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Hwang IS, Oh EJ, Oh CS. A novel virulence gene, cviA1 of Clavibacter michiganensis for necrosis development in the Nicotiana benthamiana plant. Microbiol Res 2024; 285:127743. [PMID: 38733725 DOI: 10.1016/j.micres.2024.127743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 04/06/2024] [Accepted: 04/30/2024] [Indexed: 05/13/2024]
Abstract
Clavibacter michiganensis is a Gram-positive bacterium that causes diverse disease symptoms in tomatoes and Nicotiana benthamiana, a surrogate host plant, including canker, blister lesions, and wilting. Previously, we reported that C. michiganensis also causes necrosis in N. benthamiana leaves. Here, to identify novel virulence genes of C. michiganensis required for necrosis development in N. benthamiana leaves, we screened 1,862 transposon-inserted mutants and identified a mutant strain that exhibited weak and delayed necrosis, whereas there was no discernible difference in blister lesions, canker, or wilting symptoms. Notably, this mutant caused canker similar to that of the wild-type strain, but caused mild wilting in tomato. This mutant carried a transposon in a chromosomal gene, called Clavibactervirulence gene A1 (cviA1). CviA1 encodes a 180-amino acid protein with a signal peptide (SP) at the N-terminus and two putative transmembrane domains (TMs) at the C-terminus. Interestingly, deletion of the SP or the C-terminus, including the two putative TMs, in CviA1 failed to restore full necrosis in the mutant, highlighting the importance of protein secretion and the putative TMs for necrosis. A paralog of cviA1, cviA2 is located on the large plasmid pCM2 of C. michiganensis. Despite its high similarity to cviA1, the introduction of cviA2 into the cviA1 mutant strain did not restore virulence. Similarly, the introduction of cviA1 into the Clavibacter capsici type strain PF008, which initially lacks cviA1, did not enhance necrosis symptoms. These results reveals that the chromosomal cviA1 gene in C. michiganensis plays an important role in necrosis development in N. benthamiana leaves.
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Affiliation(s)
- In Sun Hwang
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, the Republic of Korea
| | - Eom-Ji Oh
- Plant Immunity Research Center, Seoul National University, Seoul 08826, the Republic of Korea
| | - Chang-Sik Oh
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, the Republic of Korea; Plant Immunity Research Center, Seoul National University, Seoul 08826, the Republic of Korea; Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, the Republic of Korea; Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, the Republic of Korea.
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2
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Oelmüller R, Tseng YH, Gandhi A. Signals and Their Perception for Remodelling, Adjustment and Repair of the Plant Cell Wall. Int J Mol Sci 2023; 24:ijms24087417. [PMID: 37108585 PMCID: PMC10139151 DOI: 10.3390/ijms24087417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/04/2023] [Accepted: 04/08/2023] [Indexed: 04/29/2023] Open
Abstract
The integrity of the cell wall is important for plant cells. Mechanical or chemical distortions, tension, pH changes in the apoplast, disturbance of the ion homeostasis, leakage of cell compounds into the apoplastic space or breakdown of cell wall polysaccharides activate cellular responses which often occur via plasma membrane-localized receptors. Breakdown products of the cell wall polysaccharides function as damage-associated molecular patterns and derive from cellulose (cello-oligomers), hemicelluloses (mainly xyloglucans and mixed-linkage glucans as well as glucuronoarabinoglucans in Poaceae) and pectins (oligogalacturonides). In addition, several types of channels participate in mechanosensing and convert physical into chemical signals. To establish a proper response, the cell has to integrate information about apoplastic alterations and disturbance of its wall with cell-internal programs which require modifications in the wall architecture due to growth, differentiation or cell division. We summarize recent progress in pattern recognition receptors for plant-derived oligosaccharides, with a focus on malectin domain-containing receptor kinases and their crosstalk with other perception systems and intracellular signaling events.
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Affiliation(s)
- Ralf Oelmüller
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Department of Plant Physiology, Friedrich-Schiller-University, 07743 Jena, Germany
| | - Yu-Heng Tseng
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Department of Plant Physiology, Friedrich-Schiller-University, 07743 Jena, Germany
| | - Akanksha Gandhi
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Department of Plant Physiology, Friedrich-Schiller-University, 07743 Jena, Germany
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3
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Deletion of pbpC Enhances Bacterial Pathogenicity on Tomato by Affecting Biofilm Formation, Exopolysaccharides Production, and Exoenzyme Activities in Clavibacter michiganensis. Int J Mol Sci 2023; 24:ijms24065324. [PMID: 36982399 PMCID: PMC10049144 DOI: 10.3390/ijms24065324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 02/14/2023] [Accepted: 03/07/2023] [Indexed: 03/18/2023] Open
Abstract
Penicillin-binding proteins (PBPs) are considered essential for bacterial peptidoglycan biosynthesis and cell wall assembly. Clavibacter michiganensis is a representative Gram-positive bacterial species that causes bacterial canker in tomato. pbpC plays a significant role in maintaining cell morphological characteristics and stress responses in C. michiganensis. The current study demonstrated that the deletion of pbpC commonly enhances bacterial pathogenicity in C. michiganensis and revealed the mechanisms through which this occurs. The expression of interrelated virulence genes, including celA, xysA, xysB, and pelA, were significantly upregulated in △pbpC mutants. Compared with those in wild-type strains, exoenzyme activities, the formation of biofilm, and the production of exopolysaccharides (EPS) were significantly increased in △pbpC mutants. It is noteworthy that EPS were responsible for the enhancement in bacterial pathogenicity, with the degree of necrotic tomato stem cankers intensifying with the injection of a gradient of EPS from C. michiganensis. These findings highlight new insights into the role of pbpC affecting bacterial pathogenicity, with an emphasis on EPS, advancing the current understanding of phytopathogenic infection strategies for Gram-positive bacteria.
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Xu X, Li J, Yang X, Zhang L, Wang S, Shen G, Hui B, Xiao J, Zhou C, Wang X, Zhao J, Xiang W. Epicoccum spp. Causing Maize Leaf Spot in Heilongjiang Province, China. PLANT DISEASE 2022; 106:3050-3060. [PMID: 35612576 DOI: 10.1094/pdis-09-21-1948-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Maize leaf spot occurs worldwide and affects maize production. Maize can be infected by several pathogens causing leaf spot, such as Bipolaris zeicola, Bipolaris maydis, Curvularia species, Alternaria species, etc. In the current study, 30 Epicoccum isolates recovered from symptomatic maize leaves were identified based on morphological characteristics, pathogenicity, and multilocus sequence analyses of nuLSU, ITS, tub2, and rpb2. These maize isolates were grouped into five Epicoccum species, including E. nigrum, E. layuense, E. sorghinum, E. latusicollum, and E. pneumoniae. Pathogenicity tests showed that all five Epicoccum species could produce small ellipse- and spindle-shaped spots on maize leaves. The lesion center was grayish yellow to dark gray and surrounded by a chlorotic area. Furthermore, the Epicoccum isolates exhibited high pathogenicity to 20 main maize varieties of Heilongjiang Province but showed different sensitivities to the commonly used fungicides carbendazim and tebuconazole. In addition, these Epicoccum isolates showed different production capacity of pectinase, cellulase, protease, amylase, laccase, and gelatinase, but all showed high lipase activity. This is the first report globally of E. layuense, E. latusicollum, and E. pneumoniae as causal agents of maize leaf spot. E. pneumoniae was first reported as a plant pathogen.
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Affiliation(s)
- Xi Xu
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, P.R. China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, P.R. China
| | - Jingjing Li
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, P.R. China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, P.R. China
| | - Xilang Yang
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, P.R. China
| | - Li Zhang
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, P.R. China
| | - Shuo Wang
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, P.R. China
| | - Guijin Shen
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, P.R. China
| | - Bing Hui
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, P.R. China
| | - Jialei Xiao
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, P.R. China
| | - Changjian Zhou
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, P.R. China
| | - Xiangjing Wang
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, P.R. China
| | - Junwei Zhao
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, P.R. China
| | - Wensheng Xiang
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, P.R. China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, P.R. China
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Current Techniques to Study Beneficial Plant-Microbe Interactions. Microorganisms 2022; 10:microorganisms10071380. [PMID: 35889099 PMCID: PMC9317800 DOI: 10.3390/microorganisms10071380] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 06/28/2022] [Accepted: 07/05/2022] [Indexed: 02/04/2023] Open
Abstract
Many different experimental approaches have been applied to elaborate and study the beneficial interactions between soil bacteria and plants. Some of these methods focus on changes to the plant and others are directed towards assessing the physiology and biochemistry of the beneficial plant growth-promoting bacteria (PGPB). Here, we provide an overview of some of the current techniques that have been employed to study the interaction of plants with PGPB. These techniques include the study of plant microbiomes; the use of DNA genome sequencing to understand the genes encoded by PGPB; the use of transcriptomics, proteomics, and metabolomics to study PGPB and plant gene expression; genome editing of PGPB; encapsulation of PGPB inoculants prior to their use to treat plants; imaging of plants and PGPB; PGPB nitrogenase assays; and the use of specialized growth chambers for growing and monitoring bacterially treated plants.
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Osdaghi E, van der Wolf JM, Abachi H, Li X, De Boer S, Ishimaru CA. Bacterial ring rot of potato caused by Clavibacter sepedonicus: A successful example of defeating the enemy under international regulations. MOLECULAR PLANT PATHOLOGY 2022; 23:911-932. [PMID: 35142424 PMCID: PMC9190974 DOI: 10.1111/mpp.13191] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/20/2022] [Accepted: 01/24/2022] [Indexed: 05/03/2023]
Abstract
BACKGROUND Bacterial ring rot of potato (Solanum tuberosum) caused by the gram-positive coryneform bacterium Clavibacter sepedonicus is an important quarantine disease threatening the potato industry around the globe. Since its original description in 1906 in Germany, management of ring rot has been a major problem due to the seedborne nature (via seed tubers not true seeds) of the pathogen allowing the bacterium to be transmitted long distances via infected tubers. DISEASE SYMPTOMS On growing potato plants: interveinal chlorosis on leaflets leading to necrotic areas and systemic wilt. On infected tubers: vascular tissues become yellowish brown with a cheesy texture due to bacterial colonization and decay. HOST RANGE Potato is the main host of the pathogen, but natural infection also occurs on eggplant, tomato, and sugar beet. TAXONOMIC STATUS OF THE PATHOGEN Class: Actinobacteria; Order: Actinomycetales; Family: Microbacteriaceae; Genus: Clavibacter; Species: Clavibacter sepedonicus (Spieckermann and Kotthoff 1914) Li et al. 2018. SYNONYMS (NONPREFERRED SCIENTIFIC NAMES) Aplanobacter sepedonicus; Bacterium sepedonicum; Corynebacterium sepedonicum; Corynebacterium michiganense pv. sepedonicum; Clavibacter michiganensis subsp. sepedonicus. MICROBIOLOGICAL PROPERTIES Gram-positive, club-shaped cells with creamy to yellowish-cream colonies for which the optimal growth temperature is 20-23°C. DISTRIBUTION Asia (China, Japan, Kazakhstan, Nepal, North Korea, Pakistan, South Korea, Uzbekistan, the Asian part of Russia), Europe (Belarus, Bulgaria, Czech Republic, Estonia, Finland, Georgia, Germany, Greece, Hungary, Latvia, Lithuania, Norway, Poland, Romania, European part of Russia, Slovakia, Spain, Sweden, Turkey, Ukraine), and North America (Canada, Mexico, USA). PHYTOSANITARY CATEGORIZATION CORBSE: EPPO A2 list no. 51. EU; Annex designation I/A2.
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Affiliation(s)
- Ebrahim Osdaghi
- Department of Plant ProtectionCollege of AgricultureUniversity of TehranKarajIran
| | - Jan M. van der Wolf
- Business Unit Biointeractions and Plant HealthWageningen University and ResearchWageningenNetherlands
| | - Hamid Abachi
- Department of Plant ProtectionCollege of AgricultureUniversity of TehranKarajIran
| | - Xiang Li
- Canadian Food Inspection Agency, Charlottetown LaboratoryCharlottetownPECanada
| | - Solke H. De Boer
- Canadian Food Inspection Agency, Charlottetown LaboratoryCharlottetownPECanada
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Park IW, Hwang IS, Oh EJ, Kwon CT, Oh CS. Nicotiana benthamiana, a Surrogate Host to Study Novel Virulence Mechanisms of Gram-Positive Bacteria, Clavibacter michiganensis, and C. capsici in Plants. FRONTIERS IN PLANT SCIENCE 2022; 13:876971. [PMID: 35620684 PMCID: PMC9127732 DOI: 10.3389/fpls.2022.876971] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/25/2022] [Indexed: 06/11/2023]
Abstract
Clavibacter michiganensis is a Gram-positive bacterium that causes bacterial canker and wilting in host plants like tomato. Two major virulence genes encoding a cellulase (celA) and a putative serine protease (pat-1) have been reported. Here we show that Nicotiana benthamiana, a commonly used model plant for studying molecular plant-pathogen interactions, is a surrogate host of C. michiganensis and C. capsici. When a low concentration of two Clavibacter species, C. michiganensis and C. capsici, were infiltrated into N. benthamiana leaves, they caused blister-like lesions closely associated with cell death and the generation of reactive oxygen species and proliferated significantly like a pathogenic bacterium. By contrast, they did not cause any disease symptoms in N. tabacum leaves. The celA and pat-1 mutants of C. michiganensis still caused blister-like lesions and cankers like the wild-type strain. When a high concentration of two Clavibacter species and two mutant strains were infiltrated into N. benthamiana leaves, all of them caused strong and rapid necrosis. However, only C. michiganensis strains, including the celA and pat-1 mutants, caused wilting symptoms when it was injected into stems. When two Clavibacter species and two mutants were infiltrated into N. tabacum leaves at the high concentration, they (except for the pat-1 mutant) caused a strong hypersensitive response. These results indicate that C. michiganensis causes blister-like lesions, canker, and wilting in N. benthamiana, and celA and pat-1 genes are not necessary for the development of these symptoms. Overall, N. benthamiana is a surrogate host of Clavibacter species, and their novel virulence factors are responsible for disease development in this plant.
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Affiliation(s)
- In Woong Park
- Department of Horticultural Biotechnology, Kyung Hee University, Yongin, South Korea
| | - In Sun Hwang
- Department of Horticultural Biotechnology, Kyung Hee University, Yongin, South Korea
| | - Eom-Ji Oh
- Department of Horticultural Biotechnology, Kyung Hee University, Yongin, South Korea
| | - Choon-Tak Kwon
- Department of Horticultural Biotechnology, Kyung Hee University, Yongin, South Korea
| | - Chang-Sik Oh
- Department of Horticultural Biotechnology, Kyung Hee University, Yongin, South Korea
- Graduate School of Green-Bio Science, Kyung Hee University, Yongin, South Korea
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Dora S, Terrett OM, Sánchez-Rodríguez C. Plant-microbe interactions in the apoplast: Communication at the plant cell wall. THE PLANT CELL 2022; 34:1532-1550. [PMID: 35157079 PMCID: PMC9048882 DOI: 10.1093/plcell/koac040] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 01/29/2022] [Indexed: 05/20/2023]
Abstract
The apoplast is a continuous plant compartment that connects cells between tissues and organs and is one of the first sites of interaction between plants and microbes. The plant cell wall occupies most of the apoplast and is composed of polysaccharides and associated proteins and ions. This dynamic part of the cell constitutes an essential physical barrier and a source of nutrients for the microbe. At the same time, the plant cell wall serves important functions in the interkingdom detection, recognition, and response to other organisms. Thus, both plant and microbe modify the plant cell wall and its environment in versatile ways to benefit from the interaction. We discuss here crucial processes occurring at the plant cell wall during the contact and communication between microbe and plant. Finally, we argue that these local and dynamic changes need to be considered to fully understand plant-microbe interactions.
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Advances in the Characterization of the Mechanism Underlying Bacterial Canker Development and Tomato Plant Resistance. HORTICULTURAE 2022. [DOI: 10.3390/horticulturae8030209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Bacterial canker caused by the Gram-positive actinobacterium Clavibacter michiganensis is one of the most serious bacterial diseases of tomatoes, responsible for 10–100% yield losses worldwide. The pathogen can systemically colonize tomato vascular bundles, leading to wilting, cankers, bird’s eye lesions, and plant death. Bactericidal agents are insufficient for managing this disease, because the pathogen can rapidly migrate through the vascular system of plants and induce systemic symptoms. Therefore, the use of resistant cultivars is necessary for controlling this disease. We herein summarize the pathogenicity of C. michiganensis in tomato plants and the molecular basis of bacterial canker pathogenesis. Moreover, advances in the characterization of resistance to this pathogen in tomatoes are introduced, and the status of genetics-based research is described. Finally, we propose potential future research on tomato canker resistance. More specifically, there is a need for a thorough analysis of the host–pathogen interaction, the accelerated identification and annotation of resistance genes and molecular mechanisms, the diversification of resistance resources or exhibiting broad-spectrum disease resistance, and the production of novel and effective agents for control or prevention. This review provides researchers with the relevant information for breeding tomato cultivars resistant to bacterial cankers.
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Oh EJ, Hwang IS, Park IW, Oh CS. Comparative Genome Analyses of Clavibacter michiganensis Type Strain LMG7333 T Reveal Distinct Gene Contents in Plasmids From Other Clavibacter Species. Front Microbiol 2022; 12:793345. [PMID: 35178040 PMCID: PMC8844524 DOI: 10.3389/fmicb.2021.793345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 12/16/2021] [Indexed: 11/13/2022] Open
Abstract
Clavibacter michiganensis, a Gram-positive, plant-pathogenic bacterium belonging to Actinobacteria, is a causal agent of bacterial canker in tomatoes. Although LMG7333T is the type strain of C. michiganensis, it has not been used in many studies, probably because of a lack of the complete genome sequence being available. Therefore, in this study, the complete genome sequence of this type strain was obtained, and comparative genome analysis was conducted with the genome sequences of two other C. michiganensis strains and type strains of Clavibacter species, of which their complete genome sequences are available. C. michiganensis LMG7333T carries one chromosome and two plasmids, pCM1 and pCM2, like two other C. michiganensis strains. All three chromosomal DNA sequences were almost identical. However, the DNA sequences of two plasmids of LMG7333T are similar to those of UF1, but different from those of NCPPB382, indicating that both plasmids carry distinct gene content among C. michiganensis strains. Moreover, 216 protein-coding sequences (CDSs) were only present in the LMG7333T genome compared with type strains of other Clavibacter species. Among these 216 CDSs, approximately 83% were in the chromosome, whereas others were in both plasmids (more than 6% in pCM1 and 11% in pCM2). However, the ratio of unique CDSs of the total CDSs in both plasmids were approximately 38% in pCM1 and 30% in pCM2, indicating that the high gene content percentage in both plasmids of C. michiganensis are different from those of other Clavibacter species, and plasmid DNAs might be derived from different origins. A virulence assay with C. michiganensis LMG7333T using three different inoculation methods, root-dipping, leaf-clipping, and stem injection, resulted in typical disease symptoms, including wilting and canker in tomato. Altogether, our results indicate that two plasmids of C. michiganensis carry distinct gene content, and the genome information of the type strain LMG7333T will help to understand the genetic diversity of the two plasmids of Clavibacter species, including C. michiganensis.
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Affiliation(s)
- Eom-Ji Oh
- Department of Horticultural Biotechnology, College of Life Science, Kyung Hee University, Yongin, South Korea
| | - In Sun Hwang
- Department of Horticultural Biotechnology, College of Life Science, Kyung Hee University, Yongin, South Korea
| | - In Woong Park
- Department of Horticultural Biotechnology, College of Life Science, Kyung Hee University, Yongin, South Korea
| | - Chang-Sik Oh
- Department of Horticultural Biotechnology, College of Life Science, Kyung Hee University, Yongin, South Korea.,Graduate School of Biotechnology, Kyung Hee University, Yongin, South Korea
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Jang H, Kim ST, Sang MK. Suppressive Effect of Bioactive Extracts of Bacillus sp. H8-1 and Bacillus sp. K203 on Tomato Wilt Caused by Clavibacter michiganensis subsp. michiganensis. Microorganisms 2022; 10:microorganisms10020403. [PMID: 35208859 PMCID: PMC8880269 DOI: 10.3390/microorganisms10020403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/30/2022] [Accepted: 02/07/2022] [Indexed: 12/10/2022] Open
Abstract
Tomatoes are cultivated worldwide, and are economically important. Clavibacter michiganensis subsp. michiganensis (Cmm) is a pathogen that causes canker and wilting in tomatoes, resulting in serious damage to tomato plants. We aimed to control Cmm proliferation using substances produced by useful microorganisms. The water extracts of strains H8-1 and K203 inhibited wilting caused by Cmm and slowed the pathogenic colonization in tomato plants. The relative expressions of celA, celB, pat1, and pelA of Cmm treated with the bacterial water extracts were reduced by 0.41-, 0.01-, 0.15-, and 0.14-fold for H8-1, respectively, and 0.45-, 0.02-, 0.13-, and 0.13-fold for K203, respectively, compared to controls at 72 h after treatments. In tomato plants inoculated with Cmm, when water extracts of H8-1 and K203 were treated, relative expression of ACO encoding 1-aminocyclopropane-1-carboxylic acid oxidase was suppressed by 0.26- and 0.23-fold, respectively, while PR1a was increased by 1.94- and 2.94-fold, respectively; PI2 expression was increased by 3.27-fold in water extract of H8-1-treated plants. As antioxidant enzymes of plants inoculated with Cmm, peroxidase and glutathione peroxidase levels were increased in K203-water-extract-treated plants, and catalase was increased in the case of the H8-1 water extract at 10 days after inoculation. In terms of soil enzyme activity, each water extract tended to increase urease activity and microbial diversity; in addition, K203 water extract increased plant growth. Thus, H8-1 and K203 water extracts can be used as potential biocontrol agents against Cmm.
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Affiliation(s)
- Hwajin Jang
- Division of Agricultural Microbiology, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Korea; (H.J.); (S.T.K.)
- Department of Applied Bioscience, Dong-A University, Busan 49315, Korea
| | - Sang Tae Kim
- Division of Agricultural Microbiology, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Korea; (H.J.); (S.T.K.)
- Department of Applied Bioscience, Dong-A University, Busan 49315, Korea
| | - Mee Kyung Sang
- Division of Agricultural Microbiology, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Korea; (H.J.); (S.T.K.)
- Correspondence: ; Tel.: +82-63-238-3055; Fax: +82-63-238-3834
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12
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Abebe AM, Oh CS, Kim HT, Choi G, Seo E, Yeam I, Lee JM. QTL-Seq Analysis for Identification of Resistance Loci to Bacterial Canker in Tomato. FRONTIERS IN PLANT SCIENCE 2022; 12:809959. [PMID: 35154207 PMCID: PMC8826648 DOI: 10.3389/fpls.2021.809959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 12/03/2021] [Indexed: 06/14/2023]
Abstract
Bacterial canker caused by Clavibacter michiganensis (Cm) is one of the most economically important vascular diseases causing unilateral leaf wilting, stem canker, a bird's-eye lesion on fruit, and whole plant wilting in tomato. There is no commercially available cultivar with bacterial canker resistance, and genomics-assisted breeding can accelerate the development of cultivars with enhanced resistance. Solanum lycopersicum "Hawaii 7998" was found to show bacterial canker resistance. A Quantitative trait loci (QTL)-seq was performed to identify the resistance loci using 909 F2 individuals derived from a cross between S. lycopersicum "E6203" (susceptible) and "Hawaii 7998," and a genomic region (37.24-41.15 Mb) associated with bacterial canker resistance on chromosome 6 (Rcm6) was found. To dissect the Rcm6 region, 12 markers were developed and several markers were associated with the resistance phenotypes. Among the markers, the Rcm6-9 genotype completely matched with the phenotype in the 47 cultivars. To further validate the Rcm6 as a resistance locus and the Rcm6-9 efficiency, subsequent analysis using F2 and F3 progenies was conducted. The progeny individuals with homozygous resistance allele at the Rcm6-9 showed significantly lower disease severity than those possessing homozygous susceptibility alleles. Genomes of five susceptible and two resistant cultivars were analyzed and previously known R-genes were selected to find candidate genes for Rcm6. Nucleotide-binding leucine-rich repeat, receptor-like kinase, and receptor-like protein were identified to have putative functional mutations and show differential expression upon the Cm infection. The DNA markers and candidate genes will facilitate marker-assisted breeding and provide genetic insight of bacterial canker resistance in tomato.
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Affiliation(s)
- Alebel Mekuriaw Abebe
- Department of Horticultural Science, Kyungpook National University, Daegu, South Korea
| | - Chang-Sik Oh
- Department of Horticultural Biotechnology, College of Life Science, Kyung Hee University, Yongin, South Korea
| | - Hyoung Tae Kim
- Department of Horticultural Science, Kyungpook National University, Daegu, South Korea
| | - Giwon Choi
- Department of Horticultural Science, Kyungpook National University, Daegu, South Korea
| | - Eunyoung Seo
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Inhwa Yeam
- Department of Horticulture and Breeding, Andong National University, Andong, South Korea
| | - Je Min Lee
- Department of Horticultural Science, Kyungpook National University, Daegu, South Korea
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13
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Hwang IS, Oh EJ, Song E, Park IW, Lee Y, Sohn KH, Choi D, Oh CS. An Apoplastic Effector Pat-1 Cm of the Gram-Positive Bacterium Clavibacter michiganensis Acts as Both a Pathogenicity Factor and an Immunity Elicitor in Plants. FRONTIERS IN PLANT SCIENCE 2022; 13:888290. [PMID: 35432427 PMCID: PMC9006514 DOI: 10.3389/fpls.2022.888290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/14/2022] [Indexed: 05/09/2023]
Abstract
Clavibacter michiganensis, a Gram-positive plant-pathogenic bacterium, utilizes apoplastic effectors for disease development in host plants. Here, we determine the roles of Pat-1Cm (a putative serine protease) in pathogenicity and plant immunity. Pat-1Cm was found to be a genuine secreted protein, and the secreted mature form did not carry the first 33 amino acids predicted to be a signal peptide (SP). The pat-1Cm mutant impaired to cause wilting, but still caused canker symptom in tomato. Moreover, this mutant failed to trigger the hypersensitive response (HR) in a nonhost Nicotiana tabacum. Among orthologs and paralogs of pat-1Cm , only chp-7Cs from Clavibacter sepedonicus, a potato pathogen, successfully complemented pat-1Cm function in pathogenicity in tomato, whereas all failed to complement pat-1Cm function in HR induction in N. tabacum. Based on the structural prediction, Pat-1Cm carried a catalytic triad for putative serine protease, and alanine substitution of any amino acids in the triad abolished both pathogenicity and HR-inducing activities of Pat-1Cm in C. michiganensis. Ectopic expression of pat-1Cm with an SP from tobacco secreted protein triggered HR in N. tabacum, but not in tomato, whereas a catalytic triad mutant failed to induce HR. Inoculation of the pat-1Cm mutant mixed with the mutant of another apoplastic effector CelA (cellulase) caused severe wilting in tomato, indicating that these two apoplastic effectors can functionally cooperate in pathogenicity. Overall, these results indicate that Pat-1Cm is a distinct secreted protein carrying a functional catalytic triad for serine protease and this enzymatic activity might be critical for both pathogenicity and HR-eliciting activities of Pat-1Cm in plants.
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Affiliation(s)
- In Sun Hwang
- Department of Horticultural Biotechnology, College of Life Science, Kyung Hee University, Yongin, South Korea
| | - Eom-Ji Oh
- Department of Horticultural Biotechnology, College of Life Science, Kyung Hee University, Yongin, South Korea
| | - Eunbee Song
- Department of Horticultural Biotechnology, College of Life Science, Kyung Hee University, Yongin, South Korea
| | - In Woong Park
- Department of Horticultural Biotechnology, College of Life Science, Kyung Hee University, Yongin, South Korea
| | - Yoonyoung Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, South Korea
| | - Kee Hoon Sohn
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, South Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, South Korea
| | - Doil Choi
- Department of Plant Science, Plant Immunity Research Center, Plant Genomics and Breeding Institute, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| | - Chang-Sik Oh
- Department of Horticultural Biotechnology, College of Life Science, Kyung Hee University, Yongin, South Korea
- Graduate School of Biotechnology, Kyung Hee University, Yongin, South Korea
- *Correspondence: Chang-Sik Oh,
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14
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Chen X, Tan Q, Lyu Q, Yu C, Jiang N, Li J, Luo L. Unmarked Gene Editing in Clavibacter michiganensis Using CRISPR/Cas9 and 5-Fluorocytosine Counterselection. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2022; 35:4-14. [PMID: 34543054 DOI: 10.1094/mpmi-07-21-0179-ta] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Plant-pathogenic bacteria in the genus Clavibacter are important quarantine species that cause considerable economic loss worldwide. The development of effective gene editing techniques and additional selectable markers is essential to expedite gene functional analysis in this important Gram-positive genus. The current study details a highly efficient unmarked CRISPR/Cas9-mediated gene editing system in Clavibacter michiganensis, which couples the expression of cas9 and single-guide RNA with homology-directed repair templates and the negative selectable marker codA::upp within a single plasmid. Initial experiments indicated that CRISPR/Cas9-mediated transformation could be utilized for both site-directed mutagenesis, in which an A to G point mutation was introduced at the 128th nucleotide of the C. michiganensis rpsL gene to generate a streptomycin-resistant mutant, and complete gene knockout, in which the deletion of the C. michiganensis celA or katA genes resulted in transformants that lacked cellulase and catalase activity, respectively. In subsequent experiments, the introduction of the codA::upp cassette into the transformation vector facilitated the counterselection of unmarked transformants by incubation in the absence of the selective antibiotic, followed by plating on M9 agar containing 5-fluorocytosine at 100 μg/ml, in which an unmarked katA mutant lacking the transformation vector was recovered. Compared with conventional homologous recombination, the unmarked CRISPR/Cas9-mediated system was more useful and convenient because it allowed the template plasmid to be reused repeatedly to facilitate the editing of multiple genes, which constitutes a major advancement that could revolutionize research into C. michiganensis and other Clavibacter spp.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Xing Chen
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, Beijing Key Laboratory of Seed Disease Testing and Control, China Agricultural University; Beijing, P. R. China
| | - Qing Tan
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, Beijing Key Laboratory of Seed Disease Testing and Control, China Agricultural University; Beijing, P. R. China
| | - Qingyang Lyu
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, Beijing Key Laboratory of Seed Disease Testing and Control, China Agricultural University; Beijing, P. R. China
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, P. R. China
| | - Chengxuan Yu
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, Beijing Key Laboratory of Seed Disease Testing and Control, China Agricultural University; Beijing, P. R. China
| | - Na Jiang
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, Beijing Key Laboratory of Seed Disease Testing and Control, China Agricultural University; Beijing, P. R. China
| | - Jianqiang Li
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, Beijing Key Laboratory of Seed Disease Testing and Control, China Agricultural University; Beijing, P. R. China
| | - Laixin Luo
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, Beijing Key Laboratory of Seed Disease Testing and Control, China Agricultural University; Beijing, P. R. China
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15
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Valenzuela M, González M, Velásquez A, Dorta F, Montenegro I, Besoain X, Salvà-Serra F, Jaén-Luchoro D, Moore ERB, Seeger M. Analyses of Virulence Genes of Clavibacter michiganensis subsp. michiganensis Strains Reveal Heterogeneity and Deletions That Correlate with Pathogenicity. Microorganisms 2021; 9:microorganisms9071530. [PMID: 34361965 PMCID: PMC8305413 DOI: 10.3390/microorganisms9071530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 07/07/2021] [Accepted: 07/15/2021] [Indexed: 12/04/2022] Open
Abstract
Clavibacter michiganensis subsp. michiganensis (Cmm) is the causal agent of bacterial canker of tomato. Differences in virulence between Cmm strains have been reported. The aim of this study was the characterization of nine Cmm strains isolated in Chile to reveal the causes of their differences in virulence. The virulence assays in tomato seedlings revealed different levels of severity associated with the strains, with two highly virulent strains and one causing only mild symptoms. The two most virulent showed increased cellulase activity, and no cellulase activity was observed in the strain causing mild symptoms. In three strains, including the two most virulent strains, PCR amplification of the 10 virulence genes analyzed was observed. In the strain causing mild symptoms, no amplification was observed for five genes, including celA. Sequence and cluster analyses of six virulence genes grouped the strains, as has been previously reported, except for gene pelA1. Gene sequence analysis from the genomes of five Chilean strains revealed the presence of deletions in the virulence genes, celB, xysA, pat-1, and phpA. The results of this study allow us to establish correlations between the differences observed in disease severity and the presence/absence of genes and deletions not previously reported.
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Affiliation(s)
- Miryam Valenzuela
- Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química, Universidad Técnica Federico Santa María, Valparaíso 2390123, Chile;
- Centro de Biotecnología “Dr. Daniel Alkalay Lowitt”, Universidad Técnica Federico Santa María, Valparaíso 2390136, Chile;
- Correspondence: (M.V.); (M.S.)
| | - Marianela González
- Instituto de Química, Pontificia Universidad Católica de Valparaíso, Valparaíso 2373223, Chile;
| | - Alexis Velásquez
- Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química, Universidad Técnica Federico Santa María, Valparaíso 2390123, Chile;
- Centro de Biotecnología “Dr. Daniel Alkalay Lowitt”, Universidad Técnica Federico Santa María, Valparaíso 2390136, Chile;
| | - Fernando Dorta
- Centro de Biotecnología “Dr. Daniel Alkalay Lowitt”, Universidad Técnica Federico Santa María, Valparaíso 2390136, Chile;
| | - Iván Montenegro
- Escuela de Obstetricia y Puericultura, Facultad de Medicina, Universidad de Valparaíso, Valparaíso 2540064, Chile;
| | - Ximena Besoain
- Escuela de Agronomía, Pontificia Universidad Católica de Valparaíso, Quillota 2260000, Chile;
| | - Francisco Salvà-Serra
- Department of Infectious Diseases, Institute for Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-41346 Gothenburg, Sweden; (F.S.-S.); (D.J.-L.); (E.R.B.M.)
- Culture Collection University of Gothenburg (CCUG), Sahlgrenska Academy, University of Gothenburg, SE-41346 Gothenburg, Sweden
- Microbiology, Department of Biology, University of the Balearic Islands, 071 22 Palma de Mallorca, Spain
| | - Daniel Jaén-Luchoro
- Department of Infectious Diseases, Institute for Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-41346 Gothenburg, Sweden; (F.S.-S.); (D.J.-L.); (E.R.B.M.)
- Culture Collection University of Gothenburg (CCUG), Sahlgrenska Academy, University of Gothenburg, SE-41346 Gothenburg, Sweden
| | - Edward R. B. Moore
- Department of Infectious Diseases, Institute for Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-41346 Gothenburg, Sweden; (F.S.-S.); (D.J.-L.); (E.R.B.M.)
- Culture Collection University of Gothenburg (CCUG), Sahlgrenska Academy, University of Gothenburg, SE-41346 Gothenburg, Sweden
| | - Michael Seeger
- Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química, Universidad Técnica Federico Santa María, Valparaíso 2390123, Chile;
- Centro de Biotecnología “Dr. Daniel Alkalay Lowitt”, Universidad Técnica Federico Santa María, Valparaíso 2390136, Chile;
- Correspondence: (M.V.); (M.S.)
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16
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Peritore-Galve FC, Tancos MA, Smart CD. Bacterial Canker of Tomato: Revisiting a Global and Economically Damaging Seedborne Pathogen. PLANT DISEASE 2021; 105:1581-1595. [PMID: 33107795 DOI: 10.1094/pdis-08-20-1732-fe] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The gram-positive actinobacterium Clavibacter michiganensis is the causal agent of bacterial canker of tomato, an economically impactful disease with a worldwide distribution. This seedborne pathogen systemically colonizes tomato xylem leading to unilateral leaflet wilt, marginal leaf necrosis, stem and petiole cankers, and plant death. Additionally, splash dispersal of the bacterium onto fruit exteriors causes bird's-eye lesions, which are characterized as necrotic centers surrounded by white halos. The pathogen can colonize developing seeds systemically through xylem and through penetration of fruit tissues from the exterior. There are currently no commercially available resistant cultivars, and bactericidal sprays have limited efficacy for managing the disease once the pathogen is in the vascular system. In this review, we summarize research on epidemiology, host colonization, the bacterial genetics underlying virulence, and management of bacterial canker. Finally, we highlight important areas of research into this pathosystem that have the potential to generate new strategies for prevention and mitigation of bacterial canker.
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Affiliation(s)
- F Christopher Peritore-Galve
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Geneva, NY 14456
| | - Matthew A Tancos
- Foreign Disease-Weed Science Research Unit, United States Department of Agriculture-Agricultural Research Service, Frederick, MD 21702
| | - Christine D Smart
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Geneva, NY 14456
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17
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Host Cell Wall Damage during Pathogen Infection: Mechanisms of Perception and Role in Plant-Pathogen Interactions. PLANTS 2021; 10:plants10020399. [PMID: 33669710 PMCID: PMC7921929 DOI: 10.3390/plants10020399] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/15/2021] [Accepted: 02/16/2021] [Indexed: 12/21/2022]
Abstract
The plant cell wall (CW) is a complex structure that acts as a mechanical barrier, restricting the access to most microbes. Phytopathogenic microorganisms can deploy an arsenal of CW-degrading enzymes (CWDEs) that are required for virulence. In turn, plants have evolved proteins able to inhibit the activity of specific microbial CWDEs, reducing CW damage and favoring the accumulation of CW-derived fragments that act as damage-associated molecular patterns (DAMPs) and trigger an immune response in the host. CW-derived DAMPs might be a component of the complex system of surveillance of CW integrity (CWI), that plants have evolved to detect changes in CW properties. Microbial CWDEs can activate the plant CWI maintenance system and induce compensatory responses to reinforce CWs during infection. Recent evidence indicates that the CWI surveillance system interacts in a complex way with the innate immune system to fine-tune downstream responses and strike a balance between defense and growth.
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18
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Rocha J, Shapiro LR, Kolter R. A horizontally acquired expansin gene increases virulence of the emerging plant pathogen Erwinia tracheiphila. Sci Rep 2020; 10:21743. [PMID: 33303810 PMCID: PMC7729394 DOI: 10.1038/s41598-020-78157-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 11/09/2020] [Indexed: 12/16/2022] Open
Abstract
Erwinia tracheiphila is a bacterial plant pathogen that causes a fatal wilt infection in some cucurbit crop plants. Wilt symptoms are thought to be caused by systemic bacterial colonization through xylem that impedes sap flow. However, the genetic determinants of within-plant movement are unknown for this pathogen species. Here, we find that E. tracheiphila has horizontally acquired an operon with a microbial expansin (exlx) gene adjacent to a glycoside hydrolase family 5 (gh5) gene. Plant inoculation experiments with deletion mutants in the individual genes (Δexlx and Δgh5) and the full operon (Δexlx-gh5) resulted in decreased severity of wilt symptoms, decreased mortality rate, and impaired systemic colonization compared to the Wt strain. Co-inoculation experiments with Wt and Δexlx-gh5 rescued the movement defect of the mutant strain, suggesting that expansin and GH5 function extracellularly. Together, these results show that expansin-GH5 contributes to systemic movement through xylem, leading to rapid wilt symptom development and higher rates of plant death. The presence of expansin genes in diverse species of bacterial and fungal wilt-inducing pathogens suggests that microbial expansin proteins may be an under-appreciated virulence factor for many pathogen species.
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Affiliation(s)
- Jorge Rocha
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.
- Conacyt-Centro de Investigación y Desarrollo en Agrobiotecnología Alimentaria, San Agustin Tlaxiaca, 42163, Hidalgo, Mexico.
| | - Lori R Shapiro
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Roberto Kolter
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
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19
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Hwang IS, Oh EJ, Oh CS. Transcriptional Changes of Plant Defense-Related Genes in Response to Clavibacter Infection in Pepper and Tomato. THE PLANT PATHOLOGY JOURNAL 2020; 36:450-458. [PMID: 33082729 PMCID: PMC7542022 DOI: 10.5423/ppj.oa.07.2020.0124] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/20/2020] [Accepted: 08/24/2020] [Indexed: 06/11/2023]
Abstract
Pepper and tomato plants infected with two Clavibacter species, C. capsici and C. michiganensis have shown different patterns of disease development depending on their virulence. Here, we investigated how pepper and tomato plants respond to infection by the high-virulent or low-virulent Clavibacter strains. For this, we chose two strains of each Clavibacter species to show different virulence level in the host plants. Although low-virulent strains showed less disease symptoms, they grew almost the same level as the high-virulent strains in both plants. To further examine the response of host plants to Clavibacter infection, we analyzed the expression patterns of plant defense-related genes in the leaves inoculated with different strains of C. capsici and C. michiganensis. Pepper plants infected with high-virulent C. capsici strain highly induced the expression of CaPR1, CaDEF, CaPR4b, CaPR10, and CaLOX1 at 5 days after inoculation (dai), but their expression was much less in low-virulent Clavibacter infection. Expression of CaSAR8.2 was induced at 2 dai, regardless of virulence level. Expression of GluA, Pin2, and PR2 in tomato plants infected with high-virulent C. michiganensis were much higher at 5 dai, compared with mock or low-virulent strain. Expression of PR1a, Osmotin-like, Chitinase, and Chitinase class 2 was increased, regardless of virulence level. Expression of LoxA gene was not affected by Clavibacter inoculation. These results suggested that Clavibacter infection promotes induction of certain defense-related genes in host plants and that differential expression of those genes by low-virulent Clavibacter infection might be affected by their endophytic lifestyle in plants.
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Affiliation(s)
- In Sun Hwang
- Department of Horticultural Biotechnology, College of Life Science, Kyung Hee University, Yongin 704, Korea
| | - Eom-Ji Oh
- Graduate School of Biotechnology, Kyung Hee University, Yongin 17104, Korea
| | - Chang-Sik Oh
- Department of Horticultural Biotechnology, College of Life Science, Kyung Hee University, Yongin 704, Korea
- Graduate School of Biotechnology, Kyung Hee University, Yongin 17104, Korea
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20
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Hwang IS, Lee HM, Oh E, Lee S, Heu S, Oh C. Plasmid composition and the chpG gene determine the virulence level of Clavibacter capsici natural isolates in pepper. MOLECULAR PLANT PATHOLOGY 2020; 21:808-819. [PMID: 32196887 PMCID: PMC7214350 DOI: 10.1111/mpp.12932] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 02/21/2020] [Accepted: 02/22/2020] [Indexed: 05/23/2023]
Abstract
The gram-positive bacterial species Clavibacter capsici causes necrosis and canker in pepper plants. Genomic and functional analyses of C. capsici type strain PF008 have shown that multiple virulence genes exist in its two plasmids. We aimed to identify the key determinants that control the virulence of C. capsici. Pepper leaves inoculated with 54 natural isolates exhibited significant variation in the necrosis. Six isolates showed very low virulence, but their population titres in plants were not significantly different from those of the highly virulent isolates. All six isolates lacked the pCM1Cc plasmid that carries chpG, which has been shown to be required for virulence and encodes a putative serine protease, but two of them, isolates 1,106 and 1,207, had the intact chpG elsewhere in the genome. Genomic analysis of these two isolates revealed that chpG was located in the pCM2Cc plasmid, and two highly homologous regions were present next to the chpG locus. The chpG expression in isolate 1,106 was not induced in plants. Introduction of chpG of the PF008 strain into the six low-virulence isolates restored their virulence to that of PF008. Our findings indicate that there are at least three different variant groups of C. capsici and that the plasmid composition and the chpG gene are critical for determining the virulence level. Moreover, our findings also indicate that the virulence level of C. capsici does not directly correlate with bacterial titres in plants.
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Affiliation(s)
- In Sun Hwang
- Department of Horticultural BiotechnologyCollege of Life SciencesKyung Hee UniversityYonginSouth Korea
| | - Hyo Min Lee
- Department of Horticultural BiotechnologyCollege of Life SciencesKyung Hee UniversityYonginSouth Korea
| | - Eom‐Ji Oh
- Department of Horticultural BiotechnologyCollege of Life SciencesKyung Hee UniversityYonginSouth Korea
| | - Seungdon Lee
- Planning and Coordination DivisionNational Institute of Agricultural SciencesRural Development AdministrationWanjuSouth Korea
| | - Sunggi Heu
- Crop Cultivation and Environment Research DivisionNational Institute of Crop ScienceRural Development AdministrationSuwonSouth Korea
| | - Chang‐Sik Oh
- Department of Horticultural BiotechnologyCollege of Life SciencesKyung Hee UniversityYonginSouth Korea
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21
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Chase WR, Zhaxybayeva O, Rocha J, Cosgrove DJ, Shapiro LR. Global cellulose biomass, horizontal gene transfers and domain fusions drive microbial expansin evolution. THE NEW PHYTOLOGIST 2020; 226:921-938. [PMID: 31930503 DOI: 10.1111/nph.16428] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 12/19/2019] [Indexed: 05/23/2023]
Abstract
Plants must rearrange the network of complex carbohydrates in their cell walls during normal growth and development. To accomplish this, all plants depend on proteins called expansins that nonenzymatically loosen noncovalent bonding between cellulose microfibrils. Surprisingly, expansin genes have more recently been found in some bacteria and microbial eukaryotes, where their biological functions are largely unknown. Here, we reconstruct a comprehensive phylogeny of microbial expansin genes. We find these genes in all eukaryotic microorganisms that have structural cell wall cellulose, suggesting expansins evolved in ancient marine microorganisms long before the evolution of land plants. We also find expansins in an unexpectedly high diversity of bacteria and fungi that do not have cellulosic cell walls. These bacteria and fungi inhabit varied ecological contexts, mirroring the diversity of terrestrial and aquatic niches where plant and/or algal cellulosic cell walls are present. The microbial expansin phylogeny shows evidence of multiple horizontal gene transfer events within and between bacterial and eukaryotic microbial lineages, which may in part underlie their unusually broad phylogenetic distribution. Overall, expansins are unexpectedly widespread in bacteria and eukaryotes, and the contribution of these genes to microbial ecological interactions with plants and algae has probbaly been underappreciated.
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Affiliation(s)
- William R Chase
- Department of Biology, Pennsylvania State University, University Park, PA, 16801, USA
| | - Olga Zhaxybayeva
- Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA
- Department of Computer Science, Dartmouth College, Hanover, NH, 03755, USA
| | - Jorge Rocha
- Department of Microbiology and Immunology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA
| | - Daniel J Cosgrove
- Department of Biology, Pennsylvania State University, University Park, PA, 16801, USA
| | - Lori R Shapiro
- Department of Microbiology and Immunology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA
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