The Salmonella pathogenicity islands(SPIs) play crucial roles in the progression of Salmonella infection. In this study, we constructed an improved λ Red homologous recombination system to prepare single and triple d...The Salmonella pathogenicity islands(SPIs) play crucial roles in the progression of Salmonella infection. In this study, we constructed an improved λ Red homologous recombination system to prepare single and triple deletion mutants of 3 prominent SPIs(SPI-1, 2, and 3), aiming at the impact of deletion on morphology, carbon source metabolism, adhesion and invasion capacity, in vivo colonization, and immune efficacy in chicks. Our examination revealed that the surface of the single deletion mutants(SM6ΔSPI1, ΔSPI2, and ΔSPI3) exhibited a more rugged texture and appeared to be enveloped in a layer of transparent colloid, whereas the morphology of the triple deletion mutant(SM6ΔSPI1&2&3) remained unaltered when compared to the parent strain. The carbon metabolic spectrum of the SPI mutants underwent profound alterations, with a notable and statistically significant modification observed in 30 out of 95 carbon sources, primarily carbohydrates(17 out of 30). Furthermore, the adhesion capacity of the 4 mutants to Caco-2 cells was significantly reduced when compared to that of the parent strain. Moreover,the invasion capacity of mutants SM6ΔSPI1 and SM6ΔSPI1&2&3 exhibited a substantial decrease, while it was enhanced to varying degrees for SM6ΔSPI3 and SM6ΔSPI2. Importantly, none of the 4 mutants induced any clinical symptoms in the chicks. However, they did transiently colonize the spleen and liver. Notably, the SM6ΔSPI1&2&3mutant was rapidly cleared from both the spleen and liver within 8 days post-infection and no notable pathological changes were observed in the organs. Additionally, when challenged, the mutants immunized groups displayed a significant increase in antibody levels and alterations in the CD3+CD4+ and CD3+CD8+ subpopulations, and the levels of IL-4 and IFN-γ cytokines in the SM6ΔSPI1&2&3 immunized chicken serum surpassed those of other groups.In summary, the successful construction of the 4 SPI mutants lays the groundwork for further exploration into the pathogenic(including metabolic) mechanisms of SPIs and the development of safe and effective live attenuated Salmonella vaccines or carriers.展开更多
Coffee wilt represents one of the most devastating diseases of Arabica coffee(Coffea arabica L.)plantations in the primary coffee-producing regions.In this study,coffee trees manifesting wilt symptoms accompanied by t...Coffee wilt represents one of the most devastating diseases of Arabica coffee(Coffea arabica L.)plantations in the primary coffee-producing regions.In this study,coffee trees manifesting wilt symptoms accompanied by the defoliation and drying of the whole tree were observed in the Jazan,El Baha,Najran,and Asir regions.The purpose of this investigation was to isolate and identify the Fusarium species recovered from symptomatic coffee trees.The developed fungi were initially characterized based on their morphological features followed by molecular phylogenetic multi-locus analysis of the combined sequences of ITS,TEF1-α,RPB2,and CaM.Twenty-five isolates were recovered from 28 samples.All fungal isolates were categorized morphologically under the genus Fusarium.Phylogenetic analysis positioned all the representative 15 isolates into one cluster grouping together with Neocosmospora falciformis(formerly F.falciforme)confirming their taxonomic position.Pathogenicity tests of the N.falciformis isolates were subsequently conducted on coffee seedlings,and the results revealed that all isolates induced wilt symptoms resembling those recorded in the field,and the incidence was 100%.The fungicide sensitivity test of seven investigated fungicides revealed that Maxim XL^(®) followed by Moncut^(®) exhibited the highest inhibitory effect against N.falciformis KSA 24-14,reaching 93.33%and 91.67%,respectively.To our knowledge,N.falciformis is a new causal pathogen of coffee wilt in Saudi Arabia.Remarkably,these results offer important insights for devising effective approaches to monitor and control such diseases.展开更多
Grape white rot caused by Coniella vitis is a global concern in the grape industry.pH regulation is essential for cell growth,reproductive processes and pathogenicity in phytopathogenic fungi.In this study,we observed...Grape white rot caused by Coniella vitis is a global concern in the grape industry.pH regulation is essential for cell growth,reproductive processes and pathogenicity in phytopathogenic fungi.In this study,we observed that the growth rate,spore production and virulence of C.vitis significantly declined in alkaline pH,as well as the suppressive effect on secretion of hydrolytic enzymes.Transcriptomic and metabolomic analyses were used to investigate the responses of C.vitis to acidic(pH 5),neutral(pH 7)and alkaline environments(pH 9).We identified 728,1,780 and 3,386 differentially expressed genes(DEGs)at pH 5,pH 7 and pH 9,when compared with the host pH(pH 3),and 2,122 differently expressed metabolites(DEMs)in negative and positive ion mode.Most DEGs were involved in carbohydrate metabolic process,transmembrane transport,tricarboxylic acid cycle,peptide metabolic process,amide biosynthetic process,and organic acid metabolic process.In addition,metabolomic analysis revealed ABC transporters,indole alkaloid biosynthesis,diterpenoid biosynthesis,and carotenoid biosynthesis pathways in response to the pH change.Furthermore,we found that the aspartate synthesis metabolic route associated with the TCA cycle is a key limiting factor for the growth and development of C.vitis in alkaline environments,and aspartate supplementation enables C.vitis to grow in alkaline environments.Plant cell wall-degrading enzymes(PCWDEs)could contribute to the pathogenicity,when C.vitis infected at pH 3.Importantly,aflatrem biosynthesis in acidic environment might contribute to the virulence of C.vitis and has a risk of causing human health problems due to its acute neurotoxic effects.展开更多
Magnaporthe oryzae is the causal agent of rice blast. Glycosylation plays key roles in vegetative growth,development, and infection of M. oryzae. However, several glycosylation-related genes have not been characterize...Magnaporthe oryzae is the causal agent of rice blast. Glycosylation plays key roles in vegetative growth,development, and infection of M. oryzae. However, several glycosylation-related genes have not been characterized.In this study, we identified a Glyco_transf_22 domain-containing protein, MoAlg9, and found that MoAlg9 islocalized to the endoplasmic reticulum(ER). Deletion of MoALG9 significantly affected conidial production, normalappressorium formation, responses to stressors, and pathogenicity of M. oryzae. We also found that the ΔMoalg9mutant was defective in glycogen utilization, appressorial penetration, and invasive growth in host cells. Moreover,we further demonstrated that MoALG9 regulates the transcription of several target genes involved in conidiation,appressorium formation, and cell wall integrity. In addition, we found that the Glyco_transf_22 domain is essentialfor normal MoAlg9 function and localization. We also provide evidence that MoAlg9 is involved in N-glycosylationpathway in M. oryzae. Taken together, these results show that MoAlg9 is important for conidiation, appressoriumformation, maintenance of cell wall integrity, and the pathogenesis of M. oryzae.展开更多
In Candida species,the endoplasmic reticulum(ER)stress response—regulated by the unfolded protein response(UPR)—serves as a critical adaptive mechanism affecting both pathogenicity and antifungal resistance.This rev...In Candida species,the endoplasmic reticulum(ER)stress response—regulated by the unfolded protein response(UPR)—serves as a critical adaptive mechanism affecting both pathogenicity and antifungal resistance.This review aims to synthesize current knowledge on ER stress pathways in Candida glabrata and Candida albicans,highlighting their species-specific adaptations and therapeutic implications.We systematically analyzed peer-reviewed literature on ER stress mechanisms in Candida,focusing on comparative studies of UPR signaling.Emphasis was placed on C.glabrata’s inositol-requiring enzyme 1(IRE1)-dependent Regulated IRE1-Dependent Decay(RIDD)pathway and C.albicans’IRE1/HAC1 and calcium-mediated pathways.Connections to virulence and drug resistance were evaluated through genetic,transcriptomic,and phenotypic evidence.Candida species employ divergent UPR strategies:C.glabrata mitigates ER stress primarily via RIDD-mediated mRNA decay to reduce protein load,while C.albicans enhances folding capacity through HAC1 splicing and calcium homeostasis.These adaptations promote survival in hostile host environments(e.g.,oxidative stress,immune attacks)and are linked to resistance against azoles and echinocandins.Pharmacological disruption of UPR components(e.g.,IRE1 inhibitors)sensitizes Candida to antifungals in experimental models.ER stress response pathways are promising targets for antifungal drug development.Understanding species-specific UPR mechanisms in Candida could guide novel therapies to overcome resistance and improve treatment outcomes.展开更多
Background:New variants of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)continue to drive global epidemics and pose significant health risks.The pathogenicity of these variants evolves under immune press...Background:New variants of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)continue to drive global epidemics and pose significant health risks.The pathogenicity of these variants evolves under immune pressure and host factors.Understanding these changes is crucial for epidemic control and variant research.Methods:Human angiotensin-converting enzyme 2(hACE2)transgenic mice were in-tranasally challenged with the original strain WH-09 and the variants Delta,Beta,and Omicron BA.1,while BALB/c mice were challenged with Omicron subvariants BA.5,BF.7,and XBB.1.To compare the pathogenicity differences among variants,we con-ducted a comprehensive analysis that included clinical symptom observation,meas-urement of viral loads in the trachea and lungs,evaluation of pulmonary pathology,analysis of immune cell infiltration,and quantification of cytokine levels.Results:In hACE2 mice,the Beta variant caused significant weight loss,severe lung inflammation,increased inflammatory and chemotactic factor secretion,greater mac-rophage and neutrophil infiltration in the lungs,and higher viral loads with prolonged shedding duration.In contrast,BA.1 showed a significant reduction in pathogenicity.The BA.5,BF.7,and XBB.1 variants were less pathogenic than the WH-09,Beta,and Delta variants when infected in BALB/c mice.This was evidenced by reduced weight loss,diminished pulmonary pathology,decreased secretion of inflammatory factors and chemokines,reduced macrophage and neutrophil infiltration,as well as lower viral loads in both the trachea and lungs.Conclusion:In hACE2 mice,the Omicron variant demonstrated the lowest pathogenic-ity,while the Beta variant exhibited the highest.Pathogenicity of the Delta variant was comparable to the original WH-09 strain.Among BALB/c mice,Omicron subvari-ants BA.5,BF.7,and XBB.1 showed no statistically significant differences in virulence.展开更多
The recent concurrent emergence of H5N1,H5N6,and H5N8 avian influenza viruses(AIVs)has led to significant avian mortality globally.Since 2020,frequent human-animal interactions have been documented.To gain insight int...The recent concurrent emergence of H5N1,H5N6,and H5N8 avian influenza viruses(AIVs)has led to significant avian mortality globally.Since 2020,frequent human-animal interactions have been documented.To gain insight into the novel H5 subtype AIVs(i.e.,H5N1,H5N6 and H5N8),we collected 6102 samples from various regions of China between January 2021 and September 2022,and identified 41 H5Nx strains.Comparative analyses on the evolution and biological properties of these isolates were conducted.Phylogenetic analysis revealed that the 41 H5Nx strains belonged to clade 2.3.4.4b,with 13 related to H5N1,19 to H5N6,and 9 to H5N8.Analysis based on global 2.3.4.4b viruses showed that all the viruses described in this study were likely originated from H5N8,exhibiting a heterogeneous evolutionary history between H5N1 and H5N6 during 2015–2022 worldwide.H5N1 showed a higher rate of evolution in 2021–2022 and more sites under positive selection pressure in 2015–2022.The antigenic profiles of the novel H5N1 and H5N6 exhibited notable variations.Further hemagglutination inhibition assay suggested that some A(H5N1)viruses may be antigenically distinct from the circulating H5N6 and H5N8 strains.Mammalian challenge assays demonstrated that the H5N8 virus(21GD001_H5N8)displayed the highest pathogenicity in mice,followed by the H5N1 virus(B1557_H5N1)and then the H5N6 virus(220086_H5N6),suggesting a heterogeneous virulence profile of H5 AIVs in the mammalian hosts.Based on the above results,we speculate that A(H5N1)viruses have a higher risk of emergence in the future.Collectively,these findings unveil a new landscape of different evolutionary history and biological characteristics of novel H5 AIVs in clade 2.3.4.4b,contributing to a better understanding of designing more effective strategies for the prevention and control of novel H5 AIVs.展开更多
The necrotrophic fungus, Sclerotinia sclerotiorum, employs an array of cell wall-degrading enzymes(CWDEs), including cellulase, to dismantle host cell walls. However, the molecular mechanisms through which S. scleroti...The necrotrophic fungus, Sclerotinia sclerotiorum, employs an array of cell wall-degrading enzymes(CWDEs), including cellulase, to dismantle host cell walls. However, the molecular mechanisms through which S. sclerotiorum degrades cellulose remain elusive. Here, we unveil a novel secretory cellobiohydrolase, SsdchA, characterized by a signal peptide and a Glyco_hydro_7(GH7) domain. SsdchA exhibits a robust expression of during early infection stages. Interestingly, colony morphology and growth rates remain unaffected across the wild-type, SsdchA deletion strains and SsdchA overexpression strains on potato dextrose agar(PDA) medium. Nevertheless, the pathogenicity and cellobiohydrolase activity decreased in the SsdchA deletion strains, but enhanced in the SsdchA overexpression strains. Moreover,the heterologous expression of SsdchA in Arabidopsis thaliana leads to reduced cellulose content and heightened susceptibility to S. sclerotiorum. Collectively, our data underscore the pivotal role of the novel cellobiohydrolase SsdchA in the pathogenicity of S. sclerotiorum.展开更多
Litchi downy blight,caused by the plant pathogenic oomycete Peronophythora litchii,is one of the most devastating diseases on litchi and resulted in huge economic losses.Autophagy plays an essential role in the develo...Litchi downy blight,caused by the plant pathogenic oomycete Peronophythora litchii,is one of the most devastating diseases on litchi and resulted in huge economic losses.Autophagy plays an essential role in the development and pathogenicity of the filamentous fungi.However,the function of autophagy in oomycetes remain elusive.Here,an autophagy-related protein Atg3 homolog PlAtg3 was identified and characterized in P.litchii.The absence of PlATG3 through the CRISPR/Cas9 gene replacement strategy compromised vegetative growth and sexual/asexual development.Cytological analyses revealed that the deletion of PlATG3 impaired autophagosome formation with monodansylcadaverine(MDC)staining and significantly disrupted zoospore release due to defects of sporangial cleavage with FM4-64 staining.Atg8 is considered to be an autophagy marker protein in various species.Western blot analysis indicated that PlAtg3 is involved in degradation of PlAtg8-PE.Interestingly,PlAtg3 was unable to interact with PlAtg8 in yeast two hybrid(Y2H)assays,possibly due to the absence of the Atg8 family interacting motif(AIM)in PlAtg3.Furthermore,pathogenicity assays revealed that the deletion of PlATG3 considerably reduced the virulence of P.litchii.Taken together,our data reveal that PlAtg3 plays an important role in radial growth,asexual/sexual development,sporangial cleavage and zoospore release,autophagosome formation,and pathogenicity in P.litchii.This study contributes to a better understanding of the pathogenicity mechanisms of P.litchii and provides insights for the development of more effective strategies to control oomycete diseases.展开更多
Fusarium pseudograminearum is a devastating pathogen that causes Fusarium crown rot(FCR)in wheat and poses a significant threat to wheat production in terms of grain yield and quality.However,the mechanism by which F....Fusarium pseudograminearum is a devastating pathogen that causes Fusarium crown rot(FCR)in wheat and poses a significant threat to wheat production in terms of grain yield and quality.However,the mechanism by which F.pseudograminearum infects wheat remains unclear.In this study,we aimed to elucidate these mechanisms by constructing a T-DNA insertion mutant library for the highly virulent strain WZ-8A of F.pseudograminearum.By screening this mutant library,we identified nine independent mutants that displayed impaired pathogenesis in barley leaves.Among these mutants,one possessed a disruption in the gene FpRCO1 that is an ortholog of Saccharomyces cerevisiae RCO1,encoding essential component of the Rpd3S histone deacetylase complex in F.pseudograminearum.To further investigate the role of FpRCO1 in F.pseudograminearum,we employed a split-marker approach to knock out FpRCO1 in F.pseudograminearum WZ-8A.FpRCO1 deletion mutants exhibit reduced vegetative growth,conidium production,and virulence in wheat coleoptiles and barley leaves,whereas the complementary strain restores these phenotypes.Moreover,under stress conditions,the FpRCO1 deletion mutants exhibited increased sensitivity to NaCl,sorbitol,and SDS,but possessed reduced sensitivity to H_(2)O_(2)compared to these characteristics in the wild-type strain.RNA-seq analysis revealed that deletion of FpRCO1 affected gene expression(particularly the downregulation of TRI gene expression),thus resulting in significantly reduced deoxynivalenol(DON)production.In summary,our findings highlight the pivotal role of FpRCO1 in regulating vegetative growth and development,asexual reproduction,DON production,and pathogenicity of F.pseudograminearum.This study provides valuable insights into the molecular mechanisms underlying F.pseudograminearum infection in wheat and may pave the way for the development of novel strategies to combat this devastating disease.展开更多
The conserved DNA damage repair complex,MMS21-SMC5/6(Methyl methane sulfonate 21-Structural maintenance of chromosomes 5/6),has been extensively studied in yeast,animals,and plants.However,its role in phytopathogenic ...The conserved DNA damage repair complex,MMS21-SMC5/6(Methyl methane sulfonate 21-Structural maintenance of chromosomes 5/6),has been extensively studied in yeast,animals,and plants.However,its role in phytopathogenic fungi,particularly in the highly destructive rice blast fungus Magnaporthe oryzae,remains unknown.In this study,we functionally characterized the homologues of this complex,MoMMS21 and MoSMC5,in M.oryzae.We first demonstrated the importance of DNA damage repair in M.oryzae by showing that the DNA damage inducer phleomycin inhibited vegetative growth,infection-related development and pathogenicity in this fungus.Additionally,we discovered that MoMMS21 and MoSMC5 interacted in the nuclei,suggesting that they also function as a complex in M.oryzae.Gene deletion experiments revealed that both MoMMS21 and MoSMC5 are required for infection-related development and pathogenicity in M.oryzae,while only MoMMS21 deletion affected growth and sensitivity to phleomycin,indicating its specific involvement in DNA damage repair.Overall,our results provide insights into the roles of MoMMS21 and MoSMC5 in M.oryzae,highlighting their functions beyond DNA damage repair.展开更多
Swine are regarded as“intermediate hosts”or“mixing vessels”of influenza viruses,capable of generating strains with pandemic potential.From 2020 to 2021,we conducted surveillance on swine H1N2 influenza(swH1N2)viru...Swine are regarded as“intermediate hosts”or“mixing vessels”of influenza viruses,capable of generating strains with pandemic potential.From 2020 to 2021,we conducted surveillance on swine H1N2 influenza(swH1N2)viruses in swine farms located in Guangdong,Yunnan,and Guizhou provinces in southern China,as well as Henan and Shandong provinces in northern China.We systematically analyzed the evolution and pathogenicity of swH1N2 isolates,and characterized their replication and transmission abilities.The isolated viruses are quadruple reassortant H1N2 viruses containing genes from pdm/09 H1N1(PB2,PB1,PA and NP genes),triple-reassortant swine(NS gene),Eurasian Avian-like(HA and M genes),and recent human H3N2(NA gene)lineages.The NA,PB2,and NP of SW/188/20 and SW/198/20 show high gene similarities to A/Guangdong/Yue Fang277/2017(H3N2).The HA gene of swH1N2 exhibits a high evolutionary rate.The five swH1N2 isolates replicate efficiently in human,canine,and swine cells,as well as in the turbinate,trachea,and lungs of mice.A/swine/Shandong/198/2020 strain efficiently replicates in the respiratory tract of pigs and effectively transmitted among them.Collectively,these current swH1N2 viruses possess zoonotic potential,highlighting the need for strengthened surveillance of swH1N2 viruses.展开更多
Eighteen blast isolates were obtained from hybrid combination Wuyou308 using the Magnaporthe oryzae pathogen isolation method.Race identification of these isolates was conducted based on seven Chinese blast differenti...Eighteen blast isolates were obtained from hybrid combination Wuyou308 using the Magnaporthe oryzae pathogen isolation method.Race identification of these isolates was conducted based on seven Chinese blast differentials and 11 blast monogenic lines.The results indicated that the isolates were identified as the races of ZB13,ZB15 and ZC13,accounting for 66.67%,27.78%,5.56%,respectively,and the resistance genes including Pi-ta2 and Pi-sh,Pi-i were highly susceptible to these isolates,while the resistance genes like Pi-kh,Pi-1,Pi2,Pi-9 and Pi-50 showed good resistance to tested pathogens.All isolates were compatible to the original rice hybrid Wuyou308.Three isolates including GDHY-308-1401 were used for testing their pathogenicity to 45 local varieties.The results demonstrated that 13 varieties appeared highly susceptible to the tested isolates,accounting for 28.89%;two varieties appeared moderately susceptible to the tested isolates,accounting for 4.44%;30 varieties showed moderately/highly resistance,accounting for 66.67%.Among them,some of new hybrid combinations such as Wufengyou 9802,Wuyou 613,Wuyou 1179 showed good resistance to the inoculated strains,and they were recommended to be candidates in the rice region where Wuyou308 showed susceptibility.展开更多
[Objective] This study aimed to investigate the genetic variation of g E gene of an epidemic pseudorabies virus（PRV） strain and its pathogenicity to piglets. [Method] By serial passage in Vero cells, a PRV strain wa...[Objective] This study aimed to investigate the genetic variation of g E gene of an epidemic pseudorabies virus（PRV） strain and its pathogenicity to piglets. [Method] By serial passage in Vero cells, a PRV strain was isolated from the brain tissues of stillborn fetuses delivered by sows with suspected PRV infection and preliminarily identified by PCR. g E gene of the isolated PRV strain was amplified and sequenced for phylogenetic analysis. In addition, the pathogenicity of the isolated PRV strain to 6-week-old piglets was evaluated. [Result] A PRV strain was successfully isolated and named PRV N5 B strain, which could proliferate in Vero cells and TCID50 of the 15 thgeneration virus liquid reached 10^7.125/0.1 ml. Specific bands could be amplified by PCR. g E gene in the isolated PRV strain was 1 740 bp in length. A phylogenetic tree was constructed based on full-length g E sequences, which showed that PRV N5 B strain and PRV strains isolated since 2012 were clustered into the same independent category and shared 99.7%-100% homology of nucleotide sequences. Compared with related sequences published previously, there were insertions of three consecutive bases at two loci. Animal experiments showed that intranasal inoculation of 6-week-old piglets with 2 ml of PRV N5 B strain（10^6/0.1 ml） led to a mortality rate of 100%. [Conclusion] In this study,genetic variability of g E gene in PRV N5 B isolate and its pathogenicity to piglets were analyzed, which provided a theoretical basis for the development of new vaccines to prevent and control porcine pseudorabies.展开更多
[Objective] This study was conducted to investigate the pathogenicity of Plasmodiophora brassicae on cabbage grown under different temperature and soil pH conditions. [Method] The pathogenicity of P. brassicae were te...[Objective] This study was conducted to investigate the pathogenicity of Plasmodiophora brassicae on cabbage grown under different temperature and soil pH conditions. [Method] The pathogenicity of P. brassicae were tested at seven different temperatures and at six different soil pH values with the resting spore concentration of lx108 （spores/g） in the soil. The plant survival rate and incidence rate of clubroot were investigated after 90 d. [Result] The incidence rate of clubroot on cabbage among the different temperature sets varied in a descending order as follows： 30 ℃〉25 ℃〉20 ℃〉35 ℃〉15 ℃〉10 ℃〉5 ℃ at soil pH value of 6, indicating that the pathogenicity of P. brassicae was weak at 5 and 10 ~（3. The incidence rate increased with soil temperature increasing from 15 to 30 ℃, but decreased at 35 ℃. The incidence rates of clubroot were 80.36%, 100%, 65%, 10.77%, 3.23% and 0% at soil pH 4, 5, 6, 7, 8 and 9 at 25 ℃, respectively. The growth of cabbage was inhibited and the survival rate was reduced at pH 4.The incidence rates of clubroot were low at pH value of 7 and 8, and was 0% at pH 9. The Chinese cabbage grew better at pH value of 5 and 6, but had high incidence rates of clubroot. [Conclusion] The results revealed that the incidence rate of clubroot on cabbage was closely related to the temperature and soil pH.展开更多
[Objective] This study was to investigate the relationship between biological characteristics of Beauveria bassiana （Bals.） Vuill and pathogenicity to Bombyx rnori L, with the aim to provide scientific basis for the...[Objective] This study was to investigate the relationship between biological characteristics of Beauveria bassiana （Bals.） Vuill and pathogenicity to Bombyx rnori L, with the aim to provide scientific basis for the control of white muscardine in Bombyx mori L. [Method] The strains isolated and purified from the 6 Beauveria bassiana biocontrol agents from all over the country and the 3 white muscardine silkworms collected from Guangxi provincial silkworm rearing areas were identified by the morphological observation and molecular biology technology. The pathogenicity of B. bassaina to silkworms was determined, and the biological characteristics such as growth diameter, sporulation and the extracellular protease activity of the different B. bassiana strains were compared. [Result] The isolated 9 strains were all B. bassaina （Bals.） Vuillemin, and all strains had high pathogenicity to silkworm, but with different pathogenicities. The growth diameter, sporulation and extracellular protease activity of different B. bassiana strains were also different, and showed correlation with the patheogenicity to silkworms. [Conclusion] B. bassiana spores production amount and exocellular protease activity had significant positive correlation with their pathogenicity to silkworm.展开更多
In order to determine population genetic structure and pathogenicity of Ustilaginoidea virens in the major rice-growing areas of Anhui Province, total 92 U. virens strains were collected from 28 rice-planting counties...In order to determine population genetic structure and pathogenicity of Ustilaginoidea virens in the major rice-growing areas of Anhui Province, total 92 U. virens strains were collected from 28 rice-planting counties （cities） of Anhui Province. Their genetic diversity was analyzed by using REP-PCR （repetitive extragenic palindromic sequence PCR）, and pathogenicity was determined with artificial inoculation method. The results showed that U. virens in rice-growing regions of Anhui Province had a rich genetic diversity. At the similarity level of 0.76, the 92 U. virens strains could be classified into 7 groups. Significant differences were found in pathogenicity among the 24 U. virens strains belonging to different groups, which showed no association with territorial source of U. virens strain or cluster method adopted by this study. Strain pathogenicity and rice varieties showed significant specificity.展开更多
[ Objective] The paper was to study the cultural characteristic of the pathogen of Rice Sheath Blight （ Rhizoctonia solani Kuhn） and its pathogenicity in Sichuan regions. [ Method] The samples of rice sheath blight ...[ Objective] The paper was to study the cultural characteristic of the pathogen of Rice Sheath Blight （ Rhizoctonia solani Kuhn） and its pathogenicity in Sichuan regions. [ Method] The samples of rice sheath blight collected from six main rice planting areas in Sichuan regions were separated. The separated pathogen of rice sheath blight was cultured on PDA medium, and its cultural characteristic was recorded. Meanwhile, the pathogenicity of the obtained 23 strains was determined. [ Result] The growth rates among different strains had significant difference. According to the growth rate, only one strain belonged to medium strain（colony diameter： 40 mm≤（Ф≤60 mm）, the rest were all slow-type strains （colony diam- eter Ф〈40 mm）, and there was no strain with fast growth rate （colony diameter Ф 〉 60 mm）. Pathogenicity test showed that the pathogenicity among strains was significantly different, only one strain had strong pathogenicity, and the others all had moderate or weak pathogenicity. [ Conclu- sion] The study confirmed the basic biological characteristics of the pathogen of rice sheath blight in Sichuan region, which would provide theoretical basis for effective control of rice sheath blight in the region.展开更多
[Objective] In order to find the pathogenic microorganisms suitable for biological control of filth flies, the pathogenic microorganism was isolated from the dead fly, Boettcherisca peregrine. [Method] The conidia and...[Objective] In order to find the pathogenic microorganisms suitable for biological control of filth flies, the pathogenic microorganism was isolated from the dead fly, Boettcherisca peregrine. [Method] The conidia and mycelia were observed by optical microscope. The pathogenic microorganism was identified on the basis of its culture characters and the optical morphologies of the conidia and mycelia, and its biological characteristics and pathogenicity were preliminarily studied. [Result] The pathogenic microorganism isolated from the dead fly was a new strain of Verticillium lecanii. The new strain of V. lecanii was numbered as KMZW-1. The colonies of V. lecanii KMZW-1 grew fastest on potato dextrose agar medium （PDA） at 29 ℃ and pH 6.0. The LC50 of its spore suspension to the adults of B. peregrine, Lucilia sericata, Musca domestic, Piophila casei and Drosophila melanogaster were 9.50×10^5, 4.58×10^7, 4.06×10^7, 4.10×10^3 and 1.05×10^7 conidia/ml, respectively. The LT50 were 6.86, 8.17, 8.16, 8.12 and 3.22 d, respectively. [Conclusion] V. lecanii KMZW-1 is an active pathogenic microorganism to control the adults of five fly species.展开更多
[ Objective ] The paper was to confirrm the effect of hrpZpsg12 gene on the pathogenicity of Pseudomonas syringae pv. glycinea. [ Method ] hrpZpsg12 gene was cloned from P. syringae using PCR method. The knockout plas...[ Objective ] The paper was to confirrm the effect of hrpZpsg12 gene on the pathogenicity of Pseudomonas syringae pv. glycinea. [ Method ] hrpZpsg12 gene was cloned from P. syringae using PCR method. The knockout plasmid pKNOCK-Cm with suicide characteristics and cosmid pUFR034 with complementation func- tion were used to construct the mutation vector pKNOCK477-7 and complementary vector pUFR1026-68 of hrpZpsg12 gene, the mutant 477-1 and the functional com- plementation unit 1026-5 of the gene was also screened out. Three strains including wild-type Psg12, mutant 477-1 and complementary unit 1026-5 were simultane- ously inoculated into soybean leaves and tobacco leaves, then pathogenicity determination and hypersensitive reaction analysis were carried out. [ Result] All the inoculated leaves of soybean and tobacco produced reaction lesion. However, the sizes of reaction lesion were different. The lesion in the leaves inoculated with Psgl2 was relatively large, while the lesion in the leaves inoculated with 477-1 was relatively small; the lesion of complementary unit 1026-5 was similar to wild- type Psgl2. Analysis of reproduction quantity of bacteria in lesions showed that the reproduction quantity of wild-type Psg12 was the highest, while that of mutant 477-1 was the lowest. The reproduction quantity of complementary unit 1026-5 was similar to that of wild-type Psg12. [ Conclusion] hrpZpsg12 gene could enhance the pathogenicity of P. syrimgae on Soybean and produce hypersensitive response in tobacco.展开更多
基金supported by the National KeyR&DProgramof China(2022YFF0710500)the National Natural Science Foundation of China(32172853 and 32373013)the Central Public-interest Scientific Institution Basal Research Fund,China(1610302022001).
文摘The Salmonella pathogenicity islands(SPIs) play crucial roles in the progression of Salmonella infection. In this study, we constructed an improved λ Red homologous recombination system to prepare single and triple deletion mutants of 3 prominent SPIs(SPI-1, 2, and 3), aiming at the impact of deletion on morphology, carbon source metabolism, adhesion and invasion capacity, in vivo colonization, and immune efficacy in chicks. Our examination revealed that the surface of the single deletion mutants(SM6ΔSPI1, ΔSPI2, and ΔSPI3) exhibited a more rugged texture and appeared to be enveloped in a layer of transparent colloid, whereas the morphology of the triple deletion mutant(SM6ΔSPI1&2&3) remained unaltered when compared to the parent strain. The carbon metabolic spectrum of the SPI mutants underwent profound alterations, with a notable and statistically significant modification observed in 30 out of 95 carbon sources, primarily carbohydrates(17 out of 30). Furthermore, the adhesion capacity of the 4 mutants to Caco-2 cells was significantly reduced when compared to that of the parent strain. Moreover,the invasion capacity of mutants SM6ΔSPI1 and SM6ΔSPI1&2&3 exhibited a substantial decrease, while it was enhanced to varying degrees for SM6ΔSPI3 and SM6ΔSPI2. Importantly, none of the 4 mutants induced any clinical symptoms in the chicks. However, they did transiently colonize the spleen and liver. Notably, the SM6ΔSPI1&2&3mutant was rapidly cleared from both the spleen and liver within 8 days post-infection and no notable pathological changes were observed in the organs. Additionally, when challenged, the mutants immunized groups displayed a significant increase in antibody levels and alterations in the CD3+CD4+ and CD3+CD8+ subpopulations, and the levels of IL-4 and IFN-γ cytokines in the SM6ΔSPI1&2&3 immunized chicken serum surpassed those of other groups.In summary, the successful construction of the 4 SPI mutants lays the groundwork for further exploration into the pathogenic(including metabolic) mechanisms of SPIs and the development of safe and effective live attenuated Salmonella vaccines or carriers.
基金funded by the Deanship of Scientific Research,Vice Presidency for Graduate Studies and Scientific Research,King Faisal University,Saudi Arabia,for supporting this work for work through grant number KFU242134.
文摘Coffee wilt represents one of the most devastating diseases of Arabica coffee(Coffea arabica L.)plantations in the primary coffee-producing regions.In this study,coffee trees manifesting wilt symptoms accompanied by the defoliation and drying of the whole tree were observed in the Jazan,El Baha,Najran,and Asir regions.The purpose of this investigation was to isolate and identify the Fusarium species recovered from symptomatic coffee trees.The developed fungi were initially characterized based on their morphological features followed by molecular phylogenetic multi-locus analysis of the combined sequences of ITS,TEF1-α,RPB2,and CaM.Twenty-five isolates were recovered from 28 samples.All fungal isolates were categorized morphologically under the genus Fusarium.Phylogenetic analysis positioned all the representative 15 isolates into one cluster grouping together with Neocosmospora falciformis(formerly F.falciforme)confirming their taxonomic position.Pathogenicity tests of the N.falciformis isolates were subsequently conducted on coffee seedlings,and the results revealed that all isolates induced wilt symptoms resembling those recorded in the field,and the incidence was 100%.The fungicide sensitivity test of seven investigated fungicides revealed that Maxim XL^(®) followed by Moncut^(®) exhibited the highest inhibitory effect against N.falciformis KSA 24-14,reaching 93.33%and 91.67%,respectively.To our knowledge,N.falciformis is a new causal pathogen of coffee wilt in Saudi Arabia.Remarkably,these results offer important insights for devising effective approaches to monitor and control such diseases.
基金supported by the Shandong Provincial Natural Science Foundation,China(ZR2021QC131)the Shandong Province Key Research and Development Plan,China(2022TZXD001102)+1 种基金the Shandong Province Demonstration Project for Model Construction in Rural Revitalization Service,China(2022DXAL0226)the Innovation Project of Shandong Academy of Agricultural Sciences,China(CXGC2023F15,CXGC2023A41,and CXGC2023A47)。
文摘Grape white rot caused by Coniella vitis is a global concern in the grape industry.pH regulation is essential for cell growth,reproductive processes and pathogenicity in phytopathogenic fungi.In this study,we observed that the growth rate,spore production and virulence of C.vitis significantly declined in alkaline pH,as well as the suppressive effect on secretion of hydrolytic enzymes.Transcriptomic and metabolomic analyses were used to investigate the responses of C.vitis to acidic(pH 5),neutral(pH 7)and alkaline environments(pH 9).We identified 728,1,780 and 3,386 differentially expressed genes(DEGs)at pH 5,pH 7 and pH 9,when compared with the host pH(pH 3),and 2,122 differently expressed metabolites(DEMs)in negative and positive ion mode.Most DEGs were involved in carbohydrate metabolic process,transmembrane transport,tricarboxylic acid cycle,peptide metabolic process,amide biosynthetic process,and organic acid metabolic process.In addition,metabolomic analysis revealed ABC transporters,indole alkaloid biosynthesis,diterpenoid biosynthesis,and carotenoid biosynthesis pathways in response to the pH change.Furthermore,we found that the aspartate synthesis metabolic route associated with the TCA cycle is a key limiting factor for the growth and development of C.vitis in alkaline environments,and aspartate supplementation enables C.vitis to grow in alkaline environments.Plant cell wall-degrading enzymes(PCWDEs)could contribute to the pathogenicity,when C.vitis infected at pH 3.Importantly,aflatrem biosynthesis in acidic environment might contribute to the virulence of C.vitis and has a risk of causing human health problems due to its acute neurotoxic effects.
基金supported by the National Natural Science Foundation of China (32202253)the Natural Science Foundation of Anhui Higher Education Institutions, China (KJ2020A0102)the Talent Research Project of Anhui Agricultural University, China (rc342001)。
文摘Magnaporthe oryzae is the causal agent of rice blast. Glycosylation plays key roles in vegetative growth,development, and infection of M. oryzae. However, several glycosylation-related genes have not been characterized.In this study, we identified a Glyco_transf_22 domain-containing protein, MoAlg9, and found that MoAlg9 islocalized to the endoplasmic reticulum(ER). Deletion of MoALG9 significantly affected conidial production, normalappressorium formation, responses to stressors, and pathogenicity of M. oryzae. We also found that the ΔMoalg9mutant was defective in glycogen utilization, appressorial penetration, and invasive growth in host cells. Moreover,we further demonstrated that MoALG9 regulates the transcription of several target genes involved in conidiation,appressorium formation, and cell wall integrity. In addition, we found that the Glyco_transf_22 domain is essentialfor normal MoAlg9 function and localization. We also provide evidence that MoAlg9 is involved in N-glycosylationpathway in M. oryzae. Taken together, these results show that MoAlg9 is important for conidiation, appressoriumformation, maintenance of cell wall integrity, and the pathogenesis of M. oryzae.
文摘In Candida species,the endoplasmic reticulum(ER)stress response—regulated by the unfolded protein response(UPR)—serves as a critical adaptive mechanism affecting both pathogenicity and antifungal resistance.This review aims to synthesize current knowledge on ER stress pathways in Candida glabrata and Candida albicans,highlighting their species-specific adaptations and therapeutic implications.We systematically analyzed peer-reviewed literature on ER stress mechanisms in Candida,focusing on comparative studies of UPR signaling.Emphasis was placed on C.glabrata’s inositol-requiring enzyme 1(IRE1)-dependent Regulated IRE1-Dependent Decay(RIDD)pathway and C.albicans’IRE1/HAC1 and calcium-mediated pathways.Connections to virulence and drug resistance were evaluated through genetic,transcriptomic,and phenotypic evidence.Candida species employ divergent UPR strategies:C.glabrata mitigates ER stress primarily via RIDD-mediated mRNA decay to reduce protein load,while C.albicans enhances folding capacity through HAC1 splicing and calcium homeostasis.These adaptations promote survival in hostile host environments(e.g.,oxidative stress,immune attacks)and are linked to resistance against azoles and echinocandins.Pharmacological disruption of UPR components(e.g.,IRE1 inhibitors)sensitizes Candida to antifungals in experimental models.ER stress response pathways are promising targets for antifungal drug development.Understanding species-specific UPR mechanisms in Candida could guide novel therapies to overcome resistance and improve treatment outcomes.
基金National Science and Technology Infrastructure of China,Grant/Award Number:National Pathogen Resource Center-NPRC-32National Key Research and Development Program of China,Grant/Award Number:2023YFF0724800CAMS Innovation Fund for Medical Sciences,Grant/Award Number:2021-I2M-1-035。
文摘Background:New variants of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)continue to drive global epidemics and pose significant health risks.The pathogenicity of these variants evolves under immune pressure and host factors.Understanding these changes is crucial for epidemic control and variant research.Methods:Human angiotensin-converting enzyme 2(hACE2)transgenic mice were in-tranasally challenged with the original strain WH-09 and the variants Delta,Beta,and Omicron BA.1,while BALB/c mice were challenged with Omicron subvariants BA.5,BF.7,and XBB.1.To compare the pathogenicity differences among variants,we con-ducted a comprehensive analysis that included clinical symptom observation,meas-urement of viral loads in the trachea and lungs,evaluation of pulmonary pathology,analysis of immune cell infiltration,and quantification of cytokine levels.Results:In hACE2 mice,the Beta variant caused significant weight loss,severe lung inflammation,increased inflammatory and chemotactic factor secretion,greater mac-rophage and neutrophil infiltration in the lungs,and higher viral loads with prolonged shedding duration.In contrast,BA.1 showed a significant reduction in pathogenicity.The BA.5,BF.7,and XBB.1 variants were less pathogenic than the WH-09,Beta,and Delta variants when infected in BALB/c mice.This was evidenced by reduced weight loss,diminished pulmonary pathology,decreased secretion of inflammatory factors and chemokines,reduced macrophage and neutrophil infiltration,as well as lower viral loads in both the trachea and lungs.Conclusion:In hACE2 mice,the Omicron variant demonstrated the lowest pathogenic-ity,while the Beta variant exhibited the highest.Pathogenicity of the Delta variant was comparable to the original WH-09 strain.Among BALB/c mice,Omicron subvari-ants BA.5,BF.7,and XBB.1 showed no statistically significant differences in virulence.
基金supported by the Science and Technology Program of Guangdong Province(2022B1111010004,2021B1212030015)China Agriculture Research System of MOF and MARA(CARS-41)China National Animal Disease Surveillance and Epidemiological Survey Program(2021–2025)(No.202111).
文摘The recent concurrent emergence of H5N1,H5N6,and H5N8 avian influenza viruses(AIVs)has led to significant avian mortality globally.Since 2020,frequent human-animal interactions have been documented.To gain insight into the novel H5 subtype AIVs(i.e.,H5N1,H5N6 and H5N8),we collected 6102 samples from various regions of China between January 2021 and September 2022,and identified 41 H5Nx strains.Comparative analyses on the evolution and biological properties of these isolates were conducted.Phylogenetic analysis revealed that the 41 H5Nx strains belonged to clade 2.3.4.4b,with 13 related to H5N1,19 to H5N6,and 9 to H5N8.Analysis based on global 2.3.4.4b viruses showed that all the viruses described in this study were likely originated from H5N8,exhibiting a heterogeneous evolutionary history between H5N1 and H5N6 during 2015–2022 worldwide.H5N1 showed a higher rate of evolution in 2021–2022 and more sites under positive selection pressure in 2015–2022.The antigenic profiles of the novel H5N1 and H5N6 exhibited notable variations.Further hemagglutination inhibition assay suggested that some A(H5N1)viruses may be antigenically distinct from the circulating H5N6 and H5N8 strains.Mammalian challenge assays demonstrated that the H5N8 virus(21GD001_H5N8)displayed the highest pathogenicity in mice,followed by the H5N1 virus(B1557_H5N1)and then the H5N6 virus(220086_H5N6),suggesting a heterogeneous virulence profile of H5 AIVs in the mammalian hosts.Based on the above results,we speculate that A(H5N1)viruses have a higher risk of emergence in the future.Collectively,these findings unveil a new landscape of different evolutionary history and biological characteristics of novel H5 AIVs in clade 2.3.4.4b,contributing to a better understanding of designing more effective strategies for the prevention and control of novel H5 AIVs.
基金financially supported by the National Nature Science Foundation of China (32372077)the Project of Chongqing Science and Technology Commission (CSTB2023NSCQ-MSX0355)the Fundamental Research Funds for the Central Universities (SWU120075)。
文摘The necrotrophic fungus, Sclerotinia sclerotiorum, employs an array of cell wall-degrading enzymes(CWDEs), including cellulase, to dismantle host cell walls. However, the molecular mechanisms through which S. sclerotiorum degrades cellulose remain elusive. Here, we unveil a novel secretory cellobiohydrolase, SsdchA, characterized by a signal peptide and a Glyco_hydro_7(GH7) domain. SsdchA exhibits a robust expression of during early infection stages. Interestingly, colony morphology and growth rates remain unaffected across the wild-type, SsdchA deletion strains and SsdchA overexpression strains on potato dextrose agar(PDA) medium. Nevertheless, the pathogenicity and cellobiohydrolase activity decreased in the SsdchA deletion strains, but enhanced in the SsdchA overexpression strains. Moreover,the heterologous expression of SsdchA in Arabidopsis thaliana leads to reduced cellulose content and heightened susceptibility to S. sclerotiorum. Collectively, our data underscore the pivotal role of the novel cellobiohydrolase SsdchA in the pathogenicity of S. sclerotiorum.
基金supported by the grants from the Hainan Provincial Natural Science Foundation,China(321QN190 and 321CXTD437)the National Natural Science Foundation of China(32202246 and 32160614)+1 种基金the Open Project Program of Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests,China(MIMCP-202102)the Scientific Research Foundation of Hainan University,China(KYQD(ZR)-21042 and KYQD(ZR)-20080)。
文摘Litchi downy blight,caused by the plant pathogenic oomycete Peronophythora litchii,is one of the most devastating diseases on litchi and resulted in huge economic losses.Autophagy plays an essential role in the development and pathogenicity of the filamentous fungi.However,the function of autophagy in oomycetes remain elusive.Here,an autophagy-related protein Atg3 homolog PlAtg3 was identified and characterized in P.litchii.The absence of PlATG3 through the CRISPR/Cas9 gene replacement strategy compromised vegetative growth and sexual/asexual development.Cytological analyses revealed that the deletion of PlATG3 impaired autophagosome formation with monodansylcadaverine(MDC)staining and significantly disrupted zoospore release due to defects of sporangial cleavage with FM4-64 staining.Atg8 is considered to be an autophagy marker protein in various species.Western blot analysis indicated that PlAtg3 is involved in degradation of PlAtg8-PE.Interestingly,PlAtg3 was unable to interact with PlAtg8 in yeast two hybrid(Y2H)assays,possibly due to the absence of the Atg8 family interacting motif(AIM)in PlAtg3.Furthermore,pathogenicity assays revealed that the deletion of PlATG3 considerably reduced the virulence of P.litchii.Taken together,our data reveal that PlAtg3 plays an important role in radial growth,asexual/sexual development,sporangial cleavage and zoospore release,autophagosome formation,and pathogenicity in P.litchii.This study contributes to a better understanding of the pathogenicity mechanisms of P.litchii and provides insights for the development of more effective strategies to control oomycete diseases.
基金supported by grants from the National Natural Science Foundation of China(31901835)the Science and Technology Planning Project of Henan Province of China(212102110145)the International(Regional)Cooperation and Exchange Program of the National Natural Science Foundation of China(31961143018).
文摘Fusarium pseudograminearum is a devastating pathogen that causes Fusarium crown rot(FCR)in wheat and poses a significant threat to wheat production in terms of grain yield and quality.However,the mechanism by which F.pseudograminearum infects wheat remains unclear.In this study,we aimed to elucidate these mechanisms by constructing a T-DNA insertion mutant library for the highly virulent strain WZ-8A of F.pseudograminearum.By screening this mutant library,we identified nine independent mutants that displayed impaired pathogenesis in barley leaves.Among these mutants,one possessed a disruption in the gene FpRCO1 that is an ortholog of Saccharomyces cerevisiae RCO1,encoding essential component of the Rpd3S histone deacetylase complex in F.pseudograminearum.To further investigate the role of FpRCO1 in F.pseudograminearum,we employed a split-marker approach to knock out FpRCO1 in F.pseudograminearum WZ-8A.FpRCO1 deletion mutants exhibit reduced vegetative growth,conidium production,and virulence in wheat coleoptiles and barley leaves,whereas the complementary strain restores these phenotypes.Moreover,under stress conditions,the FpRCO1 deletion mutants exhibited increased sensitivity to NaCl,sorbitol,and SDS,but possessed reduced sensitivity to H_(2)O_(2)compared to these characteristics in the wild-type strain.RNA-seq analysis revealed that deletion of FpRCO1 affected gene expression(particularly the downregulation of TRI gene expression),thus resulting in significantly reduced deoxynivalenol(DON)production.In summary,our findings highlight the pivotal role of FpRCO1 in regulating vegetative growth and development,asexual reproduction,DON production,and pathogenicity of F.pseudograminearum.This study provides valuable insights into the molecular mechanisms underlying F.pseudograminearum infection in wheat and may pave the way for the development of novel strategies to combat this devastating disease.
基金Research and Development Program of China(2023YFD1400200)the Natural Science Foundation of Fujian Province,China(2022J01125)+2 种基金the Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests,China(MIMCP-202301)the Fujian Provincial Science and Technology Key Project,China(2022NZ030014)the National Natural Science Foundation of China(NSFC31871914).
文摘The conserved DNA damage repair complex,MMS21-SMC5/6(Methyl methane sulfonate 21-Structural maintenance of chromosomes 5/6),has been extensively studied in yeast,animals,and plants.However,its role in phytopathogenic fungi,particularly in the highly destructive rice blast fungus Magnaporthe oryzae,remains unknown.In this study,we functionally characterized the homologues of this complex,MoMMS21 and MoSMC5,in M.oryzae.We first demonstrated the importance of DNA damage repair in M.oryzae by showing that the DNA damage inducer phleomycin inhibited vegetative growth,infection-related development and pathogenicity in this fungus.Additionally,we discovered that MoMMS21 and MoSMC5 interacted in the nuclei,suggesting that they also function as a complex in M.oryzae.Gene deletion experiments revealed that both MoMMS21 and MoSMC5 are required for infection-related development and pathogenicity in M.oryzae,while only MoMMS21 deletion affected growth and sensitivity to phleomycin,indicating its specific involvement in DNA damage repair.Overall,our results provide insights into the roles of MoMMS21 and MoSMC5 in M.oryzae,highlighting their functions beyond DNA damage repair.
基金supported by Special fund for scientific innovation strategy-construction of high level Academy of Agriculture Science-Distinguished Scholar(R2020PYJC001).
文摘Swine are regarded as“intermediate hosts”or“mixing vessels”of influenza viruses,capable of generating strains with pandemic potential.From 2020 to 2021,we conducted surveillance on swine H1N2 influenza(swH1N2)viruses in swine farms located in Guangdong,Yunnan,and Guizhou provinces in southern China,as well as Henan and Shandong provinces in northern China.We systematically analyzed the evolution and pathogenicity of swH1N2 isolates,and characterized their replication and transmission abilities.The isolated viruses are quadruple reassortant H1N2 viruses containing genes from pdm/09 H1N1(PB2,PB1,PA and NP genes),triple-reassortant swine(NS gene),Eurasian Avian-like(HA and M genes),and recent human H3N2(NA gene)lineages.The NA,PB2,and NP of SW/188/20 and SW/198/20 show high gene similarities to A/Guangdong/Yue Fang277/2017(H3N2).The HA gene of swH1N2 exhibits a high evolutionary rate.The five swH1N2 isolates replicate efficiently in human,canine,and swine cells,as well as in the turbinate,trachea,and lungs of mice.A/swine/Shandong/198/2020 strain efficiently replicates in the respiratory tract of pigs and effectively transmitted among them.Collectively,these current swH1N2 viruses possess zoonotic potential,highlighting the need for strengthened surveillance of swH1N2 viruses.
基金Supported by Project of Collaborative Innovation Center of GDAAS-XTXM202202(XT202211)The Introduction of Icientific and Iechnological Ialents of Guangdong Academy of Agricultural Sciences(R2021YJ-YB3020).
文摘Eighteen blast isolates were obtained from hybrid combination Wuyou308 using the Magnaporthe oryzae pathogen isolation method.Race identification of these isolates was conducted based on seven Chinese blast differentials and 11 blast monogenic lines.The results indicated that the isolates were identified as the races of ZB13,ZB15 and ZC13,accounting for 66.67%,27.78%,5.56%,respectively,and the resistance genes including Pi-ta2 and Pi-sh,Pi-i were highly susceptible to these isolates,while the resistance genes like Pi-kh,Pi-1,Pi2,Pi-9 and Pi-50 showed good resistance to tested pathogens.All isolates were compatible to the original rice hybrid Wuyou308.Three isolates including GDHY-308-1401 were used for testing their pathogenicity to 45 local varieties.The results demonstrated that 13 varieties appeared highly susceptible to the tested isolates,accounting for 28.89%;two varieties appeared moderately susceptible to the tested isolates,accounting for 4.44%;30 varieties showed moderately/highly resistance,accounting for 66.67%.Among them,some of new hybrid combinations such as Wufengyou 9802,Wuyou 613,Wuyou 1179 showed good resistance to the inoculated strains,and they were recommended to be candidates in the rice region where Wuyou308 showed susceptibility.
基金Supported by Natural Science Foundation of Jiangsu Province(BK20131334)Fund for Independent Innovation of Agricultural Science and Technology in Jiangsu Province[CX(13)3069]~~
文摘[Objective] This study aimed to investigate the genetic variation of g E gene of an epidemic pseudorabies virus（PRV） strain and its pathogenicity to piglets. [Method] By serial passage in Vero cells, a PRV strain was isolated from the brain tissues of stillborn fetuses delivered by sows with suspected PRV infection and preliminarily identified by PCR. g E gene of the isolated PRV strain was amplified and sequenced for phylogenetic analysis. In addition, the pathogenicity of the isolated PRV strain to 6-week-old piglets was evaluated. [Result] A PRV strain was successfully isolated and named PRV N5 B strain, which could proliferate in Vero cells and TCID50 of the 15 thgeneration virus liquid reached 10^7.125/0.1 ml. Specific bands could be amplified by PCR. g E gene in the isolated PRV strain was 1 740 bp in length. A phylogenetic tree was constructed based on full-length g E sequences, which showed that PRV N5 B strain and PRV strains isolated since 2012 were clustered into the same independent category and shared 99.7%-100% homology of nucleotide sequences. Compared with related sequences published previously, there were insertions of three consecutive bases at two loci. Animal experiments showed that intranasal inoculation of 6-week-old piglets with 2 ml of PRV N5 B strain（10^6/0.1 ml） led to a mortality rate of 100%. [Conclusion] In this study,genetic variability of g E gene in PRV N5 B isolate and its pathogenicity to piglets were analyzed, which provided a theoretical basis for the development of new vaccines to prevent and control porcine pseudorabies.
基金Supported by Science and Technology Project of Yunnan Province(2014RA061)Special Fund for Modern Agriculture Research System for Rape of Yunnan Province~~
文摘[Objective] This study was conducted to investigate the pathogenicity of Plasmodiophora brassicae on cabbage grown under different temperature and soil pH conditions. [Method] The pathogenicity of P. brassicae were tested at seven different temperatures and at six different soil pH values with the resting spore concentration of lx108 （spores/g） in the soil. The plant survival rate and incidence rate of clubroot were investigated after 90 d. [Result] The incidence rate of clubroot on cabbage among the different temperature sets varied in a descending order as follows： 30 ℃〉25 ℃〉20 ℃〉35 ℃〉15 ℃〉10 ℃〉5 ℃ at soil pH value of 6, indicating that the pathogenicity of P. brassicae was weak at 5 and 10 ~（3. The incidence rate increased with soil temperature increasing from 15 to 30 ℃, but decreased at 35 ℃. The incidence rates of clubroot were 80.36%, 100%, 65%, 10.77%, 3.23% and 0% at soil pH 4, 5, 6, 7, 8 and 9 at 25 ℃, respectively. The growth of cabbage was inhibited and the survival rate was reduced at pH 4.The incidence rates of clubroot were low at pH value of 7 and 8, and was 0% at pH 9. The Chinese cabbage grew better at pH value of 5 and 6, but had high incidence rates of clubroot. [Conclusion] The results revealed that the incidence rate of clubroot on cabbage was closely related to the temperature and soil pH.
基金Supported by the Scientific Research and Technology Development Planning Program of Guangxi Province(10169-08)the Program for the Construction of Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection(Guikeneng1001Z014)~~
文摘[Objective] This study was to investigate the relationship between biological characteristics of Beauveria bassiana （Bals.） Vuill and pathogenicity to Bombyx rnori L, with the aim to provide scientific basis for the control of white muscardine in Bombyx mori L. [Method] The strains isolated and purified from the 6 Beauveria bassiana biocontrol agents from all over the country and the 3 white muscardine silkworms collected from Guangxi provincial silkworm rearing areas were identified by the morphological observation and molecular biology technology. The pathogenicity of B. bassaina to silkworms was determined, and the biological characteristics such as growth diameter, sporulation and the extracellular protease activity of the different B. bassiana strains were compared. [Result] The isolated 9 strains were all B. bassaina （Bals.） Vuillemin, and all strains had high pathogenicity to silkworm, but with different pathogenicities. The growth diameter, sporulation and extracellular protease activity of different B. bassiana strains were also different, and showed correlation with the patheogenicity to silkworms. [Conclusion] B. bassiana spores production amount and exocellular protease activity had significant positive correlation with their pathogenicity to silkworm.
基金Supported by Agricultural Science and Technology Innovation Fund of Anhui Province(14B1148)Special Fund for Talent Development in Anhui Province(13C1109)Science and Technology Major Project of Anhui Province(15CZZ03132)~~
文摘In order to determine population genetic structure and pathogenicity of Ustilaginoidea virens in the major rice-growing areas of Anhui Province, total 92 U. virens strains were collected from 28 rice-planting counties （cities） of Anhui Province. Their genetic diversity was analyzed by using REP-PCR （repetitive extragenic palindromic sequence PCR）, and pathogenicity was determined with artificial inoculation method. The results showed that U. virens in rice-growing regions of Anhui Province had a rich genetic diversity. At the similarity level of 0.76, the 92 U. virens strains could be classified into 7 groups. Significant differences were found in pathogenicity among the 24 U. virens strains belonging to different groups, which showed no association with territorial source of U. virens strain or cluster method adopted by this study. Strain pathogenicity and rice varieties showed significant specificity.
基金Supported by Public Service Sector (Agriculture) Projects (nyhyzx07-049)~~
文摘[ Objective] The paper was to study the cultural characteristic of the pathogen of Rice Sheath Blight （ Rhizoctonia solani Kuhn） and its pathogenicity in Sichuan regions. [ Method] The samples of rice sheath blight collected from six main rice planting areas in Sichuan regions were separated. The separated pathogen of rice sheath blight was cultured on PDA medium, and its cultural characteristic was recorded. Meanwhile, the pathogenicity of the obtained 23 strains was determined. [ Result] The growth rates among different strains had significant difference. According to the growth rate, only one strain belonged to medium strain（colony diameter： 40 mm≤（Ф≤60 mm）, the rest were all slow-type strains （colony diam- eter Ф〈40 mm）, and there was no strain with fast growth rate （colony diameter Ф 〉 60 mm）. Pathogenicity test showed that the pathogenicity among strains was significantly different, only one strain had strong pathogenicity, and the others all had moderate or weak pathogenicity. [ Conclu- sion] The study confirmed the basic biological characteristics of the pathogen of rice sheath blight in Sichuan region, which would provide theoretical basis for effective control of rice sheath blight in the region.
基金Supported by Yunnan Provincial Department of Education,Fund Projects of Young Teachers(06y15SB)Yunnan Science and Technology Project(2006NG16)~~
文摘[Objective] In order to find the pathogenic microorganisms suitable for biological control of filth flies, the pathogenic microorganism was isolated from the dead fly, Boettcherisca peregrine. [Method] The conidia and mycelia were observed by optical microscope. The pathogenic microorganism was identified on the basis of its culture characters and the optical morphologies of the conidia and mycelia, and its biological characteristics and pathogenicity were preliminarily studied. [Result] The pathogenic microorganism isolated from the dead fly was a new strain of Verticillium lecanii. The new strain of V. lecanii was numbered as KMZW-1. The colonies of V. lecanii KMZW-1 grew fastest on potato dextrose agar medium （PDA） at 29 ℃ and pH 6.0. The LC50 of its spore suspension to the adults of B. peregrine, Lucilia sericata, Musca domestic, Piophila casei and Drosophila melanogaster were 9.50×10^5, 4.58×10^7, 4.06×10^7, 4.10×10^3 and 1.05×10^7 conidia/ml, respectively. The LT50 were 6.86, 8.17, 8.16, 8.12 and 3.22 d, respectively. [Conclusion] V. lecanii KMZW-1 is an active pathogenic microorganism to control the adults of five fly species.
基金Supported by Scientific Research Foundation Project of Jilin Agricultural University" hrpZ Psg12 Protein Function of Pseudomonas syringae pv.glycinea" (384)Major Project of Cultivation of Genetically Modified Biological New Varieties of "Eleventh Five-Year Plan" of Ministry of Agriculture"Cultivation of New Transgenic Varieties of Soybean with Diseases and Pests Resistance"(2008ZX08004-004)~~
文摘[ Objective ] The paper was to confirrm the effect of hrpZpsg12 gene on the pathogenicity of Pseudomonas syringae pv. glycinea. [ Method ] hrpZpsg12 gene was cloned from P. syringae using PCR method. The knockout plasmid pKNOCK-Cm with suicide characteristics and cosmid pUFR034 with complementation func- tion were used to construct the mutation vector pKNOCK477-7 and complementary vector pUFR1026-68 of hrpZpsg12 gene, the mutant 477-1 and the functional com- plementation unit 1026-5 of the gene was also screened out. Three strains including wild-type Psg12, mutant 477-1 and complementary unit 1026-5 were simultane- ously inoculated into soybean leaves and tobacco leaves, then pathogenicity determination and hypersensitive reaction analysis were carried out. [ Result] All the inoculated leaves of soybean and tobacco produced reaction lesion. However, the sizes of reaction lesion were different. The lesion in the leaves inoculated with Psgl2 was relatively large, while the lesion in the leaves inoculated with 477-1 was relatively small; the lesion of complementary unit 1026-5 was similar to wild- type Psgl2. Analysis of reproduction quantity of bacteria in lesions showed that the reproduction quantity of wild-type Psg12 was the highest, while that of mutant 477-1 was the lowest. The reproduction quantity of complementary unit 1026-5 was similar to that of wild-type Psg12. [ Conclusion] hrpZpsg12 gene could enhance the pathogenicity of P. syrimgae on Soybean and produce hypersensitive response in tobacco.
