Modulation of physio-biochemical and photosynthesis parameters by overexpressing SbPIP2 gene improved abiotic stress tolerance of transgenic tobacco.

The present study aims to explore the potential of a plasma-membrane localized PIP2-type aquaporin protein sourced from the halophyte Salicornia brachiata to alleviate salinity and water deficit stress tolerance in a model plant through transgenic intervention. Transgenic plants overexpressing SbPIP2 gene showed improved physio-biochemical parameters like increased osmolytes (proline, total sugar, and amino acids), antioxidants (polyphenols), pigments and membrane stability under salinity and drought stresses compared to control plants [wild type (WT) and vector control (VC) plants]. Multivariate statistical analysis showed that, under water and salinity stresses, osmolytes, antioxidants and pigments were correlated with SbPIP2-overexpressing (SbPIP2-OE) plants treated with salinity and water deficit stress, suggesting their involvement in stress tolerance. As aquaporins are also involved in CO2 transport, SbPIP2-OE plants showed enhanced photosynthesis performance than wild type upon salinity and drought stresses. Photosynthetic gas exchange (net CO2 assimilation rate, PSII efficiency, ETR, and non-photochemical quenching) were significantly higher in SbPIP2-OE plants compared to control plants (wild type and vector control plants) under both unstressed and stressed conditions. The higher quantum yield for reduction of end electron acceptors at the PSI acceptor side [Φ( R0 )] in SbPIP2-OE plants compared to control plants under abiotic stresses indicates a continued PSI functioning, leading to retained electron transport rate, higher carbon assimilation, and less ROS-mediated injuries. In conclusion, the SbPIP2 gene functionally validated in the present study could be a potential candidate for engineering abiotic stress resilience in important crops.

SOS1 tonoplast neo-localization and the RGG protein SALTY are important in the extreme salinity tolerance of Salicornia bigelovii.

The identification of genes involved in salinity tolerance has primarily focused on model plants and crops. However, plants naturally adapted to highly saline environments offer valuable insights into tolerance to extreme salinity. Salicornia plants grow in coastal salt marshes, stimulated by NaCl. To understand this tolerance, we generated genome sequences of two Salicornia species and analyzed the transcriptomic and proteomic responses of Salicornia bigelovii to NaCl. Subcellular membrane proteomes reveal that SbiSOS1, a homolog of the well-known SALT-OVERLY-SENSITIVE 1 (SOS1) protein, appears to localize to the tonoplast, consistent with subcellular localization assays in tobacco. This neo-localized protein can pump Na+ into the vacuole, preventing toxicity in the cytosol. We further identify 11 proteins of interest, of which SbiSALTY, substantially improves yeast growth on saline media. Structural characterization using NMR identified it as an intrinsically disordered protein, localizing to the endoplasmic reticulum in planta, where it can interact with ribosomes and RNA, stabilizing or protecting them during salt stress.

Probiotic potential of a novel endophytic Streptomyces griseorubens CIBA-NS1 isolated from Salicornia sp. against Vibrio campbellii infection in shrimp.

A novel endophytic Streptomyces griseorubens CIBA-NS1 was isolated from a salt marsh plant Salicornia sp. The antagonistic effect of S. griseorubens against Vibrio campbellii, was studied both in vitro and in vivo. The strain was validated for its endophytic nature and characterized through scanning electron microscopy, morphological and biochemical studies and 16SrDNA sequencing. The salinity tolerance experiment has shown that highest antibacterial activity was at 40‰ (16 ± 1.4 mm) and lowest was at 10 ‰ salinity (6.94 ± 0.51 mm). In vivo exclusion of Vibrio by S. griseorubens CIBA-NS1 was studied in Penaeus indicus post larvae and evaluated for its ability to improve growth and survival of P. indicus. After 20 days administration of S. griseorubens CIBA-NS1, shrimps were challenged with V. campbellii. The S. griseorubens CIBA-NS1 reduced Vibrio population in test group when compared to control, improved survival (60.5 ± 6.4%) and growth, as indicated by weight gain (1.8 ± 0.05g). In control group survival and growth were 48.4 ± 3.5% and 1.4 ± 0.03 g respectively. On challenge with V. campbellii, the S. griseorubens CIBA-NS1 administered group showed better survival (85.6 ± 10%) than positive control (64.3 ± 10%). The results suggested that S. griseorubens CIBA-NS1 is antagonistic to V. campbellii, reduce Vibrio population in the culture system and improve growth and survival. This is the first report on antagonistic activity of S. griseorubens isolated from salt marsh plant Salicornia sp, as a probiotic candidate to prevent V. campbellii infection in shrimps.

In vivo Effects of Salicornia herbacea and Calystegia soldanella Extracts for Memory Improvement.

The global elderly population, aged 65 and over, reached approximately 10% in 2020, and this proportion is expected to continue rising. Therefore, the prevalence of neurodegenerative diseases such as Parkinson's disease (PD), which are characterized by declining memory capabilities, is anticipated to increase. In a previous study, we successfully restored the diminished memory capabilities in a fruit fly model of PD by administering an omija extract. To identify functional ingredients that can enhance memory akin to the effects of the omija extract, we conducted screenings by administering halophyte extracts to the PD model. Halophytes are plants that thrive in high-salt environments, and given Korea's geographic proximity to the sea on three sides, it serves as an optimal hub for the utilization of these plants. Upon examining the effects of the oral administration of 12 halophyte extracts, Salicornia herbacea and Calystegia soldanella emerged as potential candidates for ameliorating memory loss in PD model flies. Moreover, our findings suggested that C. soldanella, but not S. herbacea, can mitigate oxidative stress in DJ-1ß mutants.

Cell size and xylem differentiation regulating genes from Salicornia europaea contribute to plant salt tolerance.

Cell wall is involved in plant growth and plays pivotal roles in plant adaptation to environmental stresses. Cell wall remodelling may be crucial to salt adaptation in the euhalophyte Salicornia europaea. However, the mechanism underlying this process is still unclear. Here, full-length transcriptome indicated cell wall-related genes were comprehensively regulated under salinity. The morphology and cell wall components in S. europaea shoot were largely modified under salinity. Through the weighted gene co-expression network analysis, SeXTH2 encoding xyloglucan endotransglucosylase/hydrolases, and two SeLACs encoding laccases were focused. Meanwhile, SeEXPB was focused according to expansin activity and the expression profiling. Function analysis in Arabidopsis validated the functions of these genes in enhancing salt tolerance. SeXTH2 and SeEXPB overexpression led to larger cells and leaves with hemicellulose and pectin content alteration. SeLAC1 and SeLAC2 overexpression led to more xylem vessels, increased secondary cell wall thickness and lignin content. Notably, SeXTH2 transgenic rice exhibited enhanced salt tolerance and higher grain yield. Altogether, these genes may function in the succulence and lignification process in S. europaea. This work throws light on the regulatory mechanism of cell wall remodelling in S. europaea under salinity and provides potential strategies for improving crop salt tolerance and yields.

Rhizospheric bacteria from the Atacama Desert hyper-arid core: cultured community dynamics and plant growth promotion.

The Atacama Desert is the oldest and driest desert on Earth, encompassing great temperature variations, high ultraviolet radiation, drought, and high salinity, making it ideal for studying the limits of life and resistance strategies. It is also known for harboring a great biodiversity of adapted life forms. While desertification is increasing as a result of climate change and human activities, it is necessary to optimize soil and water usage, where stress-resistant crops are possible solutions. As many studies have revealed the great impact of the rhizobiome on plant growth efficiency and resistance to abiotic stress, we set up to explore the rhizospheric soils of Suaeda foliosa and Distichlis spicata desert plants. By culturing these soils and using 16S rRNA amplicon sequencing, we address community taxonomy composition dynamics, stability through time, and the ability to promote lettuce plant growth. The rhizospheric soil communities were dominated by the families Pseudomonadaceae, Bacillaceae, and Planococcaceae for S. foliosa and Porphyromonadaceae and Haloferacaceae for D. spicata. Nonetheless, the cultures were completely dominated by the Enterobacteriaceae family (up to 98%). Effectively, lettuce plants supplemented with the cultures showed greater size and biomass accumulation. We identified 12 candidates that could be responsible for these outcomes, of which 5 (Enterococcus, Pseudomonas, Klebsiella, Paenisporosarcina, and Ammoniphilus) were part of the built co-occurrence network. We aim to contribute to the efforts to characterize the microbial communities as key for the plant's survival in extreme environments and as a possible source of consortia with plant growth promotion traits aimed at agricultural applications.IMPORTANCEThe current scenario of climate change and desertification represents a series of incoming challenges for all living organisms. As the human population grows rapidly, so does the rising demand for food and natural resources; thus, it is necessary to make agriculture more efficient by optimizing soil and water usage, thus ensuring future food supplies. Particularly, the Atacama Desert (northern Chile) is considered the most arid place on Earth as a consequence of geological and climatic characteristics, such as the naturally low precipitation patterns and high temperatures, which makes it an ideal place to carry out research that seeks to aid agriculture in future conditions that are predicted to resemble these scenarios. Our main interest lies in utilizing microorganism consortia from plants thriving under extreme conditions, aiming to promote plant growth, improve crops, and render "unsuitable" soils farmable.

Effects of short-term nitrogen and phosphorus addition on soil bacterial community of different halophytes.

Soil microbial community composition and diversity are often affected by nutrient enrichment, which may influence soil microbes to affect nutrient cycling and plant community structure. However, the response of soil bacteria to nitrogen (N) and phosphorus (P) addition and whether it is influenced by plants remains unclear. By 16S rRNA sequencing, we investigated the response of the rhizosphere and bulk soil bacterial communities of different halophytes (salt-rejecting, salt-absorbing, and salt-secreting plant) in the Yellow River Delta to short-term N and P addition. The response of rhizosphere bacterial diversity to N and P addition was opposite in Phragmites communis and Suaeda salsa. N addition increased the rhizosphere soil bacterial α-diversity of S. salsa and Aeluropus sinensis, while P addition decreased the rhizosphere bacterial α-diversity bacteria of S. salsa. The N and P addition had a weak effect on the rhizosphere bacterial community composition and a significant effect on the bulk soil bacterial community composition of halophytes. The S. salsa and P. communis bulk soil bacterial community were mainly influenced by P addition, while it was influenced by N addition in A. sinensis. N and P addition reduced the difference in bacterial community composition between the two types of soil. N and P addition increased the eutrophic taxa (Proteobacteria and Bacteroidetes) and decreased the oligotrophic taxa (Acidobacteria). Redundancy analysis showed that soil organic matter, salt, and total N content had significant effects on the bacterial community composition. The results clarify that the response of soil bacterial communities to N and P additions is inconsistent across the three halophyte soils, and the effect of plant species on the bacterial community was stronger than short-term N and P addition. IMPORTANCE: The bulk soil bacterial community was more affected by nutrient addition. Nitrogen (N) and phosphorus (P) have different effects on bacterial community. Soil organic matter is a key factor influencing the response of bacterial community to nutrient addition. N and P influence on bacterial community changes with plants.

Genomic and Metabolomic Analyses of Nocardiopsis maritima YSL2 as the Mycorrhizosphere Bacterium of Suaeda maritima (L.) Dumort.

Nine bacteria were isolated from the episphere of Suaeda maritima (L.) Dumort. Among them, the bacterial strain YSL2 displayed the highest antimicrobial activity on agar plates and exhibited significant novelty compared with other bacteria based on 16S rRNA analysis. Consequently, Nocardiopsis maritima YSL2T was subjected to phenotypic characterization and whole-genome sequencing. Phylogenetic analysis revealed its close association with Nocardiopsis aegyptia SNG49T. Furthermore, genomic analysis of strain YSL2T revealed the presence of various gene clusters, indicating its potential for producing antimicrobial secondary metabolites. Upon cultivation on a large scale, maritiamides A and B (1 and 2) were isolated and characterized as cyclic hexapeptides based on nuclear magnetic resonance, ultraviolet, infrared, and mass spectrometric data. The absolute configurations of the amino acid residues in the maritiamides were determined through chiral derivatization, utilizing FDAA and GITC. Maritiamides 1 and 2 exhibited promising antibacterial activities against Staphylococcus epidermidis and weakly inhibited the growth of Escherichia coli and Pseudomonas fluorescens.

Ectopic expression of HaPEPC1 from the desert shrub Haloxylon ammodendron confers drought stress tolerance in Arabidopsis thaliana.

Phosphoenolpyruvate carboxylase (PEPC) plays a crucial role in the initial carbon fixation process in C4 plants. However, its nonphotosynthetic functions in Haloxylon ammodendron, a C4 perennial xerohalophytic shrub, are still poorly understood. Previous studies have reported the involvement of PEPC in plant responses to abiotic stresses such as drought and salt stress. However, the underlying mechanism of PEPC tolerance to drought stress has not been determined. In this study, we cloned the C4-type PEPC gene HaPEPC1 from H. ammodendron and investigated its biological function by generating transgenic Arabidopsis plants with ectopic expression of HaPEPC1. Our results showed that, compared with WT (wild-type) plants, ectopic expression of HaPEPC1 plants exhibited significantly greater germination rates and chlorophyll contents. Furthermore, under drought stress, the transgenic plants presented increased root length, fresh weight, photosynthetic capacity, and antioxidant enzyme activities, particularly ascorbate peroxidase and peroxidase. Additionally, the transgenic plants exhibited reduced levels of malondialdehyde, H2O2 (hydrogen peroxide), and O2- (superoxide radical). Transcriptome analysis indicated that ectopic expression of HaPEPC1 primarily regulated the expression of genes associated with the stress defence response, glutathione metabolism, and abscisic acid (ABA) synthesis and signalling pathways in response to drought stress. Taken together, these findings suggest that the ectopic expression of HaPEPC1 enhances the reduction of H2O2 and O2- in transgenic plants, thereby improving reactive oxygen species (ROS) scavenging capacity and enhancing drought tolerance. Therefore, the HaPEPC1 gene holds promise as a candidate gene for crop selection aimed at enhancing drought tolerance.

Evaluating the success of vegetation restoration in rewilded salt marshes.

Floodbank realignment is a common practice aimed at restoring salt marsh vegetation on previously embanked land. However, experiences indicate that it may take several years before salt marsh vegetation becomes fully established. Various challenges arising from ecogeomorphic feedback mechanisms could pose significant setbacks to vegetation recolonization. The widespread adoption of transplantation techniques for the restoration and rehabilitation of rewilded landscapes has indeed proven to be a valuable tool for accelerating plant development. In the Ria Formosa coastal lagoon (South of Portugal), a pilot plan was implemented, and two salt marsh pioneer species, Spartina maritima (syn. Sporobolus maritimus) and Sarcocornia perennis (syn. Salicornia perennis), were transplanted from a natural salt marsh to a rewilded marsh. Biodegradable 3D porous structures were installed to mimic transplant clumping, aid sedimentation, and enhance the plant's initial adjustment. Ecological, sediment, and hydrodynamic data were collected during the 12-month pilot restoration plan. The environmental profiles of the donor and restoration sites were compared to substantiate the success of the transplants in the rewilded salt marsh. Results show that although plant shoot density decreased after the transplanting, Spartina maritima acclimated well to the new environmental conditions of the restoration site, showing signs of growth and cover increase, whilst Sarcocornia perennis was not able to acclimatize and survive in the restoration site. The failure behind the Sarcocornia perennis acclimation might be related to the bed properties and topographic properties of the restoration site in the rewilded marsh. Major findings contribute to a more comprehensive understanding of how salt marsh pioneering vegetation successfully colonizes disturbed habitats, facilitated using 3D-biodegradable structures.

Continuous planting of euhalophyte Suaeda salsa enhances microbial diversity and multifunctionality of saline soil.

Halophyte-based remediation emerges as a novel strategy for ameliorating saline soils, offering a sustainable alternative to conventional leaching methods. While bioremediation is recognized for its ability to energize soil fertility and structure, the complex interplays among plant traits, soil functions, and soil microbial diversity remain greatly unknown. Here, we conducted a 5-year field experiment involving the continuous cultivation of the annual halophyte Suaeda salsa in saline soils to explore soil microbial diversity and their relationships with plant traits and soil functions. Our findings demonstrate that a decline in soil salinity corresponded with increases in the biomass and seed yield of S. salsa, which sustained a consistent seed oil content of approximately 22% across various salinity levels. Significantly, prolonged cultivation of halophytes substantially augmented soil microbial diversity, particularly from the third year of cultivation. Moreover, we identified positive associations between soil multifunctionality, seed yield, and taxonomic richness within a pivotal microbial network module. Soils enriched with taxa from this module showed enhanced multifunctionality and greater seed yields, correlating with the presence of functional genes implicated in nitrogen fixation and nitrification. Genomic analysis suggests that these taxa have elevated gene copy numbers of crucial functional genes related to nutrient cycling. Overall, our study emphasizes that the continuous cultivation of S. salsa enhances soil microbial diversity and recovers soil multifunctionality, expanding the understanding of plant-soil-microbe feedback in bioremediation.IMPORTANCEThe restoration of saline soils utilizing euhalophytes offers a viable alternative to conventional irrigation techniques for salt abatement and soil quality enhancement. The ongoing cultivation of the annual Suaeda salsa and its associated plant traits, soil microbial diversity, and functionalities are, however, largely underexplored. Our investigation sheds light on these dynamics, revealing that cultivation of S. salsa sustains robust plant productivity while fostering soil microbial diversity and multifunctionality. Notably, the links between enhanced soil multifunctionality, increased seed yield, and network-dependent taxa were found, emphasizing the importance of key microbial taxa linked with functional genes vital to nitrogen fixation and nitrification. These findings introduce a novel understanding of the role of soil microbes in bioremediation and advance our knowledge of the ecological processes that are vital for the rehabilitation of saline environments.

Targeting the PI3K/pAKT/mTOR/NF-κB/FOXO3a signaling pathway for suppressing the development of hepatocellular carcinoma in rats: Role of the natural remedic Suaeda vermiculata forssk.

Liver malignancy is well recognized as a prominent health concern, with numerous treatment options available. Natural products are considered a renewable source, providing inspiring chemical moieties that could be used for cancer treatment. Suaeda vermiculata Forssk has traditionally been employed for management of hepatic conditions, including liver inflammation, and liver cirrhosis, as well as to improve general liver function. The findings of our earlier study demonstrated encouraging in vivo hepatoprotective benefits against liver injury generated by paracetamol and carbon tetrachloride. Additionally, Suaeda vermiculata Forssk exhibited cytotoxic activities in vitro against Hep-G2 cell lines and cell lines resistant to doxorubicin. The present investigation aimed to examine the potential in vivo hepatoprotective efficacy of Suaeda vermiculata Forssk extract (SVE) against hepatocellular carcinoma induced by diethylnitrosamine (DENA) in rats. The potential involvement of the PI3K/AKT/mTOR/NF-κB pathway was addressed. Sixty adult male albino rats were allocated into five groups randomly (n = 10). First group received a buffer, whereas second group received SVE only, third group received DENA only, and fourth and fifth groups received high and low doses of SVE, respectively, in the presence of DENA. Liver toxicity and tumor markers (HGFR, p-AKT, PI3K, mTOR, NF-κB, FOXO3a), apoptosis markers, and histopathological changes were analyzed. The current results demonstrated that SVE inhibited PI3K/AKT/mTOR/NF-κB pathway as well as increased expression of apoptotic parameters and FOXO3a levels, which were deteriorated by DENA treatment. Furthermore, SVE improved liver toxicity markers and histopathological changes induced by DENA administration. This study provided evidence for the conventional hepatoprotective properties attributed to SV and investigated the underlying mechanism by which its extract, SVE, could potentially serve as a novel option for hepatocellular carcinoma (HCC) treatment derived from a natural source.

Arbuscular mycorrhizal fungi drive bacterial community assembly in halophyte Suaeda salsa.

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.

Valorization of Salicornia patula Duval-Jouve Young Shoots in Healthy and Sustainable Diets.

The revalorization of natural resources in food production is increasing, and the effect of climate change is negatively affecting the production of conventional crops. In recent years, edible halophytes have received more attention due to their ability to tolerate a wide range of salinities. Thus, the use of halophytes that require less water and are strongly adapted to high-salinity soil and coastal areas can provide sustainable agriculture in certain areas. In addition, there is growing interest in the study of the possibilities that these species offer as foods due to their excellent nutritional profile and antioxidant properties. For that reason, the exploitation of plants adapted to these areas is nowadays even more important than in the past to guarantee food security in arid or semiarid salinized territories. The available data about the nutrients and bioactive compounds composition of many non-cultivated edible vegetables traditionally used in the Mediterranean area, such as Salicornia edible young shoots, are still scarce. With the aim of improving the knowledge on their nutritional value, the present study provides new data about the content of some compounds with biological activity, such as fiber and organic acids, in eight samples of young shoots of S. patula Duval-Jouve gathered in great mainland and coastal salt marshes in Southwest and Central Spain. Results showed that this vegetable can be considered a healthy food and a very good source of dietary fiber (4.81-6.30 g/100 g fw total fiber). Its organic acid profile showed oxalic, malic, citric and succinic acids. Oxalic acid was the major one, with mean values of 0.151-1.691 g/100 g fw. From the results obtained in this study, S. patula shoots could be recommended as an alternative source of fiber for healthy and sustainable diets in the general adult population with no risk of renal disease.

Designing a T-cell epitope-based vaccine using in silico approaches against the Sal k 1 allergen of Salsola kali plant.

Allergens originated from Salsola kali (Russian thistle) pollen grains are one of the most important sources of aeroallergens causing pollinosis in desert and semi-desert regions. T-cell epitope-based vaccines (TEV) are more effective among different therapeutic approaches developed to alleviate allergic diseases. The physicochemical properties, and B as well as T cell epitopes of Sal k 1 (a major allergen of S. kali) were predicted using immunoinformatic tools. A TEV was constructed using the linkers EAAAK, GPGPG and the most suitable CD4+ T cell epitopes. RS04 adjuvant was added as a TLR4 agonist to the amino (N) and carboxyl (C) terminus of the TEV protein. The secondary and tertiary structures, solubility, allergenicity, toxicity, stability, physicochemical properties, docking with immune receptors, BLASTp against the human and microbiota proteomes, and in silico cloning of the designed TEV were assessed using immunoinformatic analyses. Two CD4+ T cell epitopes of Sal k1 that had high affinity with different alleles of MHC-II were selected and used in the TEV. The molecular docking of the TEV with HLADRB1, and TLR4 showed TEV strong interactions and stable binding pose to these receptors. Moreover, the codon optimized TEV sequence was cloned between NcoI and XhoI restriction sites of pET-28a(+) expression plasmid. The designed TEV can be used as a promising candidate in allergen-specific immunotherapy against S. kali. Nonetheless, effectiveness of this vaccine should be validated through immunological bioassays.

Introducing the halophyte Salicornia europaea to investigate combined impact of salt and tidal submergence conditions.

Tolerance mechanisms to single abiotic stress events are being investigated in different plant species, but how plants deal with multiple stress factors occurring simultaneously is still poorly understood. Here, we introduce Salicornia europaea as a species with an extraordinary tolerance level to both flooding and high salt concentrations. Plants exposed to 0.5MNaCl (mimicking sea water concentrations) grew larger than plants not exposed to salt. Adding more salt reduced growth, but concentrations up to 2.5MNaCl were not lethal. Regular tidal flooding with salt water (0.5MNaCl) did not affect growth or chlorophyll fluorescence, whereas continuous flooding stopped growth while plants survived. Quantitative polymerase chain reaction (qPCR) analysis of plants exposed to 1% oxygen in air revealed induction of selected hypoxia responsive genes, but these genes were not induced during tidal flooding, suggesting that S. europaea did not experience hypoxic stress. Indeed, plants were able to transport oxygen into waterlogged soil. Interestingly, sequential exposure to salt and hypoxic air changed the expression of several but not all genes as compared to their expression upon hypoxia only, demonstrating the potential to use S . europaea to investigate signalling-crosstalk between tolerance reactions to multiple environmental perturbations.

Kalidium cuspidatum colonization changes the structure and function of salt crust microbial communities.

The changes of soil moisture, salinity, and nutrients by halophyte colonization in high-salinity environment profoundly affect the assembly and structure of microbial communities. However, salt marshes in arid region have received little attention. This study was conducted in Lianhuachi Lake, a typical inland salt marsh wetland in China, to determine the physicochemical characteristics of salt crusts in [Kalidium cuspidatum (Ung.-Sternb.) Grub.] colonization areas and bulk soil, respectively, and to analyze the microbial community structure of salt crusts by high-throughput sequencing. Kalidium cuspidatum colonization significantly decreased total salinity, soil water content, and water-soluble ions of salt crusts and increased total carbon, total nitrogen, and total phosphorus content. At the same time, changes in physicochemical properties caused by Kalidium cuspidatum colonization affect the ecological processes of bacterial, fungal, and archaeal community assemblies in salt crusts. In addition, cross-kingdom network analysis showed that Kalidium cuspidatum colonization increased the complexity and stability of microbial networks in salt crust soils. Functional projections further showed that bacterial diversity had a potential driving effect on the nitrogen cycle function of salt crust. Our study further demonstrated the different ecological strategies of microorganisms for halophyte colonization in extreme environments and contributed to the understanding of restoration and management of salt marsh wetlands in arid region.

Uptake and distribution of metal(loid)s in two rare species of saltmarsh, blackseed samphire, Tecticornia pergranulata, and narrow-leafed wilsonia, Wilsonia backhousei, in New South Wales, Australia.

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.

Systematic characterization of the influence of petroleum spill on terpene metabolism in Suaeda salsa (L.) Pall from coastal wetland: Implication by compound-specific stable isotope.

With the increasing industrialization and urbanization, the ecological environment is suffering from severe deterioration in Liaohe coastal wetland, and petroleum spill is one of the pollution sources. Suaeda salsa (L.) Pall (S. salsa), one of the predominant plants in Liaohe coastal wetland, is facing the increasing degradation. Terpenes are a class of inherent compounds in plants, and play key role in maintain the growth of plants. However, the environmental stress on the terpene metabolism remained unclear in the plants. In the present study, the influence of petroleum spill on terpene metabolism in S. salsa was systematically investigated by analysis of concentrations, compositions and stable carbon isotope. Under the stress of petroleum spill, terpene concentrations showed the decreasing trend, indicating the inhibition effect of petroleum spill on terpene synthesis in S. salsa. The proportions of Sabinene and A-humulene showed the obviously increased with the influence of petroleum spill, implying that these congeners were more sensitive to petroleum spills. The significant changes in stable carbon isotope compositions were observed for Borneol, Dl-menthol, A-humulene and (-) -@-bisabolol, with the enrichment in heavier isotopes in residual fractions. This result indicated that the heavier 13C was preferentially fixed on terpene by S. salsa under the petroleum stress. The similar change trends along the incubation time was observed for A-humulene and (-) - trans caryophyllene, which might imply that A-humulene was one of the products of (-) - trans caryophyllene in S. salsa. Overall, the findings of present study verified the influence of petroleum spill on terpene metabolism in S. salsa, and were meaningful for protecting the plants in the petroleum-pollution wetlands.

Comparative analysis and characterization of the chloroplast genome of Krascheninnikovia ceratoides (Amarathaceae): a xerophytic semi-shrub exhibiting drought resistance and high-quality traits.

BACKGROUND: Krascheninnikovia ceratoides, a perennial halophytic semi-shrub belonging to the genus Krascheninnikovia (Amarathaceae), possesses noteworthy ecological, nutritional, and economic relevance. This species is primarily distributed across arid, semi-arid, and saline-alkaline regions of the Eurasian continent, encompassing Inner Mongolia, Xinjiang, Qinghai, Gansu, Ningxia, and Tibet. RESULTS: We reported the comprehensive chloroplast (cp) genome of K. ceratoides, characterized by a circular conformation spanning 151,968 bp with a GC content of 36.60%. The cp genome encompassed a large single copy (LSC, 84,029 bp), a small single copy (SSC, 19,043 bp), and a pair of inverted repeats (IRs) regions (24,448 bp each). This genome harbored 128 genes and encompassed 150 simple sequence repeats (SSRs). Through comparative analyses involving cp genomes from other Cyclolobeae (Amarathaceae) taxa, we observed that the K. ceratoides cp genome exhibited high conservation, with minor divergence events in protein-coding genes (PCGs) accD, matK, ndhF, ndhK, ycf1, and ycf2. Phylogenetic reconstructions delineated K. ceratoides as the sister taxon to Atriplex, Chenopodium, Dysphania, and Suaeda, thus constituting a robust clade. Intriguingly, nucleotide substitution ratios (Ka/Ks) between K. ceratoides and Dysphania species for ycf1 and ycf2 genes surpassed 1.0, indicating the presence of positive selection pressure on these loci. CONCLUSIONS: The findings of this study augment the genomic repository for the Amarathaceae family and furnish crucial molecular instruments for subsequent investigations into the ecological adaptation mechanisms of K. ceratoides within desert ecosystems.