Acorus tatarinowii Schott is a traditional Chinese medicine plant and has multiple bioactivities in medicine and pesticide field.In this study,the antifungal compound 1,2-dimethoxy-4(2-propenyl)benzene was isolated fr...Acorus tatarinowii Schott is a traditional Chinese medicine plant and has multiple bioactivities in medicine and pesticide field.In this study,the antifungal compound 1,2-dimethoxy-4(2-propenyl)benzene was isolated from A.tatarinowii Schott by activity-directed isolation method,and the inhibitory activity of the extract and 1,2-dimethoxy-4(2-propenyl)benzene against seven plant pathogenic fungi was evaluated.The results showed that the extract and 1,2-dimethoxy-4(2-propenyl)benzene had high inhibitory activity against hyphal growth of Thielaviopsis paradoxa(de Seynes)V.Hohnel,Pestalotia mangiferae P.Henn.,Fusarium oxysporum f.sp.niveum(E.F.Smith)Syn.et Hans.,Alternaria alternate Tanaka,Colletotrichum musae(Berk et Curt)V.Arx,Sphaceloma fawcettii Jenk.,and Mycosphaerella sentina(Fr.)Schroter.The EC50 values of extract were 1.6162,1.6811,1.1253,3.5771,1.7024,2.2284,and 2.2221 g L^-1,respectively,and the EC50 values of 1,2-dimethoxy-4(2-propenyl)benzene were 0.1021,0.0997,0.0805,0.1742,0.1503,0.1853,and 0.1924 g L^-1,respectively.1,2-Dimethoxy-4(2-propenyl)benzene also inhibited spores germination of T.paradoxa(de Seynes)V.Hohnel and F.oxysporum f.sp.niveum(E.F.Smith)Syn.et Hans.,with the inhibitory rates of 98.81 and 100%at a concentration of 0.4 g L^-1 after 8 h,respectively.1,2-Dimethoxy-4(2-propenyl)benzene is a potential botanical antifungal agent for controling of plant fungal diseases.展开更多
Phenazines are secondary metabolites with broad spectrum antibiotic activity and thus show high potential in biological control of pathogens. In this study, we identified phenazine biosynthesis （phz） genes in two ge...Phenazines are secondary metabolites with broad spectrum antibiotic activity and thus show high potential in biological control of pathogens. In this study, we identified phenazine biosynthesis （phz） genes in two genome-completed plant pathogenic bacteria Pseudomonas syringae pv. tomato （Pst） DC3000 and Xanthomonas oryzae pv. oryzae （Xoo） PXO99A. Unlike the phz genes in typical phenazine-producing pseudomonads, phz homologs in Pst DC3000 and Xoo PXO99A consisted of phzC/D/E/F/G and phzC/E1/E2/F/G, respectively, and the both were not organized into an operon. Detection experiments demonstrated that phenazine-l-carboxylic acid （PCA） of Pst DC3000 accumulated to 13.4 IJg L-1, while that of Xoo PXO99A was almost undetectable. Moreover, Pst DC3000 was resistant to 1 mg mL-1 PCA, while Xoo PXO99A was sensitive to 50 IJg mL ~ PCA. Furthermore, mutation of phzF blocked the PCA production and significantly reduced the pathogenicity of Pst DC3000 in tomato, while the complementary strains restored these phenotypes. These results revealed that Pst DC3000 produces low level of and is resistant to phenazines and thus is unable to be biologically controlled by phenazines. Additionally, phz-mediated PCA production is required for full pathogenicity of Pst DC3000. To our knowledge, this is the first report of PCA production and its function in pathogenicity of a plant pathogenic P. syringae strain.展开更多
Since the 19th century to date,the fungal pathogens have been involved in causing devastating diseases in plants.All types of fungal pathogens have been observed in important agricultural crops that lead to significan...Since the 19th century to date,the fungal pathogens have been involved in causing devastating diseases in plants.All types of fungal pathogens have been observed in important agricultural crops that lead to significant pre and postharvest losses.The application of synthetic fungicide against the fungal plant pathogens(FPP)is a traditional management practice but at the same time these fungicides kill other beneficial microbes,insects,animal,and humans and are harmful to environment.The antagonistic microorganism such as bacteria are being used as an alternate strategy to control the FPP.These antagonistic species are cost-effective and eco-friendly in nature.These biocontrol bacteria have a broad mechanism against fungal pathogens present in the phyllosphere and rhizosphere of the plant.The antagonistic bacteria have different strategies against the FPP,by producing siderophore,biofilm,volatile organic compounds(VOCs),through parasitism,antibiosis,competition for limited resources and induce systemic resistance(ISR)in the host plant by activating the immune systems.The commercial bio-products synthesized by the major bacterial species Pseudomonas syringae,Burkholderia cepacia,Streptomyces griseoviridis,Pseudomonas fluorescens and Bacillus subtilis are used to control Fusarium,Pythium,Rhizoctonia,Penicillium,Alternaria,and Geotrichum.The commercial bio-formulations of bacteria act as both antifungal and plant growth regulators.The Plant growth-promoting rhizobacteria(PGPR)played a significant role in improving plant health by nitrogen-fixing,phosphorus solubilization,phytohormones production,minimizing soil metal contamination,and by ACC deaminase antifungal activities.Different articles are available on the specific antifungal activity of bacteria in plant diseases.Therefore,this review article has summarized the information on biocontrol activity of bacteria against the FPP and the role of PGPR in plant growth promotion.This review also provided a complete picture of scattered information regarding antifungal activities of bacteria and the role of PGPR.展开更多
Fungicides are an indispensable tool in plant disease control.Various modes of action(MOAs)have been identified in different fungicides to suppress plant pathogens.The combined use of fungicides with distinct MOAs has...Fungicides are an indispensable tool in plant disease control.Various modes of action(MOAs)have been identified in different fungicides to suppress plant pathogens.The combined use of fungicides with distinct MOAs has been recommended to prevent the development of pathogen resistance.In studying MOAs,metabolomics has been proven to be a robust and high-throughput method.Because metabolites are unique and distinct depending on the biological activities of an organism,MOAs can be identified and classified by establishing metabolic fingerprinting and metabolic profiles.Similarly,if fungicide resistance is developed in a pathogen,the metabolome will change,which can be identified.In this review,we have discussed the principles and advanced applications of metabolomics in the study of MOAs and resistance mechanisms of fungicides,and the potential of metabolic data in understanding the interaction between fungicides and pathogens.Challenges are also discussed in the application of metabolomics,improvement of the study on the mechanism of fungicides in their functions against pathogens and advancing the development of novel fungicides.展开更多
Crude plant extracts of ringworm cassia, Cassia alata L. and turmeric, Curcuma longa L. were prepared by either hot water or organic solvents such as ethanol and ether. Various concentrations of the crude extract were...Crude plant extracts of ringworm cassia, Cassia alata L. and turmeric, Curcuma longa L. were prepared by either hot water or organic solvents such as ethanol and ether. Various concentrations of the crude extract were then subjected to an in vitro test for their effectiveness on mycelia growth inhibition against some important plant pathogenic fungi such as Alternaria alternata, Colletotrichum gloeosporioides, Fusarium oxysporum fsp. lycopersici, Sclerotium rolfsii, Phytophthora infestans and Pythium sp. in comparison to commercial fungicides such as copper oxychloride and mancozeb. Reduction of the fungal growth was significantly obtained with C. longa extracts and the best median effective inhibitory concentration (IC50) value of 6.07, 6.50 and 7.13 mg/ml was from the ethanol extract for S. rolfsii, C. gloeosporioides and F. oxysporum fsp. lycopersici respectively. While all extracts from C. alata were almost the least effective against these fungi. The efficacy of C. longa extracts therefore, provided an alternative regime for the control of the fungal diseases and a promising appreciable choice for a replacement of chemical fungicides.展开更多
Plant pathogenic bacteria are recognized to be harmful microbes able to decrease the quantity and quality of crop production in the world. Punica granatum peel was screened for its potential use as biological control ...Plant pathogenic bacteria are recognized to be harmful microbes able to decrease the quantity and quality of crop production in the world. Punica granatum peel was screened for its potential use as biological control agent for plant pathogenic bacteria. P. granatum peel was successfully extract using n-hexane, methanol and ethyl acetate by maceration. The highest yield obtained by ethyl acetate showed that ethyl acetate extracted more compounds that readily soluble to methanol and n-hexane. For in-vitro antibacterial activity, three different species of plant pathogenic bacteria were used namely Erwinia carotovorum subsp. Carotovorum, Ralstonia solanacearum, and Xanthomonas gardneri. For all crude extracts, four different concentrations 25, 50, 100 and 200 mg/ml were used in cup-plate agar diffusion method. Streptomycin sulfate at concentration 30 μg/ml was used as positive control while each respective solvent used for peel extraction was used as negative control. The results obtained from in vitro studies showed only ethyl acetate extract possessed antibacterial activity tested on the plant pathogenic bacteria. Methanol and n-hexane did not show any antibacterial activity against plant pathogenic bacteria selected where no inhibition zones were recorded. R. solanacearum recorded the highest diameter of inhibition zones for all range of concentrations introduced followed by E. carotovorum subsp. Carotovorum and X. gardneri. For the minimum inhbitory concentration (MIC) and minimum bactericidal concentration (MBC), only the ethyl acetate extract was subjected to the assay as only ethyl acetate extract exhibited antibacterial activity. The minimum concentration of ethyl acetate extract that was able to inhibit plant pathogenic bacteria was recorded at a concentration of 3.12 mg/ml which inhibited R. solancearum and E. carotovorum subsp. Carotovorum, followed by X. gardneri at concentration 6.25 mg/ml. For the minimum bactericidal concentration (MBC), the results showed that at the concentration of 12.5 mg/ml, the extract was still capable of killing the pathogenic bacteria, R. solanacearum, and P. caratovora sub.sp. caratovora while for the bacteria X. gardneri, the concentration that was able to kill the bacteria was 25 mg/ml. The qualitative estimation of phytochemical constituents within P. granatum L. ethyl acetate peel extracts had revealed the presence of tannins, flavonoids, phenols alkaloid, Saponins, and terpenoids. This study has demonstrated that Ethyl Acetate peel extracts of P. granatum has significant antibacterial activity against pathogenic plant bacterial, and it could be of high agricultural value.展开更多
RNA interference(RNAi)-based control technologies are gaining popularity as potential alternatives to synthetic fungicides in the ongoing effort to manage plant pathogenic fungi.Among these methods,spray-induced gene ...RNA interference(RNAi)-based control technologies are gaining popularity as potential alternatives to synthetic fungicides in the ongoing effort to manage plant pathogenic fungi.Among these methods,spray-induced gene silencing(SIGS)emerges as particularly promising due to its convenience and feasibility for development.This approach is a new technology for plant disease management,in which double-stranded RNAs(dsRNAs)targeting essential or virulence genes are applied to plants or plant products and subsequently absorbed by plant pathogens,triggering a gene silencing effect and the inhibition of the infection process.Spray-induced gene silencing has demonstrated efficacy in laboratory settings against various fungal pathogens.However,as research progressed from the laboratory to the greenhouse and field environments,novel challenges arose,such as ensuring the stability of ds RNAs and their effective delivery to fungal targets.Here,we provide a practical guide to SIGS for the control of plant pathogenic fungi.This guide outlines the essential steps and considerations needed for designing and assessing dsRNA molecules.It also addresses key challenges inherent to SIGS,including delivery and stability of ds RNA molecules,and how nanoencapsulation of dsRNAs can aid in overcoming these obstacles.Additionally,the guide underscores existing knowledge gaps that warrant further research and aims to provide assistance to researchers,especially those new to the field,encouraging the advancement of SIGS for the control of a broad range of fungal pathogens.展开更多
The antifungal effectiveness of extracts of five medicinal plant species was determined.The inhibitory activity of extracts of Eucalyptus tereticornis,Xanthium sibiricum,Artemisia argyi,Tupistra chinensis and Pyrola c...The antifungal effectiveness of extracts of five medicinal plant species was determined.The inhibitory activity of extracts of Eucalyptus tereticornis,Xanthium sibiricum,Artemisia argyi,Tupistra chinensis and Pyrola calliantha were evaluated against the mycelial growth of the plant pathogenic fungi Aspergillus niger,Botrytis cinerea,Penicillium digitatum,P.expansum,P.italicum and Rhizopus stolonifer.All plant extracts were prepared at 60°C using solvents(either water,50%ethanol(v/v),95%ethanol(v/v),ethyl acetate or petroleum ether).Fungicidal effects of all plants tested were confirmed.Different extracts from the same plant species gave different degrees of inhibition.All aqueous extracts had weak or no activity on all fungi tested.Ethyl acetate and 95%ethanol extracts from T.chinensis rhizomes gave greater inhibition and a broader spectrum inhibition than the other extracts.T.chinensis may have potential as a new natural fungicide and may be used for the preservation of agricultural and forestry products such as fruits and vegetables.展开更多
Phloem is the primary conduit for transporting photosynthates and signaling molecules in plants,facilitating communication between various plant organs.As an ancient vascular tissue,phloem transports sugars,proteins,a...Phloem is the primary conduit for transporting photosynthates and signaling molecules in plants,facilitating communication between various plant organs.As an ancient vascular tissue,phloem transports sugars,proteins,and hormones from source tissues to sinks over long distances.However,this vital transport system also serves as a battlefield where plants and pathogens compete for survival.The phloem’s nutrient-rich environment offers pathogens a secure habitat,protecting them from external threats while providing ample metabolic resources.Phloem-feeding insects,bacteria,fungi,and viruses exploit this system to access nutrients,leading to widespread diseases and yield losses.These insects can also transmit pathogens,such as viruses,which can evade the plants’defense systems,causing systemic damage throughout the transport network.This review describes the mechanisms by which pathogens invade and colonize the phloem,the plant’s defense strategies,and their dynamic interactions.Understanding the phloem’s structural intricacies,physiological functions,and defense mechanisms provides a foundation for comprehending phloem–pathogen interactions.Insights into these interactions at the molecular level are crucial for developing innovative and effective disease management strategies.Genomics,proteomics,and bioinformatics advances have elucidated the interactions between phloem defenses and pathogen offenses.Finally,this review discusses integrated disease management strategies to counteract these pathogens,paving the way for improving plant health and resilience.展开更多
Toxin, one of the most important factors of plant fungal disease, has attracted much attention of many academicians who have been studying pathogen mycotoxin in deep research. The paper summarized chemical structures ...Toxin, one of the most important factors of plant fungal disease, has attracted much attention of many academicians who have been studying pathogen mycotoxin in deep research. The paper summarized chemical structures of some host-selective plant pathogen mycotoxins discovered in recent years and the correlation between biological activity and chemical structure of toxin.展开更多
Melatonin(N-Acetyl-5-methoxytryptamine),an endogenously synthesized indoleamine,exerts pleiotropic effects in plant physiology by interacting with other phytohormones,thereby synergistically regulating plant growth,de...Melatonin(N-Acetyl-5-methoxytryptamine),an endogenously synthesized indoleamine,exerts pleiotropic effects in plant physiology by interacting with other phytohormones,thereby synergistically regulating plant growth,development,and stress responses.Recent research has also indicated that melatonin derivatives could be further developed as promising antifungal candidates.Given the significant roles of melatonin,considerable efforts have been devoted to studying its potent functions and underlying mechanisms.This review outlines recent advancements in understanding the roles of melatonin in regulating plant growth and its potential synergistic interactions with pathogens.Additionally,we present our perspectives aimed at elucidating the antifungal mechanisms of melatonin and its derivatives,which could facilitate the development of naturally sourced fungicides and offer innovative strategies for pesticide discovery.展开更多
Interactions of the stripe rust pathogen （Puccinia striiformis f. sp responses. Among various genes involved in the plant-pathogen related （PR） protein genes determine different defense responses tritici） with wh...Interactions of the stripe rust pathogen （Puccinia striiformis f. sp responses. Among various genes involved in the plant-pathogen related （PR） protein genes determine different defense responses tritici） with wheat plants activate a w^ae range OT nost nteractions, the expressions of particular pathogenesis-Different types of resistance have been recognized and utilized for developing wheat cultivars for resistance to stripe rust. All-stage resistance can be detected in seedling stage and remains at high levels throughout the plant growth stages. This type of resistance is race-specific and not durable. In contrast, plants with only high-temperature adult-plant （HTAP） resistance are susceptible in seedling stage, but become resistant when plants grow older and the weather becomes warmer. HTAP resistance controlled by a single gene is partial, but usually non-race specific and durable. The objective of this study was to analyze the expression of PR protein genes involved in different types of wheat resistance to stripe rust. The expression levels of 8 PR protein genes （PR1, PRI.2, PR2, PR3, PR4, PR5, PR9 and PRIO） were quantitatively evaluated at 0, 1, 2, 7 and 14 days after inoculation in single resistance gene lines of wheat with all-stage resistance genes YrTrl, Yr76, YrSP and YrExp2 and lines carrying HTAP resistance genes Yr52, Yr59, Yr62 and Yr7B. Races PSTv-4 and PSTv-37 for compatible and incompatible interactions were used in evaluation of PR protein gene expression in wheat lines carrying all-stage resistance genes in the seedling- stage experiment while PSTv-37 was used in the HTAP experiment. Analysis of quantitative real-time polymerase chain reaction （qRT-PCR） revealed that all of the PR protein genes were involved in the different types of resistance controlled by different Yr genes. However, these genes were upregulated at different time points and at different levels during the infection process among the wheat lines with different Yr genes for either all-stage resistance or HTAP resistance. Some of the genes were also induced in compatible interactions, but the levels were almost always higher in the incompatible interaction than in the compatible interaction at the same time point for each Yr gene. These results indicate that both salicylic acid and jasmonate signaling pathways are involved in both race-specific all-stage resistance and non-race specific HTAP resistance. Although expressing at different stages of infection and at different levels, these PR protein genes work in concert for contribution to different types of resistance controlled by different Yr genes.展开更多
In recent years, proteomics has played a key role in identifying changes in protein levels in plant hosts upon infection by pathogenic organisms and in characterizing cellular and extracellular virulence and pathogeni...In recent years, proteomics has played a key role in identifying changes in protein levels in plant hosts upon infection by pathogenic organisms and in characterizing cellular and extracellular virulence and pathogenicity factors produced by pathogens. Proteomics offers a constantly evolving set of novel techniques to study all aspects of protein structure and function. Proteomics aims to find out the identity and amount of each and every protein present in a cell and actual function mediating specific cellular processes. Structural proteomics elucidates the development and application of experimental approaches to define the primary, secondary and tertiary structures of proteins, while functional proteomics refers to the development and application of global (proteome wide or system-wide) experimental approaches to assess protein function. A detail understanding of plant defense response using successful combination of proteomic techniques and other high throughput techniques of cell biology, biochemistry as well as genomics is needed for practical application to secure and stabilize yield of many crop plants. This review starts with a brief introduction to gel- and non gel-based proteomic techniques followed by the basics of plant-pathogen interaction, the use of proteomics in recent pasts to decipher the mysteries of plant-pathogen interaction, and ends with the future prospects of this technology.展开更多
Identification of plant-pathogenic fungi is time-consuming due to cultivation and microscopic examination and can be influenced by the interpretation of the micro-morphological characters observed.The present investig...Identification of plant-pathogenic fungi is time-consuming due to cultivation and microscopic examination and can be influenced by the interpretation of the micro-morphological characters observed.The present investigation aimed to create a simple but sophisticated method for the identification of plant-pathogenic fungi by Fourier transform infrared(FTIR)spectroscopy.In this study,FTIR-attenuated total reflectance(ATR)spectroscopy was used in combination with chemometric analysis for identification of important pathogenic fungi of horticultural plants.Mixtures of mycelia and spores from 27fungal strains belonging to nine different families were collected from liquid PD or solid PDA media cultures and subjected to FTIR-ATR spectroscopy measurements.The FTIR-ATR spectra ranging from 4 000to 400cm-1 were obtained.To classify the FTIRATR spectra,cluster analysis was compared with canonical vitiate analysis(CVA)in the spectral regions of3 050~2 800and 1 800~900cm-1.Results showed that the identification accuracies achieved 97.53%and99.18%for the cluster analysis and CVA analysis,respectively,demonstrating the high potential of this technique for fungal strain identification.展开更多
Five wild plant species belonging to different families (Chenopodium album, Plantago major, Elytrigia elongata, Filipendula ulmaria and Nigella sativa) widely spread in Russian Federation and the former USSR were eval...Five wild plant species belonging to different families (Chenopodium album, Plantago major, Elytrigia elongata, Filipendula ulmaria and Nigella sativa) widely spread in Russian Federation and the former USSR were evaluated for their ability to inhibit growth of two important human food-borne pathogens (Escherichia coli O157:H7 and Listeria monocytogenes strain EGD-e) and eight plant pathogens (Alternaria alternata, Alternaria tenuissima, Bipolaris sorokiniana, Stagonospora nodorum, Fusarium solani, Fusarium oxysporum, Fusarium culmorum and Phytophtora infestans). To isolate biologically active compounds from seeds, a step-wise procedure including extraction with hexane, ethyl acetate, ethanol, and 10% acetic acid followed by reversed-phase HPLC was developed. Using disc-diffusion assay, the highest activity against E. coli O157:H7 was observed with extracts from F. ulmaria (hexane and ethyl acetate extracts and the unbound RP-HPLC fraction) and P. major (ethyl acetate extract and the unbound RP-HPLC fraction);E. elongate (the unbound RP-HPLC fraction) was less active. The extracts from P. major and E. elongate (the unbound RP-HPLC fractions) were equally highly active against L. monocytogenes, while those of F. ulmaria (the unbound RP-HPLC fraction) and N. sativa (hexane and ethyl acetate extracts) were less active against this pathogen. The dynamics of L. monocytogenes EGD-е and E. coli O157:H7 growth in the presence of two most potent extracts (RP-HPLC-unbound fractions of P. major and E. elongate and the hexane extract of F. ulmaria) was studied.展开更多
This special focus is dedicated to three parts：i）One of the most ubiquitous viral pathogens of stone fruit tree,Plum pox virus（PPV）;ii）a re-emerging pathogen,Wheat streak mosaic virus（WSMV）of cereal crops in Ce...This special focus is dedicated to three parts：i）One of the most ubiquitous viral pathogens of stone fruit tree,Plum pox virus（PPV）;ii）a re-emerging pathogen,Wheat streak mosaic virus（WSMV）of cereal crops in Central Europe;and iii）a less studied plant parasitic,cyst-forming nematode in cereal crops Heterodera avenae.展开更多
Pharmaceutical wastewater treatment plants（WWTPs） are thought to be a ＂seedbed＂ and reservoirs for multi-antibiotic resistant pathogenic bacteria which can be transmitted to the air environment through aeration. W...Pharmaceutical wastewater treatment plants（WWTPs） are thought to be a ＂seedbed＂ and reservoirs for multi-antibiotic resistant pathogenic bacteria which can be transmitted to the air environment through aeration. We quantified airborne multi-antibiotic resistance in a full-scale plant to treat antibiotics-producing wastewater by collecting bioaerosol samples from December2014 to July 2015. Gram-negative opportunistic pathogenic bacteria（GNOPB） were isolated, and antibiotic susceptibility tests against 18 commonly used antibiotics, including 11 β-lactam antibiotics, 3 aminoglycosides, 2 fluoroquinolones, 1 furan and 1 sulfonamide, were conducted.More than 45% of airborne bacteria isolated from the pharmaceutical WWTP were resistant to three or more antibiotics, and some opportunistic pathogenic strains were resistant to 16 antibiotics, whereas 45.3% and 50.3% of the strains isolated from residential community and municipal WWTP showed resistance to three or more antibiotics. The calculation of the multiple antibiotic resistance（MAR） index demonstrated that the air environment in the pharmaceutical WWTP was highly impacted by antibiotic resistance, while the residential community and municipal WWTP was less impacted by antibiotic resistance. In addition, we determined that the dominant genera of opportunistic pathogenic bacteria isolated from all bioaerosol samples were Acinetobacter, Alcaligenes, Citrobacter, Enterobacter, Escherichia, Klebsiella, Pantoea, Pseudomonas and Sphingomonas. Collectively, these results indicate the proliferations and spread of antibiotic resistance through bioaerosols in WWTP treating cephalosporin-producing wastewater, which imposed a potential health risk for the staff and residents in the neighborhood, calling for administrative measures to minimize the air-transmission hazard.展开更多
Soybean root diseases are associated with numerous fungal and oomycete pathogens;however,the community dynamics and interactions of these pathogens are largely unknown.We performed 13 loop-mediated isothermal amplific...Soybean root diseases are associated with numerous fungal and oomycete pathogens;however,the community dynamics and interactions of these pathogens are largely unknown.We performed 13 loop-mediated isothermal amplification(LAMP)assays that targeted specific soybean root pathogens,and traditional isolation assays.A total of 159 samples were collected from three locations in the Huang-Huai-Hai region of China at three soybean growth stages(30,60,and 90 days after planting)in 2016.In LAMP results,we found that pathogen communities differed slightly among locations,but changed dramatically between soybean growth stages.Phytophthora sojae,Rhizoctonia solani,and Fusarium oxysporum were most frequently detected at the early stage,whereas Phomopsis longicolla,Fusarium equiseti,and Fusarium virguliforme were most common in the later stages.Most samples(86%)contained two to six pathogen species.Interestingly,the less detectable species tended to exist in the samples containing more detected species,and some pathogens preferentially co-occurred in diseased tissue,including P.sojae–R.solani–F.oxysporum and F.virguliforme–Calonectria ilicicola,implying potential interactions during infection.The LAMP detection results were confirmed by traditional isolation methods.The isolated strains exhibited different virulence to soybean,further implying a beneficial interaction among some pathogens.展开更多
The study was conducted to make clear the activity of azoxystrobin to 4 plant pathogens and the synergistic effects of salicylhydroxamic acid （SHAM）, which acted on the alternative oxidase. It was also conducted to ...The study was conducted to make clear the activity of azoxystrobin to 4 plant pathogens and the synergistic effects of salicylhydroxamic acid （SHAM）, which acted on the alternative oxidase. It was also conducted to be aware of the mechanism of azoxystrobin in inhibition on mycelial respiration and the influence of SHAM. The activity test of azoxystrobin and SHAM was carried out with a mycelial linear growth test and spore germination test. Other related biological properties were also observed. Inhibition of azoxystrobin and SHAM on 4 pathogens was determined by using SP-II oxygraph system. Azoxystrobin inhibited mycelial growth in Colletotrichum capsici, Botrytis cinerea, Rhizoctonia solani, and Magnaporthe grisea, respectively; it also inhibited conidia germination, and conidia production in C. capsici, B. cinerea M. grisea, and sclerotia formation in R. solani. Moreover, it created stayed pigment biosynthesis in C. capsici and M. grisea somehow. Salicylhydroxamic acid enhanced inhibition by azoxystrobin. An oxygen consuming test of the mycelia showed that azoxystrobin inhibited all the 4 fungi＇s respiration in the early stages. With the concentration rising up, the effectiveness increased. However, as time went on, the respiration of the mycelia treated with fungicides recovered and SHAM could not inhibit the oxygen consuming. This reaction between the mycelia and the fungicides appeared not to initiate alternative respiration but rather the other mechanism created a lack of efficacy.展开更多
基金supported by the Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources(Guangxi Normal University,China),Ministry of Education of China(07109001-11)Guangxi Natural Science Fund Project,China(0991097)
文摘Acorus tatarinowii Schott is a traditional Chinese medicine plant and has multiple bioactivities in medicine and pesticide field.In this study,the antifungal compound 1,2-dimethoxy-4(2-propenyl)benzene was isolated from A.tatarinowii Schott by activity-directed isolation method,and the inhibitory activity of the extract and 1,2-dimethoxy-4(2-propenyl)benzene against seven plant pathogenic fungi was evaluated.The results showed that the extract and 1,2-dimethoxy-4(2-propenyl)benzene had high inhibitory activity against hyphal growth of Thielaviopsis paradoxa(de Seynes)V.Hohnel,Pestalotia mangiferae P.Henn.,Fusarium oxysporum f.sp.niveum(E.F.Smith)Syn.et Hans.,Alternaria alternate Tanaka,Colletotrichum musae(Berk et Curt)V.Arx,Sphaceloma fawcettii Jenk.,and Mycosphaerella sentina(Fr.)Schroter.The EC50 values of extract were 1.6162,1.6811,1.1253,3.5771,1.7024,2.2284,and 2.2221 g L^-1,respectively,and the EC50 values of 1,2-dimethoxy-4(2-propenyl)benzene were 0.1021,0.0997,0.0805,0.1742,0.1503,0.1853,and 0.1924 g L^-1,respectively.1,2-Dimethoxy-4(2-propenyl)benzene also inhibited spores germination of T.paradoxa(de Seynes)V.Hohnel and F.oxysporum f.sp.niveum(E.F.Smith)Syn.et Hans.,with the inhibitory rates of 98.81 and 100%at a concentration of 0.4 g L^-1 after 8 h,respectively.1,2-Dimethoxy-4(2-propenyl)benzene is a potential botanical antifungal agent for controling of plant fungal diseases.
基金supported by the grants from the Genetically Modified Organisms Breeding Major Projects, China (2014ZX0800905B)the Fundamental Research Funds for the Central Universities, Chinathe Program for New Century 151 Talents of Zhejiang Province, China
文摘Phenazines are secondary metabolites with broad spectrum antibiotic activity and thus show high potential in biological control of pathogens. In this study, we identified phenazine biosynthesis （phz） genes in two genome-completed plant pathogenic bacteria Pseudomonas syringae pv. tomato （Pst） DC3000 and Xanthomonas oryzae pv. oryzae （Xoo） PXO99A. Unlike the phz genes in typical phenazine-producing pseudomonads, phz homologs in Pst DC3000 and Xoo PXO99A consisted of phzC/D/E/F/G and phzC/E1/E2/F/G, respectively, and the both were not organized into an operon. Detection experiments demonstrated that phenazine-l-carboxylic acid （PCA） of Pst DC3000 accumulated to 13.4 IJg L-1, while that of Xoo PXO99A was almost undetectable. Moreover, Pst DC3000 was resistant to 1 mg mL-1 PCA, while Xoo PXO99A was sensitive to 50 IJg mL ~ PCA. Furthermore, mutation of phzF blocked the PCA production and significantly reduced the pathogenicity of Pst DC3000 in tomato, while the complementary strains restored these phenotypes. These results revealed that Pst DC3000 produces low level of and is resistant to phenazines and thus is unable to be biologically controlled by phenazines. Additionally, phz-mediated PCA production is required for full pathogenicity of Pst DC3000. To our knowledge, this is the first report of PCA production and its function in pathogenicity of a plant pathogenic P. syringae strain.
文摘Since the 19th century to date,the fungal pathogens have been involved in causing devastating diseases in plants.All types of fungal pathogens have been observed in important agricultural crops that lead to significant pre and postharvest losses.The application of synthetic fungicide against the fungal plant pathogens(FPP)is a traditional management practice but at the same time these fungicides kill other beneficial microbes,insects,animal,and humans and are harmful to environment.The antagonistic microorganism such as bacteria are being used as an alternate strategy to control the FPP.These antagonistic species are cost-effective and eco-friendly in nature.These biocontrol bacteria have a broad mechanism against fungal pathogens present in the phyllosphere and rhizosphere of the plant.The antagonistic bacteria have different strategies against the FPP,by producing siderophore,biofilm,volatile organic compounds(VOCs),through parasitism,antibiosis,competition for limited resources and induce systemic resistance(ISR)in the host plant by activating the immune systems.The commercial bio-products synthesized by the major bacterial species Pseudomonas syringae,Burkholderia cepacia,Streptomyces griseoviridis,Pseudomonas fluorescens and Bacillus subtilis are used to control Fusarium,Pythium,Rhizoctonia,Penicillium,Alternaria,and Geotrichum.The commercial bio-formulations of bacteria act as both antifungal and plant growth regulators.The Plant growth-promoting rhizobacteria(PGPR)played a significant role in improving plant health by nitrogen-fixing,phosphorus solubilization,phytohormones production,minimizing soil metal contamination,and by ACC deaminase antifungal activities.Different articles are available on the specific antifungal activity of bacteria in plant diseases.Therefore,this review article has summarized the information on biocontrol activity of bacteria against the FPP and the role of PGPR in plant growth promotion.This review also provided a complete picture of scattered information regarding antifungal activities of bacteria and the role of PGPR.
基金funded by the National Key R&D Program of China(grant no.2022YFD1400900).
文摘Fungicides are an indispensable tool in plant disease control.Various modes of action(MOAs)have been identified in different fungicides to suppress plant pathogens.The combined use of fungicides with distinct MOAs has been recommended to prevent the development of pathogen resistance.In studying MOAs,metabolomics has been proven to be a robust and high-throughput method.Because metabolites are unique and distinct depending on the biological activities of an organism,MOAs can be identified and classified by establishing metabolic fingerprinting and metabolic profiles.Similarly,if fungicide resistance is developed in a pathogen,the metabolome will change,which can be identified.In this review,we have discussed the principles and advanced applications of metabolomics in the study of MOAs and resistance mechanisms of fungicides,and the potential of metabolic data in understanding the interaction between fungicides and pathogens.Challenges are also discussed in the application of metabolomics,improvement of the study on the mechanism of fungicides in their functions against pathogens and advancing the development of novel fungicides.
文摘Crude plant extracts of ringworm cassia, Cassia alata L. and turmeric, Curcuma longa L. were prepared by either hot water or organic solvents such as ethanol and ether. Various concentrations of the crude extract were then subjected to an in vitro test for their effectiveness on mycelia growth inhibition against some important plant pathogenic fungi such as Alternaria alternata, Colletotrichum gloeosporioides, Fusarium oxysporum fsp. lycopersici, Sclerotium rolfsii, Phytophthora infestans and Pythium sp. in comparison to commercial fungicides such as copper oxychloride and mancozeb. Reduction of the fungal growth was significantly obtained with C. longa extracts and the best median effective inhibitory concentration (IC50) value of 6.07, 6.50 and 7.13 mg/ml was from the ethanol extract for S. rolfsii, C. gloeosporioides and F. oxysporum fsp. lycopersici respectively. While all extracts from C. alata were almost the least effective against these fungi. The efficacy of C. longa extracts therefore, provided an alternative regime for the control of the fungal diseases and a promising appreciable choice for a replacement of chemical fungicides.
文摘Plant pathogenic bacteria are recognized to be harmful microbes able to decrease the quantity and quality of crop production in the world. Punica granatum peel was screened for its potential use as biological control agent for plant pathogenic bacteria. P. granatum peel was successfully extract using n-hexane, methanol and ethyl acetate by maceration. The highest yield obtained by ethyl acetate showed that ethyl acetate extracted more compounds that readily soluble to methanol and n-hexane. For in-vitro antibacterial activity, three different species of plant pathogenic bacteria were used namely Erwinia carotovorum subsp. Carotovorum, Ralstonia solanacearum, and Xanthomonas gardneri. For all crude extracts, four different concentrations 25, 50, 100 and 200 mg/ml were used in cup-plate agar diffusion method. Streptomycin sulfate at concentration 30 μg/ml was used as positive control while each respective solvent used for peel extraction was used as negative control. The results obtained from in vitro studies showed only ethyl acetate extract possessed antibacterial activity tested on the plant pathogenic bacteria. Methanol and n-hexane did not show any antibacterial activity against plant pathogenic bacteria selected where no inhibition zones were recorded. R. solanacearum recorded the highest diameter of inhibition zones for all range of concentrations introduced followed by E. carotovorum subsp. Carotovorum and X. gardneri. For the minimum inhbitory concentration (MIC) and minimum bactericidal concentration (MBC), only the ethyl acetate extract was subjected to the assay as only ethyl acetate extract exhibited antibacterial activity. The minimum concentration of ethyl acetate extract that was able to inhibit plant pathogenic bacteria was recorded at a concentration of 3.12 mg/ml which inhibited R. solancearum and E. carotovorum subsp. Carotovorum, followed by X. gardneri at concentration 6.25 mg/ml. For the minimum bactericidal concentration (MBC), the results showed that at the concentration of 12.5 mg/ml, the extract was still capable of killing the pathogenic bacteria, R. solanacearum, and P. caratovora sub.sp. caratovora while for the bacteria X. gardneri, the concentration that was able to kill the bacteria was 25 mg/ml. The qualitative estimation of phytochemical constituents within P. granatum L. ethyl acetate peel extracts had revealed the presence of tannins, flavonoids, phenols alkaloid, Saponins, and terpenoids. This study has demonstrated that Ethyl Acetate peel extracts of P. granatum has significant antibacterial activity against pathogenic plant bacterial, and it could be of high agricultural value.
基金funded by the Spanish Ministry of Science,Innovation and Universities(Project No.PID2023-148417OAI00)the Spanish Ministry of Science and Innovation and by the European Union through the Next Generation Funds(Project No.PLEC2021-008076)+5 种基金funded by the Junta de Castilla y León through the projects“VAP208P20”,“VA178P23”the program“CLU-2019-01 and CL-EI-2021-05-iuFOR Unit of Excellence”co-funded by the European Regional Development Fundsupport from the European Union's Horizon Europe research and innovation programme under the MSCA agreement No.101068728PhD fellowships funded by Junta de Castilla y León(Orden EDU/601/2020 and Orden EDU/1508/2020)a Juan de la Cierva postdoctoral fellowship funded by MCIU/AEI/10.13039/501100011033 and“NextGenerationEU”/PRTR(Spain)。
文摘RNA interference(RNAi)-based control technologies are gaining popularity as potential alternatives to synthetic fungicides in the ongoing effort to manage plant pathogenic fungi.Among these methods,spray-induced gene silencing(SIGS)emerges as particularly promising due to its convenience and feasibility for development.This approach is a new technology for plant disease management,in which double-stranded RNAs(dsRNAs)targeting essential or virulence genes are applied to plants or plant products and subsequently absorbed by plant pathogens,triggering a gene silencing effect and the inhibition of the infection process.Spray-induced gene silencing has demonstrated efficacy in laboratory settings against various fungal pathogens.However,as research progressed from the laboratory to the greenhouse and field environments,novel challenges arose,such as ensuring the stability of ds RNAs and their effective delivery to fungal targets.Here,we provide a practical guide to SIGS for the control of plant pathogenic fungi.This guide outlines the essential steps and considerations needed for designing and assessing dsRNA molecules.It also addresses key challenges inherent to SIGS,including delivery and stability of ds RNA molecules,and how nanoencapsulation of dsRNAs can aid in overcoming these obstacles.Additionally,the guide underscores existing knowledge gaps that warrant further research and aims to provide assistance to researchers,especially those new to the field,encouraging the advancement of SIGS for the control of a broad range of fungal pathogens.
文摘The antifungal effectiveness of extracts of five medicinal plant species was determined.The inhibitory activity of extracts of Eucalyptus tereticornis,Xanthium sibiricum,Artemisia argyi,Tupistra chinensis and Pyrola calliantha were evaluated against the mycelial growth of the plant pathogenic fungi Aspergillus niger,Botrytis cinerea,Penicillium digitatum,P.expansum,P.italicum and Rhizopus stolonifer.All plant extracts were prepared at 60°C using solvents(either water,50%ethanol(v/v),95%ethanol(v/v),ethyl acetate or petroleum ether).Fungicidal effects of all plants tested were confirmed.Different extracts from the same plant species gave different degrees of inhibition.All aqueous extracts had weak or no activity on all fungi tested.Ethyl acetate and 95%ethanol extracts from T.chinensis rhizomes gave greater inhibition and a broader spectrum inhibition than the other extracts.T.chinensis may have potential as a new natural fungicide and may be used for the preservation of agricultural and forestry products such as fruits and vegetables.
基金Ministry of Agriculture and Farmers Welfare,Government of India,for providing Netaji Subhas ICAR International Fellowship 2021–22(F.No.18(03)/2021-EQR-Edn).
文摘Phloem is the primary conduit for transporting photosynthates and signaling molecules in plants,facilitating communication between various plant organs.As an ancient vascular tissue,phloem transports sugars,proteins,and hormones from source tissues to sinks over long distances.However,this vital transport system also serves as a battlefield where plants and pathogens compete for survival.The phloem’s nutrient-rich environment offers pathogens a secure habitat,protecting them from external threats while providing ample metabolic resources.Phloem-feeding insects,bacteria,fungi,and viruses exploit this system to access nutrients,leading to widespread diseases and yield losses.These insects can also transmit pathogens,such as viruses,which can evade the plants’defense systems,causing systemic damage throughout the transport network.This review describes the mechanisms by which pathogens invade and colonize the phloem,the plant’s defense strategies,and their dynamic interactions.Understanding the phloem’s structural intricacies,physiological functions,and defense mechanisms provides a foundation for comprehending phloem–pathogen interactions.Insights into these interactions at the molecular level are crucial for developing innovative and effective disease management strategies.Genomics,proteomics,and bioinformatics advances have elucidated the interactions between phloem defenses and pathogen offenses.Finally,this review discusses integrated disease management strategies to counteract these pathogens,paving the way for improving plant health and resilience.
基金Supported by the National Science Foundation Program (30271084).
文摘Toxin, one of the most important factors of plant fungal disease, has attracted much attention of many academicians who have been studying pathogen mycotoxin in deep research. The paper summarized chemical structures of some host-selective plant pathogen mycotoxins discovered in recent years and the correlation between biological activity and chemical structure of toxin.
基金supported by the National Natural Science Foundation of China(22071072,21801086)the Fundamental Research Funds for the Central Universities of China(2662022LXYJ001)。
文摘Melatonin(N-Acetyl-5-methoxytryptamine),an endogenously synthesized indoleamine,exerts pleiotropic effects in plant physiology by interacting with other phytohormones,thereby synergistically regulating plant growth,development,and stress responses.Recent research has also indicated that melatonin derivatives could be further developed as promising antifungal candidates.Given the significant roles of melatonin,considerable efforts have been devoted to studying its potent functions and underlying mechanisms.This review outlines recent advancements in understanding the roles of melatonin in regulating plant growth and its potential synergistic interactions with pathogens.Additionally,we present our perspectives aimed at elucidating the antifungal mechanisms of melatonin and its derivatives,which could facilitate the development of naturally sourced fungicides and offer innovative strategies for pesticide discovery.
基金supported by the U.S. Department of Agriculture, Agricultural Research Service (2090-22000018-00D)the Washington Grain Commission, USA (13C3061-5665)+2 种基金the Idaho Wheat Commission, USA (13C3061-5665 13C-3061-4232)The Fulbright fellowship
文摘Interactions of the stripe rust pathogen （Puccinia striiformis f. sp responses. Among various genes involved in the plant-pathogen related （PR） protein genes determine different defense responses tritici） with wheat plants activate a w^ae range OT nost nteractions, the expressions of particular pathogenesis-Different types of resistance have been recognized and utilized for developing wheat cultivars for resistance to stripe rust. All-stage resistance can be detected in seedling stage and remains at high levels throughout the plant growth stages. This type of resistance is race-specific and not durable. In contrast, plants with only high-temperature adult-plant （HTAP） resistance are susceptible in seedling stage, but become resistant when plants grow older and the weather becomes warmer. HTAP resistance controlled by a single gene is partial, but usually non-race specific and durable. The objective of this study was to analyze the expression of PR protein genes involved in different types of wheat resistance to stripe rust. The expression levels of 8 PR protein genes （PR1, PRI.2, PR2, PR3, PR4, PR5, PR9 and PRIO） were quantitatively evaluated at 0, 1, 2, 7 and 14 days after inoculation in single resistance gene lines of wheat with all-stage resistance genes YrTrl, Yr76, YrSP and YrExp2 and lines carrying HTAP resistance genes Yr52, Yr59, Yr62 and Yr7B. Races PSTv-4 and PSTv-37 for compatible and incompatible interactions were used in evaluation of PR protein gene expression in wheat lines carrying all-stage resistance genes in the seedling- stage experiment while PSTv-37 was used in the HTAP experiment. Analysis of quantitative real-time polymerase chain reaction （qRT-PCR） revealed that all of the PR protein genes were involved in the different types of resistance controlled by different Yr genes. However, these genes were upregulated at different time points and at different levels during the infection process among the wheat lines with different Yr genes for either all-stage resistance or HTAP resistance. Some of the genes were also induced in compatible interactions, but the levels were almost always higher in the incompatible interaction than in the compatible interaction at the same time point for each Yr gene. These results indicate that both salicylic acid and jasmonate signaling pathways are involved in both race-specific all-stage resistance and non-race specific HTAP resistance. Although expressing at different stages of infection and at different levels, these PR protein genes work in concert for contribution to different types of resistance controlled by different Yr genes.
文摘In recent years, proteomics has played a key role in identifying changes in protein levels in plant hosts upon infection by pathogenic organisms and in characterizing cellular and extracellular virulence and pathogenicity factors produced by pathogens. Proteomics offers a constantly evolving set of novel techniques to study all aspects of protein structure and function. Proteomics aims to find out the identity and amount of each and every protein present in a cell and actual function mediating specific cellular processes. Structural proteomics elucidates the development and application of experimental approaches to define the primary, secondary and tertiary structures of proteins, while functional proteomics refers to the development and application of global (proteome wide or system-wide) experimental approaches to assess protein function. A detail understanding of plant defense response using successful combination of proteomic techniques and other high throughput techniques of cell biology, biochemistry as well as genomics is needed for practical application to secure and stabilize yield of many crop plants. This review starts with a brief introduction to gel- and non gel-based proteomic techniques followed by the basics of plant-pathogen interaction, the use of proteomics in recent pasts to decipher the mysteries of plant-pathogen interaction, and ends with the future prospects of this technology.
基金the National Natural Science Foundation of China(31201473)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-IVFCAAS)funded by the Key Laboratory of Biology and Genetic Improvement of Horticultural Crops,Ministry of Agriculture,P.R.China
文摘Identification of plant-pathogenic fungi is time-consuming due to cultivation and microscopic examination and can be influenced by the interpretation of the micro-morphological characters observed.The present investigation aimed to create a simple but sophisticated method for the identification of plant-pathogenic fungi by Fourier transform infrared(FTIR)spectroscopy.In this study,FTIR-attenuated total reflectance(ATR)spectroscopy was used in combination with chemometric analysis for identification of important pathogenic fungi of horticultural plants.Mixtures of mycelia and spores from 27fungal strains belonging to nine different families were collected from liquid PD or solid PDA media cultures and subjected to FTIR-ATR spectroscopy measurements.The FTIR-ATR spectra ranging from 4 000to 400cm-1 were obtained.To classify the FTIRATR spectra,cluster analysis was compared with canonical vitiate analysis(CVA)in the spectral regions of3 050~2 800and 1 800~900cm-1.Results showed that the identification accuracies achieved 97.53%and99.18%for the cluster analysis and CVA analysis,respectively,demonstrating the high potential of this technique for fungal strain identification.
文摘Five wild plant species belonging to different families (Chenopodium album, Plantago major, Elytrigia elongata, Filipendula ulmaria and Nigella sativa) widely spread in Russian Federation and the former USSR were evaluated for their ability to inhibit growth of two important human food-borne pathogens (Escherichia coli O157:H7 and Listeria monocytogenes strain EGD-e) and eight plant pathogens (Alternaria alternata, Alternaria tenuissima, Bipolaris sorokiniana, Stagonospora nodorum, Fusarium solani, Fusarium oxysporum, Fusarium culmorum and Phytophtora infestans). To isolate biologically active compounds from seeds, a step-wise procedure including extraction with hexane, ethyl acetate, ethanol, and 10% acetic acid followed by reversed-phase HPLC was developed. Using disc-diffusion assay, the highest activity against E. coli O157:H7 was observed with extracts from F. ulmaria (hexane and ethyl acetate extracts and the unbound RP-HPLC fraction) and P. major (ethyl acetate extract and the unbound RP-HPLC fraction);E. elongate (the unbound RP-HPLC fraction) was less active. The extracts from P. major and E. elongate (the unbound RP-HPLC fractions) were equally highly active against L. monocytogenes, while those of F. ulmaria (the unbound RP-HPLC fraction) and N. sativa (hexane and ethyl acetate extracts) were less active against this pathogen. The dynamics of L. monocytogenes EGD-е and E. coli O157:H7 growth in the presence of two most potent extracts (RP-HPLC-unbound fractions of P. major and E. elongate and the hexane extract of F. ulmaria) was studied.
文摘This special focus is dedicated to three parts：i）One of the most ubiquitous viral pathogens of stone fruit tree,Plum pox virus（PPV）;ii）a re-emerging pathogen,Wheat streak mosaic virus（WSMV）of cereal crops in Central Europe;and iii）a less studied plant parasitic,cyst-forming nematode in cereal crops Heterodera avenae.
基金supported by the National Natural Science Foundation of China(No.51478237)
文摘Pharmaceutical wastewater treatment plants（WWTPs） are thought to be a ＂seedbed＂ and reservoirs for multi-antibiotic resistant pathogenic bacteria which can be transmitted to the air environment through aeration. We quantified airborne multi-antibiotic resistance in a full-scale plant to treat antibiotics-producing wastewater by collecting bioaerosol samples from December2014 to July 2015. Gram-negative opportunistic pathogenic bacteria（GNOPB） were isolated, and antibiotic susceptibility tests against 18 commonly used antibiotics, including 11 β-lactam antibiotics, 3 aminoglycosides, 2 fluoroquinolones, 1 furan and 1 sulfonamide, were conducted.More than 45% of airborne bacteria isolated from the pharmaceutical WWTP were resistant to three or more antibiotics, and some opportunistic pathogenic strains were resistant to 16 antibiotics, whereas 45.3% and 50.3% of the strains isolated from residential community and municipal WWTP showed resistance to three or more antibiotics. The calculation of the multiple antibiotic resistance（MAR） index demonstrated that the air environment in the pharmaceutical WWTP was highly impacted by antibiotic resistance, while the residential community and municipal WWTP was less impacted by antibiotic resistance. In addition, we determined that the dominant genera of opportunistic pathogenic bacteria isolated from all bioaerosol samples were Acinetobacter, Alcaligenes, Citrobacter, Enterobacter, Escherichia, Klebsiella, Pantoea, Pseudomonas and Sphingomonas. Collectively, these results indicate the proliferations and spread of antibiotic resistance through bioaerosols in WWTP treating cephalosporin-producing wastewater, which imposed a potential health risk for the staff and residents in the neighborhood, calling for administrative measures to minimize the air-transmission hazard.
基金supported by the grants to Prof.Zheng Xiaobo and Prof.Wang Yuanchao from the National Key R&D Program of China(2018YFD0201000)the earmarked fund for China Agriculture Research System(CARS-004-PS14)+1 种基金the National Natural Science Foundation of China(31721004)by the grant to Associate Prof.Ye Wenwu from the National Natural Science Foundation of China(31772140)。
文摘Soybean root diseases are associated with numerous fungal and oomycete pathogens;however,the community dynamics and interactions of these pathogens are largely unknown.We performed 13 loop-mediated isothermal amplification(LAMP)assays that targeted specific soybean root pathogens,and traditional isolation assays.A total of 159 samples were collected from three locations in the Huang-Huai-Hai region of China at three soybean growth stages(30,60,and 90 days after planting)in 2016.In LAMP results,we found that pathogen communities differed slightly among locations,but changed dramatically between soybean growth stages.Phytophthora sojae,Rhizoctonia solani,and Fusarium oxysporum were most frequently detected at the early stage,whereas Phomopsis longicolla,Fusarium equiseti,and Fusarium virguliforme were most common in the later stages.Most samples(86%)contained two to six pathogen species.Interestingly,the less detectable species tended to exist in the samples containing more detected species,and some pathogens preferentially co-occurred in diseased tissue,including P.sojae–R.solani–F.oxysporum and F.virguliforme–Calonectria ilicicola,implying potential interactions during infection.The LAMP detection results were confirmed by traditional isolation methods.The isolated strains exhibited different virulence to soybean,further implying a beneficial interaction among some pathogens.
基金sponsored by the National 973 Program of China (2009CB118906, 2006CB101907)the National 863 Program of China (2006AA10A211,2008AA10Z414)the National Natural Science Foundation of China (30671048, 30671384)
文摘The study was conducted to make clear the activity of azoxystrobin to 4 plant pathogens and the synergistic effects of salicylhydroxamic acid （SHAM）, which acted on the alternative oxidase. It was also conducted to be aware of the mechanism of azoxystrobin in inhibition on mycelial respiration and the influence of SHAM. The activity test of azoxystrobin and SHAM was carried out with a mycelial linear growth test and spore germination test. Other related biological properties were also observed. Inhibition of azoxystrobin and SHAM on 4 pathogens was determined by using SP-II oxygraph system. Azoxystrobin inhibited mycelial growth in Colletotrichum capsici, Botrytis cinerea, Rhizoctonia solani, and Magnaporthe grisea, respectively; it also inhibited conidia germination, and conidia production in C. capsici, B. cinerea M. grisea, and sclerotia formation in R. solani. Moreover, it created stayed pigment biosynthesis in C. capsici and M. grisea somehow. Salicylhydroxamic acid enhanced inhibition by azoxystrobin. An oxygen consuming test of the mycelia showed that azoxystrobin inhibited all the 4 fungi＇s respiration in the early stages. With the concentration rising up, the effectiveness increased. However, as time went on, the respiration of the mycelia treated with fungicides recovered and SHAM could not inhibit the oxygen consuming. This reaction between the mycelia and the fungicides appeared not to initiate alternative respiration but rather the other mechanism created a lack of efficacy.
