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Chen C, Che S, Dong Z, Sui J, Tian Y, Su Y, Zhang M, Sun W, Fan J, Xie J, Xie H. A genome-wide association study reveals that epistasis underlies the pathogenicity of Pectobacterium. Microbiol Spectr 2023; 11:e0176423. [PMID: 37712699 PMCID: PMC10580964 DOI: 10.1128/spectrum.01764-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/28/2023] [Indexed: 09/16/2023] Open
Abstract
Pectobacterium spp. are important bacterial pathogens that cause soft rot symptoms in various crops. However, their mechanism of pathogenicity requires clarity to help control their infections. Here, genome-wide association studies (GWAS) were conducted by integrating genomic data and measurements of two phenotypes (virulence and cellulase activity) for 120 various Pectobacterium strains in order to identify the genetic basis of their pathogenicity. An artificial intelligence-based software program was developed to automatically measure lesion areas on Chinese cabbage, thereby facilitating accurate and rapid data collection for virulence phenotypes for use in GWAS analysis. The analysis discovered 428 and 158 loci significantly associated with Pectobacterium virulence (lesion area) and cellulase activity, respectively. In addition, 1,229 and 586 epistasis loci pairs were identified for the virulence and cellulase activity phenotypes, respectively. Among them, the AraC transcriptional regulator exerted epistasis effects with another three nutrient transport-related genes in pairs contributing to the virulence phenotype, and their epistatic effects were experimentally confirmed for one pair with knockout mutants of each single gene and double gene. This study consequently provides valuable insights into the genetic mechanism underlying Pectobacterium spp. pathogenicity. IMPORTANCE Plant diseases and pests are responsible for the loss of up to 40% of food crops, and annual economic losses caused by plant diseases reach more than $220 billion. Fighting against plant diseases requires an understanding of the pathogenic mechanisms of pathogens. This study adopted an advanced approach using population genomics integrated with virulence-related phenotype data to investigate the genetic basis of Pectobacterium spp., which causes serious crop losses worldwide. An automated software program based on artificial intelligence was developed to measure the virulence phenotype (lesion area), which greatly facilitated this research. The analysis predicted key genomic loci that were highly associated with virulence phenotypes, exhibited epistasis effects, and were further confirmed as critical for virulence with mutant gene deletion experiments. The present study provides new insights into the genetic determinants associated with Pectobacterium pathogenicity and provides a valuable new software resource that can be adapted to improve plant infection measurements.
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Affiliation(s)
- Changlong Chen
- Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Shu Che
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Zhou Dong
- EVision Technology (Beijing) Co. Ltd, Beijing, China
| | - Jiayi Sui
- Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Yu Tian
- Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Yanyan Su
- Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Meng Zhang
- Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Wangwang Sun
- Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Jiaqin Fan
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Jianbo Xie
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Hua Xie
- Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
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Zhang L, Sun L, Srinivasan R, Lin M, Gong L, Lin X. Unveiling a Virulence-Regulating Mechanism in Aeromonas hydrophila: a Quantitative Exoproteomic Analysis of an AraC-Like Protein. Front Immunol 2023; 14:1191209. [PMID: 37228602 PMCID: PMC10203433 DOI: 10.3389/fimmu.2023.1191209] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 04/17/2023] [Indexed: 05/27/2023] Open
Abstract
Bacterial AraC is a transcription factor family that initiates transcription by recruiting RNA polymerase to the promoter and directly regulating various bacterial phenotypes. It also directly regulates various bacterial phenotypes. However, how this transcription factor regulates bacterial virulence and affects host immunity is still largely unknown. In this study, deleting the orf02889 (AraC-like transcription factor) gene in virulent Aeromonas hydrophila LP-2 affected several important phenotypes, such as increasing biofilm formation and siderophore production abilities. Moreover, Δorf02889 also significantly decreased the virulence of A. hydrophila and has promising attenuated vaccine potential. To better understand the effects of orf02889 on biological functions, a data independent acquisition (DIA)-based quantitative proteomics method was performed to compare the differentially expressed proteins between Δorf02889 and the wild-type strain in extracellular fractions. The following bioinformatics analysis suggested that ORF02889 may regulate various metabolic pathways, such as quorum sensing and ATP binding cassette (ABC) transporter metabolism. Moreover, 10 selected genes from the top 10 decreasing abundances in proteomics data were deleted, and their virulence to zebrafish was evaluated, respectively. The results showed that ΔcorC, Δorf00906, and Δorf04042 significantly reduced bacterial virulence. Finally, the following chromatin immunoprecipitation and polymerase chain reaction (ChIP-PCR) assay validated that the promoter of corC was directly regulated by ORF02889. Overall, these results provide insight into the biological function of ORF02889 and demonstrate its inherent regulatory mechanism for the virulence of A. hydrophila.
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Affiliation(s)
- Lishan Zhang
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring (School of Life Sciences, Fujian Agriculture and Forestry University), Fuzhou, China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, China
| | - Lina Sun
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring (School of Life Sciences, Fujian Agriculture and Forestry University), Fuzhou, China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, China
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Ramanathan Srinivasan
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring (School of Life Sciences, Fujian Agriculture and Forestry University), Fuzhou, China
- Centre for Research, Centre for Materials Engineering and Regenerative Medicine, Bharath Institute of Higher Education and Research, Selaiyur, Chennai, Tamil Nadu, India
| | - Meizhen Lin
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring (School of Life Sciences, Fujian Agriculture and Forestry University), Fuzhou, China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, China
| | - Lanqing Gong
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring (School of Life Sciences, Fujian Agriculture and Forestry University), Fuzhou, China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, China
| | - Xiangmin Lin
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring (School of Life Sciences, Fujian Agriculture and Forestry University), Fuzhou, China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, China
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Fontana R, Macchi G, Caproni A, Sicurella M, Buratto M, Salvatori F, Pappadà M, Manfredini S, Baldisserotto A, Marconi P. Control of Erwinia amylovora Growth by Moringa oleifera Leaf Extracts: In Vitro and in Planta Effects. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11070957. [PMID: 35406937 PMCID: PMC9003111 DOI: 10.3390/plants11070957] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/22/2022] [Accepted: 03/29/2022] [Indexed: 06/12/2023]
Abstract
Erwinia amylovora (EA) is a phytopathogenic bacterium, the causative agent of bacterial fire blight, a disease that affects Rosaceaes. In order to replace antibiotics and copper, the antimicrobial activity of three extracts of Moringa oleifera Lam., methanolic (MeOH-MOE), hydroalcoholic (HA-MOE) and hydroalcoholic with maltodextrins (HAMD-MOE), was tested on eleven strains of EA isolated from apple trees by the Emilia-Romagna Phytosanitary Department. MIC and MBC have been evaluated; biofilm formation, swarming motility and amylovoran production were performed with the crystalviolet, soft-agar assay and the amylovoran method. All extracts demonstrated bacteriostatic activity at a concentration of 1 mg/mL, resulting in a 80% reduction in biofilm formation. HAMD-MOE, MeOH-MOE and HA-MOE caused an inhibition of motility of 60%, 65% and 30% after 6 days and a decrease in amylovoran synthesis of 84%, 63% and 93%, respectively. In planta results showed how the compounds were able to inhibit EA virulence on apple trees, mainly if they were applied as a preventive treatment, although the treatment showed a significant reduction in fire blight symptoms progression. The antibacterial activity of the extracts is mainly due to the high concentration of polyphenolic compounds detected in the extracts that was able to alter the permeability of bacterial membrane, resulting in slowing the synthesis of ATP and consequently of all ATP-dependent functions, such as motility and less selectivity towards harmful compounds, which can, thus, enter the cytoplasm and inhibit enzymes involved in replication and quorum sensing. The efficacy, eco-compatibility and low cost make such extracts a potential tool for the control of bacterial fire blight.
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Affiliation(s)
- Riccardo Fontana
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, 44121 Ferrara, Italy; (R.F.); (A.C.); (M.B.); (F.S.); (M.P.)
- Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy; (G.M.); (A.B.)
| | - Giovanna Macchi
- Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy; (G.M.); (A.B.)
| | - Anna Caproni
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, 44121 Ferrara, Italy; (R.F.); (A.C.); (M.B.); (F.S.); (M.P.)
| | - Mariaconcetta Sicurella
- Department of Environmental Sciences and Prevention, University of Ferrara, 44121 Ferrara, Italy;
| | - Mattia Buratto
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, 44121 Ferrara, Italy; (R.F.); (A.C.); (M.B.); (F.S.); (M.P.)
| | - Francesca Salvatori
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, 44121 Ferrara, Italy; (R.F.); (A.C.); (M.B.); (F.S.); (M.P.)
| | - Mariangela Pappadà
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, 44121 Ferrara, Italy; (R.F.); (A.C.); (M.B.); (F.S.); (M.P.)
| | - Stefano Manfredini
- Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy; (G.M.); (A.B.)
| | - Anna Baldisserotto
- Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy; (G.M.); (A.B.)
| | - Peggy Marconi
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, 44121 Ferrara, Italy; (R.F.); (A.C.); (M.B.); (F.S.); (M.P.)
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