PLANT DISEASE
·
2019
·Vol. 103
·期 10
·
IF 3.583
Yuchun Wang,Fei Xiong,Qinhua Lu,Xinyuan Hao,Mengxia Zheng,Lu Wang,Nana Li,Changqing Ding,Xinchao Wang,Yajun Yang
Several Pestalotiopsis -like species cause gray blight disease in tea plants, resulting in severe tea production losses. However, systematic and comprehensive research on the diversity, geographical distribution, and pathogenicity of pathogenic species associated with tea plants in China is limited. In this study, 168 Pestalotiopsis -like isolates were obtained from diseased tea plant leaves from 13 primary tea-producing provinces and cities in China. Based on a multilocus (internal transcribed spacer, translation elongation factor 1-α, and β-tubulin gene region) phylogenetic analysis coupled with an assessment of conidial characteristics, 20 Neopestalotiopsis unclassified isolates, seven Pestalotiopsis species, including two novel ( Pestalotiopsis menhaiensis and Pestalotiopsis sichuanensis ), four known ( Pestalotiopsis camelliae , Pestalotiopsis chamaeropis , Pestalotiopsis kenyana , and Pestalotiopsis rhodomyrtus ) and one indistinguishable species, and three Pseudopestalotiopsis species, including two known ( Pseudopestalotiopsis camelliae-sinensis and Pseudopestalotiopsis chinensis ) and one indistinguishable species, were identified. This study is the first to evaluate Pestalotiopsis chamaeropis on tea plants in China. The geographical distribution and pathogenicity tests showed Pseudopestalotiopsis camelliae-sinensis to be the dominant cause of gray blight of tea plants in China. In vitro antifungal assays demonstrated that theobromine not only derepressed mycelial growth of the 29 representative isolates but also increased their growth. Correlation analysis revealed a linear positive relationship between the mycelial growth rate and pathogenicity ( P = 0.0148).
研究领域:
植物病理学
·
真菌学
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2022
·Vol. 23
·期 17
·10201
·
IF 6.208
Xiamei Kang,Xiao Zhou,Yanting Tang,Zhijie Jiang,Jiaqi Chen,Muhammad Mohsin,Min Yue
Salmonella enterica,serovar Gallinarum, biovar Pullorum, is an avian-specific pathogen which has caused considerable economic losses to the poultry industry worldwide. Two-component systems (TCSs) play an essential role in obtaining nutrients, detecting the presence of neighboring bacteria and regulating the expression of virulence factors. The genome analysis ofS. Pullorum strain S06004 suggesting the carriage of 22 pairs of TCSs, which belong to five families named CitB, OmpR, NarL, Chemotaxis and LuxR. In the CitB family, three pairs of TCSs, namely CitA-CitB, DcuS-DcuR and DpiB-DpiA, remain unaddressed inS. Pullorum. To systematically investigate the function of the CitB family inS. Pullorum, four mutants, ΔcitAB(abbreviated as Δcit), ΔdcuSR(Δdcu), ΔdpiBA(Δdpi) and ΔcitABΔdcuSRΔdpiBA(Δ3), were made using the CRISPR/Cas9 system. The results demonstrated that the CitB family did not affect the growth of bacteria, the results of biochemical tests, invasion and proliferation in chicken macrophage HD-11 cells and the expression of fimbrial protein. But the mutants showed thicker biofilm formation, higher resistance to antimicrobial agents, enhanced tolerance to inhibition by egg albumen and increased virulence in chicken embryos. Moreover, the deletion of Dpi TCS was detrimental to survival after exposure to hyperosmotic and oxidative environments, as well as the long-term colonization of the small intestine of chickens. Collectively, we provided new knowledge regarding the possible role of the CitB family involved in the pathogenic processes ofS. Pullorum.Keywords:SalmonellaPullorum;CitB family;Two-component system;Pathogenesis
研究领域:
微生物学
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分子生物学
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PubMed
高影响因子
MICROBIAL PATHOGENESIS
·
2018
·
IF 2.332
Tengteng Lv,Tongxiang Song,Huijie Liu,Ruibing Peng,Xiamin Jiang,Weiwei Zhang,Qingxi Han
Vibrio alginolyticus is a ubiquitous marine opportunistic pathogen that can infect various hosts in marine environment. In the present study, V. alginolyticus strain Wz11 was isolated from diseased cuttlefish , Sepia pharaonis , with 20% of promoted death and high survival capacity in skin mucus and tissue liquid. Its growth, siderophore production, and expressions of haemolysin and swarming related genes were characterized under iron limited conditions. The minimal inhibitory concentration (MIC) of 2,2′-dipyridyl (DP) to V. alginolyticus strain Wz11 was 640 μM. While growth of V. alginolyticus strain Wz11 was inhibited by DP , production of iron-seizing substances, haemolytic activity and swarming motility were increased. Moreover, expressions of haemolysin related genes tlh , tdh and vah and flagellar related genes flgH , fliC , fliD and fliS were also characterized using real-time reverse transcriptase PCR. Expression of tdh was up-regulated to 7.7-fold, while expressions of tlh and vah were down-regulated to 0.016-fold and 0.03-fold, respectively. The expression of fliC , flgH , fliD and fliS was up-regulated to 4.9-, 3.8-, 8.6- and 4.5-fold, respectively. Concluded from our results suggested that V. alginolyticus strain Wz11 was considered as a potential pathogen of S. pharaonis , and iron level played an important role in the production of iron-seizing substances, and activities of haemolysin and bacterial swarming as well as their related gene expressions.
研究领域:
微生物学
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海洋生物学
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水产养殖学
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DOI
PubMed
高影响因子
MOLECULAR PLANT PATHOLOGY
·
2024
·Vol. 25
·期 9
·e70001
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IF 4.8
Meilin Li,Liya Xiong,Wenhan Chen,YiSha Li,Abdullah Khan,Charles A. Powell,Baoshan Chen,Muqing Zhang
Xanthomonas albilineans (Xal) is a gram-negative bacterial pathogen responsible for developing sugarcane leaf scald disease, which engenders significant economic losses within the sugarcane industry. In the current study, homologous recombination exchange was carried out to induce mutations within the virB/D4 -like type IV secretion system (T4SS) genes of Xal. The results revealed that the virB11 -deletion mutant (Δ virB11 ) exhibited a loss in swimming and twitching motility. Application of transmission electron microscopy analysis further demonstrated that the Δ virB11 failed to develop flagella formation and type IV pilus morphology and exhibited reduced swarming behaviour and virulence. However, these alterations had no discernible impact on bacterial growth. Comparative transcriptome analysis between the wild-type Xal JG43 and the deletion-mutant Δ virB11 revealed 123 differentially expressed genes (DEGs), of which 28 and 10 DEGs were notably associated with flagellar assembly and chemotaxis, respectively. In light of these findings, we postulate that virB11 plays an indispensable role in regulating the processes related to motility and chemotaxis in Xal.
研究领域:
微生物学
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植物病理学
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分子生物学
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DOI
高影响因子
Plants-Basel
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2024
·Vol. 13
·期 18
·2576
·
IF 4
Yiqun Hu,Qingqing Chen,Aifang Zhang,Liyuan Zhang,Hansong Dong
Small non-coding RNAs (sRNAs) are pivotal post-transcriptional regulatory factors influencing biological activity. Studies on the rice bacterial blight pathogenXanthomonas oryzaepathovaroryzaestrain PXO99A, previously identified a virulence-associated sRNA, trans3287. A mutant strain lacking this sRNA, named SK01, resulted in markedly diminished virulence towards rice. This study aims to further elucidate the underlying bacterial virulent function of trans3287. The expression of trans3287 was quantified in virulence-inducing and standard nutritional conditions to clarify its production mechanism. The detection of virulence-associated genes revealed that trans3287 regulated the synthesis processes of extracellular polysaccharides, lipopolysaccharides, and the type III secretion system. Moreover, bioinformatics prediction and quantitative PCR indicated a potential direct target of trans3287,PXO_03470, encoding cardiolipin synthase. A dual-plasmid system fusing with GFP tag and protein immunoblotting confirmed that sRNA trans3287 negatively regulatedPXO_03470. Bacterial biofilms demonstrated trans3287 regulated the disruption of biofilm integrity through cardiolipin synthase. This study provides preliminary insights into the mechanistic underpinnings of the role of sRNA trans3287 in mediating bacterial virulence through cardiolipin synthase.
研究领域:
微生物学
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植物病理学
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分子生物学
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DOI
PubMed
高影响因子
Frontiers in Cellular and Infection Microbiology
·
2023
·
IF 5.7
Guo Lili,Dai Huilin,Feng Saixiang,Zhao Yongda
Introduction: Salmonella Typhimurium is the leading cause of foodborne illnesses in China, resulting in major epidemics and economic losses in recent years. Uridine diphosphate–glucose pyrophosphorylase galU plays an important role in thebiosynthesis of the bacterial envelope. Herein, we evaluated the role of galU in S. Typhimurium infection in chicken. Methods: A galU gene mutant was successfully constructed by red homologous recombination technology, and biological characteristics were studied.Results: The galU mutant strain had a rough phenotype;was defective in biofilm formation, autoagglutination, and motility; exhibited greater sensitivity to most antibiotics, serum, and egg albumen; and had lowercapacity for adhesion to chicken embryo fibroblasts cell line (DF-1). The galU mutant showed dramatically attenuated pathogenicity in chicken embryos (100,000-fold), BALB/c mice (420-fold), and chicks (100-fold).Discussion: The results imply that galU is an important virulence factor in the pathogenicity of S. Typhimurium, and it may serve a target for the development of veterinary drugs, providing a theoretical basis for the prevention and control of S. Typhimurium.
研究领域:
微生物学
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感染性疾病
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兽医学
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DOI
PubMed
高影响因子
Frontiers in Microbiology
·
2022
·
IF 6.064
Tan Xiao-Juan,Zhang Zhi-Wei,Xiao Jing-Jing,Wang Wei,He Feng,Gao Xuan,Jiang Bin,Shen Liang,Wang Xu,Sun Yang,Zhu Guo-Ping
Soft rot caused by Dickeya zeae is an important bacterial disease affecting rice and other plants worldwide. In this study, Nanopore and Illumina sequencing platforms were used to sequence the high-quality complete genome of a novel D. zeae strain WH1 (size: 4.68 Mb; depth: 322.37x for Nanopore, 243.51x for Illumina; GC content: 53.59%), which was isolated from healthy rice root surface together with Paenibacillus polymyxa, a potential biocontrol bacterium against D. zeae strain WH1. However, the pure WH1 culture presented severe pathogenicity. Multilocus sequence analysis (MLSA) indicated that strains WH1, EC1, and EC2 isolated from rice were grouped into a clade differentiated from other D. zeae strains. The average nucleotide identity (ANI) and DNA-DNA hybridization (DDH) analyses demonstrated that WH1 was phylogenetically closest to EC2. Furthermore, the pathogenicity determinants and virulence factors of WH1 were mainly analyzed through genomic comparison with complete genomes of other D. zeae strains with high virulence (EC1, EC2, MS1, and MS2). The results revealed that plant cell wall-degrading extracellular enzymes (PCWDEs), flagellar and chemotaxis, and quorum sensing were highly conserved in all analyzed genomes, which were confirmed through phenotypic assays. Besides, WH1 harbored type I, II, III, and VI secretion systems (T1SS, T2SS, T3SS, and T6SS), but lost T4SS and T5SS. Like strains MS1 and MS2 isolated from bananas, WH1 harbored genes encoding both capsule polysaccharide (CPS) and exopolysaccharide (EPS) biosynthesis. The results of pathogenicity assays demonstrated that WH1 produced severe soft rot symptoms on potato tubers, carrots, radishes, and Chinese cabbage. Meanwhile, WH1 also produced phytotoxin(s) to inhibit rice seed germination with an 87% inhibitory rate in laboratory conditions. More importantly, we confirmed that phytotoxin(s) produced by WH1 are different from zeamines produced by EC1. Comparative genomics analyses and phenotypic and pathogenicity assays suggested that WH1 likely evolved through a pathway different from the other D. zeae strains from rice, producing a new type of rice foot rot pathogen. These findings highlight the emergence of a new type of D. zeae strain with high virulence, causing soft rot in rice and other plants.
研究领域:
微生物学
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植物病理学
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分子生物学
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DOI
高影响因子
Fungal Biology
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2018
·
IF 2.571
Zhi Li,He Zhang,Guohuai Li
Lasiodiplodia theobromae , a phytopathogenic fungus that causes peach gummosis , is considered one of the major constraints to peach production worldwide. Here, we report the characteristics of toxic metabolites and the proteomics investigation of the secreted proteins of L. theobromae from its in vitro culture. The phytotoxins of L. theobromae from the culture filtrate of Richard’s liquid medium showed high toxicity on peach current year shoots with large lesion diameter and high gum weight. The toxicity measurement showed that 23.6 and 21.2 mg gum were induced from peach shoots by solvent fractions of ethyl acetate and dichloromethane, respectively, with significant differences from other organic solvents. A total of 23 proteins were identified by liquid chromatography–mass spectrometry from the in vitro secretome of L. theobromae . Sequence analysis indicated that 14 proteins were extracellular proteins based on signal peptides and localization. The expression profiles of the analyzed fungal genes were significantly upregulated from 1 day postinoculation (dpi) to 2 dpi, indicating that the early stage is an important stage for the infection of L. theobromae . The present study has provided insights into the extracellular phytotoxins and secreted proteins that are possibly associated with pathogenicity of the peach gummosis.
研究领域:
植物病理学
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分子生物学
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蛋白质组学
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DOI
PubMed
高影响因子
Frontiers in Microbiology
·
2018
·
IF 4.019
Lu Qinhua,Wang Yuchun,Li Nana,Ni Dejiang,Yang Yajun,Wang Xinchao
Colletotrichum, the causative agent of anthracnose, is an important pathogen that invades the tea plant (Camellia sinensis). In this study, 38 isolates were obtained from the diseased leaves of tea plants collected in different areas of Zhejiang Province, China. A combination of multigene (ITS, ACT, GAPDH, TUB2, CAL, and GS) and morphology analyses showed that the 38 strains belonged to two different species, namely, C. camelliae (CC), and C. fructicola (CF). Pathogenicity tests revealed that CC was more invasive than CF. In vitro inoculation experiments demonstrated that CC formed acervuli at 72 hpi and developed appressoria on wound edges, but CF did not develop these structures. Under treatment with catechins and caffeine, the growth inhibition rates of CF were remarkably higher than those of CC, indicating that the nonpathogenic species CF was more vulnerable to catechins and caffeine. Growth condition testing indicated that CF grew at a wide temperature range of 15–35°C and that the optimum temperature for CC growth was 25°C. Growth of both CC and CF did not differ between acidic and weakly alkaline environments (pH 5–8), but the growth of CC was significantly reduced at pH values of 9 and 10. Furthermore, the PacC/RIM101 gene, which associated with pathogenicity, was identified from CC and CF genomes, and its expression was suppressed in the hyphae of both species under pH value of 5 and 10, and much lower expression level was detected in CC than that in CF at pH 6. These results indicated that temperature has more important effect than pH for the growth of two Colletotrichum species. In conclusion, the inhibition by secondary metabolite is an important reason why the pathogenicity by CC and CF are different to tea plant, although the environmental factors including pH and temperature effect the growth of two Colletotrichum species.
研究领域:
植物病理学
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分子生物学
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微生物学
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PubMed
高影响因子
Biomolecules
·
2024
·Vol. 14
·期 4
·452
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IF 4.8
Bingbing Zong,Yong Xiao,Peiyi Wang,Wei Liu,Mingxing Ren,Changyan Li,Shulin Fu,Yanyan Zhang,Yinsheng Qiu
Porcine extraintestinal pathogenicEscherichia coli(ExPEC) is a pathogenic bacterium that causes huge economic losses to the pig farming industry and considerably threatens human health. The quorum sensing (QS) system plays a crucial role in the survival and pathogenesis of pathogenic bacteria. Hence, it is a viable approach to prevent ExPEC infection by compromising the QS system, particularly the LuxS/AI-2 system. In this study, we investigated the effects of baicalin on the LuxS/AI-2 system of ExPEC. Baicalin at concentrations of 25, 50, and 100 μg/mL significantly diminished the survival ability of ExPEC in hostile environments and could inhibit the biofilm formation and autoagglutination ability in ExPEC. Moreover, baicalin dose-dependently decreased the production of AI-2 and down-regulated the expression level ofluxSin PCN033. These results suggest that baicalin can weaken the virulence of PCN033 by inhibiting the LuxS/AI-2 system. After the geneluxSwas deleted, AI-2 production in PCN033 was almost completely eliminated, similar to the effect of baicalin on the production of AI-2 in PCN033. This indicates that baicalin reduced the production of AI-2 by inhibiting the expression level ofluxSin ExPEC. In addition, the animal experiment further showed the potential of baicalin as a LuxS/AI-2 system inhibitor to prevent ExPEC infection. This study highlights the potential of baicalin as a natural quorum-sensing inhibitor for therapeutic applications in preventing ExPEC infection by targeting the LuxS/AI-2 system.
研究领域:
微生物学
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药理学
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兽医学
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DOI
PubMed
高影响因子
Microorganisms
·
2023
·Vol. 11
·期 8
·2027
·
IF 4.5
Liushen Lu,Junwei Wang,Ting Qin,Kai Chen,Jun Xie,Bingwen Xi
Bacterial quorum sensing (QS) plays a crucial role in chemical communication between bacteria involving autoinducers and receptors and controls the production of virulence factors in bacteria. Therefore, reducing the concentration of signaling molecules in QS is an effective strategy for mitigating the virulence of pathogenic bacteria. In this study, we demonstrated that carvacrol at 15.625 μg/mL (1/4 MIC), a natural compound found in plants, exhibits potent inhibitory activity against QS inChromobacterium violaceum, as evidenced by a significant reduction (62.46%) in violacein production. Based on its impressive performance, carvacrol was employed as a natural QS inhibitor to suppress the pathogenicity ofAeromonas hydrophilaNJ-35. This study revealed a significant reduction (36.01%) in the concentration of N-acyl-homoserine lactones (AHLs), a QS signal molecular secreted byA. hydrophilaNJ-35, after 1/4 MIC carvacrol treatment. Moreover, carvacrol was found to down-regulate the expression ofahyR/I, two key genes in the QS system, which further inhibited the QS system ofA. hydrophilaNJ-35. Finally, based on the above results and molecular docking, we proposed that carvacrol alleviate the pathogenicity ofA. hydrophilaNJ-35 through QS inhibition. These results suggest that carvacrol could serve as a potential strategy for reducing the virulence of pathogenic bacteria and minimizing the reliance on antibiotics in aquaculture.Keywords:A. hydrophila;carvacrol;N-acyl-homoserine lactones;pathogenicity;quorum sensing
研究领域:
微生物学
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水产养殖
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药理学
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PubMed
高影响因子
PARASITOLOGY RESEARCH
·
2023
·Vol. 123
·期 1
·1-6
·
IF 2
Wang Bingxiang,Zhao Ningning,Sun Lingyu,Tan Qianqian,Xiao Qianqian,Chen Junpeng,Li Jinxuan,Zhang Xiao,Zhao Xiaomin
Difficulties of in vitro culture and genetic manipulation of Eimeria tenella have hindered the screening of virulence factors in this parasite. In this study, the E. tenella rhoptry protein 30 (EtROP30) was expressed in Toxoplasma gondii (RH∆Ku80-EtROP30), and its effect on the proliferation and virulence of parasites was investigated. The results revealed that the expression of EtROP30 had no impact on the invasion and egress processes. However, the RH∆Ku80-EtROP30 strain formed larger plaques compared to the RH∆Ku80, indicating that the EtROP30 expression promotes T. gondii proliferation. Furthermore, the RH∆Ku80-EtROP30 strain exhibited greater pathogenicity, resulting in earlier mortality and shorter overall survival time compared to RH∆Ku80. These results imply that EtROP30 expression facilitates parasite intracellular proliferation and virulence in mice, suggesting that EtROP30 might be a candidate virulence factor of E. tenella.
研究领域:
寄生虫学
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分子生物学
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传染病学
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PubMed
高影响因子
危险品化学品经营许可证（带存储）