Role of ectomycorrhizal colonization in enhancement of nutrients for survival of plants collected from mountainous cold stress areas.

BACKGROUND: Ectomycorrhizal (ECM and ECM-like) structures associated with plant root systems are a challenge for scientists. The dispersion pattern of roots within the soil profile and the nutritional conditions are both favourable factors to motivate the plants to make ECM associations. RESULTS: This study discusses the colonization of mycorrhizal associations in Kobresia and Polygonum species including Polygonum viviparum, Kobresia filicina, K. myosuroides, Alnus nitida, Betula pendula, Pinus sylvestris, and Trifolium repens grown naturally in cold stressed soils of Gilgit-Baltistan (high-altitude alpine Deosai plains), Hazara, Swat, Dir, and Bajaur. Sieved soil batches were exposed to +5 °C (control), -10, -20, -30, -40, -50, -125 °C for 5 h, and selected plants were sown to these soils for 10 weeks under favourable conditions for ECM colonization. Ectomycorrhizal associations were examined in the above mentioned plants. Some ECM fungi have dark mycelia that look like the mantle and Hartig net. Examples of these are Kobresia filicina, K. myosuroides, and Polygonum viviparum. Findings of this study revealed that K. myosuroides excelled in ECM root tip length, dry mass, and NH4 concentration at -125 °C. Contrarily, A. nitida demonstrated the lower values, indicated its minimum tolerance. Notably, T. repens boasted the highest nitrogen concentration (18.7 ± 1.31 mg/g), while P. sylvestris led in phosphorus (3.2 ± 0.22 mg/g). The B. pendula showed the highest potassium concentration (9.4 ± 0.66 mg/g), emphasising species-specific nutrient uptake capabilities in extreme cold conditions. The PCA analysis revealed that the parameters, e.g., NH4 in soil mix (NH4), NO3 in soil mix (NO3), phosphorus in soil in species of Polygonum viviparum, Kobresia filicina, K. myosuroides, Alnus nitida, Betula pendula, Pinus sylvestris, and Trifolium repens are most accurately represented in cases of + 5 °C, -10 °C, and -20 °C temperatures. On the other hand, the parameters for ECM root tips (ECM) and Dry Mass (DM) are best described in -40 °C, -50 °C, and - 125 °C temperatures. All parameters have a strong influence on the variability of the system indicated the efficiency of ECM. The heatmap supported the nutrients positively correlated with ECM colonization with the host plants. CONCLUSION: At lower temperatures, hyphae and spores in roots were reduced, while soluble phosphorus concentrations of leaves were increased in cold stress soils. Maximum foliar nutrient concentrations were found in K. myosuroides at the lowest temperature treatments due to efficient functioning and colonization of ECM.

Physiological and molecular responses in phosphorus-hyperaccumulating Polygonum species to high phosphorus exposure.

Phosphorus (P)-hyperaccumulators for phytoextraction from P-polluted areas generally show rapid growth and accumulate large amounts of P without any toxicity symptom, which depends on a range of physiological processes and gene expression patterns that have never been explored. We investigated growth, leaf element concentrations, P fractions, photosynthetic traits, and leaf metabolome and transcriptome response in amphibious P-hyperaccumulators, Polygonum hydropiper and P. lapathifolium, to high-P exposure (5 mmol L-1), with 0.05 mmol L-1 as the control. Under high-P exposure, both species demonstrated good growth, allocating more P to metabolite P and inorganic P (Pi) accompanied by high potassium and calcium. The expression of a cluster of unigenes associated with photosynthesis was maintained or increased in P. lapathifolium, explaining the increase in net photosynthetic rate and the rapid growth under high-P exposure. Metabolites of trehalose metabolism, including trehalose 6-phosphate and trehalose, were sharply increased in both species by the high-P exposure, in line with the enhanced expression of associated unigenes, indicating that trehalose metabolic pathway was closely related to high-P tolerance. These findings elucidated the physiological and molecular responses involved in the photosynthesis and trehalose metabolism in P-hyperaccumulators to high-P exposure, and provides potential regulatory pathways to improve the P-phytoextraction capability.

Immunomodulatory effect of tibetan medicine compound extracts against ORFV in vitro by metabolomics.

Ovine contagious pustular dermatitis (ORF) is one of the main diseases of sheep and is a zoonotic disease caused by Ovine contagious pustular dermatitis virus (ORFV) infection, posing a significant constraint on sheep breeding industry and human health. The Tibetan medical formulation composed of Polygonum leucoides, Polygonum xanthoxylum and Acanthophora rotunda significantly regulated lymphocyte immune function following ORFV stimulation, although the mechanism remains unclear. In order to study the immunomodulatory effects and mechanism of three Tibetan medicinal extracts (Polygonum leucoides, Polygonum xanthoxylum, and Acanthophora rotunda) against ORFV in vitro, sheep peripheral blood lymphocytes were isolated in vitro and treated with different concentrations of Tibetan medicine compound extract solution after ORFV infection. The cytokine expression levels in lymphocytes were measured at 4 h, 8 h and 12 h. Additionally endogenous metabolites in lymphocytes at 0 h, 4 h, 8 h and 12 h were quantified by untargeted metabolomics method. The results showed that, the extracts could regulate the lymphocyte immune factors altered by ORFV, and regulate the lymphocyte immune function through cysteine and methionine metabolic pathways as well as the pyrimidine metabolic pathways, potentially alleviating the immune evasion induced by ORFV.

Phytochemical profiling, in vitro biological activities, and in silico (molecular docking and absorption, distribution, metabolism, excretion, toxicity) studies of Polygonum cognatum Meissn.

Polygonum cognatum Meissn, a perennial herbaceous belonging to the Polygonaceae family, is an aromatic plant. High-performance liquid chromatography/diode array detector method was developed and validated for the phytochemical analysis of the plant. Also, various methods were used to investigate the antioxidant, antimicrobial, and cytotoxic activities of the methanolic extracts. Antioxidant activities were researched by 2,2'-diphenyl-1-picrylhydrazyl and cupric reducing antioxidant capacity methods. Among the tested standard microbial strains, Candida albicans was found to be more sensitive with a 24.60 ± 0.55 mm inhibition zone according to the diffusion tests. In the microdilution tests, the minimum inhibitory concentration and minimum bactericidal/fungicidal concentration values were 4.75 and ≥ 4.75 mg/mL, respectively, for all tested pathogens. Human colon carcinoma cells were used to investigate cytotoxicity by using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide analysis (IC50  = 2891 µg/mL for Plant A, IC50  = 3291 µg/mL for Plant B). Molecular docking and absorption, distribution, metabolism, excretion, and toxicity analysis were used to explain inhibition mechanisms of major phenolic compounds of plants against Tankyrase 1, Tankyrase 2 enzymes, and deoxyribonucleic acid gyrase subunit B and found compatible with experimental results.

Phytochemical analysis and hepatotoxicity assessment of braised Polygoni Multiflori Radix (Wen-He-Shou-Wu).

Polygoni Multiflori Radix (PMR) is a medicinal herb commonly used in China and Eastern Asia. Recently, the discovery of hepatotoxicity in PMR has received considerable attention from scientists. Processing is a traditional Chinese medicine technique used for the effective reduction of toxicity. One uncommon technique is the braising method-also known as 'Wen-Fa' in Chinese-which is used to prepare tonics or poisonous medications. Braised PMR (BPMR)-also known as 'Wen-He-Shou-Wu'-is one of the processed products of the braising method. However, the non-volatile components of BPMR have not been identified and examined in detail, and therefore, the hepatotoxic advantage of BPMR remains unknown. In this study, we compared the microscopic characteristics of different samples in powder form using scanning electron microscopy (SEM), investigated the non-volatile components, assessed the effects of different processed PMR products on the liver, and compared the differences between BPMR and PMR Praeparata recorded in the Chinese Pharmacopoeia (2020 edition). We found that the hepatotoxicity of BPMR was dramatically decreased, which may be related to an increase in polysaccharide content and a decrease in toxic substances. The present study provides an important foundation for future investigations of the processing mechanisms of BPMR.

Evaluation of antidiabetic and antioxidant effects of Polygonum cognatum Meisn. and phytochemical analysis of effective extracts.

Polygonum cognatum Meisn. (Polygonaceae) is used both as food and as a folk medicine to treat diabetes. This study aimed to evaluate the effect of the extracts, along with isolated compounds, from P. cognatum aerial parts on diabetes. In vitro studies were conducted using an α-glucosidase inhibitory assay, while in vivo antidiabetic studies were carried out on streptozotocin-induced diabetic rats. Effective extracts were subjected to isolation studies, and structures of the compounds were elucidated by spectroscopic methods. The ethyl acetate and n-butanol extracts had the highest effect in both in vitro and in vivo experiments. They also decreased aspartate transaminase, alanine transaminase and malondialdehyde levels, while increasing glutathione and superoxide dismutase activity in rats. From the active extracts, 11 phenolic compounds were isolated and characterized. Among the isolated compounds, quercetin was found to be the most active according to α-glucosidase inhibitory activity studies. This study provided scientific evidence for the traditional use of P. cognatum as a folk medicine for treating diabetes. The findings suggest that the ethyl acetate and n-butanol extracts, as well as quercetin, have the potential for development as antidiabetic agents.

Thrombin-targeted screening of anticoagulant active components from Polygonum amplexicaule D. Don var. sinense Forb by affinity ultrafiltration coupled with UPLC-Q-TOF-MS.

INTRODUCTION: Polygonum amplexicaule D. Don var. sinense Forb (PAF), a medicinal plant, has the effect of promoting blood circulation and removing blood stasis. However, the active compounds and targets of its anticoagulant effect are still unclear. OBJECTIVES: This study aims to establish an effective reversely thrombin-targeted screening method for anticoagulant active components in PAF by affinity ultrafiltration (AUF) coupled with ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectroscopy (UPLC-Q-TOF-MS). METHODS: Different polar parts of PAF were screened for potential thrombin ligands by AUF-HPLC and identified by UPLC-Q-TOF-MS. After studying the affinity between ligands and thrombin by molecular docking, the antithrombotic activity of ligands was detected in vivo by zebrafish thrombus model, and in vitro by chromogenic substrate method. The mechanism of such ligands on thrombin was further studied by coagulation factor assay. RESULTS: Eleven potential thrombin ligands from PAF were screened by the AUF-UPLC-Q-TOF-MS method, and two compounds (butyl gallate and ß-sitosterol) with significant anticoagulant activity were discovered via in vitro and in vivo activity testing. CONCLUSION: A method system based on AUF-UPLC-Q-TOF-MS, molecular docking and in vivo and in vitro experiments also provided a powerful tool for further exploration of anticoagulant active components in PAF.

Structural Characterization and Antidepressant-like Effects of Polygonum sibiricum Polysaccharides on Regulating Microglial Polarization in Chronic Unpredictable Mild Stress-Induced Zebrafish.

Polysaccharides are one of the main active ingredients of Polygonum sibiricum (PS), which is a food and medicine homolog used throughout Chinese history. The antidepressant-like effects of PSP and its underlying mechanisms remain elusive, especially the regulation of microglial polarization. The current study determined the chemical composition and structural characteristics of PSP. Then, the chronic unpredictable mild stress (CUMS) procedure was carried out on the zebrafish for 5 weeks, and PSP was immersed for 9 days (1 h/d). The body weight of zebrafish was monitored, and behavioral tests, including the novel tank test and light and dark tank test, were performed to evaluate the antidepressant-like effects of PSP. Then, the function of the hypothalamic-pituitary-interrenal (HPI) axis, the levels of peripheral inflammation, neuronal and blood-brain barrier damage in the mesencephalon and telencephalon, and the mRNA expression of M1/M2 phenotype genes in the brain were examined. PSP samples had the typical structural characteristics of polysaccharides, consisting of glucose, mannose, and galactose, with an average Mw of 20.48 kDa, which presented porous and agglomerated morphologies. Compared with untreated zebrafish, the depression-like behaviors of CUMS-induced zebrafish were significantly attenuated. PSP significantly decreased the levels of cortisol and pro-inflammatory cytokines and increased the levels of the anti-inflammatory cytokines in the body of CUMS-induced depressive zebrafish. Furthermore, PSP remarkably reversed the neuronal and blood-brain barrier damage in the mesencephalon and telencephalon and the mRNA expression of M1/M2 phenotype genes in the brain. These findings indicated that the antidepressant-like effects of PSP were related to altering the HPI axis hyperactivation, suppressing peripheral inflammation, inhibiting neuroinflammation induced by microglia hyperactivation, and modulating microglial M1/M2 polarization. The current study provides the foundations for future examinations of PSP in the functional foods of emotional regulation.

[Experimental study on improvement of cognitive impairment in Alzheimer's disease by different degrees of steaming and sunning of Polygoni Multiflori Radix based on fecal metabolomics].

The fecal metabolomics method was employed to investigate the cognitive improvement mechanism of Polygoni Multiflori Radix in Alzheimer's disease(AD) and examine the effects of different degrees of steaming and sunning on cognitive function in AD model mice. Additionally, the processing principle of Polygoni Multiflori Radix was discussed. Forty-eight 5-month-old APP/PS1 mice were randomly assigned to the following groups: model group, positive group, raw product group, three-steaming and three-sunning product group, six-steaming and six-sunning product group, and nine-steaming and nine-sunning product group. Seven negative control mice from the same litter were included as the blank group. After 150 days of intragastric administration, the learning and memory abilities of mice in each group were assessed by using the Barnes maze and dark avoidance tests. Fecal samples were collected for extensive targeted metabolomics testing. Principal component analysis(PCA), orthogonal partial least squares discriminant analysis(OPLS-DA), and other multivariate statistical methods were utilized to analyze metabolites in mouse feces. Comparison of behavioral results between the model group and different product groups demonstrated that the six-steaming and six-sunning product group exhibited significantly reduced latency in the Barnes maze positioning and navigation test(P<0.05), as well as a notable decrease in the number of errors in the space exploration experiment(P<0.05). Moreover, the latency of mice entering the dark box for the first time in the dark avoidance experiment was significantly prolonged(P<0.05), indicating the best overall improvement in the learning and memory ability of AD model mice. Metabolomics results revealed that compared with the model group, the differential metabolites in other groups in descending order were as follows: six-steaming and six-sunning product group > nine-steaming and nine-sunning product group > raw product group > three-steaming and three-sunning product group, encompassing 146, 120, 95, and 81 potential biomarkers, respectively. Among them, 16 differential metabolites were related to AD disease. Further comparisons based on the degree of processing indicated that the six-steaming and six-sunning product group exhibited the most significant adjustments in total metabolic pathways, particularly regulating the interconversion of pentose and glucuronic acid, as well as amino acid anabolism and other pathways. In summary, the mechanism of Polygoni Multiflori Radix after processing in enhancing the learning and memory ability of APP/PS1 mice may be associated with improved amino acid metabolism and increased energy metabolism in the body. The six-steaming and six-sunning yielded the best outcomes.

Paenibacillus polygoni sp. nov., an endophytic bacterium isolated from Polygonum lapathifolium L. in wetland.

A Gram-stain-positive, aerobic, rod-shaped, non-motile, yellowish and glossy strain, C31T, was isolated from a wetland plant Polygonum lapathifolium L. located south of Poyang Lake, Jiangxi Province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain C31T showed similarity values of lower than 97.0 % to other type species belonging to the genus Paenibacillus. The genomic average nucleotide identity values between strain C31T and its reference type species ranged from 68.9-70.9 % and the digital DNA-DNA hybridization values were lower than 27.8 %. The genomic DNA G+C content of strain C31T was 41.9 mol%. The optimal growth temperature, pH and NaCl concentration were 37 °C, pH 7 and 0.5 %, respectively. The major cellular fatty acids (>5.0 %) of strain C31T were anteiso-C15 : 0 (73.7 %), anteiso-C17 : 0 (8.4 %) and iso-C15 : 0 (5.2 %). The polar lipids of strain C31T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and unidentified phospholipids. The respiratory quinone was MK-7. Based on these phylogenetic and phenotypic characterizations, strain C31T represents a novel species within the genus Paenibacillus. Therefore, the proposed name for this newly identified species is Paenibacillus polygoni sp. nov. and the type strain is C31T (=CCTCC AB 2022349T=KCTC 43565T).