Chinese medicine Phragmites communis (Lu Gen) for acute respiratory tract infections: a systematic review and meta-analysis of randomized controlled trials

Background: Acute respiratory tract infections (ARTIs) are the most common cause of morbidity and mortality worldwide, with most people experiencing at least one episode per year. Current treatment options are mainly symptomatic therapy. Antivirals, antibiotics, and glucocorticoids are of limited benefit for most infections. Traditional Chinese medicine has shown potential benefits in the treatment of ARTIs. Objective: The objective of this study was to determine the efficacy, effectiveness, and safety of Phragmites communis Trin. (P. communis, a synonym of Phragmites australis (Cav.) Trin. ex Steud) as monotherapy or as part of an herb mixture for ARTIs. Method: Eight databases and two clinical trial registries were searched from inception to 8 February 2023 for randomized controlled trials (RCTs) evaluating any preparation involving P. communis without language restrictions. The Risk of Bias Tool 2.0 was used to assess the risk of bias of the included trials. RevMan 5.3 software was used for data analyses with effects estimated as risk ratios (RRs), mean differences (MDs), or standardized mean differences (SMDs) with 95% confidence intervals (CIs). The online GRADEpro tool was used to assess the certainty of the evidence, if available. Results: Forty-two RCTs involving 6,879 patients with ARTIs were included, with all trials investigating P. communis as part of an herbal mixture. Of the included trials, the majority (38/42) were considered high risk. Compared to the placebo, P. communis preparations improved the cure rate [RR = 1.60, 95% CI (1.13, 2.26)] and fever clearance time [MD = -2.73 h, 95% CI (-4.85, -0.61)]. Compared to usual care alone, P. communis preparations also significantly improved the cure rate [RR = 1.57, 95% CI (1.36, 1.81)] and fever clearance time [SMD = -1.24, 95% CI (-2.37, -0.11)]. P. communis preparations plus usual care compared to usual care alone increased the cure rate [RR = 1.55, 95% CI (1.35, 1.78)], shortened the fever clearance time [MD = -19.31 h, 95% CI (-33.35, -5.27)], and improved FEV1 [ MD = 0.19 L, 95% CI (0.13, 0.26)] and FVC [ MD = 0.16 L, 95% CI (0.03, 0.28)]. Conclusion: Low- or very low-certainty evidence suggests that P. communis preparations may improve the cure rate of ARTIs, shorten the fever clearance time in febrile patients, and improve the pulmonary function of patients with acute exacerbation of chronic obstructive pulmonary disease or chronic bronchitis. However, these findings are inconclusive and need to be confirmed in rigorously designed trials. Systematic review registration: PROSPERO, identifier CRD42021239936.

Responses of Phragmites communis and its rhizosphere bacteria to different exposure sequences of molybdenum disulfide and levofloxacin

The effect of the molybdenum disulfide (MoS2)/levofloxacin (LVF) co-exposure was explored on Phragmites communis and rhizosphere soil bacterial communities. The sequence of MoS2/LVF exposure and the different MoS2 dosages (10 mg/kg and 100 mg/kg) contributed to different degrees of effect on the plant after 42 days of exposure. The treatment with priority addition of low dosage MoS2 significantly ameliorated P. communis growth, with root length growing up to 532.22 ± 46.29 cm compared to the sole LVF stress (200.04 ± 29.13 cm). Besides, MoS2 served as an alleviator and reduced the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA) in P. communis under LVF stress, and activated bacteria in rhizosphere soil. These rhizosphere soil microbes assisted in mitigating toxic pollution in the soil and inducing plant resistance to external stress, such as bacteria genera Bacillus, Microbacterium, Flavihumibacter and altererythrobacter. Potential functional profiling of bacterial community indicated the addition of MoS2 contributed to relieve the reduction in functional genes associated with amino acid metabolism and the debilitation of gram_negative and aerobic phenotypic traits caused by LVF stress. This finding reveals the effect of different exposure sequences of MoS2 nanoparticles and antibiotic for plant-soil systems.

Plants changed the response of bacterial community to the nitrogen and phosphorus addition ratio

INTRODUCTION

Human activities have increased the nitrogen (N) and phosphorus (P) supply ratio of the natural ecosystem, which affects the growth of plants and the circulation of soil nutrients. However, the effect of the N and P supply ratio and the effect of plant on the soil microbial community are still unclear.

METHODS

In this study, 16s rRNA sequencing was used to characterize the response of bacterial communities in Phragmites communis (P.communis) rhizosphere and non-rhizosphere soil to N and P addition ratio.

RESULTS

The results showed that the a-diversity of the P.communis rhizosphere soil bacterial community increased with increasing N and P addition ratio, which was caused by the increased salt and microbially available C content by the N and P ratio. N and P addition ratio decreased the pH of non-rhizosphere soil, which consequently decreased the a-diversity of the bacterial community. With increasing N and P addition ratio, the relative abundance of Proteobacteria and Bacteroidetes increased, while that of Actinobacteria and Acidobacteria decreased, which reflected the trophic strategy of the bacterial community. The bacterial community composition of the non-rhizosphere soil was significantly affected by salt, pH and total carbon (TC) content. Salt limited the relative abundance of Actinobacteria, and increased the relative abundance of Bacteroidetes. The symbiotic network of the rhizosphere soil bacterial community had lower robustness. This is attributed to the greater selective effect of plants on the bacterial community influenced by nutrient addition.

DISCUSSION

Plants played a regulatory role in the process of N and P addition affecting the bacterial community, and nutrient uptake by the root system reduced the negative impact of N and P addition on the bacterial community. The variations in the rhizosphere soil bacterial community were mainly caused by the response of the plant to the N and P addition ratio.

A Salt-Tolerant Streptomyces paradoxus D2-8 from Rhizosphere Soil of Phragmites communis Augments Soybean Tolerance to Soda Saline-Alkali Stress

Soil salinity and alkalization limit plant growth and agricultural productivity worldwide. The application of salt-tolerant plant growth-promoting rhizobacteria (PGPR) effectively improved plant tolerance to saline-alkali stress. To obtain the beneficial actinomyces resources with salt tolerance, thirteen isolates were isolated from rhizosphere saline and alkaline soil of Phragmites communis. Among these isolates, D2-8 was moderately halophilic to NaCl and showed 120 mmol soda saline-alkali solution tolerance. Moreover, the plant growth-promoting test demonstrated that D2-8 produced siderophore, IAA, 1-aminocyclopropane-1-carboxylate deaminase (ACCD), and organic acids. D2-8 showed 99.4% homology with the type strain Streptomyces paradoxus NBRC 14887T and shared the same branch, and, therefore, it was designated S. paradoxus D2-8. Its genome was sequenced to gain insight into the mechanism of growth-promoting and saline-alkali tolerance of D2-8. IAA and siderophore biosynthesis pathway, genes encoding ACC deaminase, together with six antibiotics biosynthesis gene clusters with antifungal or antibacterial activity, were identified. The compatible solute ectoine biosynthesis gene cluster, production, and uptake of choline and glycine betaine cluster in the D2-8 genome may contribute to the saline-alkali tolerance of the strain. Furthermore, D2-8 significantly promoted the seedling growth even under soda saline-alkali stress, and seed coating with D2-8 isolate increased by 5.88% of the soybean yield in the field. These results imply its significant potential to improve soybean soda saline-alkali tolerance and promote crop health in alkaline soil.

[Distribution of Micro-plastics in the Soil Covered by Different Vegetation in Yellow River Delta Wetland]

Micro-plastics (MPs) pollution has been a hotspot in soil environment. To explore the correlation of the vegetation cover and the distribution of MPs in Yellow River Delta wetland, the characters of MPs in the soil sampled at 16 sites where reed (Phragmites communis, a low-salt dominant species) and Suaeda salsa (a high-salt dominant species) covered were investigated. The abundance of MPs here ranged to 80-4640 n·kg^-1, and the particle size ranged to 13 μm-5 mm. The main components of MPs with large size were polyethylene (PE), polyethylene terephthalate (PET) and polystyrene (PS), and the content of PET ranged to 0.22-1.16 μg·kg^-1. The barrier effect of reed on MPs was higher than that of Suaeda salsa. The average abundance of MPs and PET contents at the sites where reed covered were 1423 n·kg^-1 and 0.62 μg·kg^-1, and they mainly consisted of small particles with a size less than 50 μm. The average abundance of MPs and PET contents at the site Suaeda salsa covered were 584 n·kg^-1 and 0.33 μg·kg^-1, and they mainly consisted of fragments and fibers with a size ranged to 100-1000 μm. The abundance of MPs in the soil was significantly correlated with the growth statues of the vegetations (P=0.001). Therefore, the distribution of MPs in the soil in the same area covered by different vegetation might be spatial different.

Influence of Phragmites communis and Zizania aquatica on rhizosphere soil enzyme activity and bacterial community structure in a surface flow constructed wetland treating secondary domestic effluent in China

The present study aims to investigate the effects of Phragmites communis and Zizania aquatica on rhizosphere soil enzyme activity and bacterial community structure in a surface flow constructed wetland (SFCW) for the treatment of domestic sewage from the Shanxi province of China. The basic physical and chemical properties of the soil, the contents of soil urease (UE), alkaline phosphatase (ALP), soil microbial biomass carbon and nitrogen (SMBC, SMBN), and bacterial community structure were measured in the Phragmites communis group (PG), Zizania aquatica group (ZG), and control group (CG), respectively. The results showed that (1) the contents of UE, ALP, SMBC, and SMBN in rhizosphere soil of PG were more than those of ZG; (2) the highest bacterial abundance and α-diversity appeared in PG, in which Gp6 was the most abundant bacterial genus in PG; (3) the main functions of the dominant bacteria Gp6 and Longilinea in PG were involved in metabolizing multiple carbohydrates and participating in the carbon cycle in the soil based on the clusters of orthologous groups pathway analysis data; (4) the bacterial community of PG was mainly affected by the positive correlation with arsenic, nickel, or SMBC via the redundancy analysis. Collectively, Phragmites communis is a recommended species for wastewater wetland treatment system in Shanxi province, and the special enzymes and dominant bacteria in plant rhizosphere soil had obvious functions of removing organic pollutants. Besides, the influences of environmental factors on rhizosphere bacteria and the combined effects of Phragmites communis and dominant bacteria in wetland wastewater treatment system should be taken seriously.

The size and distribution of tidal creeks affects salt marsh restoration

Salt marshes are changeable and important ecosystems that currently face various threats, including global climate change and human activities. The influence of these factors can result in the degradation of salt marshes. Tidal creeks, which are an important source of nutrients and other substances for salt marsh vegetation, play an important role in the health of salt marshes. In this study, the morphological characteristics of tidal creeks and the characteristics of two typical plants, Suaeda glauca (SG) and Phragmites communis (PC), in the Yellow River Delta, China were investigated to determine the effect of tidal creeks on these plants. Aerial photography and field measurements of tidal creeks were carried out from May to July 2018 in the study area. At the same time, nine line-intercepts were set in the vertical direction of tidal creeks to investigate plants. The results showed that different grades of tidal creek exerted no significant influence on the growth of either S. glauca or P. communis. However, unlike grade, the size of a creek and the distance from it had marked effects on these plants. The cross-sectional area of a tidal creek had a significant positive impact on the density of S. glauca (r = 0.39, p = 0.02). For P. communis, the depth of a tidal creek had a strong correlation with this species' density (r = 0.51, p = 0.04) and height (r = 0.63, p = 0.01). Meanwhile, there was a negative relationship between the distance from tidal creeks and the height of S. glauca (r = -0.52, p = 0.02). Conversely, the height (r = 0 0.90, p = 0.00) and density (r = 0.62, p = 0.01) of P. communis were positively affected by its vertical distance from tidal creeks. We found that the subtidal zone near a tidal creek was more conducive to the recovery and growth of S. glauca, and that areas further away from a tidal creek, located in the intertidal and subtidal zones, were more conducive to the recovery and growth of P. communis. The parameters associated with tidal creeks in the subtidal zone (cross sectional area 4.55 m², distance 0-10 m) were beneficial for the growth of S. glauca. For P. communis, relevant features in the intertidal and subtidal zones (depth 0.40-0.45 m, distance 20-60 m) are useful. Our results suggest that attention should be paid to the effects of size and distribution of tidal creeks during the process of salt marsh restoration. This work also provides practical guidance for the restoration of native salt marshes in China.

Metabolic response and correlations between ions and metabolites in Phragmites communis under long-term salinity toxicity

Phragmites communis has a long history in Songnen grassland of China and has a series of biological, ecological as well as genetic characteristics contributing to its adaptation to the specific local climatic and edaphic conditions. The aim of the present study was to investigate the ions balance and their relationship to metabolites in P. communis under three salinity stress conditions. Results showed that the contents of Na⁺, Cl^-, and SO₄^2- significantly increased in P. communis leaves, while K⁺, Mg²⁺, and Mn²⁺ decreased. Moreover, Na⁺ and Cl^- had significant negative correlations with metabolites involved in the tricarboxylic acid cycle (TCA cycle), and significant positive correlations with glycolysis. The metabolite results showed that high contents of sugars and proline played important roles in developing salinity tolerance, indicating that glycolysis and proline biosynthesis were enhanced; however, this consumes large amounts of energy and likely caused the TCA cycle to be inhibited. The results suggested that P. communis might enhance its salinity tolerance mainly through increased glycolysis and energy consumption. In addition, restricting Na⁺ accumulation and increasing of Cl^-, and rearrangement of metabolite production in P. communis tissues are possible causes of salinity tolerance. Therefore, salinity caused systems alterations in widespread metabolic networks involving TCA cycle, glycolysis and proline biosynthesis. These findings provided new insights for the P. communis metabolic adaptation to salinity and demonstrated the ions balance and metabolites in P. communis are possibly attributable to development of salinity tolerance.

[Arbuscular mycorrhizal fungi enhance cadmium uptake of wetland plants in contaminated water]

Arbuscular mycorrhizal fungi (AMF) play an important role in plant growth enhancement, tolerance to heavy metal toxicity, and rehabilitation of contaminated ecosystems. An experiment was carried out with Phragmites communis and Pennisetum alopecuroides inoculated with or without Funneliformis mosseae (Fm), or Rhizophagus intraradices (Ri) under the simulated wetland system with Cd polluted water (0, 5, 10 or 20 mg·L^-1). The results showed that Cd addition significantly decreased mycorrhizal colonization. AMF increased plant height, dry mass, leaf chlorophyll, N and Cd contents in shoot and root of P. communis and P. alopecuroides, enhanced Cd enrichment capability by roots, and decreased Cd transfer coefficient. Under Cd 5 mg·L^-1 treatment, all of the indices in Fm + P. communis combination treatment were higher than those of other treatments, with 60.6% of AMF colonization, and the entry points and vesicles per mm root length were 2.3 and 3.7, respectively. Under the inoculation treatment, dry mass of shoot and root was improved by 69.1%, and 75.0%, nitrogen contents in shoot and root were increased by 38.7% and 27.8%, and the chlorophyll content and plant height were increased by 3.8% and 11.1%, respectively. There was a significant positive correlation between Cd concentration in wetland system and Cd content in shoot and root. Under Cd 20 mg·L^-1 treatment, Fm + P. communis combination had the maximum Cd contents of 182.4 mg·kg^-1 and 663.3 mg·kg^-1 in shoot and root, respectively, the lowest Cd transfer coefficient (0.27), and the highest enrichment coefficient (0.55). In conclusion, Fm + P. communis was the best combination for absorbing Cd in polluted water.

nov., isolated from the roots of Phragmites communis in the Kumtag Desert

A Gram-negative, aerobic, non-spore-forming, rod-shaped, motile bacterium, named strain 59N8^T, was isolated from Phragmites communis roots in the Kumtag Desert. Phylogenetic analysis based on the 16S rRNA gene sequence showed that the isolate belongs to the genus Zobellella within the family Aeromonadaceae. The analysis showed that strain 59N8^T was most closely related to Zobellella taiwanensis ZT1^T. The average nucleotide identity value with Zobellella taiwanensis ZT1^T was 88.2 %, and the digital DNA-DNA hybridization value was 29.7±2.4 %, which was calculated using the Genome-to-Genome Distance Calculator. The G+C content of strain 59N8^T was 62.8 mol%. Strain 59N8^T grew at 0-5 % (w/v) NaCl (optimum, 0-4 %), pH 6.0-9.0 (optimum, 7.0-8.0) and at 10-45 °C. The major cellular fatty acids were summed feature 8 (C18 : 1ω7c/C18 : 1ω6c), summed feature 3 (C16 : 1ω7c/C16 : 1ω6c) and C16 : 0. The major polar lipids in strain 59N8^T were phosphatidylethanolamine and phosphatidylglycerol. Based on the chemotaxonomic, phylogenetic and phenotypic data, strain 59N8^T represents a novel species in the genus Zobellella, for which the name Zobellellaendophytica sp. nov. is proposed. The type strain is 59N8^T (=ACCC 60074^T=KCTC 62456^T).

[Effects of Soil Microbial Diversity on the Phosphate Fraction in the Rhizosphere of Phragmites communis in the Yeyahu Wetland in Beijing, China]

In this research, microorganisms in rhizosphere/non-rhizosphere soils of Phragmites communis in the Yeyahu Wetland were studied. A sequential extraction procedure was used to analyze the phosphorus (P) forms in the rhizosphere/non-rhizosphere soil with a variety of plant growth conditions (April, July, October). The soil bacteria community structure and the diversity was measured using the high-throughput of 16S rRNA amplicons. Furthermore, the complete crystallographic analysis (CCA) method was used to analyze the relationship between phosphate solubilizing microorganisms and P transformation in the soil samples. The results showed that the rank order of inorganic P (IP) fractions in the soil was generally as follows:Ca-bound P (Ca-P) > Occluded P (Oc-P) > Fe-bound P (Fe-P) > Exchangeable P (Ex-P) > Al-bound P (Al-P). The IP content was most affected by the growth of Phragmites communis. The minimum content of IP appeared in the vigorous growth period and the total IP content in the rhizosphere soil was generally lower than in the non-rhizosphere soil. The rank order of organic P (OP) fractions were highly resistant OP (HR-OP) > moderately resistant OP (MR-OP) > moderately labile OP (ML-OP) > labile OP (L-OP), and all the components of OP first decreased and then increased with the growth of plant. The major phylogenic groups in rhizosphere/non-rhizosphere soil of Phragmites communis, included Proteobacteria, Acidobacteria, Chloroflexi, and Actinobacteria among which, Proteobacteria was the majority group in the community composition. Furthermore, the rhizosphere/non-rhizosphere microbial community structure was significantly affected by seasonal changes and existing differences between the rhizosphere and non-rhizosphere soils. In addition, the main functional groups of the modal transformation of P bacteria genera were Bacillus, Enterobacter, Pseudomonas, Burkholderia, Acinetobacter, which can make use of most OP and IP, playing an important role in the transformation of P in wetland soils.