Amina HadayatZahir Ahmad ZahirPeng CaiChun-Hui Gao...
125-136页
查看更多>>摘要：·Herbicide-based weeds control impacts wheat crops as well.·SynComs of Pseudomonas strains reduce the need for high-dose herbicides.·100％Axial provides less weed control compared to 75％Axial with C4 SynCom.·Axial 75％with C4 SynCom promotes wheat growth than the 75％Axial alone.To address environmental concerns and manage resistant weeds,there is a growing demand for eco-friendly altema-tives.In this study,we propose the integration of synthetic communities(SynComs)to reduce herbicide consumption.Four SynComs,consisting of bacteria isolated from weed or wheat rhizospheres,were first evaluated under greenhouse conditions.All SynComs enhanced wheat growth,which was manifested by increased Soil Plant Analysis Development(SPAD)values and fresh biomass.At the same time,SynCom C4 effectively reduced SPAD values and fresh biomass of the infesting weed,Phalaris minor,when combined with low-dose Axial herbicide.A field trial was then conducted using the C4 SynCom and various doses of Axial(100％,75％,50％,and 25％).Remarkably,the combination of C4 with 50％and 75％Axial significantly improved wheat growth by mitigating the side effects of herbicide on wheat.Weed infestation reduced grain yield by 16％and 25％at the dose of 50％and 75％Axial,respectively.The combination of Axial with C4 rescued up to 22％of grain yield loss under infested weed compared with Axial alone.Our findings suggested that the combination of herbicides with SynComs exhibited synergistic effects for controlling Phalaris minor and promoting wheat growth,so that such combination provides a sustainable and eco-friendly weed control strategy.
查看更多>>摘要：·ARB was investigated in different soil types following manure application.·CTC-manure induced more resistance of soil indigenous microbes in fluvo-aquic soil.·Lactobacillus,Dyella,Ralstonia,and Bacillus were the key different genera.·Manure control is an effective way to reduce the risk of soil ARB.Swine manure,commonly applied as organic compost in agricultural fields,is an important reservoir of antibiotic-resistant bacteria(ARB).Previous work indicated that manure application led to more antibiotic resistance genes in red soil compared with black soil and fluvo-aquic soil.Accordingly,the influencing mechanisms of soil types on the distribution of ARB was worthy of further exploration by a soil column experiment.The results showed that a higher shift in the operational taxonomic units and the community composition of chlortetracycline(CTC)-resistant bacteria(CRB)were observed in fluvo-aquic soil than in black and red soils.CTC induced antibiotic resistance development in soil indigenous microorganisms(Streptomyces,Pseudomonas,Bacillus,Rhodococcus,and Paenibacillus),and the induction was most obvious in fluvo-aquic soil.Streptomyces was significantly positively correlated with pH and organic matter.Additionally,LEfSe analysis indicated that the key different genera were Microbacteriaceae(black soil),Lactobacillus,unclassified c_Bacilli and Paenibacillus(fluvo-aquic soil),and Dyella,Ralstonia and Bacillus(red soil).It was concluded that manure application led to higher CRB risk in fluvo-aquic soil compared with black and red soils.Overall,appropriate methods according to soil types are important ways to reduce the risk of soil resistant bacteria during manure return.
查看更多>>摘要：·Changes in soil properties and microbial communities regulated rhizosphere protistan assemblages.·Bacterial community was more sensitive to soil amendments than protists and fungi.·Soil amendments trigger the role of specific protistan taxa Cercozoa on microbial interactions.Understanding the responses of different rhizosphere microbial lineages to soil amendments during in situ remediation of Cd-contaminated soil is of great impor-tance in the assessment of the restoration and crop health.Here,we evaluated the effects of lime(LM),biochar(BC),pig manure(PM),and a commercial Mg-Ca-Si conditioner(CMC)on the rice rhizosphere soil physicochemical properties and community assembly of bacteria,fungi,and protists in a six-year consecutive application of soil amendments field trial.Our results indicated that among the four amendments,the BC and CMC had the best efficiency in increasing soil pH,which were 5.2％and 16.2％,respectively.Despite the differ-ences in soil Cd concentrations is not noticeable,all the soil amendment treatments significantly decreased the proportion of available Cd in total Cd compared to the control.Soil amendments significantly altered the diversity of bacterial community,while they had no effect on fungal and protistan communities.Linear discriminant analysis effect size(LEfSe)showed that the bacteria was more sensitive to soil amendment-induced changes.For protists,treatments with LM and BC changed the groups of protistan consumers,while treatments with PM and CMC significantly increased the relative abundances of protistan phototrophs.Co-occurrence network analysis revealed that soil amendments increased microbial network complexity and triggered the role of protists,especially for the predatory protists Cercozoa,on microbial trophic interactions.Further vari-ation partitioning analysis revealed that edaphic properties,bacterial and fungal communities compositions together explained the 77％of the total variation in protistan community,and the stronger correlations between diversity of bacterial and protistan communities suggested that the bacteria community was a more important biotic driver of the protistan community.Overall,our findings demonstrate the distinct responses of rice rhizosphere microbial communities to soil amendment applications,highlighting the interactive associations between microbiomes,which is vital for enhancing our ability to develop effective strategies for sustainable soil management.This study enhances our understanding of the ecological roles of protists under soil amendment applications and highlights their potential contributions in bioremediation and environmental applications for Cd-contaminated soil.
查看更多>>摘要：·Soil abundant taxa diversity positively related to multifunctionality under Hg stress.·Microbial network complexity of soil abundant taxa supported the strength of SBF.·Stochastic assembly of soil abundant subcommunity supported the strength of SBF.·Stochastic ratio was the most important predictor for the strength of SBF.It is known that soil microbial communities are intricately linked to multiple ecosystem functions and can maintain the relationship between soil biodiversity and multifunctionality(SBF)under environmental stresses.However,the relative contributions and driving forces of abundant and rare taxa within the communities in maintaining soil biodiversity-multifunctionality rela-tionship under pollution stresses are still unclear.Here,we conducted microcosm experiments to estimate the importance of soil abundant and rare taxa in predicting these relationships under heavy metal mercury(Hg)stress in paired paddy and upland fields.The results revealed that the diversity of abundant taxa,rather than rare taxa,was positively related to multifunctionality,with the abundant subcommunity tending to maintain a larger proportion of soil functions including chitin degradation,protein degradation,and phosphorus mineralization.Soil multitrophic network complexity consisting of abundant species showed positive correlations with biodiversity and multifunctionality,and supported the strength of SBF within a network complexity range.Stochastic assembly processes of the abundant subcommunity were positively correlated with the strength of SBF,although stochastic processes decreased the biodiversity and the multifunctionality,respectively.After simultaneously accounting for multiple factors on the strength of SBF,we found that the stochastic community assembly ratio of abundant taxa was the most important predictor for SBF strength under Hg stress.Our results highlight the importance of abundant taxa in supporting soil multifunctionality,and elucidate the linkages between community assembly,network complexity and SBF relationship under environmental stresses.
查看更多>>摘要：·Rice planting decreased total iron but increased active iron.·Iron activation varied greatly among different paddy soils but not in woodland soils.·Paddy soil iron was mainly affected by pH,SOC and particle composition.·The decrease of soil Fe was mainly in the form of Fec and was closely related to SOC.Human activities have intensified the activity and morphological transformation of iron in soils,but there is a lack of quantitative assessment of the loss or of the transformation pattern.By studying Fe-rich rice soils in southern China and comparing them with corresponding woodland soils,it was found that rice planting reduced the total iron(Fet)content,mainly of crystalline iron(Fec),along soil profiles(0-100 cm)while increasing the content of active iron(Feo).The activation degree of Feo(Feo％)varied significantly among different parent materials in paddy soils but showed less variation in woodland soils.Regression analysis revealed significant correlations between both the content of Fec and the content of Feo in paddy soils with soil organic carbon(SOC)and particle composition(p＜0.05).The Feo％was primarily influenced by pH,SOC,and particle composition.The iron loss in paddy soil was mainly Fec and was closely related to SOC,whereas the transformation of active iron(Feo)was influenced by a combination of soil factors and environmental conditions.The results demonstrate that human activities accelerate the loss and activation of active iron in the soil,thereby altering the iron cycling process in rice paddy ecosystems.
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