Search

• Salt-coping strategies were studied investigating roots through a rhizoslide setup. • Different salt tolerance mechanisms were identified in the two halophyte species. • New Zealand spinach accumulated sodium and showed increased WUE at 100 mM NaCl. • Quinoa behaved as a sodium excluder with restricted growth at 100 mM NaCl. • Salinity affected both root architecture and plant transpiration. Soil salinity, root sodium concentration, and transpiration rate are important environmental factors impacting plant growth and productivity. This study investigates the salt-coping strategies of two plant species under varying salinity levels: New Zealand spinach species grown at three salinity levels (i.e., 0, 100, and 200 mM NaCl) and three varieties of quinoa, i.e., "Vikinga", "Dave 407" and "Red Head", grown with or without salt (i.e., 0 and 100 mM NaCl). The plants were grown on glass fiber sheets (rhizoslides) under controlled laboratory conditions. The relationship between transpiration rate, salinity, and root architecture was analyzed for each species. The root apparatus of New Zealand spinach was significantly more developed in plants grown at 100 mM NaCl compared to both 200 mM NaCl and control. The quinoa varieties responded differently to the increasing salt concentrations, with salt-treated "Red Head" plants significantly reducing their total root length and salt-treated "Vikinga" significantly reducing its lateral roots compared to the controls. Salt concentration near New Zealand spinach roots was lower compared to areas without roots, suggesting active salt uptake. In contrast, quinoa rhizoslides exhibited higher salt concentration in proximity to the roots, indicative of salt exclusion. The study provides insights into the adaptation and tolerance mechanisms of these two species to salinity, elucidating the mechanisms by which plants regulate their sodium uptake and root growth. The obtained results suggest that not only the selection of appropriate plant species (halophytes), but also varieties, plays a crucial role in improving crop productivity in salt-affected areas. Elucidating the salt-coping mechanisms of halophytes in relation to soil and climatic conditions is important to better predict their behavior in various saline environments. [ABSTRACT FROM AUTHOR]

• Reference transcriptome of the halophyte AVF was proposed. • After statistical analysis of SSRs, SNPs, and InDels, moderate polymorphism was shown. • Potential candidate genes that contributed to salt tolerance were revealed by analyzing genetic diversity combined with gene expressions. Apocyni Veneti Folium (AVF), the dried leaf of Apocynum venetum L., is a commonly used salt-tolerant Chinese medicinal herb. However, comprehensive research on the breeding of AVL varieties under salt stress has not been conducted. The purpose of this study was to identify AVF genetic variability and candidate genes conferring tolerance to salinity. Apocynum venetum L. was treated with four levels of salt stress (control, 100, 200, and 300 mM NaCl, respectively) and subjected to de novo -based RNA sequencing. Subsequently, MISA, Samtools, and Varscan programs were employed to analyze the characteristics of SSRs, SNPs, and InDels in the transcriptome sequences, respectively. The sequencing results showed that 7046 SSRs (in 54,276 unigenes) and a total of 409 repetitive motifs were found with a frequency of 12.98 %. The mainly repetitive types of SSRs were mononucleotide (49.09 %), dinucleotide (23.91 %), and trinucleotide (14.53 %); a total of 4912 SSRs with a motif length of 12–20 bp accounted for 69.17 %, indicating moderate polymorphism. At the same time, a total of 77,474 SNPs were detected, with the main type being transition (62.46 %); 114,651 InDels in 7656 unigenes were found, with a frequency of 2.03 per kb, and one locus was the most prevalent. The potential candidate genes that contributed to salt tolerance, such as c29028_g1_i1 encoding glycosyltransferase, were screened by analyzing genetic diversity combined with gene expressions. Transcriptome sequencing of AVF provides a reference for its molecular-assisted breeding to the quality identification and genetic diversity analysis. [ABSTRACT FROM AUTHOR]

• Salinity as the catastrophic abiotic stressors significantly affects soybean plants. • Melatonin uses variety of action mechanism to mitigate salt stress in soybean plants. • Beneficial microbes also have potential role in mitigating salt stress effects. An economically valuable crop like soybean is badly impacted by salt stress, a significant environmental stress factor. Researchers have concentrated on the potential of melatonin and microorganisms to reduce the adverse impacts of salinity on soybean plants. The methods by which melatonin (MT) and helpful microorganisms can decrease salt stress in soybean plants are discussed in this review paper. In plants under salinity, MT has been demonstrated to modify ion homeostasis, boost antioxidant defense, and improve osmotic adjustment. The beneficial microorganisms have been demonstrated to improve growth attributes and nutrient uptake, assist plants in ionic adjustment, potassium-mobilization, management of oxidative stress, regulation of stress tolerance genes, and production of plant hormone. Additionally, research has been done on how MT and advantageous microbes work together to improve the salt tolerance of soybean plants. Future research directions are also underlined, including figuring out the molecular processes by which MT and helpful microorganisms work, creating efficient microbial inoculants, looking into alternative treatments, and conducting field tests. Valuable insights into the potential of MT and beneficial microbes for improving soybean productivity and sustainability under salt stress conditions were discussed, highlighting future research directions in this area. This review article suggests developing new agricultural strategies incorporating these agents for improving soybean productivity and sustainability. [ABSTRACT FROM AUTHOR]

• Sapota is a salt-tolerant fruit tree species that can provide significant ecological and economic benefits in salt-affected agroecosystems. • Saline and sodic irrigation water significantly reduced the growth attributes of Sapota in the range of 20–50%, but some cultivars (CSRS 13 and CSRS 15) showed better adaptation to these conditions. • Saline irrigation water increased the Na+ ion content while decreasing the K+ ion content and K+/Na+ ratio, while sodicity stress modulated the physiological processes in Sapota. • Sapota could be successfully cultivated with RSC 2.5 meq/l and EC iw 8 ds/m, using specific cultivars that can tolerate these conditions, such as CSRS 13 and CSRS 15. Salt stress adversely affects the growth and physiological relations in most tree fruit species. Little is known about genetic variation for salt tolerance, and the physiological mechanisms underlying salt tolerance in sapota (Achras zapota), an underutilized fruit crop valued for its nutritive and medicinal properties. Here, we examined the effects of saline (EC iw 4, 8, 12, and 16 dS/m) and sodic (RSC 2.5 and 5.0meq/l) water treatments on plant growth, physiology, and ion homeostasis in the different genotypes of Sapota. Although saline and sodic treatments appreciably reduced the plant growth (i.e., by 20–50%) compared to salt-free plants, genotypes 'CSRS-13' and 'CSRS-15' performed better than others. Salt-induced reductions in leaf area were indicative of the ability of sapota to better acclimatize to prolonged salinity stress by regulating the biomass production. Saline and sodic irrigation treatments increased the leaf Na+ and decreased the leaf K+; albeit with clear-cut genotypic differences. We observed better ion homeostasis in genotype 'CSRS-17' under salinity stress, and better physiological adaptations in genotypes 'CSRS-11' and 'CSRS-17' under sodicity stress. Principal Component Analysis revealed strikingly different responses of sapota genotypes to 'low' and 'high' salinity/sodicity treatments. Strong cultivar-specific responses to salinity and sodicity stresses evinced the existence of genetic variation for salt tolerance in sapota. Overall, our findings demonstrated the feasibility of sapota cultivation in areas with moderate sodicity (RSC ∼2.5 meq/l), and moderate-to-high salinity (∼8.0 dS/m). [ABSTRACT FROM AUTHOR]

MYB transcription factors (TFs) are important regulators of the stress response in plants. In the present study, we characterized the CgMYB1 gene in Chenopodium glaucum , a member of the R2R3-MYB TF family. CgMYB1 was located in the nucleus with an activating domain at the C terminus. The CgMYB1 gene could be induced by salt and cold stress in C. glaucum. Overexpressing CgMYB1 in Arabidopsis significantly enhanced salt and cold tolerance, probably by improving physiological performance and stress-related gene expression. Further analysis suggests that the positive response of CgMYB1 to abiotic stress may partially be attributed to the interaction between CgMYB1 and the CgbHLH001 promoter followed by activation of downstream stress-responsive genes, which mediates stress tolerance. Our findings should contribute to further understanding of the function of R2R3 MYB TF in response to abiotic stress. • CgMYB1 has two conserved MYB domains at N-terminus and variable C terminal region functioning in transcriptional activation. • CgMYB1 TF could bind at MYB recognition site of the CgbHLH001 promoter, and positively mediate the stress tolerance. • Overexpression of CgMYB1 gene enhances salt and cold tolerance in transgenic Arabidopsis. [ABSTRACT FROM AUTHOR]

As a main desert plant from arid regions of Central Asia, Populus euphratica always encounters with nitrogen shortage in its long life, apart from salt or drought stress. However, it remains unknown how this species responds to low nitrogen and combined stresses of low nitrogen and salinity. Thus, saplings of P. euphratica with uniform size were exposed to normal or low nitrogen condition (150 and 15 ppm ammonium nitrate separately) individually or in combination with salinity. Under low nitrogen conditions we found a positive effect on P. euphratica root growth, which could be associated to high level of nitrogen allocation to support root growth and effective regulation of nitrogen assimilation in comparison with the other poplar species reported before. Under salt stress the root growth of P. euphratica was significantly inhibited, with the side effects of oxidative stress, as saplings stored higher Na+ and Cl− contents in roots. Under the combined stressors of both salinity and low nitrogen, P. euphratica undergo a risky strategy, as stimulated root growth is accompanied by further oxidative stress.The concentrations of root K+ and whole plant NO 3 − were increased to support the tolerance of the combined stressors in P. euphratica , showing same characteristics with halophytes. Overall, our results provide evidence that the desert poplar can adapt to the salt stress/low nitrogen bundle, by effective regulation of nitrogen assimilation and ion homoeostasis. • The growth of Populus euphratica roots are inhibited by salt but stimulated by low nitrogen application. • The Populus euphatica saplings store much Na+ and Cl− in the roots to avoid the accumulation of these toxic ion in the leaves. • It is important to keep a suitable nitrate level in leaves and roots to counteract salt stress. • Populus euphratica samplings undergo a risky strategy under the combined low nitrogen and salt stress, as stimulated root growth is accompanied by oxidative stress. • Ion transporters in the different organs contributes to ion homoeostasis and nitrogen nutrition. [ABSTRACT FROM AUTHOR]

• ROS homeostasis during early lifecycle stages of Panicum antidotale were studied. • H 2 O 2 and MDA contents of germinating seeds increased with salinity. • Ascorbate and glutathione levels of germinating seeds decreased at high salinity. • Levels of H 2 O 2 and most antioxidant enzymes in seedlings increased with salinity. • Membrane integrity loss in seedlings was evident only at high salinity. Information about reactive oxygen species (ROS) homeostasis during seed germination and early seedling stage of halophyte grasses is scant. This study examined the effects of increasing salinity on levels of hydrogen peroxide (H 2 O 2 , a common ROS), membrane damage and antioxidant defense during seed germination and early seedling stage of a C 4 xerohalophyte fodder grass Panicum antidotale. Increases in salinity resulted in decreased seed germination. Contents of H 2 O 2 and malondialdehyde (MDA, a common membrane damage marker) in germinating seeds increased with salinity, despite increased activities of most antioxidant enzymes. Whereas, high salinity resulted in decreased ascorbate and glutathione levels in germinating seeds. Growth of the early seedlings decreased with increases in salinity. Sap osmotic potential and chlorophyll content of the seedlings decreased with salinity increments. H 2 O 2 content and activities of most antioxidant enzymes (except catalase) increased with increases in salinity. However, membrane integrity loss (an indicator of membrane damage) increased only at high (400 mM NaCl) but not at moderate (200 mM NaCl) salinity. These data indicate incidence of salinity-induced oxidative damage in both germinating seeds and seedlings of P. antidotale, especially under high salinity. [ABSTRACT FROM AUTHOR]

This study investigated the effect of NaCl on the uptake, translocation, compartmentalization, and chelation of cadmium (Cd) in the halophyte Inula crithmoides. Seedlings were subjected hydroponically for 21 days to 25 and 50 μM Cd applied alone or combined with 100 mM NaCl. Findings revealed that, Cd alone induced intense chlorosis and necrosis and altered plant development resulting in diminished biomass production. However, NaCl alleviated Cd-induced toxicity by increasing biomass accumulation, associated with restoration of photosynthesis activity. At the level of whole plant, NaCl reduced Cd concentration in different organs as well as its translocation toward the shoots. At the cellular level, Na Cl changed the cell-compartmentalization of Cd in the shoots and roots by inducing a preferential accumulation into the soluble fraction (vacuole). NaCl increased the chelation of Cd to chloride and nitrate. As compared to Cd alone, salt addition to Cd-treated plants enhanced significantly succinic acid concentration in the leaves suggesting a possible role of this acid in Cd-chelation. Globally, NaCl alleviated Cd-induced phytotoxicity in this halophyte by reducing Cd absorption, translocation and increased Cd fixation to organic acids as well as through the changes in Cd2+ cell compartmentalization. Obtained data suggested that this fast growing halophyte could be used to rehabilitate Cd polluted saline soils. [Display omitted] • In the absence of NaCl, Cd induced severe toxicity in Inula critmoidess L. • NaCl alleviated Cd toxcity and restored plant growth and photosynthesis. • NaCl reduced Cd-absorption, translocation and modified Cd-cell compartmentalization. • NaCl induced mineral (chloride) and organic (Succinic acid acid) Cd-chelation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Integration of electrodes in CW improved brackish sewage treatment performance. • Electric circuit alleviated salt stress in J. ridigus and improved plant growth. • Electrodes promoted microbial activity in MEBS. • Voltage generation correlated with COD concentration. • Halophyte-based MEBS is well suited for treating brackish sewage in coastal regions. Constructed wetland-microbial fuel cells (CW-MFC) can be the future of sustainable wastewater management. This study developed a multistage CW-MFC based on the halophyte Juncus ridigus for treating brackish sewage. Its treatment efficiency was compared with a multistage constructed wetland without electrodes (CW) and a control (C), which had neither electrodes nor plants. The CW-MFC showed significantly higher removal efficiency for COD, BOD, PO 4 3--P, NH 4 +-N, NO 2 –-N, and NO 3 –-N, with removal efficiency of 81 %, 88 %, 83.58 %, 90.75 %, 80.96 %, and 78.75 %, respectively. Up to a 40.6 % decrease in salinity was observed in CW-MFC, followed by CW and C. Plant absorption and electrode adsorption were the primary mechanisms for removing major salt-contributing ions and elements like Cl-, SO 4 2-, Na, Mg, and Ca. It was further confirmed by their increased deposits in plant tissues and electrodes, as revealed by SEM-EDX. A second-order kinetic model was used to investigate the efficiency of the CW-MFC system regarding pollutant removal. CW-MFC efficiently removed several emerging contaminants from sewage, including phenol, 3,5-bis(1,1-dimethyl ethyl)-, which was also found to be accumulated in the shoots of J. ridigus. Plants in CW experienced stress, as evidenced by lower biomass (47.47 % lower than CW-MFC) and decreased chlorophyll content (20 %), whereas in CW-MFC, they were extremely healthy. Interestingly, CW-MFC had a higher bacterial population than CW, which indicates increased microbial activity. CW-MFC was found to be the most efficient treatment system as it alleviated plant stress and increased bioaccumulation and microbial activity for treating brackish sewage. [ABSTRACT FROM AUTHOR]

The basic region/leucine zipper transcription factors (bZIPs) are one of the largest transcription factor families in eukaryotes, and play a key role in growth, development, and response to abiotic stresses. Limonium bicolor is a typical recretohalophyte, which can excrete excess salts from body to outside through the salt glands located on the stems and leaves to maintain ionic balance in the body. In this study, 58 L. bicolor bZIP members (LbbZIP1 – 58) were identified, which were unevenly distributed on 8 chromosomes and divided into 11 groups. The bioinformatics analysis revealed strong colinearity between LbbZIP s and GmbZIP s of soybean (Glycine max). And promoter cis -acting elements of LbbZIPs were related to stress responses and phytohormone responses. Most LbbZIP members responded to abiotic stresses such as NaCl, PEG, and ABA. Silencing LbbZIP28 in L. bicolor increased salt glands density and salt secretion capacity of leaves, and salt tolerance by means of up-regulating the expression levels of genes involved in salt gland development and ion transport. These results provide new information for LbbZIPs and help to interpret salt gland development and salt secretion in L. bicolor. Our results will provide a reference for a deeper understanding of the molecular foundation of LbbZIPs in L.bicolor. • Limonium bicolor is a pioneer plant for improving and utilizing saline-alkali land. • we identified 58 bZIP genes in L. bicolor genome, and the bioinformatic analysis was carried out. • Silencing LbbZIP28 in L. bicolor increased salt gland density, salt secretion from leaves, and overall salt tolerance. • Our findings provided fundamental information on the structure and evolutionary relationship of LbbZIP gene family in L. bicolor. [ABSTRACT FROM AUTHOR]

Information regarding microbiological hazards in edible macroalgae and halophytes is scarce, and standard methods for detecting norovirus in vegetables have not yet been validated for these types of food products. Accordingly, the suitability of the NF EN ISO 15216-2 standard method for macroalgae and halophytes was evaluated using 57 samples collected along the Western coast of mainland Portugal. The presence of Salmonella in 46 samples was also tested to confirm potential hazard. The viral extraction process was validated for 72% of the samples, with results showing that the standard method is suitable for green and red macroalgae, as well as for halophytes. For brown macroalgae, a process optimization should be considered. None of the samples revealed the presence of norovirus genomes, neither genogroups I nor II. Salmonella was detected in one of the samples analysed. The present study shows the great potential of Portuguese coastal areas for marine agriculture. [ABSTRACT FROM AUTHOR]

Salt stress continues to exert notable impacts on the growth and development of cotton plants. In various biological processes of plants and in response to abiotic stress, long noncoding RNAs (lncRNAs) play a crucial regulatory role. In this study, we conducted transcriptome sequencing of cotton plants grown under salt stress and normal water conditions. A total of 519 lncRNAs and 75,376 messenger RNAs (mRNAs) were identified. Compared with mRNAs, lncRNAs have shorter transcript lengths and open reading frames, fewer exons, and lower expression levels. By comparing and analyzing the differentially expressed lncRNAs (DELs) and differentially expressed coding genes (DEGs) after salt treatment, we identified a total of 60 DELs and 217 DEGs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that these target genes are enriched primarily in intracellular organelles and participate in metabolic regulation pathways. Ultimately, lncRNA XLOC_043671, along with its target gene Gohir.D02G125200 , and the lncRNA XLOC_034831, along with its target gene Gohir.A12G114800 was identified as a participant in salt tolerance regulation in cotton. RNA-seq and RT qPCR revealed that both these lncRNAs and their target genes exhibited significantly enhanced expression under salt stress. Subsequently, utilizing virus-induced gene silencing (VIGS) technology, we successfully silenced the two lncRNAs in cotton plants, which resulted in reduced expression levels of the corresponding target genes, rendering the plants less salt tolerant than did the control plants. Similarly, we successfully silenced these two target genes in cotton seedlings, and the silenced plants demonstrated a pronounced salt-sensitive phenotype. In summary, our transcriptome analysis revealed a significant number of differentially expressed lncRNAs and their corresponding coding genes. These findings lay the foundation for further investigating the mechanisms of lncRNAs and their target genes in the salt stress response of cotton. • Transcriptome analysis revealed cotton salt tolerance lncRNAs and target genes. • Virus-induced gene silencing technology was used to verify genes' function. • Target genes are enriched primarily in intracellular organelles. • Salt tolerant lncRNA XLOC_043671 and its target gene Gohir.D02G125200 are found. • Salt tolerant lncRNA XLOC_034831 and its target gene Gohir.A12G114800 are found. [ABSTRACT FROM AUTHOR]

Suaeda glauca (Bunge) is a pivotal halophyte species, well-known for its rich nutrient content and its importance as a superior vegetable and oil crop, offering significant health benefits for both human and animal consumption. However, the absence of an efficient regeneration technique has severely hindered its genetic development. Consequently, there is an urgent need to establish an effective in vitro organogenesis initiation method for this valuable plant. In this study, our primary objective was to develop a comprehensive protocol for micropropagating S. glauca , primarily capitalizing on the synergistic effects of 6-benzylaminopurine (6-BAP) and indole-6-butyric acid (IBA). We explored the impact of different combinations of 6-benzylaminopurine (6-BAP), 2,4-dichloroacetic acid (2,4-D), and IBA on callus induction, organogenesis, and rooting using various explants (cotyledons, hypocotyls, and leaves) under two different photoperiod regimes during in vitro culture. Our results unveiled noteworthy variations in several variables related to organogenesis. The optimal combination of plant growth regulators (PGRs) for inducing embryonic callus from cotyledon (COT) was pinpointed at 4.44 μM 6-BAP and 2.71 μM 2,4-D. By employing 6-BAP concentrations ranging from 8.88 μM to 13.33 μM, alongside 0.49 μM IBA, 3% sucrose, and 0.3% phytagel in full MS media under light conditions, we achieved a remarkable 100% regeneration rate through the direct organogenesis pathway. Our findings underscore the pivotal role of 6-BAP in triggering multiple shoots and attaining a 3.6% callus differentiation rate, while 0.98 μM IBA resulted in a 65.28% root induction rate, facilitating the successful acclimatization of plants. Based on the synergistic effects of 6-BAP and IBA, we propose a robust protocol for S. glauca organogenesis, which holds great promise for streamlining micropropagation in S. glauca tissue culture. This standardized protocol has the potential to advance genetic improvement and promote the commercial cultivation of S. glauca as a valuable halophyte species. [Display omitted] • In this work, we establish an efficient, simple, and repeatable in vitro plant regeneration method using direct and callus-mediated plant regeneration in the S. glauca. • This is the first report of direct multiple shoot induction and callus proliferation in this plant. • This protocol is ideal for further genetic transformation of S. glauca. • This technique can be used to produce a large number of in vitro plantlets for commercial production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Non-alkaline salinity stress of the plants mainly results from interactions of NaCl, Na 2 SO 4. • Alkaline salinity stress of the plants is mainly caused by NaHCO 3 and Na 2 CO 3. • Indicators of alkaline soda habitats: Aster tripolium, Puccinellia limosa , Suaeda pannonica. • Indicators of saline habitats: Juncus maritimus , Salicornia prostrata, Suaeda salsa. • Solid Earth surface heat flow was identified as a new extreme factor of the halophytes. From an ecological standpoint, saline and alkaline habitats are considered as extreme environments for vascular plants because salinity and alkalinity serve as primary structuring factors that significantly influence the species richness of vegetation cover. The non-alkaline salinity stress on plants primarily results from interactions of NaCl, Na 2 SO 4 , and other neutral salts, whereas alkalinity stress is caused by NaHCO 3 and Na 2 CO 3 , accompanied by an increase in pH. Some halophytes and salt-tolerant plants are well-adapted to such permanent abiotic stress. Surprisingly, they are able to survive and reproduce under environmental conditions of more than 200 mM NaCl concentration and are also able to live permanently in extreme conditions. The aim of this study was to identify characteristic and indicator plant species for permanently alkaline soda and non-alkaline saline wetland habitats, and to analyze the relationship between the chemical composition of water and the plant's saturation index. Based on the obtained results we can conclude that plant species identified to live in high saline conditions may also grow under high alkaline conditions. Two groups were distinguished based on the salinity and alkalinity: "Saline group" includes all types of halophytes and halotolerant species, while "Soda group" includes obligate alkalophytes and alkalotolerant species. However, the diversity of plants in alkaline environment is bigger than in saline environment, and most of the halotolerant species grow in both alkaline soda and saline habitats. It is possible to identify three indicator species requiring alkaline soda habitats to live in (Aster tripolium, Puccinellia limosa , Suaeda pannonica) and three indicator species that dominantly grow in non-alkaline saline habitats (Juncus maritimus , Salicornia prostrata, Suaeda salsa). Different independent variables have been identified and analyzed to understand their influence on the species saturation index by calculating percentage of characteristic plant species of the entire region. It was identified that the plant saturation index has a significant positive relationship with the Mean Temperature of the Warmest Quarter, Topsoil Sand, and Clay fraction variables, and there is a significant negative relationship with the Solid Earth surface heat flow, as the heating can increase the extremity of the environment. Identification of indicator species of salinity and alkalization makes it possible to determine the type of soil, water bodies and habitats as a rapid biomonitoring method as a visual observation, without the use of expensive equipment and chemical laboratory tests. [ABSTRACT FROM AUTHOR]

White birch (Betula platyphylla Suk.) is an important pioneer tree which plays a critical role in maintaining ecosystem stability and forest regeneration. The growth of birch is dramatically inhibited by salt stress, especially the root inhibition. Salt Overly Sensitive 1 (SOS1) is the only extensively characterized Na+ efflux transporter in multiple plant species. The salt-hypersensitive mutant, sos1 , display significant inhibition of root growth by NaCl. However, the role of SOS1 in birch responses to salt stress remains unclear. Here, we characterized a putative Na+/H+ antiporter BpSOS1 in birch and generated the loss-of-function mutants of the birch BpSOS1 by CRISPR/Cas9 approach. The bpsos1 mutant exhibit exceptional increased salt sensitivity which links to excessive Na+ accumulation in root, stem and old leaves. We observed a dramatic reduction of K+ contents in leaves of the bpsos1 mutant plants under salt stress. Furthermore, the Na+/K+ ratio of roots and leaves is significant higher in the bpsos1 mutants than the wild-type plants under salt stress. The ability of Na+ efflux in the root meristem zone is found to be impaired which might result the imbalance of Na+ and K+ in the bpsos1 mutants. Our findings indicate that the Na+/H+ exchanger BpSOS1 plays a critical role in birch salt tolerance by maintaining Na+ homeostasis and provide evidence for molecular breeding to improve salt tolerance in birch and other trees. • We created sos1 loss-of-function mutants via CRISPR-Cas9 technology. • The Na+/H+ exchanger BpSOS1 is conserved in birch. • BpSOS1 plays a critical role in birch salt tolerance by sodium efflux and Na+ homeostasis. [ABSTRACT FROM AUTHOR]

The escalating salinity levels in cultivable soil pose a significant threat to agricultural productivity and, consequently, human sustenance. This problem is being exacerbated by natural processes and human activities, coinciding with a period of rapid population growth. Developing halophytic crops is needed to ensure food security is not impaired and land resources can be used sustainably. Evolution has created many close halophyte relatives of our major glycophytic crops, such as Puccinellia tenuiflora (relative of barley and wheat), Oryza coarctata (relative of rice) and Glycine soja (relative of soybean). There are also some halophytes have been subjected to semi-domestication and are considered as minor crops, such as Chenopodium quinoa. In this paper, we examine the prevailing comprehension of robust salinity resilience in halophytes. We summarize the existing strategies and technologies that equip researchers with the means to enhance the salt tolerance capabilities of primary crops and investigate the genetic makeup of halophytes. • Developing halophytic crops is needed to ensure food security is not impaired and land resources can be used sustainably. • The study of these halophytes will help us improve the salt tolerance of our existing crops and diversify the human diets. • We conclude the available strategies and technologies that enable the researchers to improve the salt tolerance performance of the major crops and the genetics of halophytes. [ABSTRACT FROM AUTHOR]

The use of halophytes in conjunction with arbuscular mycorrhizal (AM) fungi has been found to enhance the removal efficacy of heavy metals and salts in heavy metals contaminated saline soil. The mechanisms of AM fungi on promoting halophyte growth and regulating metabolism remain unclear. In this study, combinations of 0 g kg−1 NaCl and 3 mg kg−1 Cd (S0Cd3), 6 g kg−1 NaCl and 3 mg kg−1 Cd (S6Cd3), and 12 g kg−1 NaCl and 3 mg kg−1 Cd (S12Cd3) were employed to explore the impact of Funneliformis mosseae on the growth and metabolism of Suaeda salsa. The results showed that AM fungi increased the biomass and the P, K+, Ca2+, and Mg2+ accumulations, reduced the Cd and Na+ concentrations in S0Cd3 and S6Cd3, and increased the Cd concentrations in S12Cd3. AM fungi inoculation reduced the Cd and Na+ transfer factors and increased the Cd and Na+ accumulations in S6Cd3. The metabolomics of S6Cd3 showed that AM fungi upregulated the expression of 5-hydroxy-L-tryptophan and 3-indoleacid acid in tryptophan metabolism, potentially acting as crucial antioxidants enabling plants to actively cope with abiotic stresses. AM fungi upregulated the expression of arbutin in glycolysis process, enhancing the plants' osmoregulation capacity. AM fungi upregulated the expression of 2-hydroxycinnamic acid in phenylalanine metabolism and dopaquinone in tyrosine metabolism. These two metabolites help effectively remove reactive oxygen species. Correspondingly, AM fungi decreased MDA content and increased soluble sugar content. These results indicate that AM fungi improve the stress resistance of S. salsa by increasing nutrient uptake and regulating physiological and metabolic changes. [Display omitted] • AMF increased biomass, nutrient elements and toxic ions accumulations of Suaeda salsa. • AMF upregulated the expression of amino acid and phytohormone-related metabolites. • AM fungi activated glycolysis/gluconeogenesis metabolic pathways. [ABSTRACT FROM AUTHOR]

Two saltmarsh locations within Lake Macquarie, NSW, Australia were selected to investigate the uptake and partitioning of metal(loid)s Cu, Zn, As, Se, Cd and Pb in the Australian saltmarsh halophyte, Sarcocornia quinqueflora and the associated sub-lethal effects of metal(loid)s on plant health, including photosynthetic performance, biomass, and productivity. Metal(loid)s primarily accumulated to roots (BCF > 1). Barriers to transport were observed at the root to non-photosynthetic stem transition (TF < 1) for all metal(loid)s, suggesting this species is suitable for phytostabilisation. Sediment and plant tissue metal(loid) concentrations were significantly correlated with photosynthetic performance and plant biomass. As such, the action of sediment and tissue metal(loid)s on photosynthetic performance and the subsequent effect on biomass of S.quinqueflora appear to be suitable targets for molecular analyses to further elucidate mechanisms responsible for the observed adverse effects and the development of adverse outcome pathways. • S. quinqueflora suitable for phytostabilisation of metal(loid)s • Essential metals regulated whilst non-essential metals accumulated in S.quinqueflora • Roots suitable bioindicator of Cd and Pb contamination • Metal(loid)s in sediment or tissues correlated with Chl fluorescence and biomass • Chl fluorescence parameters correlated with S.quinqueflora biomass [ABSTRACT FROM AUTHOR]

Halophytes are characterized by their ability to survive in environments with high salinity, and many of these species eliminate excess salts through secretory structures, such as salt glands or bladders. Rhizophora mangle , however, is a halophyte that does not have specialized structures for eliminating salts, but it does have lenticels located on the lower surface of the leaves. These lenticels are not only involved in oxygenating plant tissues, but they can also eliminate toxic substances. Thus, we hypothesized that the lenticels could act as structures involved in the elimination of excess salts. In this study, we used light microscopy to observe the occurrence of lenticels on the stipules and both young and adult leaves of R. mangle. Using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX), we also analyzed the composition of chemical elements found in the extrusion content of lenticels. The origin of lenticels, both stipular and foliar, is stomatal, and, at the end of development, the stomatal complex is degraded, generating the opening pore. Sea salt was observed on the surface of leaf lenticels, as evidenced by EDX-SEM. The most representative elements on the surface of the lenticels were Cl, Ca, and Na, respectively. In this way, we suggest that the lenticels in R. mangle act as pores through which minerals, such as Na, Cl, Ca, K, Mg, P, S, and Si, can be eliminated by the leaves, an important strategy to maintain the osmotic balance of a typical mangrove species growing in a tropical region. • Secretion of salt and pollutants via lenticels. • New function of leaf lenticels. • Anatomical structure of Rhizophora mangle leaves. [ABSTRACT FROM AUTHOR]

The plasmalemma Na+/H+ antiporter Salt Overly Sensitive 1 (SOS1) is responsible for the efflux of Na+ from the cytoplasm, an important determinant of salt resistance in plants. In this study, an ortholog of SOS1 , referred to as NsSOS1 , was cloned from Nitraria sibirica , a typical halophyte that grows in deserts and saline-alkaline land, and its expression and function in regulating the salt tolerance of forest trees were evaluated. The expression level of NsSOS1 was higher in leaves than in roots and stems of N. sibirica , and its expression was upregulated under salt stress. Histochemical staining showed that β-glucuronidase (GUS) driven by the NsSOS1 promoter was strongly induced by abiotic stresses and phytohormones including salt, drought, low temperature, gibberellin, and methyl jasmonate, suggesting that NsSOS1 is involved in the regulation of multiple signaling pathways. Transgenic 84 K poplar (Populus alba × P. glandulosa) overexpressing NsSOS1 showed improvements in survival rate, root biomass, plant height, relative water levels, chlorophyll and proline levels, and antioxidant enzyme activities versus non-transgenic poplar (NT) under salt stress. Transgenic poplars accumulated less Na+ and more K+ in roots, stems, and leaves, which had a lower Na+/K+ ratio compared to NT under salt stress. These results indicate that NsSOS1-mediated Na+ efflux confers salt tolerance to transgenic poplars, which show more efficient photosynthesis, better scavenging of reactive oxygen species, and improved osmotic adjustment under salt stress. Transcriptome analysis of transgenic poplars confirmed that NsSOS1 not only mediates Na+ efflux but is also involved in the regulation of multiple metabolic pathways. The results provide insight into the regulatory mechanisms of NsSOS1 and suggest that it could be used to improve the salt tolerance of forest trees. • A plasmalemma Na+/H+ antiporter was identified from the halophyte Nitraria sibirica. • Expression of NsSOS1 was strongly induced by abiotic stresses and phytohormones. • NsSOS1-mediated Na+ efflux confers salt tolerance to transgenic poplars. • NsSOS1 is involved in regulation of multiple metabolic pathways in transgenic plants. [ABSTRACT FROM AUTHOR]

• Cenchrus ciliaris, a potential fodder for livestock in the hot saline deserts. • Anatomical modifications for water conservation is a major strategy of salt tolerant plants. • Sclerification in Cenchrus ciliaris is an important defense mechanism from saline Desert environments. • Cenchrus ciliaris tolerate moderate to high salt stress by maintaining its forage parameters and nutrient composition. Cenchrus ciliaris is a potential forage grass that is widely distributed in saline desert condition across Africa, Australia and Asia. To examine anatomical characteristics relating to ionic and nutritional contents in response to salinity, Cenchrus ciliaris populations from the naturally salt-affected region of the Cholistan Desert, Pakistan were collected. The experiment was planned in a completely randomized design (CRD) with four replications and four treatment levels (0, 100, 200, and 300 mM NaCl) in a hydroponic system. After six months of growth in nutrient solution anatomical characteristics relating to ionic and nutritional traits were studied. It was hypothesized that C. ciliaris at higher salt stress must have developed some specific structural adaptations, which are responsible for better survival under high salt stress. At root level, C. ciliaris showed decreased root thickness with greater proportion of parenchyma cells in cortical region and increased sclerification in cortex and pith regions at high salinity levels, which are vital for water conservation under osmotic stress. At stem level increased stem area, cortical and vascular bundle cell area were recorded with increase in salinity level of external growth medium. Salt tolerance in C. ciliaris mainly associated with restricted uptake of toxic Na+ and Cl− ions at roots, accompanied by increased concentration of K + and Ca++ in shoot. Under high salinities, C. ciliaris showed increased epidermis thickness, well developed bulliform cells, and increased trichome density at leaf level. All these structural modification in this species may contribute towards water conservations under physiological stress that is caused by high level of soil salinity. Various nutritional traits such as crude protein, ash content, relative feed value, and net energy of lactation slightly improved with salinity. Present study revealed nutritional potential, ionic contents and anatomical adaptations of C. ciliaris to cope with salinity. As such this species can be used to produce valuable fodder under saline desert environment. [ABSTRACT FROM AUTHOR]

Various abiotic stresses commonly cause excessive production of reactive oxygen species (ROS) and result in oxidative stress, which challenges the physiological homeostasis of plants. Maintaining a delicate balance between ROS generation and removal is critical for plants to cope with stressful environments. Suaeda corniculata is a typical euhalophyte with strong tolerance to salt stress, but its mechanism of ROS detoxification to prevent oxidative stress is unknown. Here, a combined analysis of RNA-Seq and photosynthetic assays was performed on S. corniculata under oxidative stress to uncover the underlying mechanism that modulates oxidative tolerance. Our results showed that all genes involved in the pathway of ROS scavenging, especially the AsA-GSH pathway, were highly enriched under oxidative stress. Notably, VTC2 (GGPase), which functions in the L-galactose pathway of AsA synthesis, was significantly upregulated. Arabidopsis transgenic plants with heterologous expression of Sc VTC2 showed elevated AsA and increased tolerance to oxidative stress. Furthermore, ScVTC2 also established better photosynthetic capacity in these plants upon oxidative treatment. Thus, ScVTC2 not only functioned as an effective ROS scavenger but also as a protector of the photosynthetic apparatus in S. corniculata and allowed plants to respond to and tolerate oxidative stress. • Differentially expressed genes response to oxidative stress were highly enriched in AsA-GSH pathway. • Transcript level of AsA synthesized gene ScVTC2 was induced by oxidative, salt and alkali stress. • Over-expression of ScVTC2 contributes to oxidative tolerance by maintaining ROS homeostasis and photosynthesis capacity. [ABSTRACT FROM AUTHOR]

Prosopis strombulifera (Lam.) Benth. is a halophytic shrub abundant in high-salinity areas in central Argentina, with high tolerance against NaCl but strong growth inhibition by Na 2 SO 4. In the present study, the modulation of the antioxidant systems (enzymatic and non-enzymatic components) was analyzed under different salt treatments (NaCl, Na 2 SO 4 and the iso-osmotic mixture) in hydroponic cultivation. Na 2 SO 4 -treated plants showed strong indications of oxidative stress (H 2 O 2 and O 2 -• increase). Modifications in antioxidant enzymes activities were observed mainly under Na 2 SO 4 treatment, where CAT seems to play an important role in early detoxification of H 2 O 2 in roots, whereas SOD and APX have a predominant role in leaves. As part of the non-enzymatic system, 21 compounds were identified in leaves, being polyphenols the most abundant. Control plants contained the major variety of detected phytochemicals (14). Na 2 SO 4 -treated plants contained 10 compounds and NaCl-treated plants nine compounds, but with a different profile. NaCl-treated plants showed the highest antioxidant capacity. Our findings confirm that different types of salt treatments provoke a differential modulation of the antioxidant systems. Polyphenols and other ROS-detoxifying compounds, in a joint action with the enzymatic antioxidant system, are proposed to have a fundamental role in the cellular protection of P. strombulifera plants under severe oxidative stress. Our findings also highlight the potential of this halophyte as a valuable source of bioactive compounds with high antioxidant activity and health benefits. • Prosopis strombulifera is a halophytic shrub with high tolerance against NaCl but strong growth inhibition by Na 2 SO 4. • Prosopis strombulifera plants growing under Na 2 SO 4 treatment showed strong indications of oxidative stress. • Modifications in antioxidant enzyme activities were observed mainly under Na 2 SO 4 treatment. • Phytochemical composition was analyzed in leaves and 21 compounds were identified with different profile in each treatment. • P. strombulifera is a valuable source of bioactive compounds with high antioxidant activity and health benefits. [ABSTRACT FROM AUTHOR]

The ability of halophytes to thrive under saline conditions implies efficient ROS detoxification and signalling. In this work, the causal relationship between key membrane transport processes involved in maintaining plant ionic homeostasis and oxidative stress tolerance was investigated in a succulent perennial halophyte Sarcocornia quinqueflora. The flux responses to oxidative stresses induced by either hydroxyl radicals (OH•) or hydrogen peroxide (H 2 O 2) were governed largely by (1) the type of ROS applied; (2) the tissue-specific origin and function (parenchymatic or chlorenchymatic); and (3) the tissue location in respect to the suberized endodermal barrier. The latter implied significant differences in responses between outer (water storage-WS; palisade tissue-Pa) and inner (internal photosynthetic layer-IP; stele parenchyma-SP) stem tissues. The ability of the cell to retain K+ under OH• stress varied between different tissues and was ranked in the following descending order: WS>Pa>IP>SP. OH• always led to Ca2+ influx in all stem tissues, while treatment with H 2 O 2 induced tissue-specific Ca2+ "signatures". The inner/outer K+ ratio was the highest (~2.6) under the optimum NaCl dosage (200 mM) in comparison to non-saline (~0.4) and severe (800 mM; ~0.7) conditions, implying that a higher K+ concentration in the inner tissues is important for optimum growth. The overall results demonstrate a clear link between plant anatomical structure and ability of its tissues to maintain ionic homeostasis, via modulating their ROS sensitivity. • Perennial halophyte S. quinqueflora can tolerate severe saline conditions due to efficient ROS detoxification and signalling. • Parenchymatic and chlorenchymatic tissues possessed differential sensitivity to various ROS types. • Unique anatomy of S. quinqueflora confer its tissues, ability to maintain ionic homeostasis, via modulating ROS sensitivity. [ABSTRACT FROM AUTHOR]

This study aims to establish for the first time a comparison between the resistance to cadmium (Cd) stress of three halophyte species, Atriplex canescens , Atriplex halimus and Atriplex nummularia in addition to their already known tolerance for salt and drought. Plants were exposed to CdCl 2 (20 and 50 μM) in the presence or in the absence of salt (50 mM NaCl) for one and two months. The amount of accumulated Cd was determined in the roots and leaves as well as the amount excreted on the surface of the leaves. Physiological parameters such as chlorophyll content and stress biomarkers, including malondialdehyde and enzymatic activities, were then analyzed. The results show that these plants are able to neutralize the excess of reactive oxygen species resulting from treatments by activating the antioxidant defense mechanisms in order to restore the homeostasis of cells. All three species are also able to accumulate high amounts of Cd in the leaves (several hundred mg of Cd/kg of dry leaves) and this phenomenon is amplified in the presence of salt. All together our results allow to consider the three Atriplex species as hyperaccumulators in the presence/absence of salt and as good candidates in a strategy of Cd phytoextraction in the presence of low concentrations of the pollutant. Nevertheless, both A. canescens and A. nummularia species seem to have a higher capacity to hyper-accumulate Cd when the concentration of Cd reaches higher level of contamination. [Display omitted] • A comparison between the resistance to cadmium stress of the three halophyte species, A. canescens, A. halimus and A. nummularia. • Determination time required phytoextraction of cadmium process in three species of the genus Atriplex for the different treatments. • Evaluation of the ability to excrete cadmium in the three species on the leaf surface in the presence or not of salt. [ABSTRACT FROM AUTHOR]

• Galanthamine and lycorine content in L. aestivum were affected by salt stress. • Galanthamine in the bulb was enhanced 4 times with 4 g/L CaCl 2 treatment. • Salt stress raised enzymatic and non-enzymatic antioxidant activities in the bulbs. • Shoot length and bulb size were not affected by salt stress significantly. • L. aestivum appears to be a salt tolerant plant. Summer snowflake (Leucojum aestivum L.) is a bulbous plant to the Amaryllidaceae family. L. aestivum is a Euro-Mediterranean region plant and is a well-known source of pharmacologically important alkaloids. Galanthamine is the major bioactive compound that is widely used in the treatment of neurological disorders, including Alzheimer's disease. Another alkaloid lycorine has antitumor, antimalarial, hepatoprotective, antiviral, antifungal and antiparasitic activities. The objective of this study was to determine the effect of different salt stress treatments on galanthamine and lycorine amounts, growth and development, non-enzymatic antioxidant activities (free radical scavenging activity and total phenol-flavonoid content) and enzymatic antioxidant activities [superoxide dismutase (SOD) and catalases (CAT)] in L. aestivum. The plant was cultivated for 3.5 months watering with 3 different concentrations (2, 4 and 8 g/L) of 2 different salt types (NaCl and CaCl 2). Salt stress treatments did not change the shoot length, bulb size and water content significantly. Obtained leaves and bulbs were extracted with methanol and analyzed with HPLC-DAD system. Galanthamine and lycorine amounts were enhanced with 4 g/L CaCl 2 in the bulbs. Galanthamine in the leaves was also improved with 8 g/L NaCl. Salt stress treatments did not change the lycorine content in the leaves. Antioxidant capacity of the bulbs and leaves of L. aestivum was very low. Salt stress caused by 4 g/L CaCl 2 increased the antioxidant activity only in the leaves and total phenol-flavonoid content in the bulbs. All salt stress treatments increased the SOD activity in the bulbs. The highest SOD and CAT activities were observed with 8 g/L CaCl 2 and 4 g/L NaCl, respectively in the bulbs. Some CaCl 2 treatments (2 g/L and 4 g/L) increased the activity of SOD and CAT, respectively. It was concluded that L. aestivum is a salt tolerant plant, and 4 g/L CaCl 2 is a conspicuous treatment in terms of increased galanthamine amount and antioxidant activities (non-enzymatic and enzymatic) in the bulbs. [ABSTRACT FROM AUTHOR]

Calcium-dependent protein kinases (CDPKs) are Ca2+ decoders in plants. AtCPK1 is a positive regulator in the plant response to biotic and abiotic stress. Inactivation of the autoinhibitory domain of AtCPK1 in the mutated form KJM23 provides constitutive activity of the kinase. In the present study, we investigated the effect of overexpressed native and mutant KJM23 forms on salinity tolerance in Nicotiana tabacum. Overexpression of native AtCPK1 provided tobacco resistance to 120 mM NaCl during germination and 180 mM NaCl during long-term growth, while the resistance of plants increased to 240 mM NaCl during both phases of plant development when transformed with KJM23. Mutation in the junction KJM4, which disrupted Ca2+ induced activation, completely nullified the acquired salt tolerance up to levels of normal plants. Analysis by confocal microscopy showed that under high salinity conditions, overexpression of AtCPK1 and KJM23 inhibited reactive oxygen species (ROS) accumulation to levels observed in untreated plants. Quantitative real-time PCR analysis showed that overexpression of AtCPK1 and KJM23 was associated with changes in expression of genes encoding heat shock factors. In all cases, the KJM23 mutation enhanced the effect of AtCPK1, while the KJM4 mutation reduced it to the control level. We suggest that the autoinhibitory domains in CDPKs could be promising targets for manipulation in engineering salt-tolerant plants. • AtCPK1 provided tobacco resistance to 120 mM NaCl (germination) and 180 mM NaCl (long-term growth). • Mutated AtCPK1 , KJM23 increased the resistance of plants up to 240 mM NaCl. • Mutated AtCPK1 , KJM4 completely nullified the acquired salt tolerance up to levels of normal plants. • AtCPK1 and KJM23 inhibited early ROS accumulation under high salinity conditions. • AtCPK1 and KJM23 associated with changes in expression of genes encoding heat shock factors. [ABSTRACT FROM AUTHOR]

Knowledge about Solanaceae species naturally adapted to salinity is scarce, despite the fact that a considerable number of Solanaceae has been reported growing in saline environments. Lycium humile Phil. inhabits extreme saline soils in the Altiplano-Puna region (Central Andes, South America) and represents a promising experimental model to study salt tolerance in Solanaceae plants. Seeds, leaves and roots were collected from a saline environment (Salar del Diablo, Argentina). Seeds were scarified and 30 days after germination salt treatments were applied by adding NaCl salt pulses (up to 750 or 1000 mM). Different growth parameters were evaluated, and leaf spectral reflectance, endogenous phytohormone levels, antioxidant capacity, proline and elemental content, and morpho-anatomical characteristics in L. humile under salinity were analyzed both in controlled and natural conditions. The multiple salt tolerance mechanisms found in this species are mainly the accumulation of the phytohormone abscisic acid, the increase of the antioxidant capacity and proline content, together with the development of a large leaf water-storage parenchyma that allows Na+ accumulation and an efficient osmotic adjustment. Lycium humile is probably one of the most salt-tolerant Solanaceae species in the world, and, in controlled conditions, can effectively grow at high NaCl concentrations (at least, up to 750 mM NaCl) but also, in the absence of salts in the medium. Therefore, we propose that natural distribution of L. humile is more related to water availability, as a limiting factor of growth in Altiplano-Puna saline habitats, than to high salt concentrations in the soils. [Display omitted] • Lycium humile probably is one of the most salt-tolerant Solanaceae species. • Lycium humile can grow at high salt concentrations (at least, up to 750 mM NaCl). • Antioxidant capacity, abscisic acid and proline convey salt tolerance. • Large leaf water-storage parenchyma allows Na+ accumulation and osmotic adjustment. [ABSTRACT FROM AUTHOR]

• M. crystallinum can grow well on soil treated with solution containing 400 mM NaCl. • The salt-treated plant had a shorter flower blooming time than the control plant. • The salt-treated plant accumulated more betacyanin and EBCs than the control plant. • The seeds of salt-treated plants in Japan germinated rapidly and grew well in Vietnam. • The salt-treated plants can be used as ornamental flowers for decoration. This study presents the reproductive growth characteristics of a halophyte Mesembryanthemum crystallinum L. when grown in high-salinity soil stress conditions. The experiments were arranged and carried out continuously from 2020 to 2023, the first two years at Kyushu University in Japan and the last year at Duy Tan University in Vietnam. During the time in Japan, the effects of salinity stress on the reproductive growth stages and the morphological characteristics of M. crystallinum cultured in the soil treated with saline solutions containing 0 mM, 100 mM, and 400 mM NaCl were determined. Then, the seeds harvested from these plants were reproduced to develop them as the high salt-tolerance plants in Vietnam. The results show that 400 mM NaCl-treated plants maintained their growth and developed well during the vegetative growth stage. These plants had shorter flower blooming times than the 100 mM NaCl-treated and control ones (0 mM NaCl). The seeds harvested from NaCl-treated and control plants in Japan had regenerated in vitro plants well in the Vietnamese culture rooms. Interestingly, the 400 mM NaCl-treated M. crystallinum grew healthily in the soil, and their leaves, flowers, and seedpods tended to accumulate more betacyanin and epidermal bladder cells (EBCs) than other plants. These characteristics may be desirable for rehabilitating saline soil and developing high-salinity tolerance M. crystallinum for cultivation and growth in Vietnam. [ABSTRACT FROM AUTHOR]

Halophytes inhabit saline soils, wherein most plants cannot grow, therefore, their ecological value is outstanding. Arbuscular mycorrhizal (AM) fungi can reconstruct microbial communities to assist plants with stress tolerance. However, little information is available on the microbial community assembly of AM fungi in halophytes. A pot experiment was conducted to investigate the effects of AM fungi on rhizosphere bacterial community structure and soil physiochemical characteristics in the halophyte Suaeda salsa at 0, 100, and 400 mM NaCl. The results demonstrated that AM fungi increased soil alkaline phosphatase (ALP) activity at the three NaCl concentrations, and decreased available P, available K, and the activity of soil catalase (CAT) at 100 mM NaCl. AM fungi decreased the Shannon index of the community at 0 and 100 mM NaCl and increased Sobs index at 400 mM NaCl. Regarding the bacterial community structure, AM fungi substantially decreased the abundance of Acidobacteria phylum at 0 and 100 mM NaCl. AM fungi significantly increased the abundance of genus Ramlibacter , an oxyanion-reducing bacteria that can clean out reactive oxygen species (ROS). AM fungi recruited the genera Massilia and Arthrobacter at 0 and 100 mM NaCl, respectively. Some strains in the two genera have been ascribed to plant growth promoting bacteria (PGPB). AM fungi increased the dry weight and promoted halophyte growth at all three NaCl levels. This study supplements the understanding that AM fungi assemble rhizosphere bacterial communities in halophytes. [Display omitted] • AMF reconstructed the bacterial community. • AMF decreased Shannon at 0 and 100 mM NaCl and increased Sobs at 400 mM NaCl. • AMF decreased the abundances of phylum Acidobacteria at 0 and 100 mM NaCl. • AMF increased the abundances of genus Ramlibacter which is oxyanion-reducing bacteria. • AMF could recruit some bacteria ascribed to plant growth-promoting rhizobacteria. [ABSTRACT FROM AUTHOR]

Salt stress is a serious environmental challenge that hinders crop growth and yield. Plant growth-promoting rhizobacteria (PGPR) can successfully and environmentally friendly boost plant development in saline soils. In this study, a halotolerant Serratia sp. NTN6 was isolated from the rhizosphere soil of halophyte Puccinellia tenuiflora and its plant growth-promoting properties were determined. NTN6 inoculation significantly promoted seed germination and seedling growth in maize under salt stress. Shoot height, stem thickness, root fresh weight, shoot fresh weight, root dry weight, and shoot dry weight of salt-stressed seedlings increased by 36.3%, 32.5%, 146.4%, 193.6%, 25.0%, and 109.6%, respectively, after inoculation with NTN6. NTN6-mediated maize salt tolerance was revealed via transcriptomic, physiological, and biochemical analyses. Under salt stress, NTN6 regulated the transcript levels of genes related to chlorophyll synthesis, photosynthesis apparatus, and carbon assimilation pathways, and thus increasing chlorophyll content, Fv/Fm, and net photosynthetic rate; NTN6 reduced the content of O 2 •–, H 2 O 2 , and MDA by regulating the transcripts and activities of antioxidant enzymes; NTN6 affected the transcriptional response of genes involved in ABA synthesis and signaling to salt stress and reduced ABA level. Finally, NTN6 boosted photosynthetic capacity in salt-stressed maize by modulating photochemical activity, C 4 pathway and Calvin cycle as well as mitigating reactive oxygen species damage to the photosystem reaction center. This study first investigated the mechanism of Serratia sp.-induced salt tolerance in maize and these findings demonstrate the valuable contribution of halotolerant PGPR strain from halophytes in improving salinity tolerance in non-halophytic crops. • Serratia sp. NTN6 was isolated from the rhizosphere soil of Puccinellia tenuiflora. • NTN6 boosted maize seed germination and seedling growth under salt stress. • NTN6 upregulated antioxidant enzyme genes and activity in salt-stressed seedlings. • NTN6 alleviated the inhibition of photosynthetic genes and activity by salt stress. • NTN6 inhibited ABA content and signaling in salt-stressed maize seedlings. [ABSTRACT FROM AUTHOR]

Nitraria sibirica Pall is a halophytic shrub growing in desert steppe zones. It exhibits extraordinary adaptability to saline–alkali soil, drought, and sand burial. In this study, the high-affinity K+ transporter NsHKT1 was identified and found to play a key role in salt tolerance in N. sibirica. NsHKT1 was used to improve salt tolerance in a poplar hybrid. The expression characteristics of NsHKT1 were analyzed by transforming Arabidopsis and poplar with the β-glucuronidase (GUS) gene driven by the NsHKT1 promoter. The results showed that NsHKT1 expression was induced by various abiotic stresses and phytohormones. GUS expression was also detected in the reproductive organs of transgenic Arabidopsis, indicating its function in regulating plant reproductive growth. Transgenic 84 K poplar plants overexpressing NsHKT1 exhibited less damage, higher antioxidant capacity, higher chlorophyll and proline levels, and lower malondialdehyde content compared with non-transgenic plants under salt stress. These results are consistent with the salt tolerance results for transgenic Arabidopsis overexpressing NsHKT1 , indicating that NsHKT1 plays a key role in salt tolerance in herbaceous and ligneous plants. Inductively coupled plasma–optical emission spectrometry showed a significantly lower leaf Na+ content in transgenic poplar than in the non-transgenic line, revealing that NsHKT1, as a member of HKT family subclass 1, was highly selective to Na+ and prevented shoot Na+ accumulation. Transcriptome analysis indicated that differentially expressed genes in transgenic poplars under salt stress were associated mainly with the isoflavonoid, cutin, suberine, wax, anthocyanin, flavonoid, and cyanoamino biosynthesis pathways, as well as the MAPK signaling pathway, indicating that NsHKT1 not only regulates ion homeostasis but also influences secondary metabolism and signal transaction in transgenic plants. • NsHKT1 expression was induced by various abiotic stresses and phytohormones. • NsHKT1 overexpression enhanced salt tolerance in transgenic 84 K poplars. • NsHKT1 mediated Na+ uptake in root and prevented accumulation of Na+ in shoots in transgenic poplars. • NsHKT1 expression affected secondary metabolism and signal transaction in transgenic poplars. [ABSTRACT FROM AUTHOR]

• Maximum photochemical yield of S.quinqueflora was unaffected by Pb and/or Zn. • Lead adversely effected photosynthetic performance and growth of S. quinqueflora. • Zinc enhanced photosynthetic performance but reduced growth of S.quinqueflora. • Zinc ameliorated some of the adverse effects of Pb on S.quinqueflora. • S.quinqueflora is suitable for phytostabilisation of Pb and Zn. Saltmarsh sediments are susceptible to accumulation of excessive concentrations of anthropogenically elevated metals such as lead (Pb) and zinc (Zn). The resident salt tolerant plants of saltmarsh ecosystems form the basal underpinning of these ecosystems. As such, metal-associated adverse impacts on their physiology can have detrimental flow-on effects at individual, population, and community levels. The present study assessed the accumulation and partitioning of ecologically relevant concentrations of Pb, Zn, and their combination in a dominant Australian saltmarsh species, Sarcocornia quinqueflora. Plants were hydroponically maintained under glasshouse conditions for 16 weeks exposure to either Pb (20 µg l–1), Zn (100 µg l–1), or their mixture. We evaluated the chronic toxicological effects of single and mixed metal treatments with reference to metal uptake and partitioning, photosynthetic performance, photosynthetic pigment concentration, biomass and growth. Lead was more toxic than Zn, and Zn appeared to have an antagonistic effect on the toxicological effects of Pb in S.quinqueflora in terms of metal uptake, photosynthetic performance, photosynthetic pigment concentrations, and growth. Indeed, the tolerance index was 55 % in plants treated with Pb compared to 77 % in Zn treated plants and 73 % in Pb+Zn treated plants. Finally, Sarcocornia quinqueflora primarily accumulated both Pb and Zn in roots at concentrations exceeding unity whilst translocation of these metals to above ground tissues was restricted regardless of treatment. This suggests that S. quinqueflora may be suitable for phytostabilisation of Zn, and of Pb particularly in the presence of Zn. [ABSTRACT FROM AUTHOR]

Population-based threshold models may aid in quantification of germination niches under stressful conditions such as salinity, temperature, and their interactions to understand seedling emergence patterns. Seeds of Sarcocornia fruticosa , Sarcocornia alpini , and Salicornia emerici were subjected to various temperatures at different NaCl concentrations. The median base NaCl concentration was roughly steady (0.68, 0.73, and 0.70 M, respectively) at sub-optimal temperatures, then decreased linearly at supra-optimal temperatures until the ceiling temperature. The estimated base, optimum and ceiling temperatures, in water, were –0.5, 15, and 29 °C for Sarcocornia fruticosa , –2.5, 11, and 24 °C for Sarcocornia alpini , and 9.5, 25, and 40 °C for Salicornia emerici , respectively. For all species, the base temperature did not change with the salinity, while both optimal and ceiling temperatures decreased. S. emerici showed rapid and synchronized germination when salinity decreased during the rainy season coinciding with favorable temperatures. • S. fruticosa , S. alpini , and S. emerici seeds were subjected to various temperatures at different NaCl concentrations. • The NaCl b(50) concentration was roughly steady at sub-optimal temperatures, then decreased linearly at supra-optimal ones. • T b , T o , and T c , in 0 M NaCl, were –0.5, 15, and 29°C for S. fruticosa , –2.5, 11, and 24°C for S. alpini , and 9.5, 25, and 40°C for S. emerici , respectively. • For all species, T b did not change with the salinity, while T o and T c decreased. • S. emerici showed rapid and synchronized germination when salinity decreased during the rainy season coinciding with favorable temperatures. [ABSTRACT FROM AUTHOR]

Coastal wetlands provide valuable ecosystem services and understanding their response to past climatic changes may help predict their possible future responses. In this paper, we obtained records of pollen, algae, sediment grain-size, and other environmental proxies, from a late Holocene sediment core (CFD-E) from the Caofeidian area, on the northwest coast of the Bay of Bohai, China. Our results indicate three major stages of environmental change. During Stage I (3500–2800 cal yr BP), arboreal pollen content was high (mostly >60%), especially for Pinus and Quercus , and the PCA sample scores on Axis 1 were negative indicating that regional vegetation was temperate broadleaved forest and the climate was wet. During Stage II (2800–2350 cal yr BP), the arboreal pollen content decreased substantially (mostly <40%), and the PCA Axis 1 sample scores were positive indicating a decrease in forest vegetation, grassland expansion, and a drier climate. During Stage III (2350–1400 cal yr BP), the arboreal pollen content increased again (mostly >40%), although it remained lower than during Stage I, indicating that forests expanded under a relatively humid climate while the wetland area decreased slightly. Our results also record the 2.8 ka and 2.4 ka events of monsoon weakening, which were characterized by increases in herbaceous pollen (indicating grassland expansion) and the drying of the regional climate. There are several differences in the regional expression of these two climatic events. During the 2.4 ka event, Chenopodiaceae pollen increased substantially (average of 42.0%), indicating the expansion of halophytes; whereas during the 2.8 ka event, an increase in Artemisia indicates the occurrence of a dry climate throughout the region. We suggest that the aridity during the 2.8 ka event was triggered by decreased solar activity and the resulting changes in the El Niño-Southern Oscillation, which weakened the East Asian summer monsoon. However, we suggest that the 2.4 ka event was driven by the weakening of the Atlantic Meridional Overturning Circulation. • Significant increase in halophytic vegetation during 3500–1400 cal yr BP • The 2.8 ka and 2.4 ka events were characterized by climate drying lasting ∼150 years. • During these two events the area of forest decreased and grassland expanded. [ABSTRACT FROM AUTHOR]

Stable carbon isotopes in fossil leaf cuticles (n- alkanes, δ 13 C n − alkanes) extracted from the sediment are widely used for palaeoenvironmental reconstructions. This approach relies on a series of assumptions (such as the plant-group-specific isotopic range, or the atmospheric CO 2 being the major factor for the isotopic values) and leaves out the complexity of the carbon isotope fractionation within the plant through time, space, and different environments. The leaf cuticle is a unique archive of local environmental conditions, which has the potential to constrain individual plant habitat. To explore the applicability of the information gained from the δ 13 C n − alkanes from fossil plants, a fossil coastal environment was studied. During the Cenomanian (100.5–93.9 Ma), the basal part of the Bohemian Cretaceous Basin, including locality Pecínov (Czechia), was formed as a result of sea transgression to the Palaeozoic Bohemian Massif triggered by the Alpine orogenesis. Coastal halophytic vegetation growing in this zone of prograding sea has no extant equivalent, and there are uncertainties associated with vegetation distribution or individual taxa habitat. Therefore, we examine the relationship between δ 13 C n − alkanes extracted from individual leaves of coastal C3 plants (fossil and modern) and osmotic stress (salinity and drought) to reconstruct the individual plant habitat, thus, vegetation distribution in the coastal zone. We investigated modern mangrove and salt marsh vegetation in New Zealand and the United Kingdom, respectively, as well as transition zones (mangrove invading original salt marshes) for δ 13 C , soil moisture and salinity to build a calibration of the relationship, which is then applied to the Cenomanian fossil leaves from the locality of Pecínov. We found a positive correlation between water stress (caused by salinity or drought) and the δ 13 C values of n ‐ C 25 , n ‐ C 27 , n ‐ C 29 and n ‐ C 31 alkanes when combining all species from all modern localities. However, the absence of a strong correlation within individual species suggests a combination of several factors controlling the carbon isotopic composition. Nevertheless, the general response of δ 13 C to osmotic stress can be applied to compare the habitat of modern and fossil coastal plants. Thus, by using this relationship, we reconstructed the relative salinity and water stress of individual species of the Cenomanian plants by relating them to modern species-specific ranges of n ‐ C 29 isotopic signatures. We showed that the δ 13 C n − alkanes of fossil plant cuticles/leaves can be a valuable tool in the reconstruction of plant habitat and help us understand evolution of fossil environments in time and space. Additionally, our data further confirm that the δ 13 C acquired from plants should be used with caution when reconstructing global atmospheric CO 2 because the osmotic stress can shift the δ 13 C in plants growing in terrestrial environments, particularly in coastal sea-influenced ecosystems. • The δ13C n- alkanes from leaf cuticle provide information on local osmotic stress. • A positive correlation between water stress and the δ13C n- alkanes values of leaf waxes was found. • The δ13C n- alkanes of studied halophytes reflects their flexibility to adapt to osmotic stress. • The knowledge of modern C3 plant δ13C n- alkanes can be applied for interpreting fossil data. • The δ13C n- alkanes from fossil plant cuticles are a useful tool for determining their autecology. [ABSTRACT FROM AUTHOR]

Brackish water bodies provide critical ecosystem services supporting human and environmental health in coastal regions. Mitigation of contaminants in brackish waters is critical. Floating treatment wetlands (FTWs) are a remediation technology typically applied to improve water quality in freshwater systems. However, the applicability of FTWs to waters with fluctuating salinity has not been determined. The goal of this study was to quantify the growth and survival of four plant species and determine which aquatic macrophytes are suited for use in FTWs deployed in brackish waters. This study trialed four species common to salt marshes of the Southeastern USA (Distichlis spicata, Juncus roemerianus, Spartina alterniflora, and Spartina patens) grown under three salinity exposures (0.5, 5.0, and 18 g⋅L−1) over 7 weeks. We also quantified macro- and micro-nutrient concentrations in these species to enable determination of how plant growth in FTWs may alter nutrient partitioning in roots and shoots. The ratios of nutrients fixed in tissues of plants grown in the salt marsh vs. those grown in FTWs shifted. The ratio of Na:Ca within tissues were higher for plants grown in the saltmarsh than those grown in the FTWs. Regarding biomass production, D. spicata and J. roemerianus grew very little, regardless of salinity exposure. J. roemerianus did not survive at 18 g⋅L−1 salinity. S. alterniflora and S. patens had the highest biomass production and final nutrient concentrations in tissues across all salinities. These trials indicated that of the four species tested, S. alterniflora and S. patens hold the most promise for FTW application in brackish settings. [Display omitted] • Nutrient partitioning shifted between marsh-grown and floating wetland plants. • Spartina alterniflora and S. patens toleratsed salinity ranges from 0.5 to 18 g.L−1. • Distichlis spicata and J. roemerianus had lowest biomass production and nutrient uptake. • Plant maturity stage may influence survival more than salinity exposure. [ABSTRACT FROM AUTHOR]

NAC transcription factors regulate plant growth, development, and stress responses. However, the number, types, and biological functions of Limonium bicolor LbNAC genes have remained elusive. L. bicolor secretes excessive salt ions through salt glands on its stems and leaves to reduce salt-induced damage. Here, we identified 63 NAC members (LbNAC1 – 63) in L. bicolor , which were unevenly distributed across eight chromosomes. Cis -elements in the LbNAC promoters were related to growth and development, stress responses, and phytohormone responses. We observed strong colinearity between LbNAC s and GmNAC s from soybean (Glycine max). Thus, LbNAC genes may share similar functions with GmNAC genes. Expression analysis indicated that 16 LbNAC genes are highly expressed in roots, stems, leaves, and flowers, whereas 17 LbNAC genes were highly expressed throughout salt gland development, suggesting that they may regulate this developmental stage. Silencing LbNAC54 in L. bicolor decreased salt gland density, salt secretion from leaves, and overall salt tolerance. In agreement, genes related to salt gland development were significantly downregulated in LbNAC54 -silenced lines. Our findings shed light on LbNAC genes and help elucidate salt gland development and salt secretion in L. bicolor. Our data also provide insight into NAC functions in halophytes. • 63 NAC members were identified in Limonium bicolor , distributed across eight chromosomes. • LbNAC genes were differentially expressed under salt, drought and ABA treatment. • 16 LbNAC genes highly expressed in roots, stems, leaves, and flowers and 17 highly expressed during salt gland development. [ABSTRACT FROM AUTHOR]

The uptake and distribution of copper, zinc, arsenic, and lead was examined in two rare Australian saltmarsh species, Tecticornia pergranulata and Wilsonia backhousei. The bioconcentration factors and translocation factors were generally much lower than one, except for the Zn translocation factors for T. pergranulata. When compared to other Australian saltmarsh taxa, these species generally accumulated the lowest levels observed among taxa, especially in terms of their BCFs. Essential metals tended to be regulated, while non-essential metals increased in concentration with dose during transport among compartments, a pattern not previously observed in Australian saltmarsh taxa. The uptake of metals into roots was mainly explained by total sediment metal loads as well as more acidic pH, increased soil organic matter, and decreased salinity. The low uptake and limited translocation observed in these rare taxa may offer a competitive advantage for their establishment and survival in the last urbanised populations, where legacy metal contamination acts as a selective pressure. • Cu, Zn, As, Pb were examined in two rare saltmarsh plants in a contaminated estuary. • Metal(loid) partitioning patterns contrasted with other Australian saltmarsh species. • Uptake of both essential and non-essential metal(loid)s to roots was limited (BCF < 1). • Sediment pH, EC, and salinity influenced root metal(loid) concentrations. • Low BCF and high TF may confer competitive advantages in contaminated locations. [ABSTRACT FROM AUTHOR]

The current increase in salinity can intensify the disparity between potential and actual crop yields, thus affecting economies and food security. One of the mitigating alternatives is plant breeding via biotechnology, where advances achieved so far are significant. Considering certain aspects when developing studies related to plant breeding can determine the success and accuracy of experimental design. Besides this strategy, halophytes with intrinsic and efficient abilities against salinity can be used as models for improving the response of crops to salinity stress. As crops are mostly glycophytes, it is crucial to point out the molecular differences between these two groups of plants, which may be the key to guiding and optimizing the transformation of glycophytes with halophytic tolerance genes. Therefore, this can broaden perspectives in the trajectory of research towards the cultivation, commercialization, and consumption of salt-tolerant crops on a large scale. • A proper experimental design can drive crop improvement for salt tolerance. • The molecular profile of halophyte plants can offer resources to achieve this goal. • It is possible to optimize the transformation of glycophytes with halophytic genes. [ABSTRACT FROM AUTHOR]

The preparation, chemical properties and bio-activities of polysaccharides derived from halophytes have gained an increasing interest in the past few years. Phytochemical and pharmacological reports have shown that carbohydrates are important biologically active compounds of halophytes with numerous biological potentials. It is believed that the mechanisms involved in these bio-activities are due to the modulation of immune system. The main objective of this summary is to appraise available literature of a comparative study on the extraction, structural characterizations and biological potentials, particularly immunomodulatory effects, of carbohydrates isolated from halophytes (10 families). This review also attempts to discuss on bioactivities of polysaccharides related with their structure-activity relationship. Data indicated that the highest polysaccharides yield of around 35% was obtained under microwave irradiation. Structurally, results revealed that the most of extracted carbohydrates are pectic polysaccharides which mainly composed of arabinose (from 0.9 to 72%), accompanied by other monosaccharides (galactose, glucose, rhamnose, mannose and xylose), significant amounts of uronic acids (from 18.9 to 90.1%) and some proportions of fucose (from 0.2 to 8.3%). The molecular mass of these pectic polysaccharides was varied from 10 to 2650 kDa. Hence, the evaluation of these polysaccharides offers a great opportunity to discover novel therapeutic agents that presented especially beneficial immunomodulatory properties. Moreover, reports indicated that uronic acids, molecular weights, as well as the presence of sulfate and unmethylated acidic groups may play a significant role in biological activities of carbohydrates from halophyte species. Unlabelled Image • Polysaccharides from halophytes presented potent structural and biological feature. • Polysaccharides (PS) from different species of halophytes were firstly compared. • MAE extraction of PS from halophytes provides the higher extraction yield. • The most of PS from selected halophytes are mainly pectic polysaccharides. • Polysaccharides from halophytes possess promising immunomodulatory properties. [ABSTRACT FROM AUTHOR]

• Salinization is worldwide environmental problem. • Salinity causes stress in three ways: ionic stress, osmotic stress, and oxidative stress in plants. • The research of the salt stress related plants must be taken from laboratory to field conditions. • The efficiency of salinity tolerant genes and their effect in host must be analysed. Salinization is a worldwide environmental problem, which is negatively impacting crop yield and thus posing a threat to the world's food security. Considering the rising threat of salinity, it is need of time, to understand the salt tolerant mechanism in plants and find avenues for the development of salinity resistant plants. Several plants tolerate salinity in a different manner, thereby halophytes and glycophytes evolved altered mechanisms to counter the stress. Therefore, in this review article, physiological, metabolic, and molecular aspects of the plant adaptation to salt stress have been discussed. The conventional breeding techniques for developing salt tolerant plants has not been much successful, due to its multigenic trait. The inflow of data from plant sequencing projects and annotation of genes led to the identification of many putative genes having a role in salt stress. The bioinformatics tools provided preliminary information and were helpful for making salt stress-specific databases. The microRNA identification and characterization led to unraveling the finer intricacies of the network. The transgenic approach finally paved a way for overexpressing some important genes viz. DREB, MYB, COMT, SOS, PKE, NHX, etc. conferred salt stress tolerance. In this review, we tried to show the effect of salinity on plants, considering ion homeostasis, antioxidant defense response, proteins involved, possible utilization of transgenic plants, and bioinformatics for coping with this stress factor. An overview of previous studies related to salt stress is presented in order to assist researchers in providing a potential solution for this increasing environmental threat. [ABSTRACT FROM AUTHOR]

South African quartz fields in the Succulent Karoo and adjacent biomes are special habitats for a range of highly specialized dwarf succulents, many of which belong to the Aizoaceae. The soil chemistry of the quartz fields ranges from very acidic to slightly alkaline and from moderately to highly saline, and drives species turnover. The soil conditions are therefore critical for the vegetation composition. The aim of our study is to better understand the role of the regeneration niche of habitat specialists from different quartz-field habitats to inform conservation planning and ecological restoration. We tested germination responses to soil chemistry of 14 Aizoaceae species from quartz fields in the Succulent Karoo (Knersvlakte) and the Fynbos (Overberg) biome of South Africa. For each of the two sites we sampled species from two different quartz-field habitats. The seeds from 14 species were germinated under greenhouse conditions for 79 days on their home soils and on the natural soils of the three other habitat types as well as on salinized and acidified horticultural standard substrate and a standard substrate as control. Germination success in the control differed between the species from the two biomes. Of the seven species from the Knersvlakte, six species germinated rapidly, with 38–86% success. Only Dicrocaulon brevifolium germinated with merely 17% success. Of the seven species from Overberg only Gibbaeum hartmannianum germinated at a high percentage (83%). The other species germinated below 20% or not at all. Natural soils and manipulated substrates limited germination of all species to <20%. No seeds germinated on natural saline soils from the Knersvlakte until from day 46 to day 50, when an excess supply of rainwater diluted the ion content of the soil. The subsequent recovery of the seeds resulted in a germination percentage of 4–35% for seven species from different habitat types. Quartz fields provide a plant-adverse environment. Their soils contain a range of toxic ions at high concentrations. High volume and prolonged rainfall events that leach the soils temporarily seemed to be a requisite for successful germination. [ABSTRACT FROM AUTHOR]

• Seagrasses are the only flowering plants to recolonising the beds of the sea. • This review elaborates the phytochemical analysis and biological properties of seagrasses. • Seagrasses harbour several metabolites with multiple bioactivities. • This review identifies vital lacuna in seagrass research. Seagrasses, one of the most threatened yet overlooked ecosystems on Earth, are the only flowering plants to recolonising the seabed. Apart from their critical ecological prominence on the life of many marine organisms, seagrasses are also used as an alternative or complementary medicine to manage an array of pathological disorders such as muscle aches, wounds, abdominal pain, indigestion, hangover, and mental disorders. However, a compilation of existing work on their ethnopharmacological uses, nutritional values, pharmacological propensities and bioactive compounds is lacking. Thus, this review aims at elaborating on the biochemical composition, phytochemical analysis, and biological properties including antioxidant, antimicrobial activities of various species of seagrasses. Seagrasses harbour several metabolites with multiple bioactivities. The phytochemical compounds isolated from Zostera marina L., Thalassia testudinum K. D. Koenig. and Thalassodendron ciliatum (Forssk.) exhibit a plethora of biological activities, including cytotoxicity against cancer cell lines, anti-human immunodeficiency virus (HIV), antimicrobial, and skin regenerating properties. This review also identifies vital lacuna in seagrass research. For instance, the mechanism and site of action of compounds displaying potent biological activities has not been adequately addressed together with optimisation of extraction methods to isolate minor metabolites and applying technological advancements in biological assays. In conclusion, this review provides a synthesis of current knowledge and highlights future work that needs to be undertaken for the biomedical application of such natural resources. [ABSTRACT FROM AUTHOR]

Globally, salinity threatens the agricultural crops productivity by inhibiting plant growth and development through osmotic stress and ionic cytotoxicity. The polygenic nature of salinity offers several pragmatic shotgun approaches to improve salinity tolerance. The present study investigated the potential of glutathione (GSH; 1 mM) as an antioxidant and moringa leaf extract (MLE; 3%) as an organic biostimulant applied in sequence as seed priming and foliar spray on wheat growth, physiology and metabolic adaptation under saline conditions (9.16 dS m−1). Plants without any treatment and water spray (H 2 O) were considered controls. Salinity induced osmotic stress reduced the plant tissue water status and photosynthetic performance, and perturbed ionic (K+/Na+, Ca2+/Na+, K++Ca2+/Na+) and hormonal (IAA, GA 3 , zeatin, ABA) homeostasis, consequently affected growth and yield in wheat. Sequenced applied MLE and/or GSH improved osmotic stress tolerance by stabilizing membrane integrity and decreasing electrolyte leakage. These positive results were owed to enhanced endogenous GSH and ascorbate levels. Improved tissue water status was attributed to increased osmotic adjustment, better ionic and hormonal homeostasis contributed to improving photosynthetic efficiency and growth under salinity. Exogenously applied MLE and GSH sequences improved grain yield, which was attributed to the maintenance of green leaf area and delayed senescence associated with an increase in photosynthetic pigments and chlorophyll fluorescence traits. In crux, exogenous applied MLE and/or GSH can be the best physiological strategy to reduce the deleterious effects of salinity and improve physiological and metabolic adaptation in wheat under saline field conditions. • Sequenced applied MLE and GSH improved tissue water status and photosynthetic pigment. • Enhanced internal GSH and AsA stabilized membranes and decreased electrolyte leakage. • Enhanced osmotic stress tolerance owed to osmotic adjustment and ionic homoestasis • Higher leaf area and delayed senescence attributed high grain yield under salinity. [ABSTRACT FROM AUTHOR]

Under certain abiotic conditions (elevated irradiance, temperature and sediment salinity) observed mostly during the Mediterranean summer, the halophyte Sarcocornia fruticosa suffers a metabolic shift evidenced by a red coloration, evidencing the presence of two physiotypes (green and red). Previous works indicated that this metabolic shift has severe implications in the primary photochemistry of this species, impairing the light and carbon harvesting. Under stress plants have lower light use efficiencies and are more prone to photoinhibition, and thus this metabolic shift is essential for this species to deal with the high light intensities characteristic from this time of the year. Nevertheless, the fatty acid and lipid remodelling in green and red S. fruticosa physiotypes was not previously evaluated nor its relations with this metabolic shift. The evaluation of the lipid landscape suggests several lipid and fatty acid remodelling when comparing both red and green physiotype, as strategies to overcome stress. The galactolipids of the red physiotype suffer several changes aiming to keep chloroplast membrane structural and functional stability during water stress and can also be related to an improvement of the plants response to osmotic stress. At the phospholipid level, a readjustment of its fatty acid profiles was also observable. This remodelling allows the plants to adjust membrane fluidity the imposed osmotic stress, being this action transversal to choroplastidial, extraplastidial, and involves the action of the different phospholipids. Additionally, neutral lipids (NLs) also appear to play a role in osmotic stress adaptation, with an increase content in C18 fatty acids in the red physiotype. The resulting lipid landscape in both physiotypes presents very specific signatures that can be used as biomarkers to track this kind of metabolic shifts, in future studies with similar species. • Sarcocornia fruticosa green and red physiotypes present substantial lipid remodelling. • Galactolipids changes are compatible with an increase in chloroplast membrane stability. • Phospholipids alterations aim to adjust cell membrane fluidity. • These lipid landscapes are physiotype specific and can be used as biomarkers for metabolic shifts. [ABSTRACT FROM AUTHOR]

Prunella vulgaris L. is a moderately salt tolerant plant commonly found in China and Europe, whose spica (Prunellae Spica) has been used as a traditional medicine. The scant transcriptomic and genomic resources of Prunellae Spica have greatly hindered further exploration of the underlying salt tolerance mechanism of this species. To clarify the genetic basis of its salt tolerance, high-throughput sequencing of mRNAs was employed for de novo transcriptome assembly differential expression analysis of Prunellae Spica under salt stress. 118,664 unigenes were obtained by assembling pooled reads from all libraries with 68,119 sequences annotated. A total of 3857 unigenes were differentially expressed under low, medium and high salt stress, including 2456 up-regulated and 1401 down-regulated DEGs, respectively. Gene ontology analysis revealed that salt stress-related categories involving 'catalytic activity', 'binding', 'metabolic process' and 'cellular process' were highly enriched. KEGG pathway annotation showed that the DEGs from different salt stress treatment groups were mainly enriched in the pathways of translation, signal transduction, carbohydrate metabolism, energy metabolism, lipid metabolism and amino acid metabolism, accounting for over 60% of all DEGs. Finally, it showed that the results of quantitative real-time polymerase chain reaction (qRT-PCR) analysis for 10 unigenes that randomly selected were significantly consistent with RNA-seq data, which further assisted in the selection of salt stress-responsive candidate genes in Prunellae Spica. This study represents a significant step forward in understanding the salt tolerance mechanism of Prunellae Spica, and also provides a significant transcriptomic resource for future work. • RNA-seq analysis of mature ears of Prunellae Spica were performed. • 3857 DEGs between salt-stressed and control groups were found from Prunellae Spica. • Genes related to translation, signal transduction and carbohydrate metabolism are up-regulated by salinity.RNA-seq analysis of mature ears of Prunellae Spica were performed. [ABSTRACT FROM AUTHOR]

Phytosterols are a group of sterols exclusive to plants and fungi, but are indispensable to humans because of their medicinal and nutritional values. However, current raw materials used for phytosterols extraction add to the cost and waste in the process. For higher sterols production, major attention is drawn to plant materials abundant in phytosterols and genetic modification. To provide an insight into phytosterols metabolism, the research progress on key enzymes involved in phytosterols biosynthesis and conversions were summarized. CAS , SSR2 , SMT , DWF1 and CYP710A , the enzymes participating in the biosynthetic pathway, and PSAT , ASAT and SGT , the enzymes involved in the conversion of free sterols to conjugated ones, were reviewed. Specifically, SMT and CYP710A were emphasized for their function on modulating the percentage composition of different kinds of phytosterols. The thresholds of sterol equilibrium and the resultant phytosterols accumulation, which vary in plant species and contribute to plasma membrane remodeling under stresses, were also discussed. By retrospective analysis of the previous researches, we proposed a feedback mechanism regulating sterol equilibrium underlying sterols metabolism. From a strategic perspective, we regard salt tolerant plant as an alternative to present raw materials, which will attain higher phytosterols production in combination with gene-modification. • Summarize research progress on phytosterols biosynthesis. •Review enzymes regulating sterol accumulation and equilibrium. •Propose a feedback loop of sterol equilibrium underlying the biosynthesis. •Recommend substitution of conventional materials with halophytes for higher sterol production. [ABSTRACT FROM AUTHOR]

• Spartina maritima spikelets with non-exerted stamens increase with increasing air temperature • Fruit set decreases with increasing air temperature and sediment anoxia • Caryopsis resorption increases with temperature warming in female phase • Caryopsis resorption increases with tidal amplitude in male phase • Global warming severely limits sexual reproduction of threatened S. maritima Sexual reproduction, a critical life history process in plants, can be altered by heat stress derived from global warming. Sexual reproduction increases genetic diversity, and the ability of plants to respond to environmental changes and dispersal. The capacity for these responses is especially relevant as plants are exposed to rising environmental stress levels imposed by climate change. We investigated the influence of environmental factors that impose physiological stress that may affect the fruit set of Spartina maritima , the sole native African and European cordgrass species. To achieve our objective, we acquired locally recorded air temperatures and tidal amplitude projections. Within population sites, we measured sedimentary conditions (pH, redox potential and electrical conductivity), and the phenological stage of S. maritima inflorescences, spikelets with non-exserted stamens and caryopses produced throughout its 10-week flowering period. Fruit set decreased as flowering period advanced, and as air temperatures and the proportion of spikelets with non-exserted stamens increased. Fruit set decreased with increased sediment anoxia. The proportion of reabsorbed caryopses increased with high air temperatures during the female phase of the inflorescence, and with higher tidal amplitudes during the male phase. These environmental stress factors could terminate caryopsis development that had commenced. Our results point to a severe potential impact of global warming on the reproductive process of native S. maritima. Mitigation of global warming will be essential to maintain population persistence and support conservation and recovery of this halophyte that provides important ecosystem services in salt marshes. [ABSTRACT FROM AUTHOR]