Dynamics of soil biota and nutrients at varied depths in a Tamarix ramosissima-dominated natural desert ecosystem: Implications for nutrient cycling and desertification management.

The underground community of soil organisms, known as soil biota, plays a critical role in terrestrial ecosystems. Different ecosystems exhibit varied responses of soil organisms to soil physical and chemical properties (SPCPs). However, our understanding of how soil biota react to different soil depths in naturally established population of salinity tolerant Tamarix ramosissima in desert ecosystems, remains limited. To address this, we employed High-Throughput Illumina HiSeq Sequencing to examine the population dynamics of soil bacteria, fungi, archaea, protists, and metazoa at six different soil depths (0-100 cm) in the naturally occurring T. ramosissima dominant zone within the Taklimakan desert of China. Our observations reveal that the alpha diversity of bacteria, fungi, metazoa, and protists displayed a linear decrease with the increase of soil depth, whereas archaea exhibited an inverse pattern. The beta diversity of soil biota, particularly metazoa, bacteria, and protists, demonstrated noteworthy associations with soil depths through Non-Metric Dimensional Scaling analysis. Among the most abundant classes of soil organisms, we observed Actinobacteria, Sordariomycetes, Halobacteria, Spirotrichea, and Nematoda for bacteria, fungi, archaea, protists, and metazoa, respectively. Additionally, we identified associations between the vertical distribution of dominant biotic communities and SPCPs. Bacterial changes were mainly influenced by total potassium, available phosphorus (AP), and soil water content (SWC), while fungi were impacted by nitrate (NO3-) and available potassium (AK). Archaea showed correlations with total carbon (TC) and AK thus suggesting their role in methanogenesis and methane oxidation, protists with AP and SWC, and metazoa with AP and pH. These correlations underscore potential connections to nutrient cycling and the production and consumption of greenhouse gases (GhGs). This insight establishes a solid foundation for devising strategies to mitigate nutrient cycling and GHG emissions in desert soils, thereby playing a pivotal role in the advancement of comprehensive approaches to sustainable desert ecosystem management.

A novel flavonol-polysaccharide from Tamarix chinensis alleviates influenza A virus-induced acute lung injury. Evidences for its mechanism of action.

BACKGROUND: Tamarix chinensis Lour. is a Chinese medicine used for treating inflammation-related diseases and its crude polysaccharides (MBAP90) exhibited significant anticomplement activities in vitro. PURPOSE: To obtain anticomplement homogenous polysaccharides from MBAP90 and explore its therapeutic effects and potential mechanism on influenza A virus (IAV)-induced acute lung injury (ALI). METHODS: Anticomplement activity-guided fractionation of the water-soluble crude polysaccharides from the leaves and twigs of T. chinensis were performed by diethylaminoethyl-52 (DEAE-52) cellulose and gel permeation columns to yield a homogeneous polysaccharide MBAP-5, which was further characterized using ultra-high-performance liquid chromatography-ion trap tandem mass spectrometry (UPLC-IT-MS) and nuclear magnetic resonance (NMR) analysis. In vitro, the anticomplement activity of MBAP-5 through classical pathway was measured using a hemolytic test. The therapeutic effects of MBAP-5 on ALI were evaluated in H1N1-infected mice. H&E staining, enzyme linked immunosorbent assay (ELISA), immunohistochemistry, and western blot were used to systematically access lung histomorphology, inflammatory cytokines, degree of complement component 3c, 5aR, and 5b-9 (C3c, C5aR, and C5b-9) deposition, and inflammasome signaling pathway protein expressions in lung tissues. RESULTS: MBAP-5 was a novel flavonol-polysaccharide with the molecular weight (Mw) of 153.6 kDa. Its structure was characterized to process a backbone of →4)-α-D-GlcpA-(1→, →6)-α-D-Glcp-(1→, →3,4)-α-D-Glcp-(1→, →3,4,6)-α-D-Glcp-(1→, and →4,6)-ß-D-Glcp-(1→, as well as branches of α-L-Araf-(1→ and ß-D-Galp-(1→. Particularly, O-3 of →3,4,6)-α-D-Glcp-(1→ was substituted by quercetin. In vitro assay showed that MBAP-5 had a potent anticomplement activity with a CH50 value of 102 ± 4 µg/ml. Oral administration of MBAP-5 (50 and 100 mg/kg) effectively attenuated the H1N1-induced pulmonary injury in vivo by reducing pulmonary edema, virus replication, and inflammatory responses. Mechanistically, MBAP-5 inhibited the striking deposition and contents of complement activation products (C3c, C5aR, and C5b-9) in the lung. Toll-like receptor 4 (TLR4) /transcription factor nuclear factor κB (NF-κB) signaling pathway was constrained by MBAP-5 treatment. In addition, MBAP-5 could suppress activation of the inflammasome pathways, including Nod-like receptor pyrin domain 3 (NLRP3), cysteinyl aspartate specific proteinase-1/12 (caspase-1/12), apoptosis­associated speck­like protein (ASC), gasdermin D (GSDMD), interleukin (IL)-1ß, and IL-18 expressions. CONCLUSIONS: A novel flavonol-polysaccharide MBAP-5 isolated from T. chinensis demonstrated a therapeutic effect against ALI induced by IAV attack. The mechanism might be associated with inhibition of complement system and inflammasome pathways activation.

Involvement of TNFα, IL-1ß, COX-2 and NO in the anti-inflammatory activity of Tamarix aphylla in Wistar albino rats: an in-vivo and in-vitro study.

BACKGROUND: With the emergence of many side effects from synthetic drugs, there is an urgent need to find a natural alternative to these products. Therefore, our primary aim was to evaluate the anti-inflammatory activity of Tamarix aphylla (TA) and investigate the potential mechanism underlying this action. METHODS: Initially, to ensure the safety of the extract and for dose selection, we performed an acute oral toxicity Assay through the oral administration of graded doses up to 4 g\kg in Wistar rats. then, we used the carrageenan-induced edema model to elucidate the anti-inflammatory activity. Using specific ELISA kits, we measured the levels of TNF-α, IL-1ß, COX-2 and NO inside the inflamed paw tissue. Finally, for the in-vitro anti-inflammatory experiment, we used the erythrocyte membrane stability test. RESULTS: Based on the acute oral toxicity assay, T. aphylla was considered generally safe and three different doses of 100, 200, and 400 mg/kg were chosen for further experiments. Additionally, TA expressed a significant (P < 0.05) anti-inflammatory activity, showing the maximum inhibition percentage at the fifth hour of measurement at 53.47% and 70.06%, at doses of 200 and 400 mg/kg respectively, compared to 63.81% for the standard drug. Similarly, we found that TA effectively reduced the levels of TNF-α and IL-1ß at all tested doses (100-200-400 mg/kg) to a greater extent than the standard drug. Moreover, at 400 mg/kg, TA was able to significantly lower the levels of COX-2 and NO inside the inflamed tissue to a level comparable (P < 0.05) with that measured inside the paw tissue of normal rats. Finally, Tamarix aphylla at 100, 200 and 400 mg/kg doses significantly (P < 0.05) inhibited the heat-induced hemolysis of RBCs membrane by 67.78, 74.82 and 82.08%, respectively, compared to 83.89% produced by Aspirin. CONCLUSION: T. aphylla produced a significant (P < 0.05) anti-inflammatory activity compared to the standard drugs either through the reduction of pro-inflammatory mediators or the protection of the lysosomal membrane.

Drought resistance in two populations of invasive Tamarix compared using multiple methods.

An on-going question in plant hydraulic research is whether there is intra-specific variability and/or plasticity in xylem traits. Plasticity could be important in taxa that colonize diverse habitats. We used Tamarix, a non-native woody plant, to investigate population differences in hydraulic conductivity (Ks), vulnerability-to-embolism curves and vessel anatomy. We also conducted a season-long drought experiment to determine water potentials associated with crown dieback of field-grown plants. We measured vessel length and diameter, and compared visual (micro-computed tomography; microCT) and hydraulic methods to quantify percentage loss in hydraulic conductivity (PLC). Among plants grown in a common environment, we did not find differences in our measured traits between two populations of Tamarix that differ in salinity at their source habitats. This taxon is relatively vulnerable to embolism. Within samples, large diameter vessels displayed increased vulnerability to embolism. We found that the microCT method overestimated theoretical conductivity and underestimated PLC compared with the hydraulic method. We found agreement for water potentials leading to crown dieback and results from the hydraulic method. Saplings, grown under common conditions in the present study, did not differ in their xylem traits, but prior research has found difference among source-site grown adults. This suggests that plasticity may be key in the success of Tamarix occurring across a range of habits in the arid southwest USA.

Flavonoid substituted polysaccharides from Tamarix chinensis Lour. alleviate H1N1-induced acute lung injury via inhibiting complement system.

ETHNOPHARMACOLOGICAL RELEVANCE: Viral pneumonia is a highly pathogenic respiratory infectious disease associated with excessive activation of the complement system. Our previous studies found that the anticomplement polysaccharides from some medicinal plants could significantly alleviate H1N1-induced acute lung injury (H1N1-ALI). The leaves and twigs of Tamarix chinensis Lour. are traditionally used as a Chinese medicine Xiheliu for treating inflammatory disorders. Interestingly, its crude polysaccharides (MBAP90) showed potent anticomplement activity in vitro. AIM OF THE STUDY: To evaluate the therapeutic effects and possible mechanism of MBAP90 on viral pneumonia and further isolate and characterize the key active substance of MBAP90. MATERIALS AND METHODS: The protective effects of MBAP90 were evaluated by survival tests and pharmacodynamic experiments on H1N1-ALI mice. Histopathological changes, viral load, inflammatory markers, and complement deposition in lungs were analyzed by H&E staining, enzyme-linked immunosorbent assay (ELISA), and immunohistochemistry (IHC), respectively. An anticomplement homogenous polysaccharide (MBAP-3) was obtained from MBAP90 by bio-guided separation, and its structure was further characterized by methylation analysis and NMR spectroscopy. RESULTS: Oral administration of MBAP90 at a dose of 400 mg/kg significantly increased the survival rate of mice infected with the lethal H1N1 virus. In H1N1-induced ALI, mice treated with MBAP90 (200 and 400 mg/kg) could decrease the lung index, lung pathological injury, the levels of excessive proinflammatory cytokines (IL-6, TNF-α, MCP-1, IL-18, and IL-1ß), and complement levels (C3c and C5b-9). In addition, MBAP-3 was characterized as a novel homogenous polysaccharide with potent in vitro anticomplement activity (CH50: 0.126 ± 0.002 mg/mL), containing 10.51% uronic acids and 9.67% flavonoids, which were similar to the composition of MBAP90. The backbone of MBAP-3 consisted of →4)-α-D-Glcp-(1→, →3,4,6)-α-D-Glcp-(1→, and →3,4)-α-D-Glcp-(1→, with branches comprising α-L-Araf-(1→, α-D-GlcpA-(1→, →4,6)-α-D-Manp-(1→ and →4)-ß-D-Galp-(1 â†’ . Particularly, O-6 of →4)-ß-D-Galp-(1→ was conjugated with a flavonoid, myricetin. CONCLUSIONS: MBAP90 could ameliorate H1N1-ALI by inhibiting inflammation and over-activation of the complement system. These polysaccharides (MBAP90 and MBAP-3) with relative high contents of uronic acid and flavonoid substituent might be vital components of T. chinensis for treating viral pneumonia.

Role of bZIP Transcription Factors in Response to NaCl Stress in Tamarix ramosissima under Exogenous Potassium (K+).

Salt stress is a significant environmental factor affecting plant growth and development, with NaCl stress being one of the most common types of salt stress. The halophyte, Tamarix ramosissima Ledeb (T. ramosissima), is frequently utilized for the afforestation of saline-alkali soils. Indeed, there has been limited research and reports by experts and scholars on the regulatory mechanisms of basic leucine zipper (bZIP) genes in T. ramosissima when treated with exogenous potassium (K+) to alleviate the effects of NaCl stress. This study focused on the bZIP genes in T. ramosissima roots under NaCl stress with additional KCl applied. We identified key candidate genes and metabolic pathways related to bZIP and validated them through quantitative real-time PCR (qRT-PCR). The results revealed that under NaCl stress with additional KCl applied treatments at 0 h, 48 h, and 168 h, based on Pfam protein domain prediction and physicochemical property analysis, we identified 20 related bZIP genes. Notably, four bZIP genes (bZIP_2, bZIP_6, bZIP_16, and bZIP_18) were labeled with the plant hormone signal transduction pathway, showing a predominant up-regulation in expression levels. The results suggest that these genes may mediate multiple physiological pathways under NaCl stress with additional KCl applied at 48 h and 168 h, enhancing signal transduction, reducing the accumulation of ROS, and decreasing oxidative damage, thereby enhancing the tolerance of T. ramosissima to NaCl stress. This study provides gene resources and a theoretical basis for further breeding of salt-tolerant Tamarix species and the involvement of bZIP transcription factors in mitigating NaCl toxicity.

Insights into the phylogenetic relationships and species boundaries of the Myricaria squamosa complex (Tamaricaceae) based on the complete chloroplast genome.

Myricaria plants are widely distributed in Eurasia and are helpful for windbreak and embankment protection. Current molecular evidence has led to controversy regarding species boundaries within the Myricaria genus and interspecific phylogenetic relationships between three specific species-M. bracteata, M. paniculata and M. squamosa-which have remained unresolved. This study treated these three unresolved taxa as a species complex, named the M. squamosa complex. The genome skimming approach was used to determine 35 complete plastome sequences and nuclear ribosomal DNA sequences for the said complex and other closely related species, followed by de novo assembly. Comparative analyses were conducted across Myricaria to identify the genome size, gene content, repeat type and number, SSR (simple sequence repeat) abundance, and codon usage bias of chloroplast genomes. Tree-based species delimitation results indicated that M. bracteata, M. paniculata and M. squamosa could not be distinguished and formed two monophyletic lineages (P1 and P2) that were clustered together. Compared to plastome-based species delimitation, the standard nuclear DNA barcode had the lowest species resolution, and the standard chloroplast DNA barcode and group-specific barcodes delimitated a maximum of four out of the five species. Plastid phylogenomics analyses indicated that the monophyletic M. squamosa complex is comprised of two evolutionarily significant units: one in the western Tarim Basin and the other in the eastern Qinghai-Tibet Plateau. This finding contradicts previous species discrimination and promotes the urgent need for taxonomic revision of the threatened genus Myricaria. Dense sampling and plastid genomes will be essential in this effort. The super-barcodes and specific barcode candidates outlined in this study will aid in further studies of evolutionary history.

Tamarix articulata extract offers protection against toxicity induced by beauty products in Hs27 human skin fibroblasts.

The current study evaluates the cytotoxicity, mode of cell death and chemical analysis of selected beauty products and evaluation of the protective effect of Tamarix articulata (TA) extract against toxicity induced by beauty products in skin fibroblasts (Hs27). MTT and Crystal violet (CV) assays were used to determine the dose-dependent cytotoxic effects of beauty products against Hs27 fibroblasts. DNA fragmentation assay and annexin-V staining were conducted to determine the mode of cell killing induced by evaluated beauty products. Quantification of reactive oxygen species (ROS) and antioxidant enzyme levels were used to evaluate the oxidative stress. Chemical analysis and heavy metals were evaluated to determine beauty products. Pre-treatment with TA extract for different time points followed by time-dependent exposure with beauty products to assess the protective effect of TA extract in Hs27 cells was analyzed by MTT and CV assays. Owing to the presence of various harmful heavy metals such as arsenic (As), chromium (Cr), cadmium (Cd), nickel (Ni), and lead (Pb) in beauty products, our results revealed that all beauty products induce significant cytotoxicity over time (1, 4 h) in a dose-dependent (125, 250, 500 µg/mL) manner. DNA fragmentation assay, quantification of apoptosis by annexin-V staining, determination of ROS and antioxidant enzymes (CAT, GSH-Px and SOD) revealed that the induced cytotoxicity was caused by oxidative stress-mediated apoptosis. However, pre-incubation with a safe dose (50 µg/mL) of TA for different times (24, 48 h) followed by exposure to various doses (62.5, 125, 250, 500 µg/mL) of beauty products for different times (1, 4 h) revealed significant (*p≤0.05, **p≤0.01) protection against beauty product-mediated cytotoxicity. The effect was more pronounced for 1 h exposure to beauty products compared to 4 h. Our study demonstrates that the due to the presence of heavy metals in synthetic beauty products exhibit marked toxicity to skin fibroblasts due to oxidative stress-mediated apoptosis. However, the presence of abundant bioactive polyphenols with promising antiscavenging activity in TA extracts significantly nullifies cytotoxicity promoted by examined beauty products in skin fibroblasts (Hs27).

Potentially suitable distribution areas of Populus euphratica and Tamarix chinensis by MaxEnt and random forest model in the lower reaches of the Heihe River, China.

Populus euphratica and Tamarix chinensis play a vital role in windbreak and sand fixation, maintaining species diversity and ensuring community stability. Managing and protecting the P. euphratica and T. chinensis forests in the Heihe River's lower reaches is an urgent issue to maintain the desert region's ecological balance. In this study, based on the distribution points of P. euphratica and T. chinensis species and environmental data, MaxEnt and random forest (RF) models were used to characterize the potential distribution areas of P. euphratica and T. chinensis in the lower reaches of the Heihe River. The results showed that the accuracy of the RF model was much higher than that of the MaxEnt model. Both the RF and MaxEnt models showed that the distance to the river greatly influenced the distribution of P. euphratica and T. chinensis. Furthermore, the RF model predicted significantly larger highly suitable areas for both P. euphratica and T. chinensis than the MaxEnt model. Our study enhances the understanding of the species' spatial distribution, offering valuable insights for practical management and conservation strategies.

Phytochemical investigation, antibacterial, and ameliorative potential effects of Tamarix nilotica on LPS-induced acute lung injury model in mice.

Acute lung injury (ALI) is a serious illness with a high mortality rate of 40-60%. It is characterised by systemic inflammatory processes and oxidative stress. Gram-negative bacterial infections are the major cause of ALI, and lipopolysaccharide (LPS) is the major stimulus for the release of inflammatory mediators. Hence, there is an urgent need to develop new therapies which ameliorate ALI and prevent its serious consequences. The Middle Eastern native plant Tamarix nilotica (Ehrenb) Bunge belongs to the family Tamaricaceae, which exhibits strong anti-inflammatory and antioxidant effects. Thus, the current work aimed to ensure the plausible beneficial effects of T. nilotica different fractions on LPS-induced acute lung injury after elucidating their phytochemical constituents using LC/MS analysis. Mice were randomly allocated into six groups: Control saline, LPS group, and four groups treated with total extract, DCM, EtOAc and n-butanol fractions, respectively, intraperitoneal at 100 mg/kg doses 30 min before LPS injection. The lung expression of iNOS, TGF-ß1, NOX-1, NOX-4 and GPX-1 levels were evaluated. Also, oxidative stress was assessed via measurements of MDA, SOD and Catalase activity, and histopathological and immunohistochemical investigation of TNF-α in lung tissues were performed. T. nilotica n-butanol fraction caused a significant downregulation in iNOS, TGF-ß1, TNF-α, NOX-1, NOX-4, and MDA levels (p ˂ 0.05), and significantly elevated GPX-1 expression levels, SOD, and catalase activity (p ˂ 0.05), and alleviated all histopathological abnormalities confirming its advantageous role in ALI. The antibacterial activities of T. nilotica and its different fractions were investigated by agar well diffusion method and broth microdilution method. Interestingly, the n-butanol fraction exhibited the best antibacterial activity against Klebsiella pneumoniae clinical isolates. It also significantly reduced exopolysaccharide quantity, cell surface hydrophobicity, and biofilm formation.

Population structure and genetic diversity of Tamarix chinensis as revealed with microsatellite markers in two estuarine flats.

Background: Tamarix chinensis Lour. is a 3-6-meter-tall small tree with high salt- and alkali- tolerance and aggressive invasiveness, mainly distributed in the eastern part of China in warm-temperate and subtropical climate zones, yet there is little information available regarding genetic diversity and population structure. Methods: A total of 204 individuals of nine T. chinensis populations were investigated for genetic diversity and population structure using a set of 12 highly polymorphic microsatellite markers. Results: The total number of alleles detected was 162, the average number of effective allele was 4.607, the average polymorphism information content (PIC) value of the 12 loci was 0.685, and the mean observed heterozygosity (Ho) and the mean expected heterozygosity (He) was 0.653 and 0.711, respectively. Analysis of molecular variance (AMOVA) showed a 5.32% genetic variation among T. chinensis populations. Despite a low population differentiation, Bayesian clustering analysis, discriminant analysis of principal components (DAPC) and the unweighted pair group method with arithmetic mean (UPGMA) clearly identified three genetic clusters correlated to the populations' geographic origin: the northern populations including those from Yellow River Delta, the Fangshan (FS) population from Beijing, the Changyi (CY) population from Bohai Bay, the Huanjiabu (HHJ) population from Hangzhou Bay, and the remaining two populations from Hangzhou Bay. There was a significant relationship between the genetic distance and geographical distance of the paired populations. Gene flow (Nm) was 4.254 estimated from FST. Conclusion: T. chinensis possessed high genetic diversity comparable to tree species, and although the population differentiation is shallow, our results classified the sampled populations according to sampling localities, suggesting the different origins of the study populations.

Transcriptome profiling reveals multiple regulatory pathways of Tamarix chinensis in response to salt stress.

KEY MESSAGE: Multiple regulatory pathways of T. chinensis to salt stress were identified through transcriptome data analysis. Tamarix chinensis (Tamarix chinensis Lour.) is a typical halophyte capable of completing its life cycle in soils with medium to high salinity. However, the mechanisms underlying its resistance to high salt stress are still largely unclear. In this study, transcriptome profiling analyses in different organs of T. chinensis plants in response to salt stress were carried out. A total number of 2280, 689, and 489 differentially expressed genes (DEGs) were, respectively, identified in roots, stems, and leaves, with more DEGs detected in roots than in stems and leaves. Gene Ontology (GO) term analysis revealed that they were significantly enriched in "biological processes" and "molecular functions". Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that "Beta-alanine metabolism" was the most differentially enriched pathway in roots, stems, and leaves. In pair-to-pair comparison of the most differentially enriched pathways, a total of 14 pathways, including 5 pathways in roots and leaves, 6 pathways in roots and stems, and 3 pathways in leaves and stems, were identified. Furthermore, genes encoding transcription factor, such as bHLH, bZIP, HD-Zip, MYB, NAC, WRKY, and genes associated with oxidative stress, starch and sucrose metabolism, and ion homeostasis, were differentially expressed with distinct organ specificity in roots, stems, and leaves. Our findings in this research provide a novel approach for exploring the salt tolerance mechanism of halophytes and identifying new gene targets for the genetic breeding of new plant cultivars with improved resistance to salt stress.

Link between the aboveground and belowground biomass allocation with growing of Tamarix sp. seedlings in the hinterland of Taklimakan Desert, China.

The morphological characteristics and biomass allocation can reflect plant adaptive strategies to the environment. Tamarix sp. is an excellent shrub species used for windbreaks and fixing sand in the desert of northwest China. The successful establishment of Tamarix sp. seedlings and their growth into mature individuals require their adaptation to various environmental conditions, which is the key to naturally regenerating the Tamarix population. To clarify the root morphological characteristics, leaf structural characters, and biomass allocation of Tamarix sp. seedlings in response to drought conditions, we took the Tamarix sp. seedlings at the Daryaboyi oasis in the hinterland of Taklimakan Desert as the object of study, analyzed rooting depth, root dry weight (RDW), specific root length (SRL), root surface area (RA), specific root area (SRA), leaf area (LA), specific leaf area (SLA) and root: shoot ratio (R:S ratio). The gravimetric soil water content varied from 5.80% to 25.84% in this study area. The taproots of Tamarix sp seedlings with small basal stem diameters were shallower and had few lateral root branches and Tamarix sp. seedlings with large basal stem diameters had more obvious taproots and lateral roots. With the growth of Tamarix sp. seedlings, the taproot deepened, and the values ranged from 4.5 cm to 108.0 cm; the SRL, SRA, and SLA decreased, and the ranges of the values were 28.92-478.79 cm·g-1, 1.07-458.50 cm2·g-1, and 24.48-50.7 cm2·g-1; the RDW, RA, and LA increased, the ranges of the values were 0.16-21.34 g, 3.42-328.04 cm2, and 2.41-694.45 cm2; the more biomass was allocated to the aboveground parts, and the mean R: S ratio was 0.76. In better soil water conditions, the root growth rate decreased as Tamarix sp. seedlings grew, and more biomass was allocated to the aboveground. This further showed that stable surface water is highly significant to the biomass allocation strategy of Tamarix sp. seedlings.

Assessment of the Antivirulence Potential of Tamarix aphylla Ethanolic Extract against Multidrug-Resistant Streptococcus mutans Isolated from Iraqi Patients.

Halophytes have long been used for medicinal purposes. However, their use was entirely empirical, with no knowledge of the bioactive compounds. The plant Tamarix aphylla L. has not drawn the deserving attention for its phytochemical and bioactive explorations, but available data expressed its needs to be attended for its potential. The Streptococcus mutans SpaP gene (cell-surface antigen) mediates the binding of these bacteria to tooth surfaces. The growing problem of antibiotic resistance triggered the research on alternative antimicrobial approaches. Our study aims to explore the activity of T. aphylla ethanolic extract against the virulence gene found in Streptococcus mutans pathogenic bacteria. Samples that were previously collected and identified in our previous work (in press) were obtained from different dental clinics and hospitals in Baghdad. Three nonbiofilm-forming bacterial isolates having multidrug resistance (MDR) for 10 antibiotics (doxycycline, ofloxacin, tetracycline, erythromycin, vancomycin, clindamycin, rifampicin, imipenem, amikacin, and cefepime) were selected to examine the potential of the T. aphylla ethanolic extract. The ethanolic extract showed high antimicrobial activity against MDR. Minimum inhibition concentration (MIC) for the extract was 17.5 mg/ml, while minimum bactericidal concentration (MBC) was 35 mg/ml. The phytochemical compounds present in the ethanolic extract were determined by using high-performance liquid chromatography (HPLC) which revealed that the leaves contain thirteen different alkaloids, twelve flavonoids, and four vitamins. The extract strongly inhibited a virulence property, the adherence of S. mutans which reduced during critical growth phases. The one-step RT-PCR method was used to study the SpaP gene expression of bacterial isolates which significantly reduced. In conclusion, extraction of T. aphylla leaves showed an antimicrobial effect against MDR S. mutans. The identified phytochemicals in the T. aphylla extract are reported to be biologically important and need further investigation to develop safe and cheap drugs.

Comparative transcriptomic and metabolomic analyses provide insights into the responses to NaCl and Cd stress in Tamarix hispida.

Salinity and heavy metal pollution seriously affect plant growth. Tamarix hispida (T. hispida) has the potential to remediate soil saline-alkali and heavy metal pollution. In this study, the response mechanisms of T. hispida under NaCl, CdCl2 (Cd) and combined CdCl2 and NaCl (Cd-NaCl) stresses were explored. Overall, the antioxidant system showed changes under the three stresses. The addition of NaCl inhibited the absorption of Cd2+. However, there were obvious differences in the transcripts and metabolites identified among the three stress responses. Interestingly, the number of DEGs was greatest under NaCl stress (929), but the number of differentially expressed metabolites (DEMs) was lowest (48), with 143 and 187 DEMs identified under Cd and Cd-NaCl stress, respectively. It is worth noting that both DEGs and DEMs were enriched in the linoleic acid metabolism pathway under Cd stress. In particular, the content of lipids changed significantly under Cd and Cd-NaCl stress, suggesting that maintaining normal lipid synthesis and metabolism may be an important way to improve the Cd tolerance of T. hispida. Flavonoids may also play an important role in the response to NaCl and Cd stress. These results provide a theoretical basis for cultivating plants with improved salt and cadmium repair abilities.

Chemical profiling and cytotoxic potential of the n-butanol fraction of Tamarix nilotica flowers.

BACKGROUND: Cancer represents one of the biggest healthcare issues confronting humans and one of the big challenges for scientists in trials to dig into our nature for new remedies or to develop old ones with fewer side effects. Halophytes are widely distributed worldwide in areas of harsh conditions in dunes, and inland deserts, where, to cope with those conditions they synthesize important secondary metabolites highly valued in the medical field. Several Tamarix species are halophytic including T.nilotica which is native to Egypt, with a long history in its tradition, found in its papyri and in folk medicine to treat various ailments. METHODS: LC-LTQ-MS-MS analysis and 1H-NMR were used to identify the main phytoconstituents in the n- butanol fraction of T.nilotica flowers. The extract was tested  in vitro for its cytotoxic effect against breast (MCF-7) and liver cell carcinoma (Huh-7) using SRB assay. RESULTS: T.nilotica n-butanol fraction of the flowers was found to be rich in phenolic content, where, LC-LTQ-MS-MS allowed the tentative identification of thirty-nine metabolites, based on the exact mass, the observed spectra fragmentation patterns, and the literature data, varying between tannins, phenolic acids, and flavonoids. 1H-NMR confirmed the classes tentatively identified. The in-vitro evaluation of the n-butanol fraction showed lower activity on MCF-7 cell lines with IC50 > 100 µg/mL, while the higher promising effect was against Huh-7 cell lines with an IC50= 37 µg/mL. CONCLUSION: Our study suggested that T.nilotica flowers' n-butanol fraction is representing a promising cytotoxic candidate against liver cell carcinoma having potential phytoconstituents with variable targets and signaling pathways.

Overexpression of ThSCL32 confers salt stress tolerance by enhancing ThPHD3 gene expression in Tamarix hispida.

GRAS transcription factors belong to the plant-specific protein family. They are not only involved in plant growth and development but also in plant responses to a variety of abiotic stresses. However, to date, the SCL32(SCARECROW-like 32) gene conferring the desired resistance to salt stresses has not been reported in plants. Here, ThSCL32, a homologous gene of ArabidopsisthalianaAtSCL32, was identified. ThSCL32 was highly induced by salt stress in Tamarix hispida. ThSCL32 overexpression in T. hispida gave rise to improved salt tolerance. ThSCL32-silenced T. hispida plants were more sensitive to salt stress. RNA-seq analysis of transient transgenic T. hispida overexpressing ThSCL32 revealed significantly enhanced ThPHD3 (prolyl-4-hydroxylase domain 3 protein) gene expression. ChIP-PCR further verified that ThSCL32 probably binds to the novel cis-element SBS (ACGTTG) in the promoter of ThPHD3 to activate its expression. In brief, our results suggest that the ThSCL32 transcription factor is involved in salt tolerance in T. hispida by enhancing ThPHD3 expression.

A rapid and accurate method of mapping invasive Tamarix genotypes using Sentinel-2 images.

Background: The management of invasive Tamarix genotypes depends on reliable and accurate information of their extent and distribution. This study investigated the utility of the multispectral Sentinel-2 imageries to map infestations of the invasive Tamarix along three riparian ecosystems in the Western Cape Province of South Africa. Methods: The Sentinel-2 image was acquired from the GloVis website (http://glovis.usgs.gov/). Random forest (RF) and support vector machine (SVM) algorithms were used to classify and estimate the spatial distribution of invasive Tamarix genotypes and other land-cover types in three riparian zones viz. the Leeu, Swart and Olifants rivers. A total of 888 reference points comprising of actual 86 GPS points and additional 802 points digitized using the Google Earth Pro free software were used to ground-truth the Sentinel-2 image classification. Results: The results showed the random forest classification produced an overall accuracy of 87.83% (with kappa value of 0.85), while SVM achieved an overall accuracy of 86.31% with kappa value of 0.83. The classification results revealed that the Tamarix invasion was more rampant along the Olifants River near De Rust with a spatial distribution of 913.39 and 857.74 ha based on the RF and SVM classifiers, respectively followed by the Swart River with Tamarix coverage of 420.06 ha and 715.46 hectares, respectively. The smallest extent of Tamarix invasion with only 113.52 and 74.27 hectares for SVM and RF, respectively was found in the Leeu River. Considering the overall accuracy of 85% as the lowest benchmark for a robust classification, the results obtained in this study suggests that the SVM and RF classification of the Sentinel-2 imageries were effective and suitable to map invasive Tamarix genotypes and discriminate them from other land-cover types.

Proteome Dynamics Analysis Reveals the Potential Mechanisms of Salinity and Drought Response during Seed Germination and Seedling Growth in Tamarix hispida.

Understanding the molecular mechanisms of seed germination and seedling growth is vital for mining functional genes for the improvement of plant drought in a desert. Tamarix hispida is extremely resistant to drought and soil salinity perennial shrubs or trees. This study was the first to investigate the protein abundance profile of the transition process during the processes of T. hispida seed germination and seedling growth using label-free proteomics approaches. Our data suggested that asynchronous regulation of transcriptomics and proteomics occurs upon short-term seed germination and seedling growth of T. hispida. Enrichment analysis revealed that the main differentially abundant proteins had significant enrichment in stimulus response, biosynthesis, and metabolism. Two delta-1-pyrroline-5-carboxylate synthetases (P5CS), one Ycf3-interacting protein (Y3IP), one low-temperature-induced 65 kDa protein-like molecule, and four peroxidases (PRX) were involved in both water deprivation and hyperosmotic salinity responses. Through a comparative analysis of transcriptomics and proteomics, we found that proteomics may be better at studying short-term developmental processes. Our results support the existence of several mechanisms that enhance tolerance to salinity and drought stress during seedling growth in T. hispida.

Effects of Variation in Tamarix chinensis Plantations on Soil Microbial Community Composition in the Middle Yellow River Floodplain.

Floodplains have important ecological and hydrological functions in terrestrial ecosystems, experience severe soil erosion, and are vulnerable to losing soil fertility. Tamarix chinensis Lour. plantation is the main vegetation restoration measure for maintaining soil quality in floodplains. Soil microorganisms are essential for driving biogeochemical cycling processes. However, the effects of sampling location and shrub patch size on soil microbial community composition remain unclear. In this study, we characterized changes in microbial structure, as well as the factors driving them, in inside- and outside-canopy soils of three patch sizes (small, medium, large) of T. chinensis plants in the middle Yellow River floodplain. Compared with the outside-canopy soils, inside-canopy had higher microbial phospholipid fatty acids (PLFAs), including fungi, bacteria, Gram-positive bacteria (GP), Gram-negative bacteria (GN), and arbuscular mycorrhizal fungi. The ratio of fungi to bacteria and GP to GN gradually decreased as shrub patch size increased. Differences between inside-canopy and outside-canopy soils in soil nutrients (organic matter, total nitrogen, and available phosphorus) and soil salt content increased by 59.73%, 40.75%, 34.41%, and 110.08% from small to large shrub patch size. Changes in microbial community composition were mainly driven by variation in soil organic matter, which accounted for 61.90% of the variation in inside-canopy soils. Resource islands could alter microbial community structure, and this effect was stronger when shrub patch size was large. The results indicated that T. chinensis plantations enhanced the soil nutrient contents (organic matter, total nitrogen, and available phosphorus) and elevated soil microbial biomass and changed microbial community composition; T. chinensis plantations might thus provide a suitable approach for restoring degraded floodplain ecosystems.