Rhizobacteria isolated from xerophyte Haloxylon ammodendron manipulate root system architecture and enhance drought and salt tolerance in Arabidopsis thaliana / Las rizobacterias aisladas del xerófito Haloxylon ammodendron manipulan la arquitectura del sistema radicular y mejoran la tolerancia a la sequía y la sal en Arabidopsis thaliana

The objective of this study was to identify bacteria from the rhizosphere of the black saxaul (Haloxylon ammodendron) and test the possibility of using the bacteria for enhancement of drought and/or salt tolerance in the model plant, Arabidopsis thaliana. We collected rhizosphere and bulk soil samples from a natural habitat of H. ammodendron in Iran and identified 58 morphotypes of bacteria that were enriched in the rhizosphere. From this collection, we focused our further experiments on eight isolates. Microbiological analyses showed that these isolates have different levels of tolerance to heat, salt, and drought stresses, and showed different capabilities of auxin production and phosphorous solubilization. We first tested the effects of these bacteria on the salt tolerance of Arabidopsis on agar plate assays. The bacteria substantially influenced the root system architecture, but they were not effective in increasing salt tolerance significantly. Pot assays were then conducted to evaluate the effects of the bacteria on salt or drought tolerance of Arabidopsis on peat moss. Results showed that three of these bacteria (Pseudomonas spp. and Peribacillus sp.) effectively enhanced drought tolerance in Arabidopsis, so that while none of the mock-inoculated plants survived after 19 days of water withholding, the survival rate was 50–100% for the plants that were inoculated with these bacteria. The positive effects of the rhizobacteria on a phylogenetically-distant plant species imply that the desert rhizobacteria may be used to enhance abiotic stress in crops.(AU)

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.

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.

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.

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.

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.

[Prediction of Soil Bacterial Community Structure and Function in Minqin Desert-oasis Ecotone Artificial Haloxylon ammodendron Forest].

Exploring the effects of artificial Haloxylon ammodendron forest planting on the structure and function of a desert soil bacterial community provides data reference for soil micro-ecological restoration and land quality improvement in desert oasis transition zones. Illumina high-throughput sequencing technology and PICRUSt2 functional prediction analysis were used to identify and analyze the structure and function of soil bacterial communities, and the Mantel correlation test and RDA analysis were used to explain the physicochemical factors affecting the structure and function of soil bacterial communities. The results showed that:① the soil bacterial OTU number, Chao1 index, and Shannon index were significantly higher in the H. ammodendron forest than in the mobile dune soil, and the PCoA analysis and Adonis test showed significant differences in the soil bacterial community structure between H. ammodendron and mobile dune soil (P=0.001). ② A total of 34 phyla, 89 classes, 174 orders, 262 families, and 432 genera of bacteria were detected in all samples, and the phyla Proteobacteria, Actinobacteria, Cyanobacteria, and Chloroflexi accounted for 76.05% of the relative abundance of soil bacteria, which belonged to the dominant soil bacteria, among which the relative abundance of Actinobacteria in H. ammodendron forest soil was extremely significantly higher than that in mobile dune soil (P < 0.01). ③PICRUSt2 function prediction revealed that the soil bacterial community of H. ammodendron forest included six categories of primary functions and 28 categories of secondary functions, among which the metabolism of carbohydrates, metabolism of amino acids, and metabolism of cofactors and vitamins were all greater than 10% in relative abundance and were the main metabolic functions of H. ammodendron forest soil bacteria. ④ The planting of H. ammodendron forest significantly improved the nutrient content of soil organic matter and other nutrients. Soil pH, organic matter, total nitrogen, and fast-acting phosphorus were the main physicochemical factors affecting the bacterial community, with soil organic matter significantly affecting the soil bacterial community structure (P < 0.05) and metabolic function (P < 0.05). In conclusion, the artificial H. ammodendron forest helped to increase desert soil microbial diversity, increase the relative abundance of soil bacterial metabolic function genes, and improve the desert soil microenvironment.

The complete chloroplast genome of the halophyte flowering plant Suaeda monoica from Jeddah, Saudi Arabia.

The complete chloroplast genome (plastome) of the annual flowering halophyte herb Suaeda monoica Forssk. ex J. F. Gmel. family (Amaranthaceae) that grows in Jeddah, Saudi Arabia, was identified for the first time in this study. Suaeda monoica is a medicinal plant species whose taxonomic classification remains controversial. Further, studying the species is useful for current conservation and management efforts. In the current study, the full chloroplast genome S. monoica was reassembled using whole-genome next-generation sequencing and compared with the previously published chloroplast genomes of Suaeda species. The chloroplast genome size of Suaeda monoica was 151,789 bp, with a single large copy of 83,404 bp, a small single copy of 18,007 bp and two inverted repeats regions of 25,189 bp. GC content in the whole genome was 36.4%. The cp genome included 87 genes that coded for proteins, 37 genes coding for tRNA, 8 genes coding for rRNA and one non-coding pseudogene. Five chloroplast genome features were compared between S. monoica and S. japonica, S. glauca, S. salsa, S. malacosperma and S. physophora. Among Suaeda genus and equal to most angiosperms chloroplast genomes, the RSCU values were conservative. Two pseudogenes (accD and ycf1), rpl16 intron and ndhF-rpl32 intergenic spacer, were highlighted as suitable DNA barcodes for different Suaeda species. Phylogenetic analyses show Suaeda cluster into three main groups; one in which S. monoica was closer to S. salsa. The obtained result provided valuable information on the characteristics of the S. monoica chloroplast genome and the phylogenetic relationships.

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.

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.

The novel chaperonin 10 like protein (SbCPN10L) from Salicornia brachiata (Roxb.) augment the heat stress tolerance in transgenic tobacco.

The heat stress is a significant environmental challenge and impede the plant growth, development and productivity. The characterization and utilization of novel genes for improving stress tolerance represents a paramount approach in crop breeding. In the present study, we report on cloning of a novel heat-induced chaperonin 10-like gene (SbCPN10L) from Salicornia brachiata and elucidation of its in-planta role in conferring the heat stress endurance. The transgenic tobacco over-expressing SbCPN10L gene exhibited enhanced growth attributes such as higher rate of seed germination, germination and vigor index at elevated (35 ± 1 °C) temperature (eT). The SbCPN10L tobacco exhibited greenish and healthy seedling growth under stress. Compared with control tobacco at eT, the transgenic tobacco had higher water contents, membrane stability index, stress tolerance index and photosynthetic pigments. Lower electrolyte leakage and less accumulation of malondialdehyde, hydrogen peroxide and reactive oxygen species indicated better heat stress tolerance in transgenic tobacco over-expressing SbCPN10L gene. Transgenic tobacco accumulated higher contents of sugars, starch, amino acids and polyphenols at eT. The negative solute potential observed in transgenic tobacco contributed to maintain water content and support improved growth under stress. The up-regulation of NtAPX, NtPOX and NtSOD in transgenic tobacco under stress indicated higher ROS scavenging ability and better physiological conditioning. The results recommend the SbCPN10L gene as a potential candidate gene with an ability to confer heat stress tolerance for climate resilient crops.

Chemical Constituents of Halophyte Suaeda glauca and Their Therapeutic Potential for Hair Loss.

Suaeda glauca, a halophyte in the Amaranthaceae family, exhibits remarkable resilience to high salt and alkali stresses despite the absence of salt glands or vesicles in its leaves. While there is growing pharmacological interest in S. glauca, research on its secondary metabolites remains limited. In this study, chemical constituents of the aerial parts of S. glauca were identified using 1D- and 2D-NMR experiments, and its biological activity concerning hair loss was newly reported. Eight compounds, including alkaloids (1~3), flavonoids (4~6), and phenolics (7 and 8), were isolated. The compounds, except the flavonoids, were isolated for the first time from S. glauca. In the HPLC chromatogram, quercetin-3-O-ß-d-glucoside, kaempferol-3-O-ß-d-glucoside, and kaempferol were identified as major constituents in the extract of S. glauca. Additionally, the therapeutic potential of the extract of S. glauca and the isolated compounds 1~8 on the expressions of VEGF and IGF-1, as well as the regulation of Wnt/ß-catenin signaling, were evaluated in human follicle dermal papilla cells (HFDPCs) and human umbilical vein endothelial cells (HUVECs). Among the eight compounds, compound 4 was the most potent in terms of increasing the expression of VEGF and IGF-1 and the regulation of Wnt/ß-catenin. These findings suggest that S. glauca extract and its compounds are potential new candidates for preventing or treating hair loss.

Ceratocarpus arenarius: Botanical Characteristics, Proximate, Mineral Composition, and Cytotoxic Activity.

Ceratocarpus arenarius (Chenopodiaceae) is an under-investigated annual plant that occurs in dry areas stretching from eastern and south-eastern Europe to East Asia. This article presents the botanical characterization and examination of proximate parameters, minerals and cytotoxic activity of C. arenarius that grows wild in Kazakhstan. The results of morphological analysis using a light microscope, based on cross-sections of stems, roots and leaves, provide the necessary data to develop a regulatory document for this herbal substance as a raw material for use in the pharmaceutical, cosmetic and food industries. The investigated proximate characteristics included moisture content (6.8 ± 0.28%), ash (5.9 ± 0.40%), fat (12.5 ± 21.28%) and protein (392.85 ± 25.50). The plant is also rich in minerals (mg/100 g dry weight); Na (20.48 ± 0.29), K (302.73 ± 1.15), Zn (4.45 ± 0.35), Fe (1.18 ± 0.03), Cu (0.11 ± 0.02), Mn (0.76 ± 0.01), Ca (131.23 ± 0.09) and Mg (60.69 ± 0.72). The ethanolic extract of C. arenarius showed no acute toxicity against the brine shrimp nauplii.

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.

Insights into the multi-chromosomal mitochondrial genome structure of the xero-halophytic plant Haloxylon Ammodendron (C.A.Mey.) Bunge ex Fenzl.

BACKGROUND: Haloxylon ammodendron holds significance as an ecological plant, showcasing remarkable adaptability to desert conditions, halophytic environments, and sand fixation. With its potential for carbon sequestration, it emerges as a promising candidate for environmental sustainability. Furthermore, it serves as a valuable C4 plant model, offering insights into the genetic foundations of extreme drought tolerance. Despite the availability of plastid and nuclear genomes, the absence of a mitochondrial genome (mitogenome or mtDNA) hinders a comprehensive understanding of its its mtDNA structure, organization, and phylogenetic implications. RESULTS: In the present study, the mitochondrial genome of H. ammodendron was assembled and annotated, resulting in a multi-chromosomal configuration with two circular chromosomes. The mtDNA measured 210,149 bp in length and contained 31 protein-coding genes, 18 tRNA and three rRNA. Our analysis identified a total of 66 simple sequence repeats along with 27 tandem repeats, 312 forward repeats, and 303 palindromic repeats were found. Notably, 17 sequence fragments displayed homology between the mtDNA and chloroplast genome (cpDNA), spanning 5233 bp, accounting for 2.49% of the total mitogenome size. Additionally, we predicted 337 RNA editing sites, all of the C-to-U conversion type. Phylogenetic inference confidently placed H. ammodendron in the Amaranthacea family and its close relative, Suaeda glacum. CONCLUSIONS: H. ammodendron mtDNA showed a multi-chromosomal structure with two fully circularized molecules. This newly characterized mtDNA represents a valuable resource for gaining insights into the basis of mtDNA structure variation within Caryophyllales and the evolution of land plants, contributing to their identification, and classification.

Insight into bacterial and archaeal community structure of Suaeda altissima and Suaeda dendroides rhizosphere in response to different salinity level.

IMPORTANCE: Suaeda play an important ecological role in reclamation and improvement of agricultural saline soil due to strong salt tolerance. At present, research on Suaeda salt tolerance mainly focuses on the physiological and molecular regulation. However, the important role played by microbial communities in the high-salinity tolerance of Suaeda is poorly studied. Our findings have important implications for understanding the distribution patterns and the driving mechanisms of different Suaeda species and soil salinity levels. In addition, we explored the key microorganisms that played an important ecological role in Suaeda rhizosphere. We provide a basis for biological improvement and ecological restoration of salinity-affected areas.

Evaluating the capacity of heavy metal pollution enrichment in green vegetation in the industrial zone, Northwest China.

It focused on heavy metal pollution of green vegetation in Tuokexun County, Xinjiang Northwest China's suburban industrial area, using inductively coupled plasma emission spectrometer to analyze the samples for Mn, Ni, Zn, Cd, Hg, Pb, As, Cu, and Cr contents. The soil's heavy metal content in the study area indicated a minor level of pollution overall (P = 1.77), with the most severe contamination being Hg, which is more likely to be caused by human activities. Heavy metal elements in trees have the most stable composition in comparison to grass and shrubs, with varying concentrations across different vegetation. The concentrations of Mn, Cd and Hg were highest in the Haloxylon ammodendron, Ni in Morus alba, Pb, As and Cu in Nitraria tangutorums, and Cr in Phragmites australis. Heavy metal restoration is most effectively performed by shrubs, and there are disparities in heavy metal enrichment among various vegetation. No significant difference was found in heavy metal enrichment between the aboveground and underground parts of vegetation. Based on the average of the membership function, Tamarix exhibits the strongest ability to enrich heavy metals, while Nitraria tangutorum comes in second, and Cynanchum chinense R.Br. is the least effective among all plant species. Morus alba is recommended as the primary planting species in the area. Nitraria tangutorum and Haloxylon ammodendron have good potential for Cd and As restoration and can be used as supporting vegetation.