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Colorectal cancer (CRC) is the third most common cancer worldwide and the second most common cause of cancer death. Nanotherapies are able to selectively target the delivery of cancer therapeutics, thus improving overall antitumor efficiency and reducing conventional chemotherapy side effects. Mesoporous silica nanoparticles (MSNs) have attracted the attention of many researchers due to their remarkable advantages and biosafety. We offer insights into the recent advances of MSNs in CRC treatment and their potential clinical application value.
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Plant-associated diazotrophs strongly relate to plant nitrogen (N) supply and growth. However, our knowledge of diazotrophic community assembly and microbial N metabolism in plant microbiomes is largely limited. Here we examined the assembly and temporal dynamics of diazotrophic communities across multiple compartments (soils, epiphytic and endophytic niches of root and leaf, and grain) of three cereal crops (maize, wheat, and barley) and identified the potential N-cycling pathways in phylloplane microbiomes. Our results demonstrated that the microbial species pool, influenced by site-specific environmental factors (e.g., edaphic factors), had a stronger effect than host selection (i.e., plant species and developmental stage) in shaping diazotrophic communities across the soil-plant continuum. Crop diazotrophic communities were dominated by a few taxa (~0.7% of diazotrophic phylotypes) which were mainly affiliated with Methylobacterium, Azospirillum, Bradyrhizobium, and Rhizobium. Furthermore, eight dominant taxa belonging to Azospirillum and Methylobacterium were identified as keystone diazotrophic taxa for three crops and were potentially associated with microbial network stability and crop yields. Metagenomic binning recovered 58 metagenome-assembled genomes (MAGs) from the phylloplane, and the majority of them were identified as novel species (37 MAGs) and harbored genes potentially related to multiple N metabolism processes (e.g., nitrate reduction). Notably, for the first time, a high-quality MAG harboring genes involved in the complete denitrification process was recovered in the phylloplane and showed high identity to Pseudomonas mendocina. Overall, these findings significantly expand our understanding of ecological drivers of crop diazotrophs and provide new insights into the potential microbial N metabolism in the phyllosphere.IMPORTANCEPlants harbor diverse nitrogen-fixing microorganisms (i.e., diazotrophic communities) in both belowground and aboveground tissues, which play a vital role in plant nitrogen supply and growth promotion. Understanding the assembly and temporal dynamics of crop diazotrophic communities is a prerequisite for harnessing them to promote plant growth. In this study, we show that the site-specific microbial species pool largely shapes the structure of diazotrophic communities in the leaves and roots of three cereal crops. We further identify keystone diazotrophic taxa in crop microbiomes and characterize potential microbial N metabolism pathways in the phyllosphere, which provides essential information for developing microbiome-based tools in future sustainable agricultural production.
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Microbiota , Microbiota/genética , Agricultura , Solo/química , Nitrogênio/análise , Produtos Agrícolas/metabolismo , Desenvolvimento VegetalRESUMO
Ammonia-oxidation process directly contribute to soil nitrous oxide (N2O) emissions in agricultural soils. However, taxonomy of the key nitrifiers (within ammonia oxidising bacteria (AOB), archaea (AOA) and complete ammonia oxidisers (comammox Nitrospira)) responsible for substantial N2O emissions in agricultural soils is unknown, as is their regulation by soil biotic and abiotic factors. In this study, cumulative N2O emissions, nitrification rates, abundance and community structure of nitrifiers were investigated in 16 agricultural soils from major crop production regions of China using microcosm experiments with amended nitrogen (N) supplemented or not with a nitrification inhibitor (nitrapyrin). Key nitrifier groups involved in N2O emissions were identified by comparative analyses of the different treatments, combining sequencing and random forest analyses. Soil cumulative N2O emissions significantly increased with soil pH in all agricultural soils. However, they decreased with soil organic carbon (SOC) in alkaline soils. Nitrapyrin significantly inhibited soil cumulative N2O emissions and AOB growth, with a significant inhibition of the AOB Nitrosospira cluster 3a.2 (D11) abundance. One Nitrosospira multiformis-like OTU phylotype (OTU34), which was classified within the AOB Nitrosospira cluster 3a.2 (D11), had the greatest importance on cumulative N2O emissions and its growth significantly depended on soil pH and SOC contents, with higher growth at high pH and low SOC conditions. Collectively, our results demonstrate that alkaline soils with low SOC contents have high N2O emissions, which were mainly driven by AOB Nitrosospira cluster 3a.2 (D11). Nitrapyrin can efficiently reduce nitrification-related N2O emissions by inhibiting the activity of AOB Nitrosospira cluster 3a.2 (D11). This study advances our understanding of key nitrifiers responsible for high N2O emissions in agricultural soils and their controlling factors, and provides vital knowledge for N2O emission mitigation in agricultural ecosystems.
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Ecossistema , Solo , Solo/química , Amônia/química , Carbono , Oxirredução , Archaea , Nitrificação , Microbiologia do SoloRESUMO
The use of microbial inoculant is a promising strategy to improve plant health, but their efficiency often faces challenges due to difficulties in successful microbial colonization in soil environments. To this end, the application of biostimulation products derived from microbes is expected to resolve these barriers via direct interactions with plants or soil pathogens. However, their effectiveness and mechanisms for promoting plant growth and disease resistance remain elusive. In this study, we showed that root irrigation with the extracts of Streptomyces ahygroscopicus strain 769 (S769) solid fermentation products significantly reduced watermelon Fusarium wilt disease incidence by 30% and increased the plant biomass by 150% at a fruiting stage in a continuous cropping field. S769 treatment led to substantial changes in both bacterial and fungal community compositions, and induced a highly interconnected microbial association network in the rhizosphere. The root transcriptome analysis further suggested that S769 treatment significantly improved the expression of the MAPK signalling pathway, plant hormone signal transduction and plant-pathogen interactions, particular those genes related to PR-1 and ethylene, as well as genes associated with auxin production and reception. Together, our study provides mechanistic and empirical evidences for the biostimulation products benefiting plant health through coordinating plant and rhizosphere microbiome interaction.
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Citrullus , Fusarium , Microbiota , Citrullus/genética , Citrullus/microbiologia , Rizosfera , Transcriptoma , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologia , Microbiologia do Solo , Solo , Raízes de Plantas/microbiologiaRESUMO
Chengde's transitional region from plateau to plain is located in the transition zone of agriculture and livestock and is extremely sensitive to climate change and human activities. This study used the net primary productivity(NPP) of vegetation as an evaluation index to quantify the degree impacts of climate change and human activities on vegetation change in the region. The Thornthwaite Memorial model was used to calculate the potential NPP, and the actual NPP was obtained based on MODIS NPP remote sensing images, using the difference between the actual and potential NPPs to express the amount of change in NPP owing to human activities. We used the slope trend and coefficient of variation method to analyze the trend and stability distribution of the actual NPP, potential NPP, and NPP influenced by human activities, and the correlation between actual NPP and annual precipitation and annual average temperature was analyzed using the correlation coefficient method. Finally, we quantified the impact of climate change and human activities on vegetation change in the region. The results showed that 99.87% of the vegetation in the region was improved and changed steadily, and the proportions of the areas showing positive correlation between actual NPP and annual precipitation and annual average temperature were 99.87% and 91.66%, respectively. The potential NPP showed an increasing trend from northwest to southeast, whereas the trend and stability of the potential NPP both showed an increasing trend from west to east. The area where climate change and human activities played a role in vegetation improvement accounted for 99.71%, and that affected by climate change accounted for 0.14%, with the proportion of human activities leading to vegetation degradation being 0.15%.
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Mudança Climática , Ecossistema , Humanos , Modelos Teóricos , Atividades Humanas , Temperatura , ChinaRESUMO
Chronic cerebral ischaemia (CCI) is a high-incidence cardiovascular and cerebrovascular disease that is very common in clinical practice. Although many pathogenic mechanisms have been explored, there is still great controversy among neuroscientists regarding the pathogenesis of CCI. Therefore, it is important to elucidate the mechanisms of CCI occurrence and progression for the prevention and treatment of ischaemic cerebrovascular disorders. Autophagy and inflammation play vital roles in CCI, but the relationship between these two processes in this disease remains unknown. Here, we review the progression and discuss the functions, actions and pathways of autophagy and inflammation in CCI, including a comprehensive view of the transition from acute disease to CCI through ischaemic repair mechanisms. This review may provide a reference for future research and treatment of CCI. Schematic diagram of the interplay between autophagy and inflammation in CCI. CCI lead to serious, life-threatening complications. This review summarizes two factors in CCI, including autophagy and inflammation, which have been focused for the mechanisms of CCI. In short, the possible points of intersection are shown in the illustration. CCI, Chronic cerebral ischaemia; ER stress, Endoplasmic reticulum stress; ROS, Reactive oxygen species.
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Isquemia Encefálica , Estresse do Retículo Endoplasmático , Humanos , Isquemia Encefálica/complicações , Inflamação/patologia , Autofagia , IsquemiaRESUMO
Temporal lobe epilepsy (TLE) leads to extensive degradation of the quality of life of patients. Glycyrrhizic acid (GA) has been reported to exert neuroprotective effects on status epilepticus. Herein, the current study set out to explore the functional mechanism of GA in TLE young rats. Firstly, TLE young rat models were established using the lithium chloride and pilocarpine regimen and then subjected to treatment with different doses of GA, miR-194-5p-antagomir, or/and sh-prostaglandin-endoperoxide synthase 2 (PTGS2) to observe changes in iron content, glutathione and malondialdehyde levels, and GPX4 (glutathione peroxidase 4) and PTGS2 protein levels in the hippocampus. Neuronal injury and apoptosis were assessed through HE, Nissl, and TUNEL staining. Additionally, the expression patterns of miR-194-5p were detected. The binding site of miR-194-5p and PTGS2 was verified with a dual-luciferase assay. Briefly, different doses of GA (20, 40, and 60 mg/kg) reduced the epileptic score, frequency, and duration in TLE young rats, along with reductions in iron content, lipid peroxidation, neuronal injury, and apoptosis in the hippocampus. Silencing of miR-194-5p partly annulled the action of GA on inhibiting ferroptosis and attenuating neuronal injury in TLE young rats. Additionally, PTGS2 was validated as a target of miR-194-5p. GA inhibited ferroptosis and ameliorated neuronal injury in TLE young rats via the miR-194-5p/PTGS2 axis. Overall, our findings indicated that GA exerts protective effects on TLE young rats against neuronal injury by inhibiting ferroptosis through the miR-194-5p/PTGS2 axis.
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Epilepsia do Lobo Temporal , Ferroptose , MicroRNAs , Animais , Ratos , Apoptose , Ciclo-Oxigenase 2/genética , Epilepsia do Lobo Temporal/tratamento farmacológico , Epilepsia do Lobo Temporal/genética , Epilepsia do Lobo Temporal/metabolismo , Ferroptose/genética , Ácido Glicirrízico/farmacologia , Ácido Glicirrízico/uso terapêutico , Ferro , MicroRNAs/metabolismoRESUMO
Soil bacteria, which are active in shrub encroachment, play key roles in regulating ecosystem structure and function. However, the differentiation characteristics and assembly process of bacterial communities in scrubbed grasslands remain unknown. Taking the Qinghai-Tibet Plateau, a hotspot of shrub encroachment, as the study area, we collected 192 soils near nine natural typical shrubs' roots on a trans-longitude transect (about 1800 km) and investigated the bacterial communities using 16S rRNA amplicon sequencing. We found that the bacterial communities exhibited plant-specific and geographic-specific differentiation. On the one hand, bacterial communities differed significantly across plant species, with widely distributed shrubs harboring high diversity communities but few plant-specific taxa, and narrowly distributed shrubs possessing low diversity communities but more plant-specific taxa. Besides, there was a significant negative correlation between bacterial community similarity and plant phylogenetic distance. On the other hand, bacterial communities differed across geographic sites, with a significant decay in bacterial community similarity with geographic distance. The bacterial alpha diversity varied in an inverted V-shape from west to east, peaking at 91°E, which could be largely driven by mean annual temperature, soil pH and soil total carbon content. Community differentiation increased with the heterogeneity degree of assembly processes, and the dominant assembly process in these two specific differentiations differed. Dominated by stochastic and deterministic forces, respectively, geography diverged bacterial communities primarily through increased dispersal limitation, whereas plants diverged bacterial communities primarily through increased variable selection. Our study provides new insight into the characteristics and mechanisms of root-surrounding soil bacteria differentiation in scrubbed grasslands, contributing to the scientific management of degraded grasslands and the prediction of bacterial community structure and ecosystem function in response to global change.
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Ecossistema , Solo , Solo/química , Tibet , Filogenia , Biodiversidade , RNA Ribossômico 16S , Plantas , Bactérias , Microbiologia do SoloRESUMO
Three new triterpenoid glycosides, 2α,3α,23,24-tetrahydroxyurs-12,19- dien-oic acid 28-O-ß- D -glucopyranoside (1), 2α,3ß,23,24-tetrahydroxyurs-12, 19(29) -dien-28-oic acid 28-O-ß- D -glucopyranoside (2), and 2α,3ß,23,24-tetrahydroxyurs-12, 18-dien-28-oic acid 28-O-ß- D -glucopyranoside (3) were isolated from Aronia melanocarpa (Michx.) Elliott. Their structures were elucidated by extensive spectroscopic methods. All the isolated compounds displayed moderate inhibitory activity against nitric oxide production in macrophages.
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Viruses can significantly influence the composition and functions of their host communities and enhance host pathogenicity via the transport of virus-encoded virulence genes. However, the contribution of viral communities to the dissemination of virulence genes across various biomes across a large scale is largely unknown. Here, we constructed 29,283 soil viral contigs (SVCs) from viral size fraction metagenomes and public databases. A total of 1310 virulence genes were identified from 1164 SVCs in a wide variety of soil biomes, including grassland, agricultural and forest soils. The virulence gene gmd was the most abundant one, followed by csrA, evpJ, and pblA. A great proportion of viruses encoding virulence genes were uncharacterized. Virus-host linkage analysis revealed that most viruses were linked to only one bacterial genus, whereas several SVCs were associated with more than one bacterial genus and even two bacterial phyla, suggesting the potential risk of spreading virulence genes across different bacterial communities via viruses. Altogether, we provided new evidence for the prevalence of virulence genes in soil viruses across biomes, which advanced our understanding of the potential role of soil viruses in driving the pathogenesis of their hosts in terrestrial ecosystems.
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Solo , Vírus , Ecossistema , Virulência/genética , Microbiologia do Solo , Vírus/genéticaRESUMO
Further investigation on the roots of Aconitum weixiense led to the isolation of two new bis-diterpenoid alkaloids, named as weisaconitines E and F (1-2), which were elucidated by IR, HR-ESI-MS, 1D- and 2D-NMR analyses. Their structures are characterized as denudatine-atisine-type bis-diterpenoid alkaloids.
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Aconitum , Alcaloides , Diterpenos , Medicamentos de Ervas Chinesas , Aconitum/química , Estrutura Molecular , Alcaloides/química , Medicamentos de Ervas Chinesas/química , Diterpenos/química , Raízes de Plantas/químicaRESUMO
OBJECTIVE: Alzheimer's disease (AD) is a neurodegenerative disease. This study aims to explore the intervention and treatment effects of aerobic exercise and different exercise modes on AD through meta-analysis. METHODS: Using the set inclusion and exclusion criteria, retrieve the China national knowledge infrastructure (CNKI), Wanfang Data Knowledge Service Platform, China Science and Technology Journal Database, Cochrane Library, and PubMed were searched from January 1, 2012, to December 31, 2021. Cochrane risk bias assessment tool was used to evaluate the quality of the included articles, and ReMan5.4.1 was used for forest plot analysis of mini-mental state exam (MMSE) score indicators included in the included articles. RESULTS: Twelve randomized controlled trials and 795 samples were included. Meta analysis of all articles: I2 = 91%, Pâ ≤â .00001, (MDâ =â 2.95, 95%CI [2.49, 3.40], Pâ ≤â .00001). Meta analysis of 5 fit aerobics groups: I2 = 4%, Pâ =â .38, (MDâ =â 1.53, 95%CI [0.72, 2.33], Pâ =â .0002); meta-analysis of three spinning groups: I2 = 3%, Pâ =â .36, (MDâ =â 1.79, 95%CI [0.29, 3.29], Pâ =â .02). CONCLUSION: Aerobic exercise can effectively improve intellectual and cognitive impairment in AD patients, and for different forms of aerobic exercise, the therapeutic effect of spinning aerobic exercise is better than that of fit aerobics.
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Doença de Alzheimer , Doenças Neurodegenerativas , Humanos , Doença de Alzheimer/tratamento farmacológico , Cognição , Exercício Físico , InteligênciaRESUMO
Sepsis is a life-threatening condition, and treatment for sepsis in clinic is often not available, partially due to insufficient understanding of the pathogenesis of sepsis. Extensive study to elucidate the pathogenesis is required to improve the clinical management and outcome of sepsis. In this study, we investigated the pathogenesis of sepsis using peripheral blood mononuclear cells (PBMCs) from septic patients and studied the underlying mechanism of miR-16-5p on aerobic glycolysis in lipopolysaccharide (LPS)-treated THP1 and Raw264.7 cells. The levels of RNA and protein were determined by real-time quantitative PCR and immunoblotting assay, respectively. The production of high mobility group box 1 (HMGB1) was measured by enzyme-linked immunosorbent assay. The levels of succinate and lactate were determined using colorimetric kits. The extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) were measured by extracellular flux analyzer. The results showed that the expression of miR-16-5p was elevated, while sirtuin 3 (SIRT3) was decreased in PBMCs from septic patients and LPS-treated cells, along with accumulation of acetylated succinate dehydrogenase complex, subunit A. Concomitantly, an increase in HMGB1, succinate, lactate, as well as ECAR and a decrease in OCR were observed. Knockdown of miR-16-5p upregulated SIRT3 expression, facilitated SDHA deacetylation, and attenuated sepsis-related aerobic glycolysis. Further study identified that SIRT3 is targeted by miR-16-5p, and overexpression of SIRT3 rescued LPS-induced responses via deacetylation of SDHA. Our findings revealed a novel miR-16-5p-regulated SIRT3-SDHA axis in sepsis and provided novel insights for sepsis treatment.
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Proteína HMGB1 , MicroRNAs , Sepse , Sirtuína 3 , Humanos , Sirtuína 3/genética , Sirtuína 3/metabolismo , Proteína HMGB1/genética , Proteína HMGB1/metabolismo , Lipopolissacarídeos/farmacologia , Lipopolissacarídeos/metabolismo , Leucócitos Mononucleares/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Sepse/genética , Glicólise , Lactatos , Succinatos , Apoptose , Complexo II de Transporte de Elétrons/metabolismoRESUMO
PURPOSE: We report two cases diagnosed as acute necrotizing encephalopathy (ANE) with acute onset and various clinical manifestations. METHODS: The patients' data were obtained from the medical records of the Binzhou Medical University Hospital in Binzhou, China. The clinical symptoms, laboratory examination, neuroimaging, treatment, and prognosis of the 2 patients were collected and analyzed. RESULTS: We report 2 adult ANE patients with acute onset. The first symptom was fever, followed by symptoms and signs of damage to the central nervous system. The patients were infected with herpes simplex virus and influenza virus, respectively. The main manifestation on brain magnetic resonance imaging was a mixed-signal of a "three-layer structure" in the bilateral thalamus. The first patient died. Based on the experience of the diagnosis and treatment of the first patient, combined with a review of the literature, the second patient was immediately treated with glucocorticoid pulse therapy combined with gamma globulin injection. This patient's condition was controlled, and the prognosis was good. CONCLUSIONS: This study describes the clinical symptoms, laboratory examination, neuroimaging evidence, and treatment experience of ANE in adults. We believe that the progress of the disease may be controlled, and the prognosis may be improved if glucocorticoid pulse therapy combined with gamma globulin injection is used as soon as possible.
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Encefalopatias , Glucocorticoides , Humanos , Adulto , Encefalopatias/diagnóstico , Encefalopatias/patologia , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , gama-GlobulinasRESUMO
Soil microbial biogeographical patterns have been widely explored from horizontal to vertical scales. However, studies of microbial vertical distributions were still limited (e.g., how soil genetic horizons influence microbial distributions). To shed light on this question, we investigated soil bacterial communities across three soil horizons (topsoil: horizon A; midsoil: horizon B; subsoil: horizon C) of 60 soil profiles along a 3500 km transect in the Qinghai-Tibet Plateau. We found that bacterial diversity was highest in the topsoil and lowest in the subsoil, and community composition significantly differed across soil horizons. The network complexity decreased from topsoil to subsoil. There were significant geographical/environmental distance-decay relationships (DDR) in three soil horizons, with a lower slope from topsoil to subsoil due to the decreased environmental heterogeneity. Variation partitioning analysis (VPA) showed that bacterial community variations were explained more by environmental than spatial factors. Although environmental selection processes played a dominant role, null model analysis revealed that deterministic processes (mainly variable selection) decreased with deeper soil horizons, while stochastic processes (mainly dispersal limitation) increased from topsoil to subsoil. These results suggested that microbial biogeographical patterns and community assembly processes were soil horizon dependent. Our study provides new insights into the microbial vertical distributions in large-scale alpine regions and highlights the vital role of soil genetic horizons in affecting microbial community assembly, which has implications for understanding the pedogenetic process and microbial responses to extreme environment under climate change.
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Microbiota , Solo , Bactérias/genética , Microbiologia do Solo , TibetRESUMO
Viruses are extremely abundant in the soil environment and have potential roles in impacting on microbial population, evolution, and nutrient biogeochemical cycles. However, how environment and climate changes affect soil viruses is still poorly understood. Here, a metagenomic approach was used to investigate the distribution, diversity, and potential biogeochemical impacts of DNA viruses in 12 grassland soils under three precipitation gradients on the Qinghai-Tibet Plateau, which is one of the most sensitive areas to climate change. A total of 557 viral operational taxonomic units were obtained, spanning 152 viral families from the 30 metagenomes. Both virus-like particles (VLPs) and microbial abundance increased with average annual precipitation. A significant positive correlation of VLP counts was observed with soil water content, total carbon, total nitrogen, soil organic matter, and total phosphorus. Among these biological and abiotic factors, SWC mainly contributed to the variability in VLP abundance. The order Caudovirales (70.1% of the identified viral order) was the predominant viral type in soils from the Qinghai-Tibet Plateau, with the Siphoviridae family being the most abundant. Remarkably, abundant auxiliary carbohydrate-active enzyme (CAZyme) genes represented by glycoside hydrolases were identified, indicating that soil viruses may play a potential role in the carbon cycle on the Qinghai-Tibet Plateau. There were more diverse hosts and abundant CAZyme genes in soil with moderate precipitation. Our study provides a strong evidence that changes in precipitation impact not only viral abundance and virus-host interactions in soil but also the viral functional potential, especially carbon cycling.
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Phosphorus deficiency is a critical limit on the cycling of carbon (C), nitrogen (N) and phosphorus (P) in forest ecosystems. Despite the pivotal roles of microbes in driving the biogeochemical cycling of C/N/P, our knowledge on the relationships of soil bacteria and archaea to P deficiency in forest ecosystems remains scarce. Here, we studied 110 acidic soils (average pH 4.5) collected across 700-km subtropical forests with a gradient of available phosphorus (AP) ranging from 0.21 to 17.6 mg/kg. We analyzed the soil C/N/P stoichiometry and studied soil bacterial and archaeal diversity/abundance via high throughput sequencing and qPCR approaches. Our results show that soil P decoupled with N or C when below 3 mg/kg but coupled with C and N when above 3 mg/kg. Archaeal diversity and abundance were significantly higher in low AP (< 3 mg/kg) soils than in high AP (>3 mg/kg) soils, while bacterial were less changed. Compared with bacteria, archaea are more strongly related with soil stoichiometry (C:N, C:P, N:P), especially when AP was less than 3 mg/kg. Taxonomic and functional composition analysis further confirmed that archaeal rather than bacterial taxonomic composition was significantly related with functional composition of microbial communities. Taken together, our results show that archaea are more important than bacteria in driving soil stoichiometry in phosphorus deficient habitats and suggest a niche differentiation of soil bacteria and archaea in regulating the soil C/N/P cycling in subtropical forests.
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Archaea , Microbiota , Bactérias , Florestas , Nitrogênio/análise , Fósforo/análise , Solo/química , Microbiologia do SoloRESUMO
BACKGROUND: Viruses are the most abundant biological entities on the planet and drive biogeochemical cycling on a global scale. Our understanding of biogeography of soil viruses and their ecological functions lags significantly behind that of Bacteria and Fungi. Here, a viromic approach was used to investigate the distribution and ecological functions of viruses from 19 soils across China. RESULTS: Soil viral community were clustered more significantly by geographical location than type of soil (agricultural and natural). Three clusters of viral communities were identified from North, Southeast and Southwest regions; these clusters differentiated using taxonomic composition and were mainly driven by geographic location and climate factors. A total of 972 viral populations (vOTUs) were detected spanning 23 viral families from the 19 viromes. Phylogenetic analyses of the phoH gene showed a remarkable diversity and the distribution of viral phoH genes was more dependent on the environment. Notably, five proteins involved in phosphorus (P) metabolism-related nucleotide synthesis functions, including dUTPase, MazG, PhoH, Thymidylate synthase complementing protein (Thy1), and Ribonucleoside reductase (RNR), were mainly identified in agricultural soils. CONCLUSIONS: The present work revealed that soil viral communities were distributed across China according to geographical location and climate factors. In addition, P metabolism genes encoded by these viruses probably drive the synthesis of nucleotides for their own genomes inside bacterial hosts, thereby affecting P cycling in the soil ecosystems.
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Chemical fumigants and organic fertilizer are commonly used in facility agriculture to control soil-borne diseases and promote soil health. However, there is a lack of evidence for the effect of non-antibiotic fumigants on the distribution of antibiotic resistance genes (ARGs) in plant rhizosphere soils. Here, the response of a wide spectrum of ARGs and mobile genetic elements (MGEs) to dazomet fumigation practice in the rhizosphere soil of watermelon was investigated along its branching, flowering and fruiting growth stages in plastic shelters using high-throughput quantitative PCR approach. Our results indicated that soil fumigation combined with organic fertilizer application significantly increased the relative abundance of ARGs and MGEs in the rhizosphere soil of watermelon plant. The positive correlations between the relative abundance of ARGs and MGEs suggested that soil fumigation might increase the horizontal gene transfer (HGT) potential of ARGs. This result was further confirmed by the enhanced associations between ARG and MGE subtypes in the networks of fumigation treatments. Moreover, bipartite associations between ARGs/MGEs and microbial communities (bacteria and fungi) revealed a higher percentage of linkage between MGEs and microbial taxa in the fumigated soils. Structural equation model analysis further suggested that the increases in antibiotic resistance after fumigation and organic fertilizer application were mainly driven by MGEs and fungal community. Together, our results provide vital evidence that dazomet fumigation process combined with organic fertilizer in plastic shelters has the great potential to promote ARGs' dissemination in the rhizosphere, and raise cautions of the acquired resistance by soil-borne fungal pathogen and the potential spreading of ARGs along soil-plant continuum.
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Citrullus , Solo , Resistência Microbiana a Medicamentos , Fertilizantes , Fumigação , Genes Bacterianos , Rizosfera , Microbiologia do SoloRESUMO
Plants form complex interaction networks with diverse microbiomes in the environment, and the intricate interplay between plants and their associated microbiomes can greatly influence ecosystem processes and functions. The phyllosphere, the aerial part of the plant, provides a unique habitat for diverse microbes, and in return the phyllosphere microbiome greatly affects plant performance. As an open system, the phyllosphere is subjected to environmental perturbations, including global change, which will impact the crosstalk between plants and their microbiomes. In this review, we aim to provide a synthesis of current knowledge of the complex interactions between plants and the phyllosphere microbiome under global changes and to identify future priority areas of research on this topic.