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Phyla nodiflora is a valuable medicinal plant growing in coastal areas, hypothesizing its adaptability to salinity; however, it has not been investigated. This study, for the first time, elucidated responses in the growth of the shoots and its physiology to different soil salinity of 50–400 mM NaCl. The data showed that the shoot’s dry biomass was not affected by the salinity levels up to 100 mM, and it only decreased 33.50–56.33% compared to the control under 200–400 mM NaCl, indicating that P. nodiflora is a salt-tolerant plant that could survive under high salinity. In addition, the plant also had physiological responses which indicated its salt-induced injuries and adaptation to the salt stress. The chlorophyll a content was increased while the chlorophyll b remained unchanged under the salt stress. The proline and salt accumulation increased under the salinity, but the K+ and NO3− accumulation decreased. Moreover, increases in malondialdehyde and electrolyte leakage were observed, indicating salt-induced membrane damages. These responses suggested that the plant might evolve adaptive mechanisms to salinity. Our findings are useful information for further research in order to elucidate the salt-tolerant mechanisms and develop this plant for saline agriculture.

Context: Identification of salt-tolerant genetic resources is of high importance due to the constant increase in salt-affected areas. Aims: This study was conducted to assess genetic variation in salt response among and within Tunisian sea barley populations and to identify useful genotypes for future breeding programmes directed towards improving salinity tolerance. Methods: The salinity response of 141 lines from 10 natural populations of Hordeum marinum ssp. marinum was characterised at a morphophysiological level, following exposure to 200 mM sodium chloride for 90 days. Key results: ANOVA revealed significant differences in growth and ion accumulation between and within populations in response to salinity. The Sebkhet Ferjouna population was less affected than Sidi Othman and Tabarka; however, it accumulated relatively higher sodium and lower potassium and potassium/sodium ratio. Stress Tolerance Index (STI) and Salt Tolerance (ST) values varied significantly among populations and lines. STI was positively correlated with potassium and negatively correlated with sodium content in roots and leaves, whereas no evidence of a relationship between both cations and ST was observed. Conclusions: SO7, SO28, LB5, LB25, TB1, MT3 and BK12 with high values of STI were identified as high yielding lines in control and salt stress conditions, whereas MT3, BK12, MT17, BF10, SL8, SL16 and SF32, with the highest values of ST, were characterised by a small yield loss and low sensitivity when exposed to salinity. Implications: These lines constitute a genetic resource with desirable adaptation characteristics for breeding programmes towards salinity tolerance in cultivated cereals. Soil salinity adversely affects plant growth and causes considerable losses in cereal crops. In this study, genetic variation in salinity tolerance was evaluated in sea barley (Hordeum marinum ssp. marinum). Based on plant growth-related traits, mineral nutrition and salt stress indices, lines with high yield under stress and non-stress conditions, or showing a small yield loss under salinity constraints, were identified. These lines will be useful for future breeding programs towards salinity tolerance in cereal crops. [ABSTRACT FROM AUTHOR]

Phyla nodiflora is a valuable medicinal plant growing in coastal areas, hypothesizing its adaptability to salinity; however, it has not been investigated. This study, for the first time, elucidated responses in the growth of the shoots and its physiology to different soil salinity of 50–400 mM NaCl. The data showed that the shoot's dry biomass was not affected by the salinity levels up to 100 mM, and it only decreased 33.50–56.33% compared to the control under 200–400 mM NaCl, indicating that P. nodiflora is a salt-tolerant plant that could survive under high salinity. In addition, the plant also had physiological responses which indicated its salt-induced injuries and adaptation to the salt stress. The chlorophyll a content was increased while the chlorophyll b remained unchanged under the salt stress. The proline and salt accumulation increased under the salinity, but the K+ and NO3− accumulation decreased. Moreover, increases in malondialdehyde and electrolyte leakage were observed, indicating salt-induced membrane damages. These responses suggested that the plant might evolve adaptive mechanisms to salinity. Our findings are useful information for further research in order to elucidate the salt-tolerant mechanisms and develop this plant for saline agriculture. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the morphological and physiological responses of P. maritima plants from five geographically isolated sites growing in habitats with different conditions to different substrate moisture levels in controlled conditions. Plants were produced from seed and cultivated in a greenhouse at four relatively constant soil moisture regimes: at 25, 50, and 75% soil water content and in soil flooded 3 cm above the surface (80% F). The two morphological traits that varied most strikingly among P. maritima accessions were the number of flower stalks and the number of leaves. Only plants from two accessions uniformly produced generative structures, and allocation to flowering was suppressed by both low moisture and flooding. Optimum shoot biomass accumulation for all accessions was at 50 and 75% soil moisture. The Performance Index Total was the most sensitive among the measured photosynthesis-related parameters, and it tended to decrease with an increase in soil water content for all P. maritima accessions. The initial hypothesis—that plants from relatively dry habitats will have a higher tolerance against low soil water levels, but plants from relatively wet habitats will have a higher tolerance against waterlogged or flooded soil—was not proven. The existence of three ecotypes of P. maritima within the five accessions from geographically isolated subpopulations on the eastern coast of the Baltic Sea at the level of morphological responses to soil water content can be proposed. P. maritima plants can be characterized as extremely tolerant to soil waterlogging and highly tolerant to soil flooding and low soil water content. [ABSTRACT FROM AUTHOR]

Abstract Grangea maderaspatana is a valuable medicinal plant growing in salt-affected areas, but its tolerance capability, physiological and biochemical responses to salinity is still unclear. To understand these traits, this study examined effects of salinity at different levels (50-400 mM NaCl) on plant growth and its responses. The results shown that the plant’s dry biomass decreased with increasing salinity levels of 100-400 mM NaCl, but its growth was maintained at 400 mM NaCl level with a dry biomass equal to 0.45 times that of the control, indicating that G. maderaspatana had a tolerance ability to high salinity. The plant also had adaptive responses to the salinity. The content of leaf chlorophylls and carotenoids were retained, even enhanced by 50-200 mM NaCl, suggesting a high adaptation of photosynthesis. Proline, Na+, and Cl- was highly accumulated while the accumulation of K+ and NO3 - was maintained with 200-400 mM NaCl, indicating that the plant had adaptive mechanisms for osmotic adjustment and ion homeostasis. Antioxidative activities of catalase, superoxide dismutase, and peroxidase were enhanced by the salinity. These findings are useful information for understanding salt tolerance mechanisms and for utilization of this medicinal plant in saline agriculture.

The question of the effect of the anion type on halophyte salt tolerance and ion accumulation is still far from the necessary generalization due to the lack of comparative studies. The aim of the present study was to compare the relatively long-term effect of treatment with various salts formed by different anions on the growth and ion accumulation of several halophyte species in controlled conditions. The main experiments with the largest variety of individual salt types were performed with Cochlearia officinalis L. and two cultivars of Limonium sinuatum (L.) Mill. In addition, experiments with Lobularia maritima (L.) Desv., Plantago maritima L., and Tripolium pannonicum (Jacq.) Dobrocz. focused on the comparison of neutral (NaCl) and alkaline (NaHCO3) salts as well as NaNO3. Acetate salts appeared to be the most toxic, with only Plantago and Tripolium plants being able to withstand full treatment while having a pronounced inhibition in growth. Only the two Limonium cultivars were more susceptible to treatment with alkaline salts in comparison to that with neutral salts. In treatments with alkaline salts, the ion accumulation potential was lower in comparison to plants treated with chlorides and nitrates. It can be concluded that the type of anion is a significant determinant of salinity tolerance and ion accumulation in halophytes, but a high genotype dependence of the responses makes it difficult to generalize the obtained results.

Mesembryanthemum crystallinum L. is an obligatory halophyte species showing optimum growth at elevated soil salinity levels, but the ionic requirements for growth stimulation are not known. The aim of the present study was to compare the effects of sodium, potassium and calcium in the form of chloride and nitrate salts on the growth, physiological performance, ion accumulation and mineral nutrition of M. crystallinum plants in controlled conditions. In a paradoxical way, while sodium and potassium had comparable stimulative effect on plant growth, the effect of calcium was strongly negative even at a relatively low concentration, eventually leading to plant death. Moreover, the effect of Ca nitrate was less negative in comparison to that of Ca chloride, but K in the form of nitrate had some negative effects. There were three components of the stimulation of biomass accumulation by NaCl and KCl salinity in M. crsytallinum: the increase in tissue water content, increase in ion accumulation, and growth activation. As optimum growth was in a salinity range from 20 to 100 mM, the increase in the dry biomass of plants at a moderate (200 mM) and high (400 mM) salinity in comparison to control plants was mostly due to ion accumulation. Among physiological indicators, changes in leaf chlorophyll concentration appeared relatively late, but the chlorophyll a fluorescence parameter, Performance Index Total, was the most sensitive to the effect of salts. In conclusion, both sodium and potassium in the form of chloride salts are efficient in promoting the optimum growth of M. crystallinum plants. However, mechanisms leading to the negative effect of calcium on plants need to be assessed further. [ABSTRACT FROM AUTHOR]

The aim of the present study was to compare morphological and physiological responses to increasing salinity of the two subspecies of Mertensia maritima during in vitro propagation in two different systems, and subsequent ex vitro cultivation. Plants were brought into culture using seeds and further propagated on Murashige and Skoog medium supplemented with thidiazuron and naphthaleneacetic acid either on agar-solidified or liquid medium with a temporary immersion system (Plantform bioreactors). Salinity tolerance were tested both in tissue culture and with ex vitro greenhouse-cultivated plants. Low concentration of NaCl increased explant biomass in agar-solidified medium, with no negative consequences even at high concentration. However, the effect of salinity on liquid medium was genotype-specific. Explants in Plantform bioreactors showed several-fold higher biomass in comparison to that on agar-solidified medium, but the multiplication potential was not significantly affected. Ex vitro plants were negatively influenced by increasing NaCl concentration in substrate. In contrast to in vitro plants, accumulation potential of Na+ in ex vitro plants was low. One of adaptations to salinity at the whole plant level was maintenance of adequate tissue mineral nutrient homeostasis, as mineral nutrient concentrations were not negatively affected by increasing salinity. [ABSTRACT FROM AUTHOR]

The question of the effect of the anion type on halophyte salt tolerance and ion accumulation is still far from the necessary generalization due to the lack of comparative studies. The aim of the present study was to compare the relatively long-term effect of treatment with various salts formed by different anions on the growth and ion accumulation of several halophyte species in controlled conditions. The main experiments with the largest variety of individual salt types were performed with Cochlearia officinalis L. and two cultivars of Limonium sinuatum (L.) Mill. In addition, experiments with Lobularia maritima (L.) Desv., Plantago maritima L., and Tripolium pannonicum (Jacq.) Dobrocz. focused on the comparison of neutral (NaCl) and alkaline (NaHCO3) salts as well as NaNO3. Acetate salts appeared to be the most toxic, with only Plantago and Tripolium plants being able to withstand full treatment while having a pronounced inhibition in growth. Only the two Limonium cultivars were more susceptible to treatment with alkaline salts in comparison to that with neutral salts. In treatments with alkaline salts, the ion accumulation potential was lower in comparison to plants treated with chlorides and nitrates. It can be concluded that the type of anion is a significant determinant of salinity tolerance and ion accumulation in halophytes, but a high genotype dependence of the responses makes it difficult to generalize the obtained results. [ABSTRACT FROM AUTHOR]

Vegetable grafting is considered a rapid, non-chemical alternative method to relatively slow and expensive breeding to overcome the adverse effect of salinity. Therefore, a soilless experiment was performed to determine the salinity tolerance of eggplant (Solanum melongena) cv. Madonna grafted onto two different rootstocks, Solanum grandifolium × Solanum melongena (SH) and Solanum torvum (ST), as well as self-grafted (SG) and self-rooted (SR) as controls. All groups of plants were treated with 0 mM NaCl or 80 mM NaCl. A significant decrease in the relative leaf chlorophyll content (SPAD value) and chlorophyll concentrations were found in response to NaCl. However, the grafted plants had a higher photosynthetic pigment level than the non-grafted plants grown under saline conditions. Grafting eggplants onto SH significantly enhanced the total fruit yield as compared to the self-rooted plants exposed to salinity by increasing the average fruit weight. Moreover, salt stress significantly increased the whitening index and oxidation potential of fruits. The plants grafted onto SH or ST accumulated more Na+ in their roots than in their fruit or leaves, thus the Na+ partitioning between the above-ground and root parts most probably determines the increased salinity tolerance of the grafted ST and SH plants. To conclude, both the SH and ST rootstocks protected the scions against salinity; the scion showed both increased photosynthetic pigment concentration and chlorophyll fluorescence parameters as well as a lower Na+ concentration under stress that resulted in a higher fruit yield and quality. [ABSTRACT FROM AUTHOR]

Salt stress is one of the major limitations to modern agriculture that negatively influences plant growth and productivity. Salt tolerant cultivar can provide excellent solution to enhance stress tolerance with plant fitness to unfavorable environments. Therefore, this study was aimed to screen salt tolerant sorghum genotypes through evaluating of different morphological, biochemical, and physiological attributes in response to salinity stress. In this study, we have been evaluated total six sorghum genotypes including Hybrid sorgo, Debgiri, BD-703, BD-706, BD-707, and BD-725 under salt stress (12 dS m−1 NaCl). The response variables included length and weight of root and shoot, root: shoot ratio (RSR), photosynthesis (A), transpiration rate (E), elemental concentrations (K+, Na+ and K+ /Na+ ), photochemical efficiency of photosystem II (Fv/Fm), water use efficiency (WUE) and pigment content (chlorophyll a, and b). The results revealed that saline environment significantly reduced all response variables under study of sorghum genotypes, however, Hybrid sorgo remained unmatched by recording the maximum root and shoot traits. The same genotype recorded higher photosynthetic efficiency which was attributed to Na+ extrusion, K+ uptake and higher K+ /Na+ ratio (1.8 at stress), while these mechanisms were not fully active in rest of genotypes. Moreover, this study also implies the involvement of proline in imparting tolerance against saline environment in Hybrid sorgo genotype. Overall, BD-703 remained the most salt sensitive genotype as evident from the minimum morphological growth traits and the least biosynthesis of osmoprotectants. These findings open new research avenues for salt stress alleviation by identifying elite salt-tolerant genotypes of sorghum for breeding programs. [ABSTRACT FROM AUTHOR]

Roots from salt-susceptible ICSR-56 (SS) sorghum plants display metaxylem elements with thin cell walls and large diameter. On the other hand, roots with thick, lignified cell walls in the hypodermis and endodermis were noticed in salt-tolerant CSV-15 (ST) sorghum plants. The secondary wall thickness and number of lignified cells in the hypodermis have increased with the treatment of sodium chloride stress to the plants (STN). Lignin distribution in the secondary cell wall of sclerenchymatous cells beneath the lower epidermis was higher in ST leaves compared to the SS genotype. Casparian thickenings with homogenous lignin distribution were observed in STN roots, but inhomogeneous distribution was evident in SS seedlings treated with sodium chloride (SSN). Higher accumulation of K+ and lower Na+ levels were noticed in ST compared to the SS genotype. To identify the differentially expressed genes among SS and ST genotypes, transcriptomic analysis was carried out. Both the genotypes were exposed to 200 mM sodium chloride stress for 24 h and used for analysis. We obtained 70 and 162 differentially expressed genes (DEGs) exclusive to SS and SSN and 112 and 26 DEGs exclusive to ST and STN, respectively. Kyoto Encyclopaedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analysis unlocked the changes in metabolic pathways in response to salt stress. qRT-PCR was performed to validate 20 DEGs in each SSN and STN sample, which confirms the transcriptomic results. These results surmise that anatomical changes and higher K+/Na+ ratios are essential for mitigating salt stress in sorghum apart from the genes that are differentially up- and downregulated in contrasting genotypes. [ABSTRACT FROM AUTHOR]

Generally, moderate to high salinity conditions and excess boron (B) occur together as limiting factors for plant growth in the soils of arid and semiarid regions. To determine the combined effect of excessive boron, salinity stress, or both, five different levels of B (0, 0.3, 0.6, 1.2, and 1.8 mM) and 80 mM sodium chloride (NaCl) were applied to lavandin plants grown in a greenhouse. The results showed that under nonsaline conditions, biomass production in shoots and roots and photosynthetic pigment contents (chlorophyll (Chl) a, b, and Chl a + b) decreased with exceptionally high B applications compared to the control. Moreover, the bioconcentration (BCF) of B (in shoots and roots), potassium (K) concentrations (in roots), K/sodium (Na) and calcium (Ca)/Na ratios (in shoots), and Ca/B ratios (in shoots and roots) decreased for all B applications compared to the control. In contrast, all B applications caused a remarkable increase in the carotenoid (Car)/ Chl ratio, B concentrations (in shoots and roots), translocation (TF) of B, and net B accumulation compared to the control. In addition, under nonsaline conditions, concentrations of K (in shoots), Ca (in shoots and roots), and K/Na and Ca/Na ratios (in roots) were significantly increased by B applications compared with the control. Under saline conditions, significant decreases in Chl b, Chl a + b, BCF of B (in shoots and roots), and Ca/B ratio (in shoots) were observed in all B applications compared to the control. However, under saline conditions, B application caused significant increases in the Car/Chl ratio, TF of B, net B accumulation, and concentrations of B (in shoots and roots), K (in shoots), Ca, and Na (in shoots and roots) compared to the control. It was concluded that although it is not seen in the growth parameters, NaCl application could effectively alleviate the harmful effects of B toxicity in lavandin plants. Under saline conditions, notable decreases in the mean B concentration in shoots could be strong evidence for this hypothesis. [ABSTRACT FROM AUTHOR]

Plant species adapted to saline habitats represent an important resource in the assessment of salinity tolerance mechanisms. The aim of the present study was to analyze salinity tolerance and ion accumulation characteristics for various accessions of Calystegia sepium from different habitats in comparison to these of Calystegia soldanella in controlled conditions. Plants were introduced in culture using stem explants with leaf and were cultivated in controlled conditions under six different substrate salinities. Salinity tolerance of both C. sepium and C. soldanella plants was relatively high, but the tolerance of particular accessions did not depend on the substrate salinity level in their natural habitats. C. sepium accession from a mesophytic non-saline habitat was only slightly negatively affected by increasing substrate salinity. However, coastal accession of C. sepium and coastal-specific species C. soldanella had some similarities in ion accumulation characteristics, both accumulating a high concentration of soluble ions in aboveground parts and excluding them from underground parts. All C. sepium accessions from different habitats represented varied physiotypes, possibly associated with their genetic differences. C. sepium accessions from different habitats can be suggested as models for further studies aiming at dissecting possible genetic, epigenetic and physiological mechanisms of adaptation to heterogeneous environmental conditions.

Purpose: Aimed to identify the differences in ion accumulation and photosynthetic electron transport between Medicago truncatula and Medicago sativa during NaCl stress, and reveal their different physiological mechanism of salt resistance. Methods: The plants were cultivated in nutrient solutions with and without 300 mM NaCl. We then measured the plant growth, leaf ion contents, prompt and delayed chlorophyll a fluorescence (PF and DF), and modulated 820 nm reflection (MR/MRO) values of the leaves on the 0 d, 10 d, 20 d, 30 d, and 40 d of NaCl stress. Results: The lower dry weight reduction and leaf wilting were found in M. sativa compared with M. truncatula under NaCl stress, and M. sativa appeared to have lower leaf Na+/K+, Na+/Ca2+, Na+/Mg2+ ratios than M. truncatula. With the NaCl treatment, the PF intensity at P-step (FP) values in the prompt chlorophyll a fluorescence transient (OJIP) curves for both species decreased gradually as the duration of exposure increased. However, the FP value of M. truncatula suggested a faster decline than that of M. sativa. Compared with M. truncatula, the DF amplitude in M. sativa exhibited a decrease that was slower and lower in response to the NaCl treatments, NaCl stress also made the lowest points of the MR/MRO appear later in M. truncatula, but not in M. sativa. Conclusion: Our results indicated that M. sativa was more effective in inhibiting Na+ and Cl− accumulation and regulating nutrient ion balance in leaves than M. truncatula during NaCl stress. Moreover, M. sativa had a strong ability to maintain stable electron transport under NaCl stress, so it is suitable for cultivation in saline soil. [ABSTRACT FROM AUTHOR]

Faba bean (Vicia faba L.) is one of the most important legume crops worldwide. High salinity is a major constraint for faba bean productivity in many countries, including Egypt. Here, we examined the effects of salinity-induced toxicity on the growth of two local faba bean genotypes by analyzing physiological and biochemical responses to identify the salt-tolerant attributes between the genotypes. In vitro experiments were carried out to characterize the response of two faba bean genotypes (Sakha 3 and Nubaria 2) to salinity imposed by different sea-salt concentrations (1000, 3000, 5000 and 7000 ppm). For both genotypes, salinity induced a marked reduction in dry matter gain along with a reduction in shoots height, roots length, leaves number and branches number. In addition, the photosynthetic pigments (chlorophyll a, b) were significantly decreased with the increase in salinity. Changes in tissue ion levels, peroxidase (POD) and polyphenol oxidase (PPO) activities depended on genotype, tissue and salinity level. The deteriorating effect of salt stress on the growth performance of genotype Nubaria 2 was lower than that of Sakha 3. This is maybe ascribed to its better antioxidant enzymes activities. Moreover, Nubaria 2 accumulated low quantities of Na+ in the shoots with a higher accumulation of ions in the roots compared to Sakha 3. The obtained results suggested Nubaria 2 seedlings have a strong ability to sustain sea-salt stress by the regulation of transport and distribution of ions and this genotype may be characterized as a salt excluder. [ABSTRACT FROM AUTHOR]

Generally, moderate to high salinity conditions and excess boron (B) occur together as limiting factors for plant growth in the soils of arid and semiarid regions. To determine the combined effect of excessive boron, salinity stress, or both, five different levels of B (0, 0.3, 0.6, 1.2, and 1.8 mM) and 80 mM sodium chloride (NaCl) were applied to lavandin plants grown in a greenhouse. The results showed that under nonsaline conditions, biomass production in shoots and roots and photosynthetic pigment contents (chlorophyll (Chl) a, b, and Chl a + b) decreased with exceptionally high B applications compared to the control. Moreover, the bioconcentration (BCF) of B (in shoots and roots), potassium (K) concentrations (in roots), K/sodium (Na) and calcium (Ca)/Na ratios (in shoots), and Ca/B ratios (in shoots and roots) decreased for all B applications compared to the control. In contrast, all B applications caused a remarkable increase in the carotenoid (Car)/Chl ratio, B concentrations (in shoots and roots), translocation (TF) of B, and net B accumulation compared to the control. In addition, under nonsaline conditions, concentrations of K (in shoots), Ca (in shoots and roots), and K/Na and Ca/Na ratios (in roots) were significantly increased by B applications compared with the control. Under saline conditions, significant decreases in Chl b, Chl a + b, BCF of B (in shoots and roots), and Ca/B ratio (in shoots) were observed in all B applications compared to the control. However, under saline conditions, B application caused significant increases in the Car/Chl ratio, TF of B, net B accumulation, and concentrations of B (in shoots and roots), K (in shoots), Ca, and Na (in shoots and roots) compared to the control. It was concluded that although it is not seen in the growth parameters, NaCl application could effectively alleviate the harmful effects of B toxicity in lavandin plants. Under saline conditions, notable decreases in the mean B concentration in shoots could be strong evidence for this hypothesis.

The aim of the present study was to evaluate the morphological and physiological responses of P. maritima plants from five geographically isolated sites growing in habitats with different conditions to different substrate moisture levels in controlled conditions. Plants were produced from seed and cultivated in a greenhouse at four relatively constant soil moisture regimes: at 25, 50, and 75% soil water content and in soil flooded 3 cm above the surface (80% F). The two morphological traits that varied most strikingly among P. maritima accessions were the number of flower stalks and the number of leaves. Only plants from two accessions uniformly produced generative structures, and allocation to flowering was suppressed by both low moisture and flooding. Optimum shoot biomass accumulation for all accessions was at 50 and 75% soil moisture. The Performance Index Total was the most sensitive among the measured photosynthesis-related parameters, and it tended to decrease with an increase in soil water content for all P. maritima accessions. The initial hypothesis—that plants from relatively dry habitats will have a higher tolerance against low soil water levels, but plants from relatively wet habitats will have a higher tolerance against waterlogged or flooded soil—was not proven. The existence of three ecotypes of P. maritima within the five accessions from geographically isolated subpopulations on the eastern coast of the Baltic Sea at the level of morphological responses to soil water content can be proposed. P. maritima plants can be characterized as extremely tolerant to soil waterlogging and highly tolerant to soil flooding and low soil water content.

The experiment aimed to investigate the impact of foliar application of spermidine on the physiological and reproductive aspects of chickpea genotypes subjected to salt stress, with a focus on its consequences for seed quality. The study involved treating chickpea genotypes (CSG 8962, HC 3, HC 5, RSG 931) with 4 and 8 dSm ^−1 Cl ^− dominate salinity during the seedling stage, and application of 0.5 and 1.0 mM spermidine at the flowering stage. Result revealed that salinity significantly reduced chlorophyll and membrane stability index by approximately 46.97% and 23.19%, respectively. Concurrently, pollen germination and viability decreased about 14.14% and 22.24%, leading to a substantial decline in seed protein content (37.70%) at 8 dSm ^−1 salinity. While there was an increase in antioxidant activity (45.83%), phenol content decreased in response to salinity stress. Foliar application of spermidine (0.5 and 1.0 mM) proved to be a promising intervention, enhancing chlorophyll stability and phenol content by approximately 24.35% and 36.05%, respectively, at 8 dSm ^−1 salinity. This improvement is associated with a notable 20.01% increase in pollen viability, resulting in a subsequent rise in protein content by about 20.73% at 1.0 mM spermidine. Additionally, the application of spermidine mitigated Na ^+ ion accumulation in chickpea seeds. The findings underscore the varying performance of chickpea genotypes under salinity stress, with CSG 8962 and RSG 931 exhibiting poorer outcomes compared to other genotypes. Notably, the positive impact of spermidine was more pronounced, especially with the use of 1.0 mM spermidine, which demonstrated a more significant positive effect in salt-sensitive chickpea genotypes. These results emphasize the potential of spermidine as a strategic tool in alleviating the adverse effects of salinity on chickpea crops, offering valuable insights for the development of sustainable practices to enhance chickpea resilience and seed quality under challenging environmental conditions.

Mesembryanthemum crystallinum L. is an obligatory halophyte species showing optimum growth at elevated soil salinity levels, but the ionic requirements for growth stimulation are not known. The aim of the present study was to compare the effects of sodium, potassium and calcium in the form of chloride and nitrate salts on the growth, physiological performance, ion accumulation and mineral nutrition of M. crystallinum plants in controlled conditions. In a paradoxical way, while sodium and potassium had comparable stimulative effect on plant growth, the effect of calcium was strongly negative even at a relatively low concentration, eventually leading to plant death. Moreover, the effect of Ca nitrate was less negative in comparison to that of Ca chloride, but K in the form of nitrate had some negative effects. There were three components of the stimulation of biomass accumulation by NaCl and KCl salinity in M. crsytallinum: the increase in tissue water content, increase in ion accumulation, and growth activation. As optimum growth was in a salinity range from 20 to 100 mM, the increase in the dry biomass of plants at a moderate (200 mM) and high (400 mM) salinity in comparison to control plants was mostly due to ion accumulation. Among physiological indicators, changes in leaf chlorophyll concentration appeared relatively late, but the chlorophyll a fluorescence parameter, Performance Index Total, was the most sensitive to the effect of salts. In conclusion, both sodium and potassium in the form of chloride salts are efficient in promoting the optimum growth of M. crystallinum plants. However, mechanisms leading to the negative effect of calcium on plants need to be assessed further.

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The aim of the present study was to develop an experimental system for an exploration of ethylene-dependent responses using intact growing Ranunculus sceleratus plants and to approbate the system for assessing the role of ethylene in salinity tolerance and ion accumulation. Plants were cultivated in sealed plastic containers in a modified gaseous atmosphere by introducing ethylene or 1-methylcyclopropene (1-MCP), a competitive inhibitor of ethylene action. High humidity inside the containers induced a fast elongation of the leaf petioles of R. sceleratus. The effect was ethylene-dependent, as 1-MCP completely blocked it, but exogenous ethylene further promoted petiole elongation. Exogenous ethylene decreased (by 48%) but 1-MCP increased (by 48%) the Na+ accumulation in leaf blades of NaCl-treated plants. The experimental system was further calibrated with ethylene and silica xerogel, and the optimum concentrations were found for inducing leaf petiole elongation (10 μL L–1 ethylene) and preventing leaf petiole elongation (200 g silica xerogel per 24 L), respectively. The second experiment involved a treatment with NaCl in the presence of 1-MCP, ethylene, or 1-MCP + ethylene, both in normal and high air humidity conditions. In high humidity conditions, NaCl inhibited petiole elongation by 25% and ethylene treatment fully reversed this inhibition and stimulated elongation by 12% in comparison to the response of the control plants. Treatment with 1-MCP fully prevented this ethylene effect. In normal humidity conditions, NaCl inhibited petiole elongation by 20%, which was reversed by ethylene without additional elongation stimulation. However, 1-MCP only partially inhibited the ethylene effect on petiole elongation. In high humidity conditions, ethylene inhibited Na+ accumulation in NaCl-treated plants by 14%, but 1-MCP reversed this effect. In conclusion, the stimulation of endogenous ethylene production in R. sceleratus plants at a high air humidity or in flooded conditions reverses the inhibitory effect of salinity on plant growth and concomitantly inhibits the accumulation of Na+ in tissues. R. sceleratus is a highly promising model species for use in studies regarding ethylene-dependent salinity responses and ion accumulation potential involving the manipulation of a gaseous environment. [ABSTRACT FROM AUTHOR]

Salt-accumulator species are of great interest for the phytoremediation of salt-affected soils to reclaim soil salinization, a major constraints causing germination retardation and growth restriction of plants as well as habitat degradation. Higher biomass production at ECe 23–36 dS m−1 indicated that this species grows better in high to moderate salinity that was linked to osmotic adjustment through higher ion accumulation (Na+, Cl‒, and Ca2+) and organic osmolytes (free amino acids and proline). Plants from highly and moderately saline habitats exhibited broader metaxylem vessels, which was associated with eased conduction of solutes leading to better growth. Leaf anatomical characteristics generally increased with increasing salinity except at the highest ECe 55 dS m−1. The increased leaf lamina thickness contributed to succulence because of increased storage parenchymatous spongy tissues (that can store high amounts of water), water contents and it is a reflection of maintaining ion homeostasis and colonizing hyper-saline soil. Reduced stomatal density and area under high salinity are critical to cope with environmental hazards. Under high salinity, compartmentalization of excessive Na+ and Cl− ions and accumulation of compatible osmolytes are directly related to high degree of salinity tolerance, and hence are useful for phyto-amelioration of salinity-impacted lands. Salinity tolerance mechanism in Suaeda vera have been explored extensively, but these mechanisms have not been addressed in the context of soil-plant interaction and functioning connection between structural and functional features with respect to phytoremediation. This work aims to provide mechanistic insight into how different morphological and physio-anatomical mechanisms in differently adapted population of Suaeda vera operate in coordinated manner to maintain ionic homeostasis under high salinity that are useful for phytoremediation. [ABSTRACT FROM AUTHOR]

The aim of the present study was to compare the effect of various salts composed of different cations (Na+, K+) and anions (chloride, nitrate, nitrite) on growth, development and ion accumulation in three Rumex species with accessions from sea coast habitats (Rumex hydrolapathum, Rumex longifolius and Rumex maritimus) and Rumex confertus from an inland habitat. Plants were cultivated in soil in an experimental automated greenhouse during the autumn–winter season. Nitrite salts strongly inhibited growth of all Rumex species, but R. maritimus was the least sensitive. Negative effects of chloride salts were rather little-pronounced, but nitrates resulted in significant growth stimulation, plant growth and development. Effects of Na+ and K+ at the morphological level were relatively similar, but treatment with K+ salts resulted in both higher tissue electrolyte levels and proportion of senescent leaves, especially for chloride salts. Increases in tissue water content in leaves were associated with anion type, and were most pronounced in nitrate-treated plants, resulting in dilution of electrolyte concentration. At the morphological level, salinity responses of R. confertus and R. hydrolapathum were similar, but at the developmental and physiological level, R. hydrolapathum and R. maritimus showed more similar salinity effects. In conclusion, the salinity tolerance of all coastal Rumex species was high, but the inland species R. confertus was the least tolerant to salinity. Similarity in effects between Na+ and K+ could be related to the fact that surplus Na+ and K+ has similar fate (including mechanisms of uptake, translocation and compartmentation) in relatively salt-tolerant species. However, differences between various anions are most likely related to differences in physiological functions and metabolic fate of particular ions. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate tolerance to salinity and different heavy metals as well as the phytoextraction potential of Ranunculus sceleratus plants from a brackish coastal sandy beach habitat. Four separate experiments were performed with R. sceleratus plants in controlled conditions: (1) the effect of NaCl gradient on growth and ion accumulation, (2) the effect of different Na+ and K+ salts on growth and ion accumulation, (3) heavy metal tolerance and metal accumulation potential, (4) the effect of different forms of Pb salts (nitrate and acetate) on plant growth and Pb accumulation. A negative effect of NaCl on plant biomass was evident at 0.5 g L−1 Na+ and growth was inhibited by 44% at 10 g L−1 Na+, and this was associated with changes in biomass allocation. The maximum Na+ accumulation (90.8 g kg−1) was found in the stems of plants treated with 10 g kg−1 Na+. The type of anion determined the salinity tolerance of R. sceleratus plants, as Na+ and K+ salts with an identical anion component had a comparable effect on plant growth: nitrates strongly stimulated plant growth, and chloride treatment resulted in slight but significant growth reduction, but plants treated with nitrites and carbonates died within 4 and 5 weeks after the full treatment, respectively. The shoot growth of R. sceleratus plants was relatively insensitive to treatment with Mn, Cd and Zn in the form of sulphate salts, but Pb nitrate increased it. Hyperaccumulation threshold concentration values in the leaves of R. sceleratus were reached for Cd, Pb and Zn. R. sceleratus can be characterized as a shoot accumulator of heavy metals and a hyperaccumulator of Na+. A relatively short life cycle together with a high biomass accumulation rate makes R. sceleratus useful for dynamic constructed wetland systems aiming for the purification of concentrated wastewaters. [ABSTRACT FROM AUTHOR]

Plant species adapted to saline habitats represent an important resource in the assessment of salinity tolerance mechanisms. The aim of the present study was to analyze salinity tolerance and ion accumulation characteristics for various accessions of Calystegia sepium from different habitats in comparison to these of Calystegia soldanella in controlled conditions. Plants were introduced in culture using stem explants with leaf and were cultivated in controlled conditions under six different substrate salinities. Salinity tolerance of both C. sepium and C. soldanella plants was relatively high, but the tolerance of particular accessions did not depend on the substrate salinity level in their natural habitats. C. sepium accession from a mesophytic non-saline habitat was only slightly negatively affected by increasing substrate salinity. However, coastal accession of C. sepium and coastal-specific species C. soldanella had some similarities in ion accumulation characteristics, both accumulating a high concentration of soluble ions in aboveground parts and excluding them from underground parts. All C. sepium accessions from different habitats represented varied physiotypes, possibly associated with their genetic differences. C. sepium accessions from different habitats can be suggested as models for further studies aiming at dissecting possible genetic, epigenetic and physiological mechanisms of adaptation to heterogeneous environmental conditions. [ABSTRACT FROM AUTHOR]

Vegetable grafting is considered a rapid, non-chemical alternative method to relatively slow and expensive breeding to overcome the adverse effect of salinity. Therefore, a soilless experiment was performed to determine the salinity tolerance of eggplant (Solanum melongena) cv. Madonna grafted onto two different rootstocks, Solanum grandifolium × Solanum melongena (SH) and Solanum torvum (ST), as well as self-grafted (SG) and self-rooted (SR) as controls. All groups of plants were treated with 0 mM NaCl or 80 mM NaCl. A significant decrease in the relative leaf chlorophyll content (SPAD value) and chlorophyll concentrations were found in response to NaCl. However, the grafted plants had a higher photosynthetic pigment level than the non-grafted plants grown under saline conditions. Grafting eggplants onto SH significantly enhanced the total fruit yield as compared to the self-rooted plants exposed to salinity by increasing the average fruit weight. Moreover, salt stress significantly increased the whitening index and oxidation potential of fruits. The plants grafted onto SH or ST accumulated more Na+ in their roots than in their fruit or leaves, thus the Na+ partitioning between the above-ground and root parts most probably determines the increased salinity tolerance of the grafted ST and SH plants. To conclude, both the SH and ST rootstocks protected the scions against salinity; the scion showed both increased photosynthetic pigment concentration and chlorophyll fluorescence parameters as well as a lower Na+ concentration under stress that resulted in a higher fruit yield and quality.

The aim of the present study was to compare changes in growth, ion accumulation and tissue water content in relatively salt-tolerant plant taxa—Beta vulgaris subsp. maritima, Beta vulgaris subsp. vulgaris var. cicla, Cochlearia officinalis, Mentha aquatica and Plantago maritima—as a result of NaCl and KCl salinity in controlled conditions. Similar growth responses to Na+ and K+ salinity in a form of chloride salts were found for all model plants, including growth stimulation at low concentrations, an increase in water content in leaves, and growth inhibition at high salinity for less salt-resistant taxa. All plant taxa were cultivated in soil except M. aquatica, which was cultivated in hydroponics. While the morphological responses of B. vulgaris subsp. vulgaris var. cicla, B. vulgaris subsp. maritima and P. maritima plants to NaCl and KCl were rather similar, C. officinalis plants tended to perform worse when treated with KCl, but the opposite was evident for M. aquatica. Plants treated with KCl accumulated higher concentrations of K+ in comparison to the accumulation of Na+ in plants treated with equimolar concentrations of NaCl. KCl-treated plants also had higher tissue levels of electrical conductivity than NaCl-treated plants. Based on the results of the present study, it seems that both positive and negative effects of Na+ and K+ on plant growth were due to unspecific ionic effects of monovalent cations or/and the specific effect of Cl−. [ABSTRACT FROM AUTHOR]

Elevated atmospheric CO2 concentrations (e[CO2]) have a significant impact on plant physiology, grain yield and quality and the specific response of plants to e[CO2] is closely linked to cultivars. Here, five Chinese wheat (Triticum aestivum L.) cultivars were grown under ambient CO2 (a[CO2], 400 ppm) and e[CO2] (800 ppm). CO2 enrichment significantly increased net photosynthetic rate and water use efficiency but depressed stomatal conductance. e[CO2] increased the carbon (C) concentration but decreased the nitrogen (N) concentration in all five cultivars, whereas the effect of e[CO2] on grain yield was highly dependent on cultivar. Moreover, e[CO2] caused a significant reduction in grain minerals and protein, although the magnitude of reduction was different among these cultivars. The starch concentrations in the grains and flour viscosity were not significantly affected at e[CO2]. These findings improve our understanding of the interactive effect of CO2 conditions and cultivars on plant performances and provide a research basis to select suitable wheat cultivars to deal with food crisis in future climate. [ABSTRACT FROM AUTHOR]

The aim of the present study was to compare tolerance to salinity and ion accumulation potential of Armeria maritima subsp. elongata. Three accessions (AM1 and AM2, both from Latvia, and AM3 from Sweden) from relatively dry sandy soil habitats in the Baltic Sea region were selected and compared using both in vitro cultivated shoot explants and long-term soil-cultivated plants at flowering stage. Growth of root non-forming explants treated with increasing concentrations of NaCl was significantly inhibited starting from 110 mmol L−1, and the rate of shoot formation was even more sensitive. Significant differences in morphology and responses to salinity were found between different accessions. For soil-grown plants, biomass accumulation in above-ground parts was relatively little affected by salinity in AM1 and AM2 in comparison to that in AM3. Differences in ion accumulation were evident between the accessions as well as in respect to cultivation system used. Maximum accumulation capacity for Na+ was up to 2.5 mol kg−1 both in shoot explant tissues and in old leaves of soil-grown plants treated with NaCl, but that for K+ reached 4.0 mol kg−1 in old leaves of soil-grown plants treated with KCl. Non-ionic component of osmotic value was relatively high in old leaves and significantly increased under NaCl treatment, especially for AM2 and AM3 plants at moderate salinity, but in AM1 only at high salinity. In contrast, it significantly decreased in old leaves of AM2 plants treated with increasing concentration of KCl. It can be concluded that a wide salinity tolerance exists within A. maritima accessions from dry sandy soil habitats, associated with the ability to accumulate surplus ions both in salt glands and old leaves. [ABSTRACT FROM AUTHOR]

Roots from salt-susceptible ICSR-56 (SS) sorghum plants display metaxylem elements with thin cell walls and large diameter. On the other hand, roots with thick, lignified cell walls in the hypodermis and endodermis were noticed in salt-tolerant CSV-15 (ST) sorghum plants. The secondary wall thickness and number of lignified cells in the hypodermis have increased with the treatment of sodium chloride stress to the plants (STN). Lignin distribution in the secondary cell wall of sclerenchymatous cells beneath the lower epidermis was higher in ST leaves compared to the SS genotype. Casparian thickenings with homogenous lignin distribution were observed in STN roots, but inhomogeneous distribution was evident in SS seedlings treated with sodium chloride (SSN). Higher accumulation of K+ and lower Na+ levels were noticed in ST compared to the SS genotype. To identify the differentially expressed genes among SS and ST genotypes, transcriptomic analysis was carried out. Both the genotypes were exposed to 200 mM sodium chloride stress for 24 h and used for analysis. We obtained 70 and 162 differentially expressed genes (DEGs) exclusive to SS and SSN and 112 and 26 DEGs exclusive to ST and STN, respectively. Kyoto Encyclopaedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analysis unlocked the changes in metabolic pathways in response to salt stress. qRT-PCR was performed to validate 20 DEGs in each SSN and STN sample, which confirms the transcriptomic results. These results surmise that anatomical changes and higher K+/Na+ ratios are essential for mitigating salt stress in sorghum apart from the genes that are differentially up- and downregulated in contrasting genotypes.

The aim of this study was to evaluate the membrane integrity and some physiological responses of rootstock citrus calli under exposure to different concentrations of NaCl. Selected salt-tolerant cell lines were compared with salt-sensitive calli of Troyer's citrange (Citrus sinensis [L.] x Citrus trifoliata [L.] Raf.) (TC) with respect to growth, water content, Na+, K+ and Cl− ion content as well as cell membrane stability under exposure to different NaCl concentrations. The results show that the stressed sensitive lines have a consistently high ion efflux. The values recorded for these sensitive calli are 3 to 6 times higher than those of the tolerant calli. Thus, only selected halotolerant calli were able to maintain the integrity of their membranes under salt stress conditions. In the sensitive calli, NaCl always induces a slowing down of growth even from 4 g L−1, and the reduction in the relative growth rate is higher than 50% and reaches more than 90% for the three culture durations at 8 g L−1 NaCl. For the salt-tolerant selected lines, the relative growth rate seems to be slightly slowed down until the second month of culture but becomes equal to that of the control at the third month, whether at 4 or 8 g L−1 NaCl. At the end of the third month, the relative growth rate of the selected calli is 100% at 8 g L−1 NaCl. The water content is twice as high in the selected tolerant calli as in the sensitive ones after three months of salt treatment at 8 g L−1 NaCl. After long-term culture, the halotolerant calli absorbed similar or even higher amounts of Na+ and Cl− than the salt-sensitive lines. However, by the 3rd month, the recorded accumulation rate dropped in the unselected but continued to increase in the tolerant calli (4-fold higher at 12 g L−1 NaCl than the control). Furthermore, exposure of both types of calli (salt-sensitive and salt-tolerant) to equal concentrations of NaCl resulted in greater loss of K+ by the NaCl-sensitive lines. However, for tolerant lines, K+ uptake is not affected at 4 g L−1 NaCl and the decrease in tissue content is less than 25% at 8 g L−1 NaCl. From this observation, it can be concluded that growth and the ability to retain high levels of internal K+ are correlated. [ABSTRACT FROM AUTHOR]

In the vestibular periphery, transmission via conventional synaptic boutons is supplemented by post-synaptic calyceal endings surrounding Type I hair cells. This review focusses on the multiple modes of communication between these receptors and their enveloping calyces as revealed by simultaneous dual-electrode recordings. Classic orthodromic transmission is accompanied by two forms of bidirectional communication enabled by the extensive cleft between the Type I hair cell and its calyx. The slowest cellular communication low-pass filters the transduction current with a time constant of 10-100 ms: potassium ions accumulate in the synaptic cleft, depolarizing both the hair cell and afferent to potentials greater than necessary for rapid vesicle fusion in the receptor and potentially triggering action potentials in the afferent. On the millisecond timescale, conventional glutamatergic quantal transmission occurs when hair cells are depolarized to potentials sufficient for calcium influx and vesicle fusion. Depolarization also permits a third form of transmission that occurs over tens of microseconds, resulting from the large voltage- and ion-sensitive cleft-facing conductances in both the hair cell and the calyx that are open at their resting potentials. Current flowing out of either the hair cell or the afferent divides into the fraction flowing across the cleft into its cellular partner, and the remainder flowing out of the cleft and into the surrounding fluid compartment. These findings suggestmultiple biophysical bases for the extensive repertoire of response dynamics seen in the population of primary vestibular afferent fibers. The results further suggest that evolutionary pressures drive selection for the calyx afferent. [ABSTRACT FROM AUTHOR]

• We assessed genotypic variation of baby corn genotypes in salinity tolerance. • Increasing salinity level above 6 dS m–1 was detrimental for germination and growth. • SG 17 Super genotype was the most susceptible to salt stress, whereas PAC 571 was the most tolerant. • SG 17 Super had 54% lower cob yield compared with PAC 571. • All other genotypes were between slightly salt-tolerant to moderately salt-tolerant category. • The selected salt-tolerant baby corn genotypes have potentials for cultivation in salt-affected soils. Soil salinity is a major global concern for sustainable crop production, and proper screening of crop genotypes against salt stress should be a major consideration before recommending a genotype for field cultivation. Germination, growth, yield, physiological, and biochemical responses of 11 hybrid baby corn genotypes (Kasetsart 3, PAC 271, PAC 321, PAC 571, SG 17 Super, CP B468, CP B905, WS 111, WS 9103, Chang Daeng 18, and HY 074656) to five levels of NaCl-induced salinity (0.7 [control], 3, 6, 9, and 12 dS m–1) were evaluated in a germination trial in petri dishes followed by a polyhouse study to assess genotypic variation of baby corn genotypes in salinity tolerance. Data on various germination traits, growth, yield, physiological, and biochemical parameters were collected. Increasing salinity level above 6 dS m–1 was equally detrimental for germination and growth of all tested genotypes. Germination response of Chang Daeng 18 genotype to salt stress was the poorest (22.2% germination rate and 7.7% mean daily germination). Growth, yield, physiological, and sodium (Na+) accumulation data revealed that SG 17 Super genotype was the most susceptible to salt stress, whereas PAC 571 was the most tolerant. SG 17 Super had 28% lower shoot dry matter, 54% lower cob yield, 25% less membrane stability index, and 158% more Na+ accumulation compared with PAC 571. All other genotypes were between slightly salt-tolerant to moderately salt-tolerant category, which was also verified by the Hierarchical cluster analysis. Physiological and biochemical parameters, such as free proline, membrane electrolyte leakage, and membrane stability index, as well as ion accumulation parameter, such as Na+, were the most representative of salt stress. Salinity reduced leaf greenness (SPAD value), while net photosynthetic rate, stomatal conductance, and transpiration rate were not affected. Na+ exclusion and higher K+/Na+ ratio in leaves of baby corn genotypes correlated well with their higher salinity tolerance, and greater K+/Na+ discrimination was shown by salt-tolerant genotypes. The relative susceptibility of baby corn genotypes to salinity should be taken into consideration for plant breeding programs. The selected salt-tolerant baby corn genotypes have potentials for cultivation in salt-affected soils for better productivity. [ABSTRACT FROM AUTHOR]

Salinity is one of the most critical crises worldwide that ultimately compromises future food security. Brassinosteroids including brassinolide (BL) are a class of polyhydroxy steroids phytohormones, that play a crucial role in several plant metabolic pathways and boost plants' stress tolerance, but less data is accessible on its function in salt-affected grapevine. The experiment was conducted throughout the 2019 and 2020 experimental seasons at EL-Baramon experimental farm, Horticulture Research Institute, Mansoura, Egypt, to recognize the remediation potential of BL (1 and 2 mg L−1) in lightening salinity (NaCl at 1000, 2000, and 3000 mg L−1) injury on Thompson seedless grapevine seedlings (H4 strain) growth and physio-anatomical attributes. Data advocated that while salinity reduced growth attributes, BL applications substantially improved the overall salt-affected plant performance. Salinity stress significantly decreased photosynthetic pigment, relative water content, and ions percentage (nitrogen, phosphorus, potassium, potassium/sodium ratio). Alternatively, BL spraying significantly (p ≤ 0.05) increased the photosynthetic pigment, maintaining a favorable potassium/sodium ratio and increasing the ions percentage. Additionally, increasing salinity levels significantly boost plant sodium percentage and induce a membrane malfunction associated with increased membrane permeability; conversely, the application of BL decreased the sodium percentage associated with decreasing membrane permeability relative to non-treated salinized plants. Moreover, salinity and/or BL significantly improved the antioxidant capacity associated with rising proline accumulation and antioxidant enzyme activities. Anatomically, salinity stress considerably modified leaf structure; meanwhile, the spraying with BL drastically mitigates the harmful effects of salinity on leaf anatomy. Additionally, salt-affected plant cells explained various obvious organelles ultrastructural modifications and cellular damage; meanwhile, BL spraying to salt-affected plants repealed the ultrastructural modifications of cell organelles. Taken together, BL, especially 2 mg L−1, has a great potential to boost the salt tolerance of Thompson seedless grapevine seedlings (H4 strain). It improves salt tolerance by sustaining higher photosynthetic pigment concentrations, maintaining ion homeostasis, regulating water status, and stimulating antioxidant capacity as well as maintaining leaf anatomical attributes. [ABSTRACT FROM AUTHOR]

In the vestibular periphery, transmission via conventional synaptic boutons is supplemented by post-synaptic calyceal endings surrounding Type I hair cells. This review focusses on the multiple modes of communication between these receptors and their enveloping calyces as revealed by simultaneous dual-electrode recordings. Classic orthodromic transmission is accompanied by two forms of bidirectional communication enabled by the extensive cleft between the Type I hair cell and its calyx. The slowest cellular communication low-pass filters the transduction current with a time constant of 10–100 ms: potassium ions accumulate in the synaptic cleft, depolarizing both the hair cell and afferent to potentials greater than necessary for rapid vesicle fusion in the receptor and potentially triggering action potentials in the afferent. On the millisecond timescale, conventional glutamatergic quantal transmission occurs when hair cells are depolarized to potentials sufficient for calcium influx and vesicle fusion. Depolarization also permits a third form of transmission that occurs over tens of microseconds, resulting from the large voltage- and ion-sensitive cleft-facing conductances in both the hair cell and the calyx that are open at their resting potentials. Current flowing out of either the hair cell or the afferent divides into the fraction flowing across the cleft into its cellular partner, and the remainder flowing out of the cleft and into the surrounding fluid compartment. These findings suggest multiple biophysical bases for the extensive repertoire of response dynamics seen in the population of primary vestibular afferent fibers. The results further suggest that evolutionary pressures drive selection for the calyx afferent.

The effects of foliar application of spermidine (Spd) on the physiological aspects of salt-stressed oat seedlings were studied under greenhouse conditions. At the seedling stage, the salt-sensitive variety, namely, Caoyou 1 and the salt-tolerant variety, namely, Baiyan 2 were treated with 70 and 100 mM of salt, followed by the foliar application of 0.75 mM Spd or distilled water. Results showed that Spd application increased the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and reduced the rate of O2⋅– production and the accumulation of H2O2 and malondialdehyde (MDA). In addition, it increased the level of zeatin riboside (ZR) and the content of endogenous polyamines. The application of Spd increased the contents of soluble sugar, soluble protein, and free proline and helped maintain the osmotic balance of oat leaves. At the same time, foliar Spd treatment helped in maintaining the ion nutrition balance. Specifically, it reduced the content of Na+ and thereby stabilized the ratio of Na+/K+, Na+/Ca2+, and Na+/Mg2+. The effects of Spd application were more obvious for the salt-sensitive cultivar Caoyou 1 and under the lighter 70 mM salt stress. [ABSTRACT FROM AUTHOR]

One of the major detrimental factors of the global rice production is salt stress, which limits it up to 50%. In this study, we compared the morphophysiological and biochemical responses of indigenous salt-tolerant 'Korgut' and salt-sensitive 'Jaya' rice (Oryza sativa L.) varieties by pot culture in controlled climatic conditions. Decreased plant growth and biomass with the increase in salinity were recorded in the 'Jaya' variety compared to those of 'Korgut'. Net photosynthesis rate (PN), transpiration rate (E), stomatal conductance (gs), internal CO2 concentration (Ci), photochemical quenching, and lower quantum efficiency of PSII system (Fv/Fm ratio) were recorded reduced in 'Jaya' compared to those of 'Korgut' as response to salinity stress. Unlike 'Korgut' that thrived well under increased salinity levels, higher concentration (160 mmol/L) of NaCl caused a decrease in the number of thylakoids. In addition, swelling of the thylakoids was observed in 'Jaya'in response to higher salt stress. The tolerance of 'Korgut' plants was mainly due to relatively lesser accumulation of Na+ and Cl- and higher accumulation of K+. 'Korgut' showed relatively higher antioxidant capacity, lower osmotic stress (proline), and oxidative damage (lipid peroxidation) compared to salt-sensitive variety 'Jaya'. Our data suggests that 'Korgut' plants preserve ion and water homeostasis and diminish oxidative stress resulting from more significant antioxidant enzymes, which enables better sustainable growth overcoming salinity stress, contrary to salt-sensitive 'Jaya' variety. These findings can support crop development in terms of salt tolerance in rice crops by the method of molecular genetics. [ABSTRACT FROM AUTHOR]

This study aimed to rigorously investigate and integrate the underlying hypothesis that an enhancing effect of gibberellic acid (GA3, 3 µM) with increased growth actually leads to a modification of the physiological role of polyamines during salinity stress (NaCl, 100 mM) in fennel. These analyses concern both reserve tissues (cotyledons) and embryonic axes in growth. Physiological results indicate a restriction of germination, growth, mineral nutrition and damages to membranes of salt-treated seedlings. This was partially attenuated in seedlings treated with an interaction effect of GA3 and NaCl. Peroxidase and catalase activities showed a reduction or an augmentation according to the treatments and organs. The three main polyamines (PA): putrescine, spermidine and spermine were elevated in the salt-treated seedlings. Meanwhile, GA3 seed priming was extremely efficient in reducing PA levels in salt-stressed seedlings compared to the control. Response of PA genes to salinity was variable. Up-regulation was noted for SPMS1, ODC1, and ADC1 in hypocotyls and cotyledons (H + C) and down-regulation for SAMDC1 in the radicle. Interaction of salt/GA3 treatment showed different responses, only ODC1 in (H + C) and ADC1 in both radicle and (H + C) were overexpressed. Concerning other genes, no change in mRNA abundance was observed in both organs compared to the salt-treated seedlings. From these results, it could be inferred that the fennel seedlings were NaCl sensitive. This sensitivity was mitigated when GA3 applied for seed priming and applied in combination with NaCl, which resulted in a reduction of the PA content. [ABSTRACT FROM AUTHOR]

Lead‐halide perovskite solar cells (PSCs) based on unusual semiconductors made with ions, have shown impressive improvement in photovoltaic performance in few years exceeding nowadays 25 % power conversion efficiency. However, PSCs suffer from a lack of stability and show significant hysteresis in current‐voltage curves, which are impeding commercialization. We confirmed the importance of halide ion migration in the hysteresis effect which has direct consequences on device efficiency. Using impedance spectroscopy, in addition to the geometrical capacitance found at high frequency for fresh samples without bias, we observed a second capacitance at low frequency after ageing or under bias. This second capacitance is interpreted as a charge accumulation layer at interfaces, which can be promoted by the presence of grain boundaries. Through glow‐discharge optical emission spectroscopy elemental depth profiles, we found that under dark conditions, iodide ions diffuse through the electron transport layer versus ageing time. These ions interact chemically with the front‐end electrode after four weeks and form silver iodide. [ABSTRACT FROM AUTHOR]

Background: Phaseolus vulgaris L.-rhizobia symbiosis has effectively enhanced common bean productivity via multiple biological mechanisms. This study aims to assess the impacts of the strain of Rhizobium on the nodulation, growth, nitrogen (N2) fixation rate and ion accumulation within Phaseolus vulgaris L. under salt stress. Methods: The Coco Blanc cultivar of the common bean was inoculated with the Ar02 rhizobia strain at 15 days after germination. Bean plants were inoculated in perlite culture to which salt was added in concentrations of 0, 25, 50 and 75 mmol L-1 NaCl. Result: Inoculation with the Ar02 rhizobia strain led to infective and effective symbiosis with the common bean plants exposed to saline solutions and non-saline solutions, respectively. Nodule biomass and nitrogen content declined under salt stress but maintained a higher number of nodules and nodule biomass at 75 mM NaCl. Plant root and shoot length increased with higher biomass under saline conditions, significantly more than the non-inoculated plant without salt. However, the progressive addition of NaCl reduced the growth of the root and shoot and the biomass within the inoculated plant. Salinity led to increased Na+ within the plant's shoot, along with a reduction in Ca+2 and K+ concentrations. The shoot's Ca+2, Na+ and K+ content were higher in the inoculated plant than the noninoculated. The salt tolerance in common bean plants inoculated with Ar02 rhizobia was linked with the plant's capability to sustain nodulation and enhance Na+ concentration in the shoot. Furthermore, salt tolerance within the same variety inoculated with Rhizobium was linked to a decline in the Ca+ and K+ concentrations in the shoot region of salt-exposed plants. [ABSTRACT FROM AUTHOR]

The aim of the present study was to compare the effect of various salts composed of different cations (Na+, K+) and anions (chloride, nitrate, nitrite) on growth, development and ion accumulation in three Rumex species with accessions from sea coast habitats (Rumex hydrolapathum, Rumex longifolius and Rumex maritimus) and Rumex confertus from an inland habitat. Plants were cultivated in soil in an experimental automated greenhouse during the autumn–winter season. Nitrite salts strongly inhibited growth of all Rumex species, but R. maritimus was the least sensitive. Negative effects of chloride salts were rather little-pronounced, but nitrates resulted in significant growth stimulation, plant growth and development. Effects of Na+ and K+ at the morphological level were relatively similar, but treatment with K+ salts resulted in both higher tissue electrolyte levels and proportion of senescent leaves, especially for chloride salts. Increases in tissue water content in leaves were associated with anion type, and were most pronounced in nitrate-treated plants, resulting in dilution of electrolyte concentration. At the morphological level, salinity responses of R. confertus and R. hydrolapathum were similar, but at the developmental and physiological level, R. hydrolapathum and R. maritimus showed more similar salinity effects. In conclusion, the salinity tolerance of all coastal Rumex species was high, but the inland species R. confertus was the least tolerant to salinity. Similarity in effects between Na+ and K+ could be related to the fact that surplus Na+ and K+ has similar fate (including mechanisms of uptake, translocation and compartmentation) in relatively salt-tolerant species. However, differences between various anions are most likely related to differences in physiological functions and metabolic fate of particular ions.

Hybrid organic–inorganic perovskite (HOIP) material‐based devices have attracted much attention in the past few years owing to their superior photoelectric performance. However, ion migration has hindered the commercialization of these devices. The accumulation of migrated ions or defects near electrodes and boundaries is inevitable under a voltage bias. This paper reports a systematic study on the optical properties of ion accumulation areas in HOIP. Quantitative electric fields are applied to MAPbX3 (MA = methylammonium and X = Cl, Br, or I) single crystals, and micro‐optical characterizations, including photoluminescence (PL) spectra, PL lifetimes, and Raman spectra, are performed. Significant differences in the intensity and peak position are observed in the PL spectrum near the anode and cathode regions, respectively. The phenomena observed in the study can be attributed to the migration and accumulation of halide ions, halide vacancies, and MA+ ions. Moreover, the results reveal that halide ions and vacancies play a significant role in carrier recombination. Finally, the Raman spectrum confirms that the migrated ions affect the interaction between the organic MA+ ions and inorganic Pb–X cages. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate tolerance to salinity and different heavy metals as well as the phytoextraction potential of Ranunculus sceleratus plants from a brackish coastal sandy beach habitat. Four separate experiments were performed with R. sceleratus plants in controlled conditions: (1) the effect of NaCl gradient on growth and ion accumulation, (2) the effect of different Na+ and K+ salts on growth and ion accumulation, (3) heavy metal tolerance and metal accumulation potential, (4) the effect of different forms of Pb salts (nitrate and acetate) on plant growth and Pb accumulation. A negative effect of NaCl on plant biomass was evident at 0.5 g L−1 Na+ and growth was inhibited by 44% at 10 g L−1 Na+, and this was associated with changes in biomass allocation. The maximum Na+ accumulation (90.8 g kg−1) was found in the stems of plants treated with 10 g kg−1 Na+. The type of anion determined the salinity tolerance of R. sceleratus plants, as Na+ and K+ salts with an identical anion component had a comparable effect on plant growth: nitrates strongly stimulated plant growth, and chloride treatment resulted in slight but significant growth reduction, but plants treated with nitrites and carbonates died within 4 and 5 weeks after the full treatment, respectively. The shoot growth of R. sceleratus plants was relatively insensitive to treatment with Mn, Cd and Zn in the form of sulphate salts, but Pb nitrate increased it. Hyperaccumulation threshold concentration values in the leaves of R. sceleratus were reached for Cd, Pb and Zn. R. sceleratus can be characterized as a shoot accumulator of heavy metals and a hyperaccumulator of Na+. A relatively short life cycle together with a high biomass accumulation rate makes R. sceleratus useful for dynamic constructed wetland systems aiming for the purification of concentrated wastewaters.

The aim of the present study was to compare changes in growth, ion accumulation and tissue water content in relatively salt-tolerant plant taxa—Beta vulgaris subsp. maritima, Beta vulgaris subsp. vulgaris var. cicla, Cochlearia officinalis, Mentha aquatica and Plantago maritima—as a result of NaCl and KCl salinity in controlled conditions. Similar growth responses to Na+ and K+ salinity in a form of chloride salts were found for all model plants, including growth stimulation at low concentrations, an increase in water content in leaves, and growth inhibition at high salinity for less salt-resistant taxa. All plant taxa were cultivated in soil except M. aquatica, which was cultivated in hydroponics. While the morphological responses of B. vulgaris subsp. vulgaris var. cicla, B. vulgaris subsp. maritima and P. maritima plants to NaCl and KCl were rather similar, C. officinalis plants tended to perform worse when treated with KCl, but the opposite was evident for M. aquatica. Plants treated with KCl accumulated higher concentrations of K+ in comparison to the accumulation of Na+ in plants treated with equimolar concentrations of NaCl. KCl-treated plants also had higher tissue levels of electrical conductivity than NaCl-treated plants. Based on the results of the present study, it seems that both positive and negative effects of Na+ and K+ on plant growth were due to unspecific ionic effects of monovalent cations or/and the specific effect of Cl−.

The aim of the present study was to compare tolerance to salinity and ion accumulation potential of Armeria maritima subsp. elongata. Three accessions (AM1 and AM2, both from Latvia, and AM3 from Sweden) from relatively dry sandy soil habitats in the Baltic Sea region were selected and compared using both in vitro cultivated shoot explants and long-term soil-cultivated plants at flowering stage. Growth of root non-forming explants treated with increasing concentrations of NaCl was significantly inhibited starting from 110 mmol L−1, and the rate of shoot formation was even more sensitive. Significant differences in morphology and responses to salinity were found between different accessions. For soil-grown plants, biomass accumulation in above-ground parts was relatively little affected by salinity in AM1 and AM2 in comparison to that in AM3. Differences in ion accumulation were evident between the accessions as well as in respect to cultivation system used. Maximum accumulation capacity for Na+ was up to 2.5 mol kg−1 both in shoot explant tissues and in old leaves of soil-grown plants treated with NaCl, but that for K+ reached 4.0 mol kg−1 in old leaves of soil-grown plants treated with KCl. Non-ionic component of osmotic value was relatively high in old leaves and significantly increased under NaCl treatment, especially for AM2 and AM3 plants at moderate salinity, but in AM1 only at high salinity. In contrast, it significantly decreased in old leaves of AM2 plants treated with increasing concentration of KCl. It can be concluded that a wide salinity tolerance exists within A. maritima accessions from dry sandy soil habitats, associated with the ability to accumulate surplus ions both in salt glands and old leaves.

In the face of climate change, water deficit and increasing soil salinity pose an even greater challenge to olive cultivation in the Mediterranean basin. Due to its tolerance to abiotic stresses, wild olive (Olea europaea subsp. europaea var. sylvestris) presents a good candidate in breeding climate-resilient olive varieties. In this study, the early response of the native Croatian wild olive genotype (WOG) to salinity was evaluated and compared with that of well-known cultivars (cv.) Leccino and Koroneiki. Potted olive plants were exposed either to 150 mM NaCl or 300 mM mannitol for 3 weeks to distinguish between the osmotic and ionic components of salt stress. To determine the impact of the plant age on salinity, 1-, 2-, and 3-year-old WOG plants were used in the study. The growth parameters of both the cultivars and WOG of different ages decreased in response to the mannitol treatment. In contrast to cv. Leccino, the NaCl treatment did not significantly affect the growth of cv. Koroneiki or WOG of any age. The contents of Na+ and Cl− were considerably higher in the salt-treated WOG, regardless of age, compared with the cultivars. However, while both treatments significantly reduced the K+ content of cv. Koroneiki, that nutrient was not significantly affected in either cv. Leccino or WOG. Unlike the cultivars and older WOG, the NaCl treatment caused a significant decline of photosynthetic pigments in the 1-year-old WOG. The cultivars and WOG of different ages experienced a similar drop in the chlorophyll a content under the isotonic mannitol treatment. The absence of lipid peroxidation, modulation of superoxide dismutase, and guaiacol peroxidase activity were noted in all WOG ages under both stressors. These data suggest that WOG resilience to salinity is associated with its large leaf capacity for Na+ and Cl− accumulation, K+ retention, and its adaptable antioxidative mechanisms. The results are promising with regard to obtaining a new olive cultivar with better resilience to soil salinity.