Plant community composition typically undergoes progressive changes along environmental gradients.However,most experimental studies have focused on individual communities,so it remains unclear how exogenous nutrient i...Plant community composition typically undergoes progressive changes along environmental gradients.However,most experimental studies have focused on individual communities,so it remains unclear how exogenous nutrient inputs affect the stability of plant communities along environmental gradients.Along a rainfall gradient on the northern Tibetan Plateau,we conducted an 8-year nitrogen(N)addition experiment in four alpine grasslands:alpine desert steppe(ADS),alpine steppe(AS),alpine meadow steppe(AMS),alpine meadow(AM),and we used twoway ANOVA to examine the effects of N addition on the temporal stability of these different alpine grasslands.We found that community aboveground biomass showed saturation trends in AM and AMS with increasing N gradients,while there was no change in AS and a gradual increase in ADS.The temporal stability showed different patterns of gradual decreases in ADS and AM,and a unimodal trend in AMS with increasing N gradients.However,N addition had no effect on the temporal stability of AS.Dominant species stability was the controlling factor for alpine grasslands along the transect,while the effect of asynchrony gradually increased with decreasing precipitation.These findings highlight that community composition,especially the dominant species,along the environmental gradient can mediate the effects of N inputs on community temporal stability.Thus,the conservation and restoration of the dominant species are particularly important under future scenarios of increased atmospheric N deposition.展开更多
Soil microbial communities are key factors in maintaining ecosystem multifunctionality(EMF).However,the distribution patterns of bacterial diversity and how the different bacterial taxa and their diversity dimensions ...Soil microbial communities are key factors in maintaining ecosystem multifunctionality(EMF).However,the distribution patterns of bacterial diversity and how the different bacterial taxa and their diversity dimensions affect EMF remain largely unknown.Here,we investigated variation in three measures of diversity(alpha diversity,community composition and network complexity)among rare,intermediate,and abundant taxa across a latitudinal gradient spanning five forest plots in Yunnan Province,China and examined their contributions on EMF.We aimed to characterize the diversity distributions of bacterial groups across latitudes and to assess the differences in the mechanisms underlying their contributions to EMF.We found that multifaceted diversity(i.e.,diversity assessed by the three different metrics)of rare,intermediate,and abundant bacteria generally decreased with increasing latitude.More importantly,we found that rare bacterial taxa tended to be more diverse,but they contributed less to EMF than intermediate or abundant bacteria.Among the three dimensions of diversity we assessed,only community composition significantly affected EMF across all locations,while alpha diversity had a negative effect,and network complexity showed no significant impact.Our study further emphasizes the importance of intermediate and abundant bacterial taxa as well as community composition to EMF and provides a theoretical basis for investigating the mechanisms by which belowground microorganisms drive EMF along a latitudinal gradient.展开更多
The northern East China Sea and Yellow Sea are highly dynamic marginal seas,serving as important fishing grounds and primary areas for aquaculture.The zooplankton community structure,including abundance,biovolume,and ...The northern East China Sea and Yellow Sea are highly dynamic marginal seas,serving as important fishing grounds and primary areas for aquaculture.The zooplankton community structure,including abundance,biovolume,and normalized biovolume size spectra(NBSS)within this ecosystem in summers 2021 and 2022 was assessed through ZooScan digital imaging system.The abundances of zooplankton in summers 2021 and 2022 were 3364.22±2190.53 and 4435.52±2520.06 inds./m^(3),respectively,whereas the corresponding biovolumes were 649.10±519.63 and 1064.86±1254.87 mm^(3)/m^(3),respectively.Small copepods as the dominant zooplankton functional group in terms of abundance in both years,while chaetognath and medusae were the dominant groups in terms of biovolume.The dominance of medusae and chaetognath in terms of biovolume,along with the flatter slopes of NBSS compared to a stable community,indicated that more energy accumulated in gelatinous organisms within the study area.There were significant positive relationships between temperature and tunicates or medusae,with a significantly higher population size observed in summer 2022 than in 2021.The lower abundance and biovolume of zooplankton,mainly of small copepods,in summer 2021 may be related to the larger population size of the large jellyfish and the proliferation of green tides.The investigation provided basic data and fundamental insights for achieving a comprehensive understanding of zooplankton community structure and their long-term dynamics.展开更多
Arsenic(As)pollution in coastal wetlands has been receiving growing attention.However,the exact mechanism of As mobility driven by tidal action is still not completely understood.The results reveal that lower total As...Arsenic(As)pollution in coastal wetlands has been receiving growing attention.However,the exact mechanism of As mobility driven by tidal action is still not completely understood.The results reveal that lower total As concentrations in solution were observed in the flood-ebb treatment(FE),with the highest concentration being 7.1μg/L,and As(V)was the predominant species.However,elevated levels of total As in solution were found in the flooded treatment(FL),with a maximum value of 14.5μg/L after 30 days,and As(III)was the predominant form.The results of dissolved organicmatter(DOM)suggest that in the early to mid-stages of the incubation,fulvic acid-like substances might be utilized by microorganisms as electron donors or shuttle bodies,facilitating the reductive release of As/Fe from sediments.Both flood-ebb and flooded treatments promoted the transformation of crystalline iron hydrous oxides-bound As into residual forms.However,prolonged flooded conditions more readily facilitated the formation of specific adsorption forms of As and the reduction of crystalline iron hydrous oxides-bound As,increasing As mobility.In addition,the flood-ebb tides have been found to increase the diversity ofmicrobial populations.The main microbial genera in the flood-ebb treatment included Salinimicrobium,Erythrobacter,Yangia,Sulfitobacter,and Marinobacter.Bacillus,Psychrobacter,and Yangia showed a significant correlation with As(V).In flooded treatment,Bacillus,Pseudomonas,and Geothermobacter played a major role in the reduction and release of As.This study significantly contributes to the current understanding of how As behaves in diverse natural environments.展开更多
Cover cropping is a diversifying agricultural practice that can improve soil structure and function by altering the underground litter diversity and soil microbial communities.Here,we tested how a wheat cover crop alt...Cover cropping is a diversifying agricultural practice that can improve soil structure and function by altering the underground litter diversity and soil microbial communities.Here,we tested how a wheat cover crop alters the decomposition of cucumber root litter.A three-year greenhouse litterbag decomposition experiment showed that a wheat cover crop accelerates the decomposition of cucumber root litter.A microcosm litterbag experiment further showed that wheat litter and the soil microbial community could improve cucumber root litter decomposition.Moreover,the wheat cover crop altered the abundances and diversities of soil bacterial and fungal communities,and enriched several putative keystone operational taxonomic units(OTUs),such as Bacillus sp.OTU1837 and Mortierella sp.OTU1236,that were positively related to the mass loss of cucumber root litter.The representative bacterial and fungal strains B186 and M3 were isolated and cultured.In vitro decomposition tests demonstrated that both B186 and M3 had cucumber root litter decomposition activity and a stronger effect was found when they were co-incubated.Overall,a wheat cover crop accelerated cucumber root litter decomposition by altering the soil microbial communities,particularly by stimulating certain putative keystone taxa,which provides a theoretical basis for using cover crops to promote sustainable agricultural development.展开更多
Protoporphyrin Ⅸ(PPⅨ), a basic porphyrin system found in nature, all “porphyrin-type”tetrapyrroles with a biological function are biosynthetically derived thereof. PPⅨ is a metalloprosthetic group of numerous pro...Protoporphyrin Ⅸ(PPⅨ), a basic porphyrin system found in nature, all “porphyrin-type”tetrapyrroles with a biological function are biosynthetically derived thereof. PPⅨ is a metalloprosthetic group of numerous proteins involved in diverse metabolic and respiratory processes across all domains of life, and is thus considered essential for respiring organisms. Determining the biotic and abiotic factors that influence marine microbial growth and community structure is critical for understanding global biogeochemical cycles. Here,we present vertical profiles of intracellular PPⅨ and four derivative products(Chlorophylla/b and Pheophytin-a/b) from two coastal sediment cores, alongside ancillary geochemical and 16S rRNA microbial community data. Our findings indicated that PPⅨ is present in the natural sediment environment and displays a decreasing trend with depth, revealing a significant positive correlation with both organic matter and microbial abundance. Cooccurrence networks revealed that the environmental distribution of PPⅨ was positively correlated with the microbial porphyrin producer(high genetic completeness), but negatively correlated with auxotrophs(absence or low genetic completeness). It emphasized the critical role of PPⅨ as a biological molecule involved in key physiological processes. These results suggest that PPⅨ is a prominent component of the shared extracellular metabolite pool, especially in anoxic marine sediments where it exists at physiologically relevant concentrations for microbial metabolism. This study highlighted the significance of PPⅨ in microbial ecology and its potential impact on biogeochemical cycles in marine sedimentary environments.展开更多
Plant growth-promoting rhizobacteria(PGPR)have been widely used for the promotion of plant performance.Predatory protists can influence the taxonomic and functional composition of rhizosphere bacteria.However,research...Plant growth-promoting rhizobacteria(PGPR)have been widely used for the promotion of plant performance.Predatory protists can influence the taxonomic and functional composition of rhizosphere bacteria.However,research on the impact of the interaction between protist and PGPR on plant performance remains at a very early stage.Here,we examined the impacts of individual inoculation of protist(Colpoda inflata,Dimastigella trypaniformis,or Vermamoeba vermiformis)or the PGPR strain Bacillus velezensis SQR9 as well as the co-inoculation of the protist C.inflata and B.velezensis SQR9 on the growth of tomato plants.We found that all individual protists and Bacillus could promote plant growth compared to the control with no microbe inoculation,with the co-inoculation of C.inflata and B.velezensis SQR9 achieving the greatest performance,including plant height,fresh weight,and dry weight.Different protists harbored distinct rhizosphere bacterial communities,with the co-inoculation of protist and Bacillus resulting in the lowest bacterial diversity and driving significant changes in community structure and composition,particularly by increasing the relative abundance of Proteobacteria.Random forest model highlighted Cellvibrio as the most important bacterial predictor of plant growth,which was enriched after protist inoculation,especially after the mixed inoculation of protist and Bacillus.We further found that bacterial functional genes of nitrogen metabolism were the key determinants of plant growth.These results indicate that the interaction between protists and Bacillus can support plant growth by reshaping rhizosphere bacterial community composition and function.Understanding the interaction mechanisms between protist and PGPR is crucial for their effective utilization in sustainable agriculture.展开更多
Land use influences soil biota community composition and diversity,and then belowground ecosystem processes and functions.To characterize the effect of land use on soil biota,soil nematode communities in crop land,for...Land use influences soil biota community composition and diversity,and then belowground ecosystem processes and functions.To characterize the effect of land use on soil biota,soil nematode communities in crop land,forest land and fallow land were investigated in six regions of northern China.Generic richness,diversity,abundance and biomass of soil nematodes was the lowest in crop land.The richness and diversity of soil nematodes were 28.8and 15.1%higher in fallow land than in crop land,respectively.No significant differences in soil nematode indices were found between forest land and fallow land,but their network keystone genera composition was different.Among the keystone genera,50%of forest land genera were omnivores-predators and 36%of fallow land genera were bacterivores.The proportion of fungivores in forest land was 20.8%lower than in fallow land.The network complexity and the stability were lower in crop land than forest land and fallow land.Soil pH,NH_(4)^(+)-N and NO_(3)^(–)-N were the major factors influencing the soil nematode community in crop land while soil organic carbon and moisture were the major factors in forest land.Soil nematode communities in crop land influenced by artificial management practices were more dependent on the soil environment than communities in forest land and fallow land.Land use induced soil environment variation and altered network relationships by influencing trophic group proportions among keystone nematode genera.展开更多
OBJECTIVE: To investigate composition of gut microbial community in a rat model of functional dyspepsia(FD) and to explore the interventional effects of Simo Tang(四磨汤, SMT). METHODS: A rat model of FD was establish...OBJECTIVE: To investigate composition of gut microbial community in a rat model of functional dyspepsia(FD) and to explore the interventional effects of Simo Tang(四磨汤, SMT). METHODS: A rat model of FD was established through the tail-clamping stimulation method. The rat model of FD was assessed by the state of rats, their weight, sucrose preference rate, and intestinal propulsion rate. The DNA was extracted from stool samples after treatment with SMT. Amplified polymerase chain reaction(PCR) products of the 16S r DNA were sequenced using Novase Q6000 after construction of libraries. Composition of gut microbial community in the stool samples was determined and analyzed by cluster analysis, bioinformatic analysis, and analysis of α-diversity and β-diversity.RESULTS: The rat model of FD was successfully established using the tail-clamping stimulation method. The statistical results of cluster analysis of operational taxonomic units(OTUs) showed that the relative abundance of OTUs in the FD group was the lowest, while it was the highest in the normal(N) group. The composition of microbiome in the four groups was similar at phyla level. Compared with the FD group, the abundance of Firmicutes was downregulated, and the abundance of Proteobacteria and Bacteroidetes was upregulated in the Simo Tang(SMT) and high-dose Simo Tang(SMT.G) groups. The ratio of Bacteroidetes/Firmicutes was also elevated. According to the analysis of α-diversity and β-diversity, the abundance of flora in FD rats was significantly reduced. The treatment using SMT appeared beneficial to improve the diversity of flora. SMT could improve the intestinal flora in FD rats. The results showed that FD rats had intestinal flora imbalance, and species diversity increased. The results suggested that SMT could regulate the disorders of intestinal flora caused by FD. CONCLUDIONS: SMT could restore gut homeostasis and maintain gut flora diversity by modulating the gut microbiota and its associated metabolites in rats, thereby treating gastrointestinal diseases.展开更多
Anaerobic digestion (AD) with thermal hydrolysis (TH) pretreatment is a promising process for excess sludge treatment,while there lacks of the knowledge from full-scale process about the impact of sludge composition a...Anaerobic digestion (AD) with thermal hydrolysis (TH) pretreatment is a promising process for excess sludge treatment,while there lacks of the knowledge from full-scale process about the impact of sludge composition and characteristics on microbial community and performance.The sludge physiochemical indices,microbial community and performance data of four full-scale TH-AD plants were characterized,and their relationships was elucidated.The four plants were operated under almost similar total organic loading rate (OLR)but their methanogenesis performance differentiate into two groups,namely superior group(SupG) and the inferior group (Inf G).In both groups,TH effectively solubilized particulate organic compounds,meanwhile raised the ammonia nitrogen (NH_(4)^(+)-N) and volatile fatty acid (VFA) concentration.Compared with the Sup G,thermal hydrolyzed sludge of Inf G had higher level of VFAs,NH_(4)^(+)-N and total chemical oxygen demand (t COD),which showed higher inhibition effect on microbes,leading to a community with lower diversity,lower abundance of carbohydrate degrading functional guild,higher protein degrading one,and methanogens that adapted to limited substrates,and further declined the methane production rate.Thus,it was recommended that OLR alone was not sufficient for controlling the system in design and operation,the concentration of VFAs,NH_(4)^(+)-N and t COD should be equally considered.Their higher concentration,together with the higher abundance of Defluviitoga and Proteiniphilum were recommended as indicators for inferior running condition.Our results proposed that microbial communities played a role of bridge between environmental factors and performance,provided implications for engineering ecology and operational regulation for full-scale sludge TH-AD process.展开更多
Brazing filler metals are widely applied,which serve as an industrial adhesive in the joining of dissimilar structures.With the continuous emergence of new structures and materials,the demand for novel brazing filler ...Brazing filler metals are widely applied,which serve as an industrial adhesive in the joining of dissimilar structures.With the continuous emergence of new structures and materials,the demand for novel brazing filler metals is ever-increasing.It is of great significance to investigate the optimized composition design methods and to establish systematic design guidelines for brazing filler metals.This study elucidated the fundamental rules for the composition design of brazing filler metals from a three-dimensional perspective encompassing the basic properties of applied brazing filler metals,formability and processability,and overall cost.The basic properties of brazing filler metals refer to their mechanical properties,physicochemical properties,electromagnetic properties,corrosion resistance,and the wettability and fluidity during brazing.The formability and processability of brazing filler metals include the processes of smelting and casting,extrusion,rolling,drawing and ring-making,as well as the processes of granulation,powder production,and the molding of amorphous and microcrystalline structures.The cost of brazing filler metals corresponds to the sum of materials value and manufacturing cost.Improving the comprehensive properties of brazing filler metals requires a comprehensive and systematic consideration of design indicators.Highlighting the unique characteristics of brazing filler metals should focus on relevant technical indicators.Binary or ternary eutectic structures can effectively enhance the flow spreading ability of brazing filler metals,and solid solution structures contribute to the formability.By employing the proposed design guidelines,typical Ag based,Cu based,Zn based brazing filler metals,and Sn based solders were designed and successfully applied in major scientific and engineering projects.展开更多
Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships w...Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships with antioxidant activity and oxidative stability,gas chromatography-mass spectrometry was performed to characterize the associated fatty acid profiles.The antioxidant activity of vegetable oils,based on their DPPH-scavenging capacity(expressed as IC_(50) values),was used to assess their impact on human health,and their oxidative stability was characterized by performing lipid oxidation analysis to determine the oxidative induction time of fats and oils.In addition,correlation analyses were performed to examine associations between the fatty acid composition of the oils and DPPH-scavenging capacity and oxidative stability.The results revealed that among the assessed oils,coffee seed oil has the highest saturated fatty acid content(355.10 mg/g),whereas Garddenia jaminoides oil has the highest unsaturated fatty acid content(844.84 mg/g).Coffee seed oil was also found have the lowest DPPH IC_(50) value(2.30 mg/mL)and the longest oxidation induction time(17.09 h).Correlation analysis revealed a significant linear relationship(P<0.05)between oxidative stability and unsaturated fatty acid content,with lower contents tending to be associated with better oxidative stability.The findings of this study provide reference data for the screening of functional edible vegetable oils.展开更多
When the dominant species in a plant community are palatable,many believe that large herbivores will reduce the dominant species and promote the proportion of previously suppressed species.However,this view may not al...When the dominant species in a plant community are palatable,many believe that large herbivores will reduce the dominant species and promote the proportion of previously suppressed species.However,this view may not always hold true.We conducted a 4-year yak grazing experiment on the Qinghai-Tibet Plateau and tracked the plant compositions of the rotational grazing(RG)and grazing exclusion(GE)grasslands during the four years.The results showed that in the absence of yaks under GE,the plant community was dominated by two palatable species,Kobresia pygmaea and Stipa capillata,due to their small leaf area and rapid growth strategy.The presence of yaks under RG significantly inhibited S.capillata and over half of the forbs,while the proportion of K.pygmaea increased and it became the absolute dominant species,contradicting the view that large herbivores inhibit palatable species.Interannually,the dominance of K.pygmaea under RG decreased in the dry year,leading to an increase in the dominance of the other eight species.Under GE,the dominance of K.pygmaea declined notably in the dry year,while S.capillata and seven other forbs increased substantially.Overall,these results suggest that K.pygmaea is grazing-tolerant but not drought-tolerant,whereas the other eight species are drought-tolerant but not grazingtolerant.At the community level,community composition shifts resulting from succession after grazing exclusion exceeded those caused by drought,drought tends to induce community species turnover while grazing tends to induce species abundance variations.In summary,our conclusions remind ranch managers that when considering the impact of livestock on plant community composition,they should factor in local conditions and climate change rather than simply assuming that livestock will suppress the palatable species.展开更多
Rice-fish coculture(RFC)has aroused extensive concern for its contribution to food security and resource conservation,but whether it can improve soil phosphorus(P)availability and affect microbe-mediated P turnover re...Rice-fish coculture(RFC)has aroused extensive concern for its contribution to food security and resource conservation,but whether it can improve soil phosphorus(P)availability and affect microbe-mediated P turnover remains elusive.Herein,we conducted a microcosm experiment to assess the impacts of RFC combined with(50 mg P kg^(-1)as KH2PO4)and without inorganic P addition on P fractions,P availability,and phoD-harboring bacterial community composition.The results revealed that RFC without P addition significantly improved P availability and phosphatase activity in paddy soil,while soil available P(AP),pH,and microbial biomass P(MBP)contributed to regulating P fractions.Moreover,the phoD-harboring bacterial abundance was linked to phosphatase activity,AP,total carbon(TC),and total P(TP)contents,and the ratios of TC to total nitrogen(TN)and TN to TP.We also found that the keystone taxa of phoD-harboring bacteria contributed to phosphatase production as well as organic P mineralization,thereby improving P availability.Our findings suggest that RFC without P addition is beneficial for promoting the expression of phoD-harboring bacterial functions to improve the capacity of P mineralization.Overall,our study provides insights into the responses of phoD-harboring bacterial functions for P turnover to RFC combined with and without P addition,showing the potential utilization of P resources in agricultural soil and the contribution of phosphatase activity to P acquisition in agriculture ecosystem.展开更多
Temperate woodland vegetation is initially determined by spatiotemporal and historical factors,mediated by complex biotic interactions.However,catastrophic events such as disease outbreaks(e.g.,sweet chestnut blight,a...Temperate woodland vegetation is initially determined by spatiotemporal and historical factors,mediated by complex biotic interactions.However,catastrophic events such as disease outbreaks(e.g.,sweet chestnut blight,ash dieback),infestations of insect pests,and human-accelerated climate change can create canopy gaps due to systematic decline in,or loss of,tree species that was once an important part of the canopy.Resultant cascade effects have the potential to alter the composition of woodland ecosystems quickly and radically,but inherent lag times make primary research into these effects challenging.Here,we explore change in woodland vegetation at 10 sites in response to canopy opening using the Elm Decline,a rapid loss of Ulmus in woodlands across northwestern Europe~5800 years ago that coexisted alongside other stressors such as increasing human activity,as a palaeoecological analogue.For arboreal taxa,community evenness significantly decreased,within-site turnover significantly increased,and richness remained unchanged.Changes in arboreal taxa were highly site-specific but there was a substantial decline in woody climbing taxa,especially Hedera(ivy),across the majority of sites.For shrub taxa,richness significantly increased but evenness and turnover remained consistent.Interestingly,however,there was a significant increase in abundance of shrubs at 70%of sites,including Calluna(heather),Ilex(holly)and Corylus(hazel),suggesting structural change.Surprisingly,there was no change in richness,evenness or turnover for herb taxa,possibly because change was highly variable spatially.However,there was a marked uptick in the disturbance indicator Plantago(plantain).Overall,these findings suggest that woodlands with sustained reduction in,or loss of,a tree species that once formed an important part of the canopy has profound,but often spatially idiosyncratic,impacts on vegetation diversity(richness),composition(evenness),stability(turnover),and on abundance of specific taxa,especially within the shrub layer.Use of this palaeoecological analogue,which was itself complicated by cooccurring changes in human activity,provides a valuable empirical insight into possible cascade effects of similar change in canopy opening in contemporary settings,including Ash Dieback.展开更多
Background:Climate change is accelerating alterations in forest species and community composition worldwide,especially following extreme events like severe droughts and windstorms.Understanding these effects on subtro...Background:Climate change is accelerating alterations in forest species and community composition worldwide,especially following extreme events like severe droughts and windstorms.Understanding these effects on subtropical forests is crucial for conservation and forest management,but it remains unclear whether the impacts are stochastic or deterministic.Methods:We analyzed a unique dataset from a 1-ha permanent plot in a subtropical monsoon broadleaf evergreen forest in China,monitored over 26 years with six surveys from 1994 to 2020.The forest has been free from anthropogenic disturbances for over 400 years.In each survey,we measured all trees with a diameter at breast height(DBH)≥1 cm,and recorded 11 plant functional traits relating to photosynthesis,wood properties,water use,and nutrient dynamics.Using this data,we calculated species and trait dispersion,assessing short-term(~5years)and long-term(26 years)trends in species and trait composition following severe droughts and windstorm events.Results:Severe droughts,and subsequent droughts,increased both species and trait dispersion,while species composition converged,and trait dispersion remained relatively stable throughout the recovery period.Windstorm events led to increased species dispersion but decreased trait dispersion.We observed a clear directional shift in both species and trait composition under these climatic stressors,with a more pronounced increase in trait dispersion compared to species dispersion.Conclusion:In the short term(~5 years),severe droughts and windstorms increased species composition divergence,while trait composition responses varied.Over 26 years,deterministic processes mainly drove community composition changes,especially for trait composition,although stochastic processes also played a role.These findings suggest enhancing forest resilience to climatic stressors by protecting adaptive species or increasing species diversity in management practices.展开更多
Rice seedling blight,caused by various fungi,including Fusarium oxysporum,poses a severe threat to rice production.As awareness grows regarding the environmental and safety hazards associated with the application of f...Rice seedling blight,caused by various fungi,including Fusarium oxysporum,poses a severe threat to rice production.As awareness grows regarding the environmental and safety hazards associated with the application of fungicides for managing rice seedling blight,there has been a shift in focus towards biological control agents.In this study,we isolated biocontrol bacteria from paddy fields that significantly inhibited the growth of F.oxysporum in vitro and identified the strains as Bacillus amyloliquefaciens T40 and Bacillus pumilus T208.Additionally,our findings indicated that the combined application of these Bacillus strains in soil was more effective in reducing the incidence of rice seedling blight than their individual use.Analysis of 16S and internal transcribed spacer rRNA gene sequencing data revealed that the mixture of the T40 and T208 strains exhibited the lowest average clustering coefficients,which were negatively correlated with the biomass of F.oxysporum-inoculated rice seedlings.Furthermore,this mixture led to higher stochastic assembly(average|βNTI|<2)and reduced selection pressures on rice rhizosphere bacteria compared with individual strain applications.The mixture of the T40 and T208 strains also significantly increased the expression of defense-related genes.In conclusion,the mixture of the T40 and T208 strains effectively modulates microbial community structures,enhances microbial network stability,and boosts the resistance against rice seedling blight.Our study supports the development and utilization of biological resources for crop protection.展开更多
With the increasing complexity of the current electromagnetic environment,excessive microwave radi-ation not only does harm to human health but also forms various electromagnetic interference to so-phisticated electro...With the increasing complexity of the current electromagnetic environment,excessive microwave radi-ation not only does harm to human health but also forms various electromagnetic interference to so-phisticated electronic instruments.Therefore,the design and preparation of electromagnetic absorbing composites represent an efficient approach to mitigate the current hazards of electromagnetic radiation.However,traditional electromagnetic absorbers are difficult to satisfy the demands of actual utilization in the face of new challenges,and emerging absorbents have garnered increasing attention due to their structure and performance-based advantages.In this review,several emerging composites of Mxene-based,biochar-based,chiral,and heat-resisting are discussed in detail,including their synthetic strategy,structural superiority and regulation method,and final optimization of electromagnetic absorption ca-pacity.These insights provide a comprehensive reference for the future development of new-generation electromagnetic-wave absorption composites.Moreover,the potential development directions of these emerging absorbers have been proposed as well.展开更多
The large-scale exploitation of vanadium(Ⅴ) bearing minerals has led to a massive accumulation of Ⅴ tailings, of which Ⅴ pollution poses severe ecological risks. Although the mechanisms of Ⅴ stress to the microbia...The large-scale exploitation of vanadium(Ⅴ) bearing minerals has led to a massive accumulation of Ⅴ tailings, of which Ⅴ pollution poses severe ecological risks. Although the mechanisms of Ⅴ stress to the microbial community have been reported, the influential pathways in a multi-medium-containing system, for example, the soil-tailings-groundwater system,are unknown. The dynamic redox conditions and substance exchange within the system exhibited complex Ⅴ stress on the local microbial communities. In this study, the influence pathways of Ⅴ stress to the microbial community in the soil-tailings-groundwater system were first investigated. High Ⅴ contents were observed in groundwater(139.2 ± 0.15 μg/L) and soil(98.0–323.8 ± 0.02 mg/kg), respectively. Distinct microbial composition was observed for soil and groundwater, where soil showed the highest level of diversity and richness. Firmicutes, Proteobacteria, Actinobacteria, and Acidobacteria were dominant in soil and groundwater with a sum relative abundance of around 80 %. Based on redundancy analysis and structural equation models, Ⅴ was one of the vital driving factors affecting microbial communities. Groundwater microbial communities were influenced by Ⅴ via Cr, dissolved oxygen, and total nitrogen, while Fe, Mn, and total phosphorus were the key mediators for Ⅴ to affect soil microbial communities. Ⅴ affected the microbial community via metabolic pathways related to carbonaceous matter, which was involved in the establishment of survival strategies for metal stress. This study provides novel insights into the influence pathways of Ⅴ on the microorganisms in tailings reservoir for pollution bioremediation.展开更多
基金financially supported by the National Natural Science Foundation of China(42071066)the West Light Foundation of the Chinese Academy of Sciences(2021)+1 种基金the National Key Research and Development Program of China(2023YFF1304304)the Natural Science Foundation of XizangAutonomous Region,China(XZ202201ZR0026G)。
文摘Plant community composition typically undergoes progressive changes along environmental gradients.However,most experimental studies have focused on individual communities,so it remains unclear how exogenous nutrient inputs affect the stability of plant communities along environmental gradients.Along a rainfall gradient on the northern Tibetan Plateau,we conducted an 8-year nitrogen(N)addition experiment in four alpine grasslands:alpine desert steppe(ADS),alpine steppe(AS),alpine meadow steppe(AMS),alpine meadow(AM),and we used twoway ANOVA to examine the effects of N addition on the temporal stability of these different alpine grasslands.We found that community aboveground biomass showed saturation trends in AM and AMS with increasing N gradients,while there was no change in AS and a gradual increase in ADS.The temporal stability showed different patterns of gradual decreases in ADS and AM,and a unimodal trend in AMS with increasing N gradients.However,N addition had no effect on the temporal stability of AS.Dominant species stability was the controlling factor for alpine grasslands along the transect,while the effect of asynchrony gradually increased with decreasing precipitation.These findings highlight that community composition,especially the dominant species,along the environmental gradient can mediate the effects of N inputs on community temporal stability.Thus,the conservation and restoration of the dominant species are particularly important under future scenarios of increased atmospheric N deposition.
基金supported by the Fundamental Research Funds of Chinese Academy of Forestry(Nos.CAFYBB2022SY037,CAFYBB2021ZA002 and CAFYBB2022QC002)the Basic Research Foundation of Yunnan Province(Grant No.202201AT070264).
文摘Soil microbial communities are key factors in maintaining ecosystem multifunctionality(EMF).However,the distribution patterns of bacterial diversity and how the different bacterial taxa and their diversity dimensions affect EMF remain largely unknown.Here,we investigated variation in three measures of diversity(alpha diversity,community composition and network complexity)among rare,intermediate,and abundant taxa across a latitudinal gradient spanning five forest plots in Yunnan Province,China and examined their contributions on EMF.We aimed to characterize the diversity distributions of bacterial groups across latitudes and to assess the differences in the mechanisms underlying their contributions to EMF.We found that multifaceted diversity(i.e.,diversity assessed by the three different metrics)of rare,intermediate,and abundant bacteria generally decreased with increasing latitude.More importantly,we found that rare bacterial taxa tended to be more diverse,but they contributed less to EMF than intermediate or abundant bacteria.Among the three dimensions of diversity we assessed,only community composition significantly affected EMF across all locations,while alpha diversity had a negative effect,and network complexity showed no significant impact.Our study further emphasizes the importance of intermediate and abundant bacterial taxa as well as community composition to EMF and provides a theoretical basis for investigating the mechanisms by which belowground microorganisms drive EMF along a latitudinal gradient.
基金Supported by the National Natural Science Foundation of China(Nos.42076166,42130411)the NSFC Ship Time Sharing Project(No.42149901)+2 种基金the Laoshan Laboratory(Nos.LSKJ202203700(or LSKJ202203704)LSKJ202204005)the National Key R&D Program of China(No.2023YFC3108202)。
文摘The northern East China Sea and Yellow Sea are highly dynamic marginal seas,serving as important fishing grounds and primary areas for aquaculture.The zooplankton community structure,including abundance,biovolume,and normalized biovolume size spectra(NBSS)within this ecosystem in summers 2021 and 2022 was assessed through ZooScan digital imaging system.The abundances of zooplankton in summers 2021 and 2022 were 3364.22±2190.53 and 4435.52±2520.06 inds./m^(3),respectively,whereas the corresponding biovolumes were 649.10±519.63 and 1064.86±1254.87 mm^(3)/m^(3),respectively.Small copepods as the dominant zooplankton functional group in terms of abundance in both years,while chaetognath and medusae were the dominant groups in terms of biovolume.The dominance of medusae and chaetognath in terms of biovolume,along with the flatter slopes of NBSS compared to a stable community,indicated that more energy accumulated in gelatinous organisms within the study area.There were significant positive relationships between temperature and tunicates or medusae,with a significantly higher population size observed in summer 2022 than in 2021.The lower abundance and biovolume of zooplankton,mainly of small copepods,in summer 2021 may be related to the larger population size of the large jellyfish and the proliferation of green tides.The investigation provided basic data and fundamental insights for achieving a comprehensive understanding of zooplankton community structure and their long-term dynamics.
基金supported by the National Natural Science Foundation of China(No.41977283)the Qing Lan Project of Jiangsu Province of China.
文摘Arsenic(As)pollution in coastal wetlands has been receiving growing attention.However,the exact mechanism of As mobility driven by tidal action is still not completely understood.The results reveal that lower total As concentrations in solution were observed in the flood-ebb treatment(FE),with the highest concentration being 7.1μg/L,and As(V)was the predominant species.However,elevated levels of total As in solution were found in the flooded treatment(FL),with a maximum value of 14.5μg/L after 30 days,and As(III)was the predominant form.The results of dissolved organicmatter(DOM)suggest that in the early to mid-stages of the incubation,fulvic acid-like substances might be utilized by microorganisms as electron donors or shuttle bodies,facilitating the reductive release of As/Fe from sediments.Both flood-ebb and flooded treatments promoted the transformation of crystalline iron hydrous oxides-bound As into residual forms.However,prolonged flooded conditions more readily facilitated the formation of specific adsorption forms of As and the reduction of crystalline iron hydrous oxides-bound As,increasing As mobility.In addition,the flood-ebb tides have been found to increase the diversity ofmicrobial populations.The main microbial genera in the flood-ebb treatment included Salinimicrobium,Erythrobacter,Yangia,Sulfitobacter,and Marinobacter.Bacillus,Psychrobacter,and Yangia showed a significant correlation with As(V).In flooded treatment,Bacillus,Pseudomonas,and Geothermobacter played a major role in the reduction and release of As.This study significantly contributes to the current understanding of how As behaves in diverse natural environments.
基金supported by the National Natural Science Foundation of China(32072655 and 32272792)。
文摘Cover cropping is a diversifying agricultural practice that can improve soil structure and function by altering the underground litter diversity and soil microbial communities.Here,we tested how a wheat cover crop alters the decomposition of cucumber root litter.A three-year greenhouse litterbag decomposition experiment showed that a wheat cover crop accelerates the decomposition of cucumber root litter.A microcosm litterbag experiment further showed that wheat litter and the soil microbial community could improve cucumber root litter decomposition.Moreover,the wheat cover crop altered the abundances and diversities of soil bacterial and fungal communities,and enriched several putative keystone operational taxonomic units(OTUs),such as Bacillus sp.OTU1837 and Mortierella sp.OTU1236,that were positively related to the mass loss of cucumber root litter.The representative bacterial and fungal strains B186 and M3 were isolated and cultured.In vitro decomposition tests demonstrated that both B186 and M3 had cucumber root litter decomposition activity and a stronger effect was found when they were co-incubated.Overall,a wheat cover crop accelerated cucumber root litter decomposition by altering the soil microbial communities,particularly by stimulating certain putative keystone taxa,which provides a theoretical basis for using cover crops to promote sustainable agricultural development.
基金supported by the Doctoral Research Initiation Fund Project of Hebei Normal University(No.L2025B19)PhD Fellowship of the State Key Laboratory of Marine Environmental Science at Xiamen University.
文摘Protoporphyrin Ⅸ(PPⅨ), a basic porphyrin system found in nature, all “porphyrin-type”tetrapyrroles with a biological function are biosynthetically derived thereof. PPⅨ is a metalloprosthetic group of numerous proteins involved in diverse metabolic and respiratory processes across all domains of life, and is thus considered essential for respiring organisms. Determining the biotic and abiotic factors that influence marine microbial growth and community structure is critical for understanding global biogeochemical cycles. Here,we present vertical profiles of intracellular PPⅨ and four derivative products(Chlorophylla/b and Pheophytin-a/b) from two coastal sediment cores, alongside ancillary geochemical and 16S rRNA microbial community data. Our findings indicated that PPⅨ is present in the natural sediment environment and displays a decreasing trend with depth, revealing a significant positive correlation with both organic matter and microbial abundance. Cooccurrence networks revealed that the environmental distribution of PPⅨ was positively correlated with the microbial porphyrin producer(high genetic completeness), but negatively correlated with auxotrophs(absence or low genetic completeness). It emphasized the critical role of PPⅨ as a biological molecule involved in key physiological processes. These results suggest that PPⅨ is a prominent component of the shared extracellular metabolite pool, especially in anoxic marine sediments where it exists at physiologically relevant concentrations for microbial metabolism. This study highlighted the significance of PPⅨ in microbial ecology and its potential impact on biogeochemical cycles in marine sedimentary environments.
基金supported by the National Natural Science Foundation of China(Nos.42377296 and 42107141)the National Key Research and Development Program of China(Nos.2023YFD1901402 and 2023YFD1901105)the Fundamental Research Funds for the Central Universities,China(No.YDZX2025046).
文摘Plant growth-promoting rhizobacteria(PGPR)have been widely used for the promotion of plant performance.Predatory protists can influence the taxonomic and functional composition of rhizosphere bacteria.However,research on the impact of the interaction between protist and PGPR on plant performance remains at a very early stage.Here,we examined the impacts of individual inoculation of protist(Colpoda inflata,Dimastigella trypaniformis,or Vermamoeba vermiformis)or the PGPR strain Bacillus velezensis SQR9 as well as the co-inoculation of the protist C.inflata and B.velezensis SQR9 on the growth of tomato plants.We found that all individual protists and Bacillus could promote plant growth compared to the control with no microbe inoculation,with the co-inoculation of C.inflata and B.velezensis SQR9 achieving the greatest performance,including plant height,fresh weight,and dry weight.Different protists harbored distinct rhizosphere bacterial communities,with the co-inoculation of protist and Bacillus resulting in the lowest bacterial diversity and driving significant changes in community structure and composition,particularly by increasing the relative abundance of Proteobacteria.Random forest model highlighted Cellvibrio as the most important bacterial predictor of plant growth,which was enriched after protist inoculation,especially after the mixed inoculation of protist and Bacillus.We further found that bacterial functional genes of nitrogen metabolism were the key determinants of plant growth.These results indicate that the interaction between protists and Bacillus can support plant growth by reshaping rhizosphere bacterial community composition and function.Understanding the interaction mechanisms between protist and PGPR is crucial for their effective utilization in sustainable agriculture.
基金supported by the National Natural Science Foundation of China(U22A20501)the National Key Research and Development Plan of China(2022YFD1500601)+4 种基金the National Science and Technology Fundamental Resources Investigation Program of China(2018FY100304)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA28090200)the Liaoning Province Applied Basic Research Plan Program,China(2022JH2/101300184)the Shenyang Science and Technology Plan Program,China(21-109-305)the Liaoning Outstanding Innovation Team,China(XLYC2008015)。
文摘Land use influences soil biota community composition and diversity,and then belowground ecosystem processes and functions.To characterize the effect of land use on soil biota,soil nematode communities in crop land,forest land and fallow land were investigated in six regions of northern China.Generic richness,diversity,abundance and biomass of soil nematodes was the lowest in crop land.The richness and diversity of soil nematodes were 28.8and 15.1%higher in fallow land than in crop land,respectively.No significant differences in soil nematode indices were found between forest land and fallow land,but their network keystone genera composition was different.Among the keystone genera,50%of forest land genera were omnivores-predators and 36%of fallow land genera were bacterivores.The proportion of fungivores in forest land was 20.8%lower than in fallow land.The network complexity and the stability were lower in crop land than forest land and fallow land.Soil pH,NH_(4)^(+)-N and NO_(3)^(–)-N were the major factors influencing the soil nematode community in crop land while soil organic carbon and moisture were the major factors in forest land.Soil nematode communities in crop land influenced by artificial management practices were more dependent on the soil environment than communities in forest land and fallow land.Land use induced soil environment variation and altered network relationships by influencing trophic group proportions among keystone nematode genera.
基金National Natural Science Foundation of China:Changes of Ras Homolog Gene Family Member A/Rho-associated Coiled-coil Kinase Signaling Pathway in Liver-Stomach Disharmony Functional Dyspepsia Rats and Intervention Mechanism of Simo Tang (No. 81803896)the Role of Gut Microbiota-diaminopimelic Acid Nucleotide-binding and Oligomerization Domain1-receptorinteracting Protein 2 Signal Pathway in Severe Process of Acute Pancreatitis and the Intervention Mechanism of Qingxia Therapy (No. 81873156)Research Project of Liaoning Provincial Department of Education:the Role of Mitochondria-Derived Reactive Oxygen Species Mediated Autophagy Activation in Myocardial Injury in Sepsis (No. LZ2020036)。
文摘OBJECTIVE: To investigate composition of gut microbial community in a rat model of functional dyspepsia(FD) and to explore the interventional effects of Simo Tang(四磨汤, SMT). METHODS: A rat model of FD was established through the tail-clamping stimulation method. The rat model of FD was assessed by the state of rats, their weight, sucrose preference rate, and intestinal propulsion rate. The DNA was extracted from stool samples after treatment with SMT. Amplified polymerase chain reaction(PCR) products of the 16S r DNA were sequenced using Novase Q6000 after construction of libraries. Composition of gut microbial community in the stool samples was determined and analyzed by cluster analysis, bioinformatic analysis, and analysis of α-diversity and β-diversity.RESULTS: The rat model of FD was successfully established using the tail-clamping stimulation method. The statistical results of cluster analysis of operational taxonomic units(OTUs) showed that the relative abundance of OTUs in the FD group was the lowest, while it was the highest in the normal(N) group. The composition of microbiome in the four groups was similar at phyla level. Compared with the FD group, the abundance of Firmicutes was downregulated, and the abundance of Proteobacteria and Bacteroidetes was upregulated in the Simo Tang(SMT) and high-dose Simo Tang(SMT.G) groups. The ratio of Bacteroidetes/Firmicutes was also elevated. According to the analysis of α-diversity and β-diversity, the abundance of flora in FD rats was significantly reduced. The treatment using SMT appeared beneficial to improve the diversity of flora. SMT could improve the intestinal flora in FD rats. The results showed that FD rats had intestinal flora imbalance, and species diversity increased. The results suggested that SMT could regulate the disorders of intestinal flora caused by FD. CONCLUDIONS: SMT could restore gut homeostasis and maintain gut flora diversity by modulating the gut microbiota and its associated metabolites in rats, thereby treating gastrointestinal diseases.
基金supported by the Major Program of National Natural Science Foundation of China (No. 52193268013)。
文摘Anaerobic digestion (AD) with thermal hydrolysis (TH) pretreatment is a promising process for excess sludge treatment,while there lacks of the knowledge from full-scale process about the impact of sludge composition and characteristics on microbial community and performance.The sludge physiochemical indices,microbial community and performance data of four full-scale TH-AD plants were characterized,and their relationships was elucidated.The four plants were operated under almost similar total organic loading rate (OLR)but their methanogenesis performance differentiate into two groups,namely superior group(SupG) and the inferior group (Inf G).In both groups,TH effectively solubilized particulate organic compounds,meanwhile raised the ammonia nitrogen (NH_(4)^(+)-N) and volatile fatty acid (VFA) concentration.Compared with the Sup G,thermal hydrolyzed sludge of Inf G had higher level of VFAs,NH_(4)^(+)-N and total chemical oxygen demand (t COD),which showed higher inhibition effect on microbes,leading to a community with lower diversity,lower abundance of carbohydrate degrading functional guild,higher protein degrading one,and methanogens that adapted to limited substrates,and further declined the methane production rate.Thus,it was recommended that OLR alone was not sufficient for controlling the system in design and operation,the concentration of VFAs,NH_(4)^(+)-N and t COD should be equally considered.Their higher concentration,together with the higher abundance of Defluviitoga and Proteiniphilum were recommended as indicators for inferior running condition.Our results proposed that microbial communities played a role of bridge between environmental factors and performance,provided implications for engineering ecology and operational regulation for full-scale sludge TH-AD process.
基金National Natural Science Foundation of China(U22A20191)。
文摘Brazing filler metals are widely applied,which serve as an industrial adhesive in the joining of dissimilar structures.With the continuous emergence of new structures and materials,the demand for novel brazing filler metals is ever-increasing.It is of great significance to investigate the optimized composition design methods and to establish systematic design guidelines for brazing filler metals.This study elucidated the fundamental rules for the composition design of brazing filler metals from a three-dimensional perspective encompassing the basic properties of applied brazing filler metals,formability and processability,and overall cost.The basic properties of brazing filler metals refer to their mechanical properties,physicochemical properties,electromagnetic properties,corrosion resistance,and the wettability and fluidity during brazing.The formability and processability of brazing filler metals include the processes of smelting and casting,extrusion,rolling,drawing and ring-making,as well as the processes of granulation,powder production,and the molding of amorphous and microcrystalline structures.The cost of brazing filler metals corresponds to the sum of materials value and manufacturing cost.Improving the comprehensive properties of brazing filler metals requires a comprehensive and systematic consideration of design indicators.Highlighting the unique characteristics of brazing filler metals should focus on relevant technical indicators.Binary or ternary eutectic structures can effectively enhance the flow spreading ability of brazing filler metals,and solid solution structures contribute to the formability.By employing the proposed design guidelines,typical Ag based,Cu based,Zn based brazing filler metals,and Sn based solders were designed and successfully applied in major scientific and engineering projects.
文摘Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships with antioxidant activity and oxidative stability,gas chromatography-mass spectrometry was performed to characterize the associated fatty acid profiles.The antioxidant activity of vegetable oils,based on their DPPH-scavenging capacity(expressed as IC_(50) values),was used to assess their impact on human health,and their oxidative stability was characterized by performing lipid oxidation analysis to determine the oxidative induction time of fats and oils.In addition,correlation analyses were performed to examine associations between the fatty acid composition of the oils and DPPH-scavenging capacity and oxidative stability.The results revealed that among the assessed oils,coffee seed oil has the highest saturated fatty acid content(355.10 mg/g),whereas Garddenia jaminoides oil has the highest unsaturated fatty acid content(844.84 mg/g).Coffee seed oil was also found have the lowest DPPH IC_(50) value(2.30 mg/mL)and the longest oxidation induction time(17.09 h).Correlation analysis revealed a significant linear relationship(P<0.05)between oxidative stability and unsaturated fatty acid content,with lower contents tending to be associated with better oxidative stability.The findings of this study provide reference data for the screening of functional edible vegetable oils.
基金financially supported by grants from the National Natural Science Foundation of China(32101315 and 32101326)the National Key R&D Program of China(2021YFE0112400)+2 种基金the Second Tibetan Plateau Scientific Expedition and Research Program,China(2019QZKK0307)the HighLevel Talent Research Start-Up Project of Chongqing Technology and Business University,China(950319097)the Scientific and Technological Research Program of Chongqing Municipal Education Commission,China(KJQN202100827)。
文摘When the dominant species in a plant community are palatable,many believe that large herbivores will reduce the dominant species and promote the proportion of previously suppressed species.However,this view may not always hold true.We conducted a 4-year yak grazing experiment on the Qinghai-Tibet Plateau and tracked the plant compositions of the rotational grazing(RG)and grazing exclusion(GE)grasslands during the four years.The results showed that in the absence of yaks under GE,the plant community was dominated by two palatable species,Kobresia pygmaea and Stipa capillata,due to their small leaf area and rapid growth strategy.The presence of yaks under RG significantly inhibited S.capillata and over half of the forbs,while the proportion of K.pygmaea increased and it became the absolute dominant species,contradicting the view that large herbivores inhibit palatable species.Interannually,the dominance of K.pygmaea under RG decreased in the dry year,leading to an increase in the dominance of the other eight species.Under GE,the dominance of K.pygmaea declined notably in the dry year,while S.capillata and seven other forbs increased substantially.Overall,these results suggest that K.pygmaea is grazing-tolerant but not drought-tolerant,whereas the other eight species are drought-tolerant but not grazingtolerant.At the community level,community composition shifts resulting from succession after grazing exclusion exceeded those caused by drought,drought tends to induce community species turnover while grazing tends to induce species abundance variations.In summary,our conclusions remind ranch managers that when considering the impact of livestock on plant community composition,they should factor in local conditions and climate change rather than simply assuming that livestock will suppress the palatable species.
基金supported by the Key-Area Research and Development Program of Guangdong Province,China(No.2021B0202030002)the Science and Technology Planning Project of Guangdong Province,China(No.2019B030301007)+2 种基金the Guangdong Provincial Special Project of Rural Revitalization Strategy,China(No.(2021)12)the Joint Team Project of Guangdong Laboratory for Lingnan Modern Agriculture,China(No.NT2021010)the Innovation Team Construction Project of Modern Agricultural Industry Technology Systems of Guangdong Province,China(No.2022KJ105).
文摘Rice-fish coculture(RFC)has aroused extensive concern for its contribution to food security and resource conservation,but whether it can improve soil phosphorus(P)availability and affect microbe-mediated P turnover remains elusive.Herein,we conducted a microcosm experiment to assess the impacts of RFC combined with(50 mg P kg^(-1)as KH2PO4)and without inorganic P addition on P fractions,P availability,and phoD-harboring bacterial community composition.The results revealed that RFC without P addition significantly improved P availability and phosphatase activity in paddy soil,while soil available P(AP),pH,and microbial biomass P(MBP)contributed to regulating P fractions.Moreover,the phoD-harboring bacterial abundance was linked to phosphatase activity,AP,total carbon(TC),and total P(TP)contents,and the ratios of TC to total nitrogen(TN)and TN to TP.We also found that the keystone taxa of phoD-harboring bacteria contributed to phosphatase production as well as organic P mineralization,thereby improving P availability.Our findings suggest that RFC without P addition is beneficial for promoting the expression of phoD-harboring bacterial functions to improve the capacity of P mineralization.Overall,our study provides insights into the responses of phoD-harboring bacterial functions for P turnover to RFC combined with and without P addition,showing the potential utilization of P resources in agricultural soil and the contribution of phosphatase activity to P acquisition in agriculture ecosystem.
文摘Temperate woodland vegetation is initially determined by spatiotemporal and historical factors,mediated by complex biotic interactions.However,catastrophic events such as disease outbreaks(e.g.,sweet chestnut blight,ash dieback),infestations of insect pests,and human-accelerated climate change can create canopy gaps due to systematic decline in,or loss of,tree species that was once an important part of the canopy.Resultant cascade effects have the potential to alter the composition of woodland ecosystems quickly and radically,but inherent lag times make primary research into these effects challenging.Here,we explore change in woodland vegetation at 10 sites in response to canopy opening using the Elm Decline,a rapid loss of Ulmus in woodlands across northwestern Europe~5800 years ago that coexisted alongside other stressors such as increasing human activity,as a palaeoecological analogue.For arboreal taxa,community evenness significantly decreased,within-site turnover significantly increased,and richness remained unchanged.Changes in arboreal taxa were highly site-specific but there was a substantial decline in woody climbing taxa,especially Hedera(ivy),across the majority of sites.For shrub taxa,richness significantly increased but evenness and turnover remained consistent.Interestingly,however,there was a significant increase in abundance of shrubs at 70%of sites,including Calluna(heather),Ilex(holly)and Corylus(hazel),suggesting structural change.Surprisingly,there was no change in richness,evenness or turnover for herb taxa,possibly because change was highly variable spatially.However,there was a marked uptick in the disturbance indicator Plantago(plantain).Overall,these findings suggest that woodlands with sustained reduction in,or loss of,a tree species that once formed an important part of the canopy has profound,but often spatially idiosyncratic,impacts on vegetation diversity(richness),composition(evenness),stability(turnover),and on abundance of specific taxa,especially within the shrub layer.Use of this palaeoecological analogue,which was itself complicated by cooccurring changes in human activity,provides a valuable empirical insight into possible cascade effects of similar change in canopy opening in contemporary settings,including Ash Dieback.
基金supported by National Natural Science Foundation of China(Nos.42130506,42071031)the Special Technology Innovation Fund of Carbon Peak and Carbon Neutrality in Jiangsu Province(No.BK20231515)。
文摘Background:Climate change is accelerating alterations in forest species and community composition worldwide,especially following extreme events like severe droughts and windstorms.Understanding these effects on subtropical forests is crucial for conservation and forest management,but it remains unclear whether the impacts are stochastic or deterministic.Methods:We analyzed a unique dataset from a 1-ha permanent plot in a subtropical monsoon broadleaf evergreen forest in China,monitored over 26 years with six surveys from 1994 to 2020.The forest has been free from anthropogenic disturbances for over 400 years.In each survey,we measured all trees with a diameter at breast height(DBH)≥1 cm,and recorded 11 plant functional traits relating to photosynthesis,wood properties,water use,and nutrient dynamics.Using this data,we calculated species and trait dispersion,assessing short-term(~5years)and long-term(26 years)trends in species and trait composition following severe droughts and windstorm events.Results:Severe droughts,and subsequent droughts,increased both species and trait dispersion,while species composition converged,and trait dispersion remained relatively stable throughout the recovery period.Windstorm events led to increased species dispersion but decreased trait dispersion.We observed a clear directional shift in both species and trait composition under these climatic stressors,with a more pronounced increase in trait dispersion compared to species dispersion.Conclusion:In the short term(~5 years),severe droughts and windstorms increased species composition divergence,while trait composition responses varied.Over 26 years,deterministic processes mainly drove community composition changes,especially for trait composition,although stochastic processes also played a role.These findings suggest enhancing forest resilience to climatic stressors by protecting adaptive species or increasing species diversity in management practices.
基金supported by the Zhejiang Provincial Natural Science Foundation,China(Grant No.LQ24C010007)Zhejiang Science and Technology Major Program on Rice New Variety Breeding,China(Grant No.2021C02063)+4 种基金the Agricultural Sciences and Technologies Innovation Program,China(Grant No.CAAS-CSCB-202301)the Key Projects of Zhejiang Provincial Natural Science Foundation,China(Grant No.LZ23C130002)the Youth Innovation Program of Chinese Academy of Agricultural Sciences(Grant No.Y2023QC22)the Joint Open Competitive Project of the Yazhou Bay Seed Laboratory and China National Seed Company Limited(Grant Nos.B23YQ1514 and B23CQ15EP)the External Cooperation Projects of Biotechnology Research Institute,Fujian Academy of Agricultural Sciences,China(Grant No.DWHZ2024-07).
文摘Rice seedling blight,caused by various fungi,including Fusarium oxysporum,poses a severe threat to rice production.As awareness grows regarding the environmental and safety hazards associated with the application of fungicides for managing rice seedling blight,there has been a shift in focus towards biological control agents.In this study,we isolated biocontrol bacteria from paddy fields that significantly inhibited the growth of F.oxysporum in vitro and identified the strains as Bacillus amyloliquefaciens T40 and Bacillus pumilus T208.Additionally,our findings indicated that the combined application of these Bacillus strains in soil was more effective in reducing the incidence of rice seedling blight than their individual use.Analysis of 16S and internal transcribed spacer rRNA gene sequencing data revealed that the mixture of the T40 and T208 strains exhibited the lowest average clustering coefficients,which were negatively correlated with the biomass of F.oxysporum-inoculated rice seedlings.Furthermore,this mixture led to higher stochastic assembly(average|βNTI|<2)and reduced selection pressures on rice rhizosphere bacteria compared with individual strain applications.The mixture of the T40 and T208 strains also significantly increased the expression of defense-related genes.In conclusion,the mixture of the T40 and T208 strains effectively modulates microbial community structures,enhances microbial network stability,and boosts the resistance against rice seedling blight.Our study supports the development and utilization of biological resources for crop protection.
基金supported by the Surface Project of Local De-velopment in Science and Technology Guided by Central Govern-ment(No.2021ZYD0041)the National Natural Science Founda-tion of China(Nos.52377026 and 52301192)+3 种基金the Natural Science Foundation of Shandong Province(No.ZR2019YQ24)the Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)the Special Financial of Shandong Province(Struc-tural Design of High-efficiency Electromagnetic Wave-absorbing Composite Materials and Construction of Shandong Provincial Tal-ent Teams)the“Sanqin Scholars”Innovation Teams Project of Shaanxi Province(Clean Energy Materials and High-Performance Devices Innovation Team of Shaanxi Dongling Smelting Co.,Ltd.).
文摘With the increasing complexity of the current electromagnetic environment,excessive microwave radi-ation not only does harm to human health but also forms various electromagnetic interference to so-phisticated electronic instruments.Therefore,the design and preparation of electromagnetic absorbing composites represent an efficient approach to mitigate the current hazards of electromagnetic radiation.However,traditional electromagnetic absorbers are difficult to satisfy the demands of actual utilization in the face of new challenges,and emerging absorbents have garnered increasing attention due to their structure and performance-based advantages.In this review,several emerging composites of Mxene-based,biochar-based,chiral,and heat-resisting are discussed in detail,including their synthetic strategy,structural superiority and regulation method,and final optimization of electromagnetic absorption ca-pacity.These insights provide a comprehensive reference for the future development of new-generation electromagnetic-wave absorption composites.Moreover,the potential development directions of these emerging absorbers have been proposed as well.
基金supported by the National Natural Science Foundation of China(No.42377415)the Natural Science Foundation of Sichuan Province(No.2023NSFSC0811),Sichuan Science and Technology Program(Nos.2021JDTD0013 and 2021YFQ0066)+1 种基金the Science and Technology Major Project of Xizhang Autonomous Region of China(No.XZ202201ZD0004G06)the Everest Scientific Research Program(No.80000-2023ZF11405).
文摘The large-scale exploitation of vanadium(Ⅴ) bearing minerals has led to a massive accumulation of Ⅴ tailings, of which Ⅴ pollution poses severe ecological risks. Although the mechanisms of Ⅴ stress to the microbial community have been reported, the influential pathways in a multi-medium-containing system, for example, the soil-tailings-groundwater system,are unknown. The dynamic redox conditions and substance exchange within the system exhibited complex Ⅴ stress on the local microbial communities. In this study, the influence pathways of Ⅴ stress to the microbial community in the soil-tailings-groundwater system were first investigated. High Ⅴ contents were observed in groundwater(139.2 ± 0.15 μg/L) and soil(98.0–323.8 ± 0.02 mg/kg), respectively. Distinct microbial composition was observed for soil and groundwater, where soil showed the highest level of diversity and richness. Firmicutes, Proteobacteria, Actinobacteria, and Acidobacteria were dominant in soil and groundwater with a sum relative abundance of around 80 %. Based on redundancy analysis and structural equation models, Ⅴ was one of the vital driving factors affecting microbial communities. Groundwater microbial communities were influenced by Ⅴ via Cr, dissolved oxygen, and total nitrogen, while Fe, Mn, and total phosphorus were the key mediators for Ⅴ to affect soil microbial communities. Ⅴ affected the microbial community via metabolic pathways related to carbonaceous matter, which was involved in the establishment of survival strategies for metal stress. This study provides novel insights into the influence pathways of Ⅴ on the microorganisms in tailings reservoir for pollution bioremediation.
