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.

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).

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.

Heavy metals reshaping the structure and function of phylloplane bacterial community of native plant Tamarix ramosissima from Pb/Cd/Cu/Zn smelting regions.

Heavy metal (HM) is noxious element that cannot be biodegraded, thus accumulating in the environment and posing a serious threat to the ecology. Plant phylloplane harbors diverse microbial communities that profoundly influence ecosystem functioning and host health. With more HM accumulating around smelters, native plants and microbes in various habitats tend to suffer from HM. However, the response of phylloplane bacteria of native plants to HM remains unclear. Thus, this study aimed to explain the response of Tamarix ramosissima, a phylloplane bacterial community to HM as well as the effect of the process on host growth in situ by investigating the potential source of HM and bacterial community shift. Results showed that, in most cases, the contaminated site with high HM level caused more accumulation of HM in phylloplane and leaves. Moreover, HM in the phylloplane was not from the internal transport of the plant but it could be due to the wind action or rains. Bacteria in phylloplane may have come from the soil due to their strong positive correlation with corresponding soil at the genus level. High HM level inhibited the relative abundance of dominant bacteria, increased the diversity and species richness of bacterial community in phylloplane, and induced more special bacteria to maintain higher productivity of the host plant, for which, Cu and Pb were the major contributors. Meanwhile, bacteria in phylloplane showed a universal positive correlation in the co-occurrence network, which showed less stability than that in corresponding soil in the smelting region, and it is helpful to regulate the growth of plants more rapidly. Nearly 25% of KEGG pathways were modulated by high HM level and bacterial function tended to stabilize HM to avoid the potential process of leaf absorption. The study illustrated that HM in phylloplane played an important role in shaping the bacterial community of phylloplane as compared to HM in leaves or phyllosphere, and the resulting increase of diversity and richness of bacterial community and special bacteria further maintained the growth of the host plant suffering from HM stress.

Mechanistic insights on the possible protective role of polyphenols extracted from Tamarix aphylla aerial parts against sodium arsenite-induced hepatotoxicity in rats.

Arsenic exposure is associated with the induction of hepatotoxicity. Current study was aimed to investigate the hepato-protective ability of polyphenolic components of Tamarix aphylla (TA) ethanolic extract against sodium arsenite (SA)-induced liver injury of rats. Significantly higher quantities of phenolic (318.7±2.5 mgg-1GAE) and flavonoid (250.69 ±3.3 mgg-1QE) contents were present. Inhibitory concentration (IC50) exhibited an excellent potential for antioxidant (IC50= 25.99 µg/mL) assay. High performance liquid chromatography (HPLC) confirmed the existence of myercetin (10.40ppm), sinapic acid (2.131ppm), kaempferol (0.486ppm), caffeic acid (5.094 ppm). Forty-two rats were divided into 7 groups. Group 1 received normal saline (2 mL/kg/day, orally for 21 days), Group 2 received SA (10mg/kg/day for 21 days), and Group 3 received SA alone for 7 days (10mg/kg) and continues with silymarine for 21 days (25mg/kg orally). Group 4, 5, 6 received SA alone for 7 days and continue with TA extract up to 21 days (125mg/kg, 250mg/kg, and 500mg/kg orally) respectively, and Group 7 received TA extract (500mg/kg) for 21 days. SA was administered to all treated groups for 21 days. Treatment with polyphenolic ethanolic extract of TA restored the hepatic indices and oxidative markers in a dose-dependent manner. The upregulation in tumor necrosis factor-α, interleukin-6, and cyclooxygenase-2 upon SA treatment suggesting inflammation was normalized by the treatment of rats. Above mentioned biochemical findings were supported well with histopathological screening. Present findings suggest that TA polyphenolic ethanolic extract could mitigate the oxidative stress and inflammation induced by SA in liver tissue.

ThASR3 confers salt and osmotic stress tolerances in transgenic Tamarix and Arabidopsis.

BACKGROUND: ASR (abscisic acid-, stress-, and ripening-induced) gene family plays a crucial role in responding to abiotic stresses in plants. However, the roles of ASR genes protecting plants against high salt and drought stresses remain unknown in Tamarix hispida. RESULTS: In this study, a salt and drought-induced ASR gene, ThASR3, was isolated from Tamarix hispida. Transgenic Arabidopsis overexpressing ThASR3 exhibited stimulating root growth and increasing fresh weight compared with wild-type (WT) plants under both salt and water deficit stresses. To further analyze the gain- and loss-of-function of ThASR3, the transgenic T. hispida plants overexpressing or RNA interference (RNAi)-silencing ThASR3 were generated using transient transformation. The overexpression of ThASR3 in Tamarix and Arabidopsis plants displayed enhanced reactive oxygen species (ROS) scavenging capability under high salt and osmotic stress conditions, including increasing the activities of antioxidant enzymes and the contents of proline and betaine, and reducing malondialdehyde (MDA) content and electrolyte leakage rates. CONCLUSION: Our results indicate that ThASR3 functions as a positive regulator in Tamarix responses to salt and osmotic stresses and confers multiple abiotic stress tolerances in transgenic plants, which may have an important application value in the genetic improvement of forest tree resistance.

The high pH value of alkaline salt destroys the root membrane permeability of Reaumuria trigyna and leads to its serious physiological decline.

Variable climatic conditions frequently have harmful effects on plants. Reaumuria trigyna, a salt-secreting xerophytic shrub, occurs in Inner Mongolia, which has a poor environment for plant growth. To explore the physiological and molecular mechanisms of R. trigyna in response to environmental stress, this study investigated the abiotic resistance of R. trigyna in terms of growth regulation, antioxidant defense, osmotic regulation, ion transport, and ion homeostasis-related genes. R. trigyna seedlings were treated with 400 mM NaCl, 400 mM neutral salts (NaCl:Na2SO4 = 9:1), 50 mM alkaline salts (NaHCO3:Na2CO3 = 9:1), 10% polyethylene glycol (PEG), and UV-B. Seedlings under 400 mM NaCl and 400 mM neutral salt stress showed less damage. While alkaline salt, PEG, and UV stress caused more damage, specifically in oxidative damage, proline levels, electrolyte leakage, and activation of antioxidant defenses. Furthermore, under the abiotic stress treatments, the accumulation of Na+ increased while the accumulation of K+ decreased. Further analysis showed that the flow rate of Na+ and K+ under alkaline salt stress was higher than under neutral salt stress. Neutral salt induced high expression of RtNHX1 and RtSOS1, while alkaline salt induced high expression of RtHKT1, and alkaline salt stress significantly reduced the activity of root cells. These results indicated that R. trigyna seedlings were more tolerant to neutral than alkaline salts; this might be because root activity decreased at high pH levels, which impaired membrane permeability and the ion transfer system, leading to an imbalance between Na+ and K+, and in turn to excessive accumulation of reactive oxygen species (ROS) and decreased plant stress resistance.

Effects of Exogenous (K+) Potassium Application on Plant Hormones in the Roots of Tamarix ramosissima under NaCl Stress.

Abiotic stresses such as salt stress seriously affect the growth and yield of plants. Tamarix ramosissima Lcdcb (T. ramosissima) is a widely cultivated halophyte in saline-alkali areas of the world. As an essential element for plant growth and development, K+ plays an irreplaceable role in improving the tolerance of plants to salt stress. However, there are few reports on the mechanism of K+ in promoting plant hormones to reduce the damage of NaCl stress to T. ramosissima. In this study, we sequenced the transcriptome of the roots of T. ramosissima which were treated with exogenous potassium (K+) for 0 h, 48 h and 168 h under NaCl stress, according to the changes in the expression levels of differentially expressed genes (DEGs) in T. ramosissima roots. Key candidate genes and metabolic pathways related to plant hormones were mined for analysis and further verified by quantitative real-time PCR (qRT-PCR). The results showed that under NaCl stress for 48 h and 168 h, there were a large number of DEGs in the roots of T. ramosissima, and the expression levels changed over time. In particular, we found that 56 plant hormone-related genes were annotated to the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and with the increase of time, their expression levels were mainly up-regulated and involved in the related metabolic pathways to resist NaCl stress. It is worth noting that 7 DEGs related to abscisic acid (ABA), 28 DEGs related to auxin, 1 DEG related to ethylene (ET), and 1 DEG related to cytokinin (CK) were added within 168 h of exogenous potassium, and they were involved in alleviating the root damage of T. ramosissima under NaCl stress and played an important role. In addition, we found the plant hormone signal transduction pathway, which plays an important role in resistance to NaCl stress. As a result of this study, the molecular mechanism of plant hormones involved in applying exogenous potassium under NaCl stress is further understood, resulting in a better understanding of how exogenous potassium can alleviate the damage caused by NaCl under stress in T. ramosissima.

Effects of Exogenous Potassium (K+) Application on the Antioxidant Enzymes Activities in Leaves of Tamarix ramosissima under NaCl Stress.

Saline soil is a worldwide distributed resource that seriously harms plants' growth and development. NaCl is the most widely distributed salt in saline soil. As a typical representative of halophytes, Tamarix ramosissima Lcdcb (T. ramosissima) is commonly grown in salinized soil, and halophytes have different abilities to retain more K+ under salt stress conditions. Halophytes can adapt to different salt environments by improving the scavenging activity of reactive oxygen species (ROS) by absorbing and transporting potassium (K+). In this study, electron microscope observation, hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents determination, primary antioxidant enzyme activity determination and transcriptome sequencing analysis were carried out on the leaves of T. ramosissima under NaCl stress at 0 h, 48 h and 168 h. The results showed that H2O2 and MDA contents increased in the 200 mM NaCl + 10 mM KCl and 200 mM NaCl groups, but the content increased the most in the 200 mM NaCl group at 168 h. In addition, the leaves of T. ramosissima in the 200 mM NaCl + 10 mM KCl group had the most salt secretion, and its superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities were all higher than those of the 200 mM NaCl group and significantly higher than those of the control group. According to the results of transcriptome sequencing, it was found that the expression of 39 genes related to antioxidant enzyme activity changed significantly at the transcriptional level. Among them, 15 genes related to antioxidant enzyme activities were upregulated, and 24 genes related to antioxidant enzyme activities were downregulated in the leaves of T. ramosissima when exogenous potassium (K+) was applied under NaCl stress for 48 h; when exogenous potassium (K+) was used for 168 h under NaCl stress, 21 antioxidant enzyme activity-related genes were upregulated, and 18 antioxidant enzyme activity-related genes were downregulated in T. ramosissima leaves. Based on the changes of expression levels at different treatment times, 10 key candidates differentially expressed genes (DEGs) (Unigene0050462, Unigene0014843, Unigene0046159, Unigene0046160, Unigene0008032, Unigene0048033, Unigene0004890, Unigene0015109, Unigene0020552 and Unigene0048538) for antioxidant enzyme activities were further screened. They played an important role in applying exogenous potassium (K+) for 48 h and 168 h to the leaves of T. ramosissima in response to NaCl stress. Their expression levels were dominated by upregulation, which enhanced the activity of antioxidant enzymes, and helped T. ramosissima mitigate NaCl poison and resist NaCl stress. Particularly, Unigene0048538 in glutathione S-transferase (GST) activity had the largest log2 fold-change in the comparison groups of 200 mM NaCl-48 h vs. 200 mM NaCl + 10 mM KCl-48 h and 200 mM NaCl-168 h vs. 200 mM NaCl + 10 mM KCl-168 h. Its expression level was upregulated and played an important role in NaCl toxicity. At the same time, the results of the phylogenetic tree analysis showed that Unigene0048538 had the closest genetic distance to Prunus persica in the evolutionary relationship. In summary, with the increase of exogenous potassium (K+) application time under NaCl stress, T. ramosissima can resist high NaCl stress by enhancing antioxidant enzymes' activity and maintaining the growth of T. ramosissima. Still, it is not enough to completely eliminate NaCl poison. This study provides a theoretical basis for the molecular mechanism of salt tolerance and K+ mitigation of NaCl poison by the representative halophyte T. ramosissima in response to NaCl stress.

Transcriptome and Metabonomic Analysis of Tamarix ramosissima Potassium (K+) Channels and Transporters in Response to NaCl Stress.

Potassium ion (K+) channels and transporters are key components of plant K+ absorption and transportation and play an important role in plant growth and development. This study revealed that K+ channels and transporters are involved in the salt tolerance molecular mechanism and metabolites of the halophyte representative plant Tamarix ramosissima (T. ramosissima) in response to NaCl stress, providing a theoretical basis for the mitigation of salt stress using halophytes. Through transcriptome sequencing and metabolite detection analysis of 0 h, 48 h and 168 h by applying exogenous K+ to the roots of T. ramosissima under NaCl stress, 15 high-quality Clean Data bases were obtained, Q20 reached more than 97%, Q30 reached more than 92%, and GC content reached 44.5%, which is in line with further bioinformatics analysis. Based on the Liquid chromatography−mass spectrometry (LC-MS) analysis, the roots of T. ramosissima were exposed to exogenous potassium for 48 h and 168 h under NaCl stress, and 1510 and 1124 metabolites were identified in positive and negative ion mode, respectively. Through orthogonal projections to latent structures discriminant analysis (OPLS-DA) model analysis, its metabolomic data have excellent predictability and stability. The results of this study showed that there were 37 differentially expressed genes (DEGs) annotated as Class 2 K+ channels (Shaker-like K+ channel and TPK channel) and Class 3 K+ transporters (HAK/KUP/KT, HKT and CPAs transporter families). Among them, 29 DEGs were annotated to the gene ontology (GO) database, and the most genes were involved in the GO Biological Process. In addition, the expression levels of Unigene0014342 in the HAK/KUP/KT transporter and Unigene0088276 and Unigene0103067 in the CPAs transporter both first decreased and then increased when treated with 200 mM NaCl for 48 h and 168 h. However, when treated with 200 mM NaCl + 10 mM KCl for 48 h and 168 h, a continuous upward trend was shown. Notably, the expression level of Unigene0016813 in CPAS transporter continued to increase when treated with 200 mM NaCl and 200 mM NaCl + 10 mM KCl for 48 h and 168 h. 3 DEGs, Unigene0088276, Unigene0016813 and Unigene0103067, were dominated by the positive regulation of their related metabolites, and this correlation was significant. The results showed that these DEGs increased the absorption of K+ and the ratio of K+/Na+ under NaCl stress at 48 h and 168 h after adding exogenous potassium and enhanced the salt tolerance of T. ramosissima. Notably, the expression level of Unigene0103067 in the CPAs transporter was consistently upregulated when 200 mM NaCl + 10 mM KCl was treated for 48 h and 168 h. The positive regulatory metabolites were always dominant, which better helped T. ramosissima resist salt stress. Unigene0103067 plays an important role in enhancing the salt tolerance of T. ramosissima and reducing the toxicity of NaCl in roots. Additionally, phylogenetic tree analysis showed that Unigene0103067 and Reaumuria trigyna had the closest genetic distance in the evolutionary relationship. Finally, 9 DEGs were randomly selected for quantitative real-time PCR (qRT-PCR) verification. Their expression trends were completely consistent with the transcriptome sequencing analysis results, proving that this study's data are accurate and reliable. This study provides resources for revealing the molecular mechanism of NaCl stress tolerance in T. ramosissima and lays a theoretical foundation for cultivating new salt-tolerant varieties.

Responses of microbial communities and metabolic profiles to the rhizosphere of Tamarix ramosissima in soils contaminated by multiple heavy metals.

Heavy metals (HMs) contamination around smelters poses serious stress to soil microbiome. However, the co-effect of multiple HMs and native vegetation rhizosphere on the soil ecosystem remains unclear. Herein, effects of high HMs level and the rhizosphere (Tamarix ramosissima) on soil bacterial community structure and metabolic profiles in sierozem were analyzed by coupling high-throughput sequencing and soil metabolomics. Plant roots alleviated the threat of HMs by absorbing and stabilizing them in soil. High HMs level decreased the richness and diversity of soil bacterial community and increased numbers of special bacteria. Plant roots changed the contribution of HMs species shaping the bacterial community. Cd and Zn were the main contributors to bacterial distribution in non-rhizosphere soil, however, Pb and Cu became the most important HMs in rhizosphere soil. HMs induced more dominant metal-tolerant bacteria in non-rhizosphere than rhizosphere soil. Meanwhile, critical metabolites varied by rhizosphere in co-occurrence networks. Moreover, the same HMs-tolerant bacteria were regulated by different metabolites, e.g. unclassified family AKYG1722 was promoted by Dodecanoic acid in non-rhizosphere soil, while promoted by Octadecane, 2-methyl- in rhizosphere soil. The study illustrated that high HMs level and rhizosphere affected soil properties and metabolites, by which soil microbial community structure was reshaped.

In vitro α-glucosidase inhibitory activity of Tamarix nilotica shoot extracts and fractions.

α-glucosidase inhibitors represent an important class of type 2 antidiabetic drugs and they act by lowering postprandial hyperglycemia. Today, only three synthetic inhibitors exist on the market, and there is a need for novel, natural and more efficient molecules exhibiting this activity. In this study, we investigated the ability of Tamarix nilotica ethanolic and aqueous shoot extracts, as well as methanolic fractions prepared from aqueous crude extracts to inhibit α-glucosidase. Both, 50% ethanol and aqueous extracts inhibited α-glucosidase in a concentration-dependent manner, with IC50 values of 12.5 µg/mL and 24.8 µg/mL, respectively. Importantly, α-glucosidase inhibitory activity observed in the T. nilotica crude extracts was considerably higher than pure acarbose (IC50 = 151.1 µg/mL), the most highly prescribed α-glucosidase inhibitor on the market. When T. nilotica crude extracts were fractionated using methanol, enhanced α-glucosidase inhibitory activity was observed in general, with the highest observed α-glucosidase inhibitory activity in the 30% methanol fraction (IC50 = 5.21 µg/mL). Kinetic studies further revealed a competitive reversible mechanism of inhibition by the plant extract. The phytochemical profiles of 50% ethanol extracts, aqueous extracts, and the methanolic fractions were investigated and compared using a metabolomics approach. Statistical analysis revealed significant differences in the contents of the crude extracts and fractions and potentially identified the molecules that were most responsible for these observed variations. Higher α-glucosidase inhibitory activity was associated with an enrichment of terpenoids, fatty acids, and flavonoids. Among the identified molecules, active compounds with known α-glucosidase inhibitory activity were detected, including unsaturated fatty acids, triterpenoids, and flavonoid glycosides. These results put forward T. nilotica as a therapeutic plant for type 2 diabetes and a source of α-glucosidase inhibitors.

Effect of salt stress on the photosynthetic characteristics and endogenous hormones, and: A comprehensive evaluation of salt tolerance in Reaumuria soongorica seedlings.

Salinity is a major limiting factor in desert ecosystems, where Reaumuria soongarica is a dominant species. It is crucial to study the growth and physiological response mechanisms of R. soongorica under salt stress for the protection and restoration of the desert ecosystems. However, the effects of salt concentration and stress duration on endogenous hormonal content and photosynthetic efficiency and salt injury index of R. soongorica leaves have not been reported. Currently, there is no systematic evaluation system to determine physiological adaptation strategies of R. soongorica seedlings in response to salt stress. In this study, simulation experiments were performed with NaCl solution mixed with soil. Enzyme-linked immunosorbent assay and LI-6800 portable photosynthesis analyzer were used to measure indole acetic acid (IAA), corn nucleoside hormone (ZR), abscisic acid (ABA), and photosynthesis-related parameters in leaves of R. soongorica seedlings at 0 (24-48 h after salt treatment), 3, 6, and 9 days. At the same time, growth indicators (salt injury index, root-to-shoot ratio), reactive oxygen species content, superoxide dismutase enzyme (SOD) activity, osmolyte content, membrane peroxidation, and leaf pigment content were measured at different salt concentrations and treatment times. Finally, principal component analysis and membership function method were used to comprehensively evaluate the salt tolerance of seedlings. The results showed that treatment with 200 mM NaCl for 3 days significantly increased SOD activity, the content of osmotic adjustment substances (proline, soluble protein), endogenous hormone content (ABA, ZR), root-to-shoot ratio, and Chla/Chlb values but decreased malondialdehyde content (MDA) in the leaves of R. soongorica seedlings. Leaf water content (LRWC), net photosynthetic rate (Pn), transpiration rate (Tr), water use efficiency (WUE), and IAA content in R. soongorica seedlings were lower than those in the control, when exposed to 400 and 500 mM NaCl solutions. Finally, the principal component analysis revealed endogenous hormone content and antioxidant enzyme activity to be useful for the comprehensive evaluation of salt tolerance in R. soongorica seedlings. The R. soongorica seedlings showed the strongest salt tolerance when exposed to 200 mM NaCl for 3 days. This study provides a theoretical foundation for gene mining and breeding of salt-tolerant species in the future.

Physiological response and proteomics analysis of Reaumuria soongorica under salt stress.

Soil salinity can severely restrict plant growth. Yet Reaumuria soongorica can tolerate salinity well. However, large-scale proteomic studies of this plant's response to salinity have yet to reported. Here, R. soongorica seedlings (4 months old) were used in an experiment where NaCl solutions simulated levels of soil salinity stress. The fresh weight, root/shoot ratio, leaf relative conductivity, proline content, and total leaf area of R. soongorica under CK (0 mM NaCl), low (200 mM NaCl), and high (500 mM NaCl) salt stress were determined. The results showed that the proline content of leaves was positively correlated with salt concentration. With greater salinity, the plant fresh weight, root/shoot ratio, and total leaf area increased initially but then decreased, and vice-versa for the relative electrical conductivity of leaves. Using iTRAQ proteomic sequencing, 47 177 136 differentially expressed proteins (DEPs) were identified in low-salt versus CK, high-salt versus control, and high-salt versus low-salt comparisons, respectively. A total of 72 DEPs were further screened from the comparison groupings, of which 34 DEPs increased and 38 DEPs decreased in abundance. These DEPs are mainly involved in translation, ribosomal structure, and biogenesis. Finally, 21 key DEPs (SCORE value ≥ 60 points) were identified as potential targets for salt tolerance of R. soongolica. By comparing the protein structure of treated versus CK leaves under salt stress, we revealed the key candidate genes underpinning R. soongolica's salt tolerance ability. This works provides fresh insight into its physiological adaptation strategy and molecular regulatory network, and a molecular basis for enhancing its breeding, under salt stress conditions.

Amelioration of hyperglycaemia and modulation of pro-inflammatory cytokines by Tamarix gallica fractions in alloxan induced diabetic rats.

Present study is engrossed in identification of phyto-constituents from aerial part extracts of Tamarix gallica and appraisal of its anti-oxidant, anti-diabetic and anti-inflammatory potential based upon its folktale use. The methanol and n-hexane fractions of aerial parts were analysed using high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) respectively. Inhibitory concentration (IC50) showed better results in case of methanolic extract for both in antioxidant (IC50= 15.47 µg/mL) and alpha amylase (IC50=18.75 µg/mL) assays. Significantly higher quantities of phenolic and flavonoid contents were present in methanolic extract. A significant correlation was found to be existed between these contents and IC50 of antioxidant assay. Alloxan induced hyperglycaemia declined along with improvement in lipid profile, C-reactive proteins (CRP), liver function tests (LFTs) and renal function tests (RFTs). Methanolic fraction (500 mg/kg) was also related to significant reduction in levels of inflammatory markers i.e. tumour necrosis factor-alpha, TNF- α (1.28 ± 0.13 g/L) and interleukin-6, IL-6 (98 ± 10.4 pg/L) as observed in diabetic rats. Based upon the above findings, the study suggests that methanolic fraction from aerial parts of the T. gallica has better anti-diabetic profile which might be attributed to its alpha amylase, anti-oxidant and anti-inflammatory potential.

RtNAC100 involved in the regulation of ROS, Na+ accumulation and induced salt-related PCD through MeJA signal pathways in recretohalophyte Reaumuria trigyna.

NAM, ATAF1/2, and CUC2 (NAC) proteins regulate plant responses to salt stress. However, the molecular mechanisms by which NAC proteins regulate salt-induced programmed cell death (PCD) are unclear. We identified 56 NAC genes, 35 of which had complete open reading frames with complete NAM domain, in the R. trigyna transcriptome. Salt stress and methyl jasmonate (MeJA) mediated PCD-induced leaf senescence in R. trigyna seedlings. Salt stress accelerated endogenous JA biosynthesis, upregulating RtNAC100 expression. This promoted salt-induced leaf senescence in R. trigyna by regulating RtRbohE and RtSAG12/20 and enhancing ROS accumulation. Transgenic assays showed that RtNAC100 overexpression aggravated salt-induced PCD in transgenic lines by promoting ROS and Na+ accumulation, ROS-Ca2+ hub activation, and PCD-related gene expression. Therefore, RtNAC100 induces PCD via the MeJA signaling pathway in R. trigyna under salt stress.

Experimental, DFT and MD Assessments of Bark Extract of Tamarix aphylla as Corrosion Inhibitor for Carbon Steel Used in Desalination Plants.

This study aimed to examine the extract of barks of Tamarix aphylla as a corrosion inhibitor. The methodology briefly includes plant sample collection, extraction of the corrosion inhibitor, gravimetric analysis, plotting potentiodynamic polarization plots, electrochemical impedance spectroscopic measurements, optimization of conditions, and preparation of the inhibitor products. The results show that the values of inhibition efficiency (IE%) increased as the concentrations of the inhibitor increased, with a maximum achievable inhibition efficiency of 85.0%. Potentiodynamic polarization (PP) tests revealed that the extract acts as a dual-type inhibitor. The results obtained from electrochemical impedance spectroscopy (EIS) measurements indicate an increase in polarisation resistance, confirming the inhibitive capacity of the tested inhibitor. The adsorption of the inhibitor on the steel surface follows the Langmuir adsorption isotherm model and involves competitive physio-sorption and chemisorption mechanisms. The EIS technique was utilized to investigate the effect of temperature on corrosion inhibition within the 298-328 K temperature range. Results confirm that the inhibition efficiency (IE%) of the inhibitor decreased slightly as the temperature increased. Lastly, the thermodynamic parameters for the inhibitor were calculated.

A leucoanthocyanidin dioxygenase gene (RtLDOX2) from the feral forage plant Reaumuria trigyna promotes the accumulation of flavonoids and improves tolerance to abiotic stresses.

Reaumuria trigyna, a Tamaricaceae archaic recretohalophyte, is an important feral forage plant in the desert steppe of northwestern China. We identified two significantly differentially expressed leucoanthocyanidin dioxygenase genes (RtLDOX/RtLDOX2) and investigated the function and characteristics of RtLDOX2. RtLDOX2 from R. trigyna was rapidly upregulated by salt, drought, and abscisic acid, consistent with the stress-related cis-regulatory elements in the promoter region. Recombinant RtLDOX2 converted dihydrokaempferol to kaempferol in vitro, and was thus interchangeable with flavonol synthase, a dioxygenase in the flavonoid pathway. Transgenic plants overexpressing RtLDOX2 accumulated more anthocyanin and flavonols under abiotic stresses, speculating that RtLDOX2 may act as a multifunctional dioxygenase in the synthesis of anthocyanins and flavonols. Overexpression of RtLDOX2 enhanced the primary root length, biomass accumulation, and chlorophyll content of salt-, drought-, and ultraviolet-B-stressed transgenic Arabidopsis. Antioxidant enzyme activity; proline content; and expression of antioxidant enzyme, proline biosynthesis, and ion-transporter genes were increased in transgenic plants. Therefore, RtLDOX2 confers tolerance to abiotic stress on transgenic Arabidopsis by promoting the accumulation of anthocyanins and flavonols. This in turn increases reactive oxygen species scavenging and activates other stress responses, such as osmotic adjustment and ion transport, and so improves tolerance to abiotic stresses.

Comprehensive analysis of the stress associated protein (SAP) gene family in Tamarix hispida and the function of ThSAP6 in salt tolerance.

Stress associated proteins (SAPs), a class of A20/AN1 zinc finger domain-containing proteins, are involved in a variety of biotic and abiotic stress responses in plants. However, little is known about the SAP gene family and their functions in Tamarix hispida. In this study, we isolated and characterized 11 SAPs from T. hispida. The expression patterns of ThSAPs were analyzed under various stresses (salt and drought) and phytohormone treatment (SA, ABA and MeJA) using real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR). Most ThSAPs exhibited transcriptional responses to abiotic stresses and phytohormones. Among these ThSAPs, ThSAP6 was significantly induced by salt stress. Gain-and loss-of-function analyses revealed that ThSAP6 was a positive regulator of salt stress response. Overexpression of ThSAP6 in T. hispida increased antioxidant enzymes activity and proline content and decreased reactive oxygen species (ROS) accumulation and cell membrane damage under salt stress, while the opposite physiological changes were observed in ThSAP6-RNAi (RNA interference) lines. This study provides a comprehensive description of the SAP gene family in T. hispida, and demonstrates that ThSAP6 is a potential candidate for biotechnological approaches to improve salt tolerance in plants.

ThNAC12 from Tamarix hispida directly regulates ThPIP2;5 to enhance salt tolerance by modulating reactive oxygen species.

NAC (NAM, ATAF1/2 and CUC2) transcription factors play critical roles in plant development and abiotic stress responses, and aquaporins have diverse functions in environmental stress responses. In this study, we described the salt-induced transcriptional responses of ThNAC12 and ThPIP2;5 in Tamarix hispida, and their regulatory mechanisms in response to salt stress. Using yeast one-hybrid (Y1H), chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays, we identified that ThNAC12 directly binds to the NAC recognition sequence (NACRS) of the ThPIP2;5 promoter and then activates the ThPIP2;5 expression. Subcellular localization and transcriptional activation assays demonstrated that ThNAC12 was a nuclear protein with a C-terminal transactivation domain. Compared with the corresponding control plants, transgenic plants overexpressing ThNAC12 exhibited enhanced salt tolerance and displayed increased reactive oxygen species (ROS) scavenging capability and antioxidant enzyme activity levels under salt stress. All results suggested that overexpression of ThNAC12 in plants enhanced salt tolerance through modulation of ROS scavenging via direct regulation of ThPIP2;5 expression in T. hispida.