presenta el primer inventario florístico de taxones halófilos en suelos halomórficos cultivados para la región que provee información útil para una gestión adecuada de los establecimientos productivos.

In the Alto Valle de Río Negro, excessive irrigation and poor drainage cause the water table to rise with dissolved salts that, combined with the texture of the soil, promote its salinization. Consequently, halophytes thrive, and both crop yields and the quality of the products decrease. This work aims to analyze the floristic diversity of halophytes in different crops and textural groups in the area. Vegetation surveys on salinized patches in different productive establishments were carried out. For each taxon, the importance value was calculated and was classified according to its geographical origin, habit, life form, and mechanism to resist salinity. The floristic comparison between environments was carried out using the ecological indices richness, diversity and evenness, and hierarchical grouping techniques. The floristic list presents 111 infrageneric taxa. The best-represented families are Poaceae, Asteraceae, and Chenopodiaceae. The 70.27 % of the taxa are pseudohalophytes, 17.11 % crinohalophytes, and 12.62 % euhalophytes. The “barda” and “media barda” soils have the highest ecological indices. The abandoned and forage crops present the highest values of diversity and equitability, while vine and abandoned crops, the highest values of specific richness. The floristic similarity values in the textural groups are low to medium, while in the crops, medium to high. The first floristic inventory of halophilic taxa in cultivated halomorphic soils for the region is presented, which provides useful information for adequate management of productive establishments., En el Alto Valle de Río Negro, el riego excesivo y drenaje deficiente ocasionan el ascenso de la capa freática con sales disueltas que, combinados con la textura del suelo, promueven su salinización. Consecuentemente, prosperan halófitos y merman los rendimientos de los cultivos y la calidad de los productos. El objetivo del presente trabajo es analizar la diversidad florística de halófitos en diferentes cultivos y grupos texturales en el área. Se realizaron relevamientos de vegetación sobre parches salinizados en diferentes establecimientos productivos. Para cada taxón se calculó el valor de importancia y se lo clasificó según su origen geográfico, hábito, forma de vida y mecanismo para resistir la salinidad. La comparación florística entre ambientes se realizó mediante los índices ecológicos riqueza, diversidad y equitatividad, y técnicas de agrupamiento jerárquico. El listado florístico presenta 111 taxones infragenéricos. Las familias mejor representadas son Poaceae, Asteraceae y Chenopodiaceae. El 70,27 % de los taxones son pseudohalófitos, el 17,11 % crinohalófitos y el 12,62 % euhalófitos. Los suelos de barda y media barda tienen los índices ecológicos más altos. Los cultivos abandonados y forrajeros presentan los mayores valores de diversidad y equitatividad, mientras que los de vid y abandonados, mayor riqueza específica. Los valores de similitud florística en los grupos texturales son bajos a medios, mientras que, en los cultivos, medios a altos. Se presenta el primer inventario florístico de taxones halófilos en suelos halomórficos cultivados para la región que provee información útil para una gestión adecuada de los establecimientos productivos.

In the Alto Valle de Río Negro, excessive irrigation and poor drainage cause the water table to rise with dissolved salts that, combined with the texture of the soil, promote its salinization. Consequently, halophytes thrive, and both crop yields and the quality of the products decrease. This work aims to analyze the floristic diversity of halophytes in different crops and textural groups in the area. Vegetation surveys on salinized patches in different productive establishments were carried out. For each taxon, the importance value was calculated and was classified according to its geographical origin, habit, life form, and mechanism to resist salinity. The floristic comparison between environments was carried out using the ecological indices richness, diversity and evenness, and hierarchical grouping techniques. The floristic list presents 111 infrageneric taxa. The best-represented families are Poaceae, Asteraceae, and Chenopodiaceae. The 70.27 % of the taxa are pseudohalophytes, 17.11 % crinohalophytes, and 12.62 % euhalophytes. The “barda” and “media barda” soils have the highest ecological indices. The abandoned and forage crops present the highest values of diversity and equitability, while vine and abandoned crops, the highest values of specific richness. The floristic similarity values in the textural groups are low to medium, while in the crops, medium to high. The first floristic inventory of halophilic taxa in cultivated halomorphic soils for the region is presented, which provides useful information for adequate management of productive establishments., En el Alto Valle de Río Negro, el riego excesivo y drenaje deficiente ocasionan el ascenso de la capa freática con sales disueltas que, combinados con la textura del suelo, promueven su salinización. Consecuentemente, prosperan halófitos y merman los rendimientos de los cultivos y la calidad de los productos. El objetivo del presente trabajo es analizar la diversidad florística de halófitos en diferentes cultivos y grupos texturales en el área. Se realizaron relevamientos de vegetación sobre parches salinizados en diferentes establecimientos productivos. Para cada taxón se calculó el valor de importancia y se lo clasificó según su origen geográfico, hábito, forma de vida y mecanismo para resistir la salinidad. La comparación florística entre ambientes se realizó mediante los índices ecológicos riqueza, diversidad y equitatividad, y técnicas de agrupamiento jerárquico. El listado florístico presenta 111 taxones infragenéricos. Las familias mejor representadas son Poaceae, Asteraceae y Chenopodiaceae. El 70,27 % de los taxones son pseudohalófitos, el 17,11 % crinohalófitos y el 12,62 % euhalófitos. Los suelos de barda y media barda tienen los índices ecológicos más altos. Los cultivos abandonados y forrajeros presentan los mayores valores de diversidad y equitatividad, mientras que los de vid y abandonados, mayor riqueza específica. Los valores de similitud florística en los grupos texturales son bajos a medios, mientras que, en los cultivos, medios a altos. Se presenta el primer inventario florístico de taxones halófilos en suelos halomórficos cultivados para la región que provee información útil para una gestión adecuada de los establecimientos productivos.

Salicornia bigelovii(Torr.)is a plant with promising agro-industrial potential and homeopathy is a natural alternative that does not affect the safety of the treated organism. The objective of the study was to evaluate the effect of the homeopathic medicineNatrum muriaticum(NaM) on productive response variables of S. bigeloviiwith different levels of salinity (NS) in hydroponic culture, applying a completely randomizedexperimental design, with factorial arrangement (3A x 3B) and three repetitions of 15 plants each. Two salinity levels (NS-50 and NS-100) and a control without salinity (NS-0) were appliedas factor A,and two centesimal dynamizations of NaM (NaM-7CH and NaM-31CH) and a control without medicine(NaM-0CH)as factor B. The response variables evaluated were aerial partlength (APL), root part length (RPL), stem thickness (ST), leaf area (LA), water potential (WP), relative water content (RWC), chlorophyll ‘a’, chlorophyll ‘b’and total chlorophyll. With the homeopathic treatment NaM-7CH, higher values were recorded in RPLand with NaM-31CH, higher average values in chlorophyll ‘a’, chlorophyll‘b’and total chlorophyll.With the saline treatmentNS-50, higher values were obtained for APL, RPL, ST, LA, RWC, chlorophylls ‘a’,‘b’and total. The highest averagevalues in plant morphology corresponded tothe interactionsNS-50/NaM-7CH and NS-50/NaM-31CH.This suggests a positive effect of NaM on relevant productive response variables of S.bigeloviiand its potential applicability in the hydroponic cultureof this coastal halophyte., Salicornia bigelovii (Torr.) es una planta con un promisorio potencial agroindustrial y la homeopatía es una alternativa natural que no afecta la inocuidad del organismo tratado. El objetivo del estudio fue evaluar el efecto del medicamento homeopático Natrum muriaticum (NaM) sobre variables de respuesta productiva de S. bigelovii con diferentes niveles de salinidad (NS) en cultivo hidropónico, aplicando un diseño experimental completamente al azar, con arreglo factorial (3A x 3B) y tres repeticiones de 15 plantas c/u. Como factor A, se aplicaron dos niveles de salinidad (NS-50 y NS-100) y un control sin salinidad (NS-0), como factor B, dos dinamizaciones centesimales de NaM (NaM-7CH y NaM-31CH) y un control sin medicamento (NaM-0CH). Las variables respuesta evaluadas fueron longitud parte aérea (LPA), longitud parte radicular (LPR), grosor de tallo (GT), área foliar (AF), potencial hídrico (PH), contenido relativo de agua (CRA), clorofila ‘a’, clorofila ‘b’ y clorofila total. Con el tratamiento homeopático NaM-7CH, se registraron valores superiores en LPR y con NaM-31CH, mayores valores promedio en clorofila ‘a’, clorofila ‘b’ y clorofila total. Con el tratamiento salino NS-50 se obtuvieron valores mayores para LPA, LPR, GT, AF, CRA, clorofilas ‘a’, ‘b’ y totales. Los valores promedio mayores en la morfología de la planta correspondieron a las interacciones NS-50/NaM-7CH y NS-50/NaM-31CH. Esto sugiere un efecto positivo NaM sobre variables relevantes de respuesta productiva de S. bigelovii y su potencial aplicabilidad en el cultivo hidropónico de esta halófita costera.

Soil contamination with Cd and Pb is a worldwide problem which not only degrades the environment but also poses a serious threat for human and animal health. Phytoremediation of these contaminated soils using halophytic plants like quinoa presents an opportunity to clean the soils and use them for crop production. The current experiment was performed to evaluate the Cd and Pb tolerance potential of quinoa and subsequently its implications for human health. Three weeks old quinoa seedlings were exposed to Cd (30, 60 and 90 mg kg−1) and Pb (50, 100 and 150 mg kg−1) levels along with a control. The results revealed that plant height decreased at highest levels of soil Cd and Pb. Shoot, root and seed dry weight decreased with increasing levels of soil Cd and Pb. Tissue Cd and Pb concentrations increased with increasing levels of Cd and Pb in soil, the highest Cd was found in roots while the lowest in seeds. The highest Pb concentration was found in shoots at low Pb level, while in roots at high level of Pb. Increasing levels of Cd and Pb stimulated the activities of measured antioxidant enzymes and decreased membrane stability index. The health risk assessments of Cd and Pb revealed that hazard quotient was < 1 for both the metals. However, the results of total hazard quotient showed that value was < 1 for Pb and 1.19 for Cd showing potential carcinogenicity. This study demonstrates that quinoa has good phytoremediation potential for Cd and Pb however, the risk of Cd toxicity is challenging for human health.

With the purpose of Plant Growth Promoting Rhizobacteria (PGPR) isolation, several authors have sampled different wetlands in the northern half of Argentina. However, to date, we do not know the existence of microbiological studies conducted in the Patagonian salt marshes, and concretely, concerning isolation of PGPR. The present work was conducted in the heavy metal polluted San Antonio salt marsh, in two areas with different grade of pollution. In those areas, we isolated cultivable bacteria from the rhizosphere of the halophytes Spartina densiflora and Sarcocornia perennis, and look for several plant growth promoting (PGP) properties among them. In total, 60 different cultivable bacteria were isolated. 50% of the rhizobacterial strains demonstrated at least one of the PGP properties assayed, 25% of them produced siderophores, 16% were able to solubilize phosphate, 11% were able to produce auxins and 7% chitinase. We could observe that PGP properties were more abundant among bacteria growing in polluted soils. Also, bacteria inhabiting S. densiflora rhizosphere showed more PGP properties related to heavy metal phytostabilization mechanisms, in line with the phytoremediation strategy of this halophyte. Overall, these findings support the idea that coastal hazardous scenarios may be a good opportunity to seek for PGPR. Indeed, some of the strains isolated in this work presented more than one PGP property, so they may be selected for further formulation of inoculants for different applications. For further research, it would be interesting to analyse other PGP properties in these strains, as well as to isolate rhizobacteria from other halophytes in diverse Patagonian salt marshes.

Tesis por compendio, [ES] El incremento en la concentración de sales en suelos y agua es una de las problemáticas que más amenazan a la humanidad por su efecto directo sobre la productividad de las cosechas. En líneas generales la pregunta a la que queremos contribuir es ¿cómo enfrentarnos a una situación de salinización en un contexto de cambio climático y crecimiento demográfico? Más concretamente estudiamos la problemática en el sureste español desde un enfoque en que los resultados puedan ser explotados en el corto y medio plazo por el sector empresarial. La Región de Murcia es una de las principales zonas productoras del sureste español donde además existen graves problemas de salinización. En la presente tesis doctoral se propone utilizar aguas salinas para riego e investigar las implicaciones de ello a nivel de absorción de agua y nutrientes, estudiando también los cambios fisiológicos en la planta para obtener aplicaciones que permitan el crecimiento económico. En este sentido se abordan dos estrategias: por un lado, el estudio de plantas halofitas, y por otro, la bioestimulación en plantas glicofitas. La mayoría de los cultivos productivos son plantas glicofitas, ven afectadas sus producciones cuando hay elevadas concentraciones de sal en el medio de cultivo. Por el contrario, las plantas halofitas han desarrollado diferentes mecanismos para resistir los efectos negativos de la salinidad. Es por ello que la explotación directa de halofitas se ha identificado como una salida económica para las zonas afectadas. Otra forma de mitigación de los efectos del cambio climático es el desarrollo de la bioestimulación para incrementar la resistencia a estreses o para incrementar la concentración de compuestos bioactivos en los alimentos. Para los estudios realizados, se seleccionaron 6 especies vegetales que fuesen representativas de los diferentes comportamientos frente a la salinidad, que fuesen propias de la localización seleccionada (Región de Murcia) y de interés para la empresa prom, [CA] L'augment de la concentració de sals en sòls i aigua és un dels problemes que més amenacen la humanitat pel seu efecte directe sobre la productivitat dels cultius. En termes generals, la qüestió a la qual volem contribuir és: com afrontar una situació de salinització en un context de canvi climàtic i creixement de la població? Més concretament, hem estudiat els problemes del sud-est d'Espanya des d'un enfocament en què els resultats poden ser explotats a curt i mitjà termini pel sector empresarial. La Regió de Múrcia és una de les principals zones productores del sud-est d'Espanya on també hi ha greus problemes de salinització. En aquesta tesi s'utilitzen aigües salines per al reg i s'investiguen les implicacions que això comporta a nivell d'absorció d'aigua i nutrients, estudiant també els canvis fisiològics en la planta per obtenir aplicacions que permetin el creixement econòmic. En aquest sentit s'aborden dues estratègies: d'una banda, l'estudi de les plantes d'halòfites i, de l'altra, la bioestimulació en plantes glicòfítes. La majoria dels cultius productius són plantes glicòfites, la seva produccions es veu afectada quan hi ha altes concentracions de sal en el medi de creiximent. Per contra, les plantes halófites han desenvolupat diferents mecanismes per resistir els efectes negatius de la salinitat. És per això que l'explotació directa d'halòfits s'ha identificat com una sortida econòmica per a les zones afectades. Una altra forma de mitigació dels efectes del canvi climàtic és el desenvolupament de bioestimulació per augmentar la resistència a estrès o augmentar la concentració de compostos bioactius en els aliments. Per als estudis realitzats en aquesta tesi doctoral es van seleccionar 6 espècies vegetals representatives dels diferents comportaments contra la salinitat, típics de la ubicació seleccionada (Regió de Múrcia) i d'interès per a l'empresa promotora del projecte de recerca (Sakata Seed Ibérica). Les espècies estudiades van ser: Brassica olera, [EN] The increase in the concentration of salts in soils and water is one of the problems that most threatens humanity due to its direct effect on crop productivity. In general terms, the question we want to contribute to is how to deal with salinization in the context of climate change and population growth? More specifically, we study the problems in south-eastern Spain from an approach in which the results can be exploited in the short and medium-term by the business sector. The region of Murcia is one of the main producing areas in south-eastern Spain where there are also serious salinization problems for various reasons. In this doctoral thesis, it is proposed to use saline water for irrigation and to investigate the implications that this entails at the level of water and nutrient absorption, also studying the physiological changes in the plant to obtain applications that allow economic growth. In this sense, two strategies are approached: on the one hand, the study of halophytic plants, and on the other hand, biostimulation in glycophyte plants. Most of the productive crops are glycophyte plants, their productions are affected when there are high concentrations of salt in the culture medium. On the contrary, halophyte plants have developed different mechanisms to resist the negative effects of salinity. That is why the direct exploitation of halophytes have been identified as an economic outlet for the salt-affected areas. Another way of mitigating the effects of climate change is the development of biostimulation to increase resistance to stresses or to increase the concentration of bioactive compounds in food. For the studies carried out in this doctoral thesis, 6 plant species were selected that were representative of the different behaviours towards salinity, that were specific to the selected location (The region of Murcia), and of interest to the company promoting the research project (Sakata Seed Ibérica). The species studied were: Brassica oleracea L.

[ES] A través de la fitosociología se ha estudiado las agrupaciones de plantas, sus interrelaciones y su dependencia con el medio ambiente en la costa del golfo Arabe en los Emiratos Arabes Unidos (EAU). La vegetacion de los Emiratos se caracteriza por la presencia del manglar paleotropical propio de las zonas intertidales en clima subtropical, acompañado por halofitas de desierto. Se han identificado 9 grupos de vegetación: (I) Asoc. Avicennietum marinae Chapman, J. 1970, (II) Asoc. Salicornietum fruticosi Br. Bl. 1928, (III) Asoc. Arthrocnemum machostachi- Halocnemetum strobiliaci Associatio nova Leandro, P. 2018, (IV) Asoc. Suaedetum verae (fruticosae) Br. Bl. ex O. Bolós & Molinier 1958. (V) Asoc. Tetraena qatarensis Associatio nova Leandro, P. 2018 (VI) Com. Calotropis procera (VII) Com. Heliotropium bacciferum (VIII) Com. Prosopis cineraria en orden deacuerdo al transecto que va dese la primera linea de costa al interior, y las comunidades nuevas como consecuencia de alteraciones en el entorno (IXa) Com. Avicennio marinae y Sesuvietum portulacastri y (IXb) Com. Avicenium y Salicornietum fruticosi. Se ha utilizado el programa TWINSPAN para la confirmacion de las mismas. Mediante los analisis de ACC se observa que las comunidades de Avicennia marina se correlacionan positivamente con la conductividad / salinidad del suelo, la alcalinidad o el pH y con las concentraciones de cationes. Se ha observado que las alteraciones antrópicas de la costa causan diferencias en la distribución normal de las poblaciones y este estudio propone medidas de restauración para garantizar la adaptación y la viabilidad de un proyecto futuro de revegetación costera a través del conocimiento geobotánico adquirido., [CA] A través de la fitosociologia s'ha estudiat les agrupacions de plantes, les seues interrelacions i la seua dependència amb el medi ambient en la costa del golf Arabe als Emirats Arabs Units (EAU). La vegetacio dels Emirats es caracteritza per la presència del manglar paleotropical propi de les zones intertidales en clima subtropical, acompanyat per halofites de desert. S'han identificat 9 grups de vegetació: (I) Assoc. Avicennietum marinae Chapman, J. 1970, (II) Assoc. Salicornietum fruticosi Br. Bl. 1928, (III) Assoc. Arthrocnemum machostachi- Halocnemetum strobiliaci Associatio nova Leandro, P. 2018, (IV) Assoc. Suaedetum verae ( fruticosae) Br. Bl. ex O. Bolós & Molinier 1958. (V) Assoc. Tetraena qatarensis Associatio nova Leandro, P. 2018 (VI) Com. Calotropis procera (VII) Com. Heliotropium bacciferum (VIII) Com. Prosopis cinerària en ordre d'acuerd al transecte que va desde la primera llínia de costa a l'interior, i les comunitats noves com a conseqüència d'alteracions a l'entorn ( IXa) Com. Avicennio marinae i Sesuvietum portulacastri i ( IXb) Com. Avicenium i Salicornietum fruticosi. S'ha utilitzat el programa TWINSPAN per a la confirmacion d'aquestes. Mitjançant els analisis de ACC s'observa que les comunitats de Avicennia marina es correlacionen positivament amb la conductivitat / salinitat del sòl, l'alcalinitat o el pH i amb les concentracions de cations. S'ha observat que les alteracions antròpiques de la costa causen diferències en la distribució normal de les poblacions i aquest estudi proposa mesures de restauració per a garantir l'adaptació i la viabilitat d'un projecte futur de revegetació costanera a través del coneixement geobotánic adquirit., [EN] Through phytosociology, plant clusters, their interrelations and their dependence on the environment on the Arabian Gulf coast in the United Arab Emirates (UAE) have been studied. The vegetation of the Emirates is characterized by the presence of paleotropical mangroves typical of intertidal areas in subtropical climate, accompanied by desert halophytes. Nine vegetation groups have been identified: (I) Assoc. Avicennietum marinae Chapman, J. 1970., (II) Assoc. Salicornietum fruticosi Br. Bl. 1928, (III) Assoc. Arthrocnemum machostachi- Halocnemetum strobiliaci nova. Leandro, P. 2018, (IV) Assoc. Suaedetum verae (fruticosae) Br. Bl. ex O. Bolós & Molinier 1958. (V) Assoc. Tetraena qatarensis nova hoc loco (VI) Com. Calotropis procera (VII) Com. Heliotropium bacciferum (VIII) Com. Prosopis cineraria, in order according to the transect that goes from the first coastline to the interior, and the new communities originated by anthropic factors are (IXa) Com. Avicennio marinae-Sesuvietum portulacastri nova and (IXb) Com. Avicenium- Salicornietum fruticosi nova. The TWINSPAN program has been used to confirm them. Through the CCA analysis, the communities of Avicennia marina can be positively correlated with the conductivity / salinity of the soil, the alkalinity or the pH and with the concentrations of cations. It has been seen that the anthropic alterations of the coast cause differences in the normal distribution of the populations and this study proposes restoration measures for the adaptation and viability of the future coastal revegetation project through the acquired geobotanical knowledge.

Tesis por compendio, [ES] El incremento en la concentración de sales en suelos y agua es una de las problemáticas que más amenazan a la humanidad por su efecto directo sobre la productividad de las cosechas. En líneas generales la pregunta a la que queremos contribuir es ¿cómo enfrentarnos a una situación de salinización en un contexto de cambio climático y crecimiento demográfico? Más concretamente estudiamos la problemática en el sureste español desde un enfoque en que los resultados puedan ser explotados en el corto y medio plazo por el sector empresarial. La Región de Murcia es una de las principales zonas productoras del sureste español donde además existen graves problemas de salinización. En la presente tesis doctoral se propone utilizar aguas salinas para riego e investigar las implicaciones de ello a nivel de absorción de agua y nutrientes, estudiando también los cambios fisiológicos en la planta para obtener aplicaciones que permitan el crecimiento económico. En este sentido se abordan dos estrategias: por un lado, el estudio de plantas halofitas, y por otro, la bioestimulación en plantas glicofitas. La mayoría de los cultivos productivos son plantas glicofitas, ven afectadas sus producciones cuando hay elevadas concentraciones de sal en el medio de cultivo. Por el contrario, las plantas halofitas han desarrollado diferentes mecanismos para resistir los efectos negativos de la salinidad. Es por ello que la explotación directa de halofitas se ha identificado como una salida económica para las zonas afectadas. Otra forma de mitigación de los efectos del cambio climático es el desarrollo de la bioestimulación para incrementar la resistencia a estreses o para incrementar la concentración de compuestos bioactivos en los alimentos. Para los estudios realizados, se seleccionaron 6 especies vegetales que fuesen representativas de los diferentes comportamientos frente a la salinidad, que fuesen propias de la localización seleccionada (Región de Murcia) y de interés para la empresa prom, [CA] L'augment de la concentració de sals en sòls i aigua és un dels problemes que més amenacen la humanitat pel seu efecte directe sobre la productivitat dels cultius. En termes generals, la qüestió a la qual volem contribuir és: com afrontar una situació de salinització en un context de canvi climàtic i creixement de la població? Més concretament, hem estudiat els problemes del sud-est d'Espanya des d'un enfocament en què els resultats poden ser explotats a curt i mitjà termini pel sector empresarial. La Regió de Múrcia és una de les principals zones productores del sud-est d'Espanya on també hi ha greus problemes de salinització. En aquesta tesi s'utilitzen aigües salines per al reg i s'investiguen les implicacions que això comporta a nivell d'absorció d'aigua i nutrients, estudiant també els canvis fisiològics en la planta per obtenir aplicacions que permetin el creixement econòmic. En aquest sentit s'aborden dues estratègies: d'una banda, l'estudi de les plantes d'halòfites i, de l'altra, la bioestimulació en plantes glicòfítes. La majoria dels cultius productius són plantes glicòfites, la seva produccions es veu afectada quan hi ha altes concentracions de sal en el medi de creiximent. Per contra, les plantes halófites han desenvolupat diferents mecanismes per resistir els efectes negatius de la salinitat. És per això que l'explotació directa d'halòfits s'ha identificat com una sortida econòmica per a les zones afectades. Una altra forma de mitigació dels efectes del canvi climàtic és el desenvolupament de bioestimulació per augmentar la resistència a estrès o augmentar la concentració de compostos bioactius en els aliments. Per als estudis realitzats en aquesta tesi doctoral es van seleccionar 6 espècies vegetals representatives dels diferents comportaments contra la salinitat, típics de la ubicació seleccionada (Regió de Múrcia) i d'interès per a l'empresa promotora del projecte de recerca (Sakata Seed Ibérica). Les espècies estudiades van ser: Brassica olera, [EN] The increase in the concentration of salts in soils and water is one of the problems that most threatens humanity due to its direct effect on crop productivity. In general terms, the question we want to contribute to is how to deal with salinization in the context of climate change and population growth? More specifically, we study the problems in south-eastern Spain from an approach in which the results can be exploited in the short and medium-term by the business sector. The region of Murcia is one of the main producing areas in south-eastern Spain where there are also serious salinization problems for various reasons. In this doctoral thesis, it is proposed to use saline water for irrigation and to investigate the implications that this entails at the level of water and nutrient absorption, also studying the physiological changes in the plant to obtain applications that allow economic growth. In this sense, two strategies are approached: on the one hand, the study of halophytic plants, and on the other hand, biostimulation in glycophyte plants. Most of the productive crops are glycophyte plants, their productions are affected when there are high concentrations of salt in the culture medium. On the contrary, halophyte plants have developed different mechanisms to resist the negative effects of salinity. That is why the direct exploitation of halophytes have been identified as an economic outlet for the salt-affected areas. Another way of mitigating the effects of climate change is the development of biostimulation to increase resistance to stresses or to increase the concentration of bioactive compounds in food. For the studies carried out in this doctoral thesis, 6 plant species were selected that were representative of the different behaviours towards salinity, that were specific to the selected location (The region of Murcia), and of interest to the company promoting the research project (Sakata Seed Ibérica). The species studied were: Brassica oleracea L.

This article presents the results of experiments conducted to study the nature of the absorption of salts in the soil of certain species of halophyte plants and the possibility of their use in struggling with soil salinity. &nbsp

This article presents the results of experiments conducted to study the nature of the absorption of salts in the soil of certain species of halophyte plants and the possibility of their use in struggling with soil salinity. &nbsp

This article presents the results of experiments conducted to study the nature of the absorption of salts in the soil of certain species of halophyte plants and the possibility of their use in struggling with soil salinity. &nbsp

This article presents the results of experiments conducted to study the nature of the absorption of salts in the soil of certain species of halophyte plants and the possibility of their use in struggling with soil salinity. &nbsp

This article presents the results of experiments conducted to study the nature of the absorption of salts in the soil of certain species of halophyte plants and the possibility of their use in struggling with soil salinity. &nbsp

This article presents the results of experiments conducted to study the nature of the absorption of salts in the soil of certain species of halophyte plants and the possibility of their use in struggling with soil salinity. &nbsp

This article presents the results of experiments conducted to study the nature of the absorption of salts in the soil of certain species of halophyte plants and the possibility of their use in struggling with soil salinity. &nbsp

[EN] Limonium is one of the most interesting and biodiverse genera of halophytes, with many species adapted to saline environments. Limonium species have a promising potential as cultivated minor crops as many have ornamental value, or are already used as medicinal plants. Other species are marketed as gourmet food or can be used for decontamination of polluted soils. Design and implementation of specific breeding programmes are needed to fully realise this potential, based on the vast genetic variation and high stress tolerance of wild species within the genus. Most Limonium species are halophytes, but many are also resistant to drought, especially those from the Mediterranean and other arid regions. Such species constitute attractive models for basic research on the mechanisms of stress tolerance, both constitutive and induced. As typical recretohalopyhtes, with excretive salt glands, Limonium species possess remarkable morpho-anatomical traits. Salt tolerance in this genus relies also on ion accumulation in the leaves, the concomitant use of diverse osmolytes for osmotic adjustment, and the activation of efficient antioxidant systems.

The genus Plantago is particularly interesting for studying the mechanisms of salt tolerance in plants, as it includes both halophytes and glycophytes, as well as species adapted to xeric environments. In this study, the salt stress responses of two halophytes, P. crassifolia and P. coronopus, were compared with those of two glycophytes, P. ovata and P. afra. Plants obtained by seed germination of the four species, collected in different regions of Tunisia, were subjected to increasing salinity treatments for one month under greenhouse conditions. Morphological traits and biochemical parameters, such as ion accumulation and the leaf contents of photosynthetic pigments, osmolytes, oxidative stress markers and antioxidant metabolites, were measured after the treatments. Salt-induced growth inhibition was more pronounced in P. afra, and only plants subjected to the lowest applied NaCl concentration (200 mM) survived until the end of the treatments. The biochemical responses were different in the two groups of plants; the halophytes accumulated higher Na+ and proline concentrations, whereas MDA levels in their leaves decreased, indicating a lower level of oxidative stress. Overall, the results showed that P. coronopus and P. crassifolia are the most tolerant to salt stress, and P. afra is the most susceptible of the four species. Plantago ovata is also quite resistant, apparently by using specific mechanisms of tolerance that are more efficient than in the halophytes, such as a less pronounced inhibition of photosynthesis, the accumulation of higher levels of Cl− ions in the leaves, or the activation of K+ uptake and transport to the aerial part under high salinity conditions.

With the purpose of Plant Growth Promoting Rhizobacteria (PGPR) isolation, several authors have sampled different wetlands in the northern half of Argentina. However, to date, we do not know the existence of microbiological studies conducted in the Patagonian salt marshes, and concretely, concerning isolation of PGPR. The present work was conducted in the heavy metal polluted San Antonio salt marsh, in two areas with different grade of pollution. In those areas, we isolated cultivable bacteria from the rhizosphere of the halophytes Spartina densiflora and Sarcocornia perennis, and look for several plant growth promoting (PGP) properties among them. In total, 60 different cultivable bacteria were isolated. 50% of the rhizobacterial strains demonstrated at least one of the PGP properties assayed, 25% of them produced siderophores, 16% were able to solubilize phosphate, 11% were able to produce auxins and 7% chitinase. We could observe that PGP properties were more abundant among bacteria growing in polluted soils. Also, bacteria inhabiting S. densiflora rhizosphere showed more PGP properties related to heavy metal phytostabilization mechanisms, in line with the phytoremediation strategy of this halophyte. Overall, these findings support the idea that coastal hazardous scenarios may be a good opportunity to seek for PGPR. Indeed, some of the strains isolated in this work presented more than one PGP property, so they may be selected for further formulation of inoculants for different applications. For further research, it would be interesting to analyse other PGP properties in these strains, as well as to isolate rhizobacteria from other halophytes in diverse Patagonian salt marshes.

Roadway deicing salt is a major pollutant of Virginia roads, damaging environmental systems, water quality, and human health. Phytoremediation of salt-affected roadside soils using salt accumulating or excreting halophytes is an inexpensive and sustainable approach to mitigating roadway pollution. An obstacle of this approach is that the highest concentrations of saline runoff occur in winter and early spring when plants are dormant. A possible solution to this challenge is adding soil amendments to increase the cation exchange capacity of soil. This would be predicted to hold Na+ and Cl– ions within the rhizosphere until spring when actively growing halophytes would absorb salt ions. Later, halophyte biomass could be harvested to effectively remove salt from a site. This review identifies candidate halophytes suitable for roadside soil desalination in Virginia. I consider potential microbial and fungal aids to support halophyte growth amidst salt stress and potentially increase salt uptake. I also review environmentally friendly soil amendments capable of binding salt for later absorption by halophytes before leached ions become pollutants.

Land salinization, resulting from the ongoing climate change phenomena, is having an increasing impact on coastal ecosystems like salt marshes. Although halophyte species can live and thrive in high salinities, they experience differences in their salt tolerance range, being this a determining factor in the plant distribution and frequency throughout marshes. Furthermore, intraspecific variation to NaCl response is observed in high-ranging halophyte species at a population level. The present study aims to determine if the environmental history, namely heavy metal pre-conditioning, can have a meaningful influence on salinity tolerance mechanisms of Spartina patens, a highly disperse grass invader in the Mediterranean marshes. For this purpose, individuals from pristine and heavy metal contaminated marsh populations were exposed to a high-ranging salinity gradient, and their intraspecific biophysical and biochemical feedbacks were analyzed. When comparing the tolerance mechanisms of both populations, S. patens from the contaminated marsh appeared to be more resilient and tolerant to salt stress, this was particularly present at the high salinities. Consequently, as the salinity increases in the environment, the heavy metal contaminated marsh may experience a more resilient and better adapted S. patens community. Therefore, the heavy metal pre-conditioning of salt mash populations appears to be able to create intraspecific physiological variations at the population level that can have a great influence on marsh plant distribution outcome.

The genus Plantago is particularly interesting for studying the mechanisms of salt tolerance in plants, as it includes both halophytes and glycophytes, as well as species adapted to xeric environments. In this study, the salt stress responses of two halophytes, P. crassifolia and P. coronopus, were compared with those of two glycophytes, P. ovata and P. afra. Plants obtained by seed germination of the four species, collected in different regions of Tunisia, were subjected to increasing salinity treatments for one month under greenhouse conditions. Morphological traits and biochemical parameters, such as ion accumulation and the leaf contents of photosynthetic pigments, osmolytes, oxidative stress markers and antioxidant metabolites, were measured after the treatments. Salt-induced growth inhibition was more pronounced in P. afra, and only plants subjected to the lowest applied NaCl concentration (200 mM) survived until the end of the treatments. The biochemical responses were different in the two groups of plants; the halophytes accumulated higher Na+ and proline concentrations, whereas MDA levels in their leaves decreased, indicating a lower level of oxidative stress. Overall, the results showed that P. coronopus and P. crassifolia are the most tolerant to salt stress, and P. afra is the most susceptible of the four species. Plantago ovata is also quite resistant, apparently by using specific mechanisms of tolerance that are more efficient than in the halophytes, such as a less pronounced inhibition of photosynthesis, the accumulation of higher levels of Cl− ions in the leaves, or the activation of K+ uptake and transport to the aerial part under high salinity conditions.

With the purpose of Plant Growth Promoting Rhizobacteria (PGPR) isolation, several authors have sampled different wetlands in the northern half of Argentina. However, to date, we do not know the existence of microbiological studies conducted in the Patagonian salt marshes, and concretely, concerning isolation of PGPR. The present work was conducted in the heavy metal polluted San Antonio salt marsh, in two areas with different grade of pollution. In those areas, we isolated cultivable bacteria from the rhizosphere of the halophytes Spartina densiflora and Sarcocornia perennis, and look for several plant growth promoting (PGP) properties among them. In total, 60 different cultivable bacteria were isolated. 50% of the rhizobacterial strains demonstrated at least one of the PGP properties assayed, 25% of them produced siderophores, 16% were able to solubilize phosphate, 11% were able to produce auxins and 7% chitinase. We could observe that PGP properties were more abundant among bacteria growing in polluted soils. Also, bacteria inhabiting S. densiflora rhizosphere showed more PGP properties related to heavy metal phytostabilization mechanisms, in line with the phytoremediation strategy of this halophyte. Overall, these findings support the idea that coastal hazardous scenarios may be a good opportunity to seek for PGPR. Indeed, some of the strains isolated in this work presented more than one PGP property, so they may be selected for further formulation of inoculants for different applications. For further research, it would be interesting to analyse other PGP properties in these strains, as well as to isolate rhizobacteria from other halophytes in diverse Patagonian salt marshes.

This article presents the results of experiments conducted to study the nature of the absorption of salts in the soil of certain species of halophyte plants and the possibility of their use in struggling with soil salinity. &nbsp

The pharmacological activities in bioactive plant extracts play an increasing role in sustainable resources for valorization and biomedical applications. Bioactive phytochemicals, including natural compounds, secondary metabolites and their derivatives, have attracted significant attention for use in both medicinal products and cosmetic products. Our review highlights the pharmacological mode-of-action and current biomedical applications of key bioactive compounds applied as anti-inflammatory, bactericidal with antibiotics effects, and pain relief purposes in controlled clinical studies or preclinical studies. In this systematic review, the availability of bioactive compounds from several salt-tolerant plant species, mainly focusing on the three promising species Aster tripolium, Crithmum maritimum and Salicornia europaea, are summarized and discussed. All three of them have been widely used in natural folk medicines and are now in the focus for future nutraceutical and pharmacological applications.

Land salinization, resulting from the ongoing climate change phenomena, is having an increasing impact on coastal ecosystems like salt marshes. Although halophyte species can live and thrive in high salinities, they experience differences in their salt tolerance range, being this a determining factor in the plant distribution and frequency throughout marshes. Furthermore, intraspecific variation to NaCl response is observed in high-ranging halophyte species at a population level. The present study aims to determine if the environmental history, namely heavy metal pre-conditioning, can have a meaningful influence on salinity tolerance mechanisms of Spartina patens, a highly disperse grass invader in the Mediterranean marshes. For this purpose, individuals from pristine and heavy metal contaminated marsh populations were exposed to a high-ranging salinity gradient, and their intraspecific biophysical and biochemical feedbacks were analyzed. When comparing the tolerance mechanisms of both populations, S. patens from the contaminated marsh appeared to be more resilient and tolerant to salt stress, this was particularly present at the high salinities. Consequently, as the salinity increases in the environment, the heavy metal contaminated marsh may experience a more resilient and better adapted S. patens community. Therefore, the heavy metal pre-conditioning of salt mash populations appears to be able to create intraspecific physiological variations at the population level that can have a great influence on marsh plant distribution outcome.

The genus Plantago is particularly interesting for studying the mechanisms of salt tolerance in plants, as it includes both halophytes and glycophytes, as well as species adapted to xeric environments. In this study, the salt stress responses of two halophytes, P. crassifolia and P. coronopus, were compared with those of two glycophytes, P. ovata and P. afra. Plants obtained by seed germination of the four species, collected in different regions of Tunisia, were subjected to increasing salinity treatments for one month under greenhouse conditions. Morphological traits and biochemical parameters, such as ion accumulation and the leaf contents of photosynthetic pigments, osmolytes, oxidative stress markers and antioxidant metabolites, were measured after the treatments. Salt-induced growth inhibition was more pronounced in P. afra, and only plants subjected to the lowest applied NaCl concentration (200 mM) survived until the end of the treatments. The biochemical responses were different in the two groups of plants; the halophytes accumulated higher Na+ and proline concentrations, whereas MDA levels in their leaves decreased, indicating a lower level of oxidative stress. Overall, the results showed that P. coronopus and P. crassifolia are the most tolerant to salt stress, and P. afra is the most susceptible of the four species. Plantago ovata is also quite resistant, apparently by using specific mechanisms of tolerance that are more efficient than in the halophytes, such as a less pronounced inhibition of photosynthesis, the accumulation of higher levels of Cl− ions in the leaves, or the activation of K+ uptake and transport to the aerial part under high salinity conditions.

With the purpose of Plant Growth Promoting Rhizobacteria (PGPR) isolation, several authors have sampled different wetlands in the northern half of Argentina. However, to date, we do not know the existence of microbiological studies conducted in the Patagonian salt marshes, and concretely, concerning isolation of PGPR. The present work was conducted in the heavy metal polluted San Antonio salt marsh, in two areas with different grade of pollution. In those areas, we isolated cultivable bacteria from the rhizosphere of the halophytes Spartina densiflora and Sarcocornia perennis, and look for several plant growth promoting (PGP) properties among them. In total, 60 different cultivable bacteria were isolated. 50% of the rhizobacterial strains demonstrated at least one of the PGP properties assayed, 25% of them produced siderophores, 16% were able to solubilize phosphate, 11% were able to produce auxins and 7% chitinase. We could observe that PGP properties were more abundant among bacteria growing in polluted soils. Also, bacteria inhabiting S. densiflora rhizosphere showed more PGP properties related to heavy metal phytostabilization mechanisms, in line with the phytoremediation strategy of this halophyte. Overall, these findings support the idea that coastal hazardous scenarios may be a good opportunity to seek for PGPR. Indeed, some of the strains isolated in this work presented more than one PGP property, so they may be selected for further formulation of inoculants for different applications. For further research, it would be interesting to analyse other PGP properties in these strains, as well as to isolate rhizobacteria from other halophytes in diverse Patagonian salt marshes.

Land salinization, resulting from the ongoing climate change phenomena, is having an increasing impact on coastal ecosystems like salt marshes. Although halophyte species can live and thrive in high salinities, they experience differences in their salt tolerance range, being this a determining factor in the plant distribution and frequency throughout marshes. Furthermore, intraspecific variation to NaCl response is observed in high-ranging halophyte species at a population level. The present study aims to determine if the environmental history, namely heavy metal pre-conditioning, can have a meaningful influence on salinity tolerance mechanisms of Spartina patens, a highly disperse grass invader in the Mediterranean marshes. For this purpose, individuals from pristine and heavy metal contaminated marsh populations were exposed to a high-ranging salinity gradient, and their intraspecific biophysical and biochemical feedbacks were analyzed. When comparing the tolerance mechanisms of both populations, S. patens from the contaminated marsh appeared to be more resilient and tolerant to salt stress, this was particularly present at the high salinities. Consequently, as the salinity increases in the environment, the heavy metal contaminated marsh may experience a more resilient and better adapted S. patens community. Therefore, the heavy metal pre-conditioning of salt mash populations appears to be able to create intraspecific physiological variations at the population level that can have a great influence on marsh plant distribution outcome.

The genus Plantago is particularly interesting for studying the mechanisms of salt tolerance in plants, as it includes both halophytes and glycophytes, as well as species adapted to xeric environments. In this study, the salt stress responses of two halophytes, P. crassifolia and P. coronopus, were compared with those of two glycophytes, P. ovata and P. afra. Plants obtained by seed germination of the four species, collected in different regions of Tunisia, were subjected to increasing salinity treatments for one month under greenhouse conditions. Morphological traits and biochemical parameters, such as ion accumulation and the leaf contents of photosynthetic pigments, osmolytes, oxidative stress markers and antioxidant metabolites, were measured after the treatments. Salt-induced growth inhibition was more pronounced in P. afra, and only plants subjected to the lowest applied NaCl concentration (200 mM) survived until the end of the treatments. The biochemical responses were different in the two groups of plants; the halophytes accumulated higher Na+ and proline concentrations, whereas MDA levels in their leaves decreased, indicating a lower level of oxidative stress. Overall, the results showed that P. coronopus and P. crassifolia are the most tolerant to salt stress, and P. afra is the most susceptible of the four species. Plantago ovata is also quite resistant, apparently by using specific mechanisms of tolerance that are more efficient than in the halophytes, such as a less pronounced inhibition of photosynthesis, the accumulation of higher levels of Cl− ions in the leaves, or the activation of K+ uptake and transport to the aerial part under high salinity conditions.

With the purpose of Plant Growth Promoting Rhizobacteria (PGPR) isolation, several authors have sampled different wetlands in the northern half of Argentina. However, to date, we do not know the existence of microbiological studies conducted in the Patagonian salt marshes, and concretely, concerning isolation of PGPR. The present work was conducted in the heavy metal polluted San Antonio salt marsh, in two areas with different grade of pollution. In those areas, we isolated cultivable bacteria from the rhizosphere of the halophytes Spartina densiflora and Sarcocornia perennis, and look for several plant growth promoting (PGP) properties among them. In total, 60 different cultivable bacteria were isolated. 50% of the rhizobacterial strains demonstrated at least one of the PGP properties assayed, 25% of them produced siderophores, 16% were able to solubilize phosphate, 11% were able to produce auxins and 7% chitinase. We could observe that PGP properties were more abundant among bacteria growing in polluted soils. Also, bacteria inhabiting S. densiflora rhizosphere showed more PGP properties related to heavy metal phytostabilization mechanisms, in line with the phytoremediation strategy of this halophyte. Overall, these findings support the idea that coastal hazardous scenarios may be a good opportunity to seek for PGPR. Indeed, some of the strains isolated in this work presented more than one PGP property, so they may be selected for further formulation of inoculants for different applications. For further research, it would be interesting to analyse other PGP properties in these strains, as well as to isolate rhizobacteria from other halophytes in diverse Patagonian salt marshes.

The market value of crustaceans depreciates during storage due to the appearance of melanosis caused by polyphenol oxidases. Sulfite derivatives are used as melanosis-inhibiting agents, but their unhealthy effects make it preferable to replace them with natural preservatives. In this work, a crude enzymatic extract from whiteleg shrimp (Penaeus vannamei) was characterized and used to test the diphenol oxidase-inhibiting activity of polyphenol extracts of five underutilized halophyte plants, namely crystalline ice plant, seaside arrowgrass, purslane, sea fennel, and seashore aster. The extracts inhibited diphenol oxidase activity more efficiently than sodium sulfite. The purslane extract was rich in isoorientins, isovitexin, and apigenin, and showed the highest inhibiting effect, being this classified as mixed or non-competitive. Hydroxyl groups in the phenyl B ring could be responsible for the inhibitory activity of the extract. The polyphenol extracts tested in this work could be promising melanosis-inhibiting agents of interest for seafood industries.

The loss of agro-biodiversity, climate changes and food insecurity are major challenges in the Mediterranean countries with potentially multidimensional consequences. With respect to salinity, approximately 18 million ha, corresponding to 25 % of total irrigated land in the Mediterranean area, are salt affected. Intensive cropping and the excessive use of expensive inputs such as water and fertilizers aggravate this situation. Understanding how we could improve crop productivity in salinized environments is therefore critical to face these challenges. Our comprehension of fundamental physiological mechanisms in plant salt stress adaptation has greatly advanced over the last decades. However, many of these mechanisms have been linked to salt tolerance in simplified experimental systems whereas they have been rarely functionally proven in real agricultural contexts. The sustainability of farming systems in salt affected Mediterranean soils can be effectively achieved by the use of salt-tolerant halophyte plants even more effective through the use of intercropping, crop rotation and aquaponics.. Moreover, if these halophyte plants are removed from the soil to grow other species, pressure on generating salt-tolerant crop plants would be reduced and much healthier crop plants would be cultivated in less stressed saline soils. This paper will focus on the sustainable practices based on the cultivation of halophytes in saline soils by highlighting some experimental activities carried out at laboratory and field levels in the last few years.

The increasing number of pharmaceuticals in the environment and their difficult biodegra-dation, can lead to bioaccumulation in different trophic compartments. Their bioaccumulation can have negative consequences, especially in the generation of bacterial resistance by antibiotics, but also in the impairment of plant and animal metabolism. The Tejo estuary in Portugal is the habitat for many plant and animal species, which are also prone to this type of contamination. There-fore, in the present study different classes of emerging pollutants (EPs) were surveyed in water samples in the Tejo estuary, including antibiotics, anticonvulsants, antidepressants, lipid-lowering drugs, anti-inflammatory drugs, beta-blockers and analgesics. According to the results, only four compounds were detected in water samples collected at the three selected salt marshes, including carbamazepine, fluoxetine hydrochloride, venlafaxine hydrochloride and acetaminophen. Having the detected substances as a basis, a subsequent study was performed aiming to investigate the uptake and biodegradation capacity of halophytes, using Tripolium pannonicum as a model plant culti-vated under controlled conditions with different concentrations of the found EPs. This experimental approach showed that T. pannonicum was able to uptake and degrade xenobiotics. Moreover, the application of sulfamethazine, as a model antibiotic, showed also that this species can uptake and degrade this compound, although the degradation rate and process proved to be compound-specific. This was also confirmed using crude plant extracts spiked with the different EPs. Thus this species is a potential candidate for the remediation of marine water and sediments contaminated with environmentally-significant EPs. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

[EN] Thalictrum maritimum is an endangered, endemic species in East Spain, growing in areas of relatively low salinity in littoral salt marshes. A regression of its populations and the number of individuals has been registered in the last decade. This study aimed at establishing the causes of this reduction using a multidisciplinary approach, including climatic, ecological, physiological and biochemical analyses. The climatic data indicated that there was a direct negative correlation between increased drought, especially during autumn, and the number of individuals censused in the area of study. The susceptibility of this species to water deficit was confirmed by the analysis of growth parameters upon a water deficit treatment applied under controlled greenhouse conditions, with the plants withstanding only 23 days of complete absence of irrigation. On the other hand, increased salinity does not seem to be a risk factor for this species, which behaves as a halophyte, tolerating in controlled treatments salinities much higher than those registered in its natural habitat. The most relevant mechanisms of salt tolerance in T. maritimum appear to be based on the control of ion transport, by (i) the active transport of toxic ions to the aerial parts of the plants at high external salinity¿where they are presumably stored in the leaf vacuoles to avoid their deleterious effects in the cytosol, (ii) the maintenance of K+ concentrations in belowground and aboveground organs, despite the increase of Na+ levels, and (iii) the salt-induced accumulation of Ca2+, particularly in stems and leaves. This study provides useful information for the management of the conservation plans of this rare and endangered species.

[EN] Thalictrum maritimum is an endangered, endemic species in East Spain, growing in areas of relatively low salinity in littoral salt marshes. A regression of its populations and the number of individuals has been registered in the last decade. This study aimed at establishing the causes of this reduction using a multidisciplinary approach, including climatic, ecological, physiological and biochemical analyses. The climatic data indicated that there was a direct negative correlation between increased drought, especially during autumn, and the number of individuals censused in the area of study. The susceptibility of this species to water deficit was confirmed by the analysis of growth parameters upon a water deficit treatment applied under controlled greenhouse conditions, with the plants withstanding only 23 days of complete absence of irrigation. On the other hand, increased salinity does not seem to be a risk factor for this species, which behaves as a halophyte, tolerating in controlled treatments salinities much higher than those registered in its natural habitat. The most relevant mechanisms of salt tolerance in T. maritimum appear to be based on the control of ion transport, by (i) the active transport of toxic ions to the aerial parts of the plants at high external salinity¿where they are presumably stored in the leaf vacuoles to avoid their deleterious effects in the cytosol, (ii) the maintenance of K+ concentrations in belowground and aboveground organs, despite the increase of Na+ levels, and (iii) the salt-induced accumulation of Ca2+, particularly in stems and leaves. This study provides useful information for the management of the conservation plans of this rare and endangered species.