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Ishii T, Tsuchida N, Hemelda NM, Saito K, Bao J, Watanabe M, Toyoda A, Matsubara T, Sato M, Toyooka K, Ishihama N, Shirasu K, Matsui H, Toyoda K, Ichinose Y, Hayashi T, Kawaguchi A, Noutoshi Y. Rhizoviticin is an alphaproteobacterial tailocin that mediates biocontrol of grapevine crown gall disease. THE ISME JOURNAL 2024; 18:wrad003. [PMID: 38365227 PMCID: PMC10811719 DOI: 10.1093/ismejo/wrad003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 10/27/2023] [Accepted: 11/06/2023] [Indexed: 02/18/2024]
Abstract
Tailocins are headless phage tail structures that mediate interbacterial antagonism. Although the prototypical tailocins, R- and F-pyocins, in Pseudomonas aeruginosa, and other predominantly R-type tailocins have been studied, their presence in Alphaproteobacteria remains unexplored. Here, we report the first alphaproteobacterial F-type tailocin, named rhizoviticin, as a determinant of the biocontrol activity of Allorhizobium vitis VAR03-1 against crown gall. Rhizoviticin is encoded by a chimeric prophage genome, one providing transcriptional regulators and the other contributing to tail formation and cell lysis, but lacking head formation genes. The rhizoviticin genome retains a nearly intact early phage region containing an integrase remnant and replication-related genes critical for downstream gene transcription, suggesting an ongoing transition of this locus from a prophage to a tailocin-coding region. Rhizoviticin is responsible for the most antagonistic activity in VAR03-1 culture supernatant against pathogenic A. vitis strain, and rhizoviticin deficiency resulted in a significant reduction in the antitumorigenic activity in planta. We identified the rhizoviticin-coding locus in eight additional A. vitis strains from diverse geographical locations, highlighting a unique survival strategy of certain Rhizobiales bacteria in the rhizosphere. These findings advance our understanding of the evolutionary dynamics of tailocins and provide a scientific foundation for employing rhizoviticin-producing strains in plant disease control.
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Affiliation(s)
- Tomoya Ishii
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Natsuki Tsuchida
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
- Present address: Division of Biological Science, Nara Institute of Science and Technology (NAIST), Ikoma, Nara 630-0192, Japan
| | - Niarsi Merry Hemelda
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
- Department of Biology, University of Indonesia, Depok 16424, Indonesia
| | - Kirara Saito
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
- Present address: Kyushu Okinawa Agricultural Research Center, National Agriculture and Food Research Organization, Miyakonojo, Miyazaki 885-0091, Japan
| | - Jiyuan Bao
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Megumi Watanabe
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Atsushi Toyoda
- Department of Genomics and Evolutionary Biology, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Takehiro Matsubara
- Okayama University Hospital Biobank, Okayama University Hospital, Okayama 700-8558, Japan
| | - Mayuko Sato
- Mass Spectrometry and Microscopy Unit, Technology Platform Division, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan
| | - Kiminori Toyooka
- Mass Spectrometry and Microscopy Unit, Technology Platform Division, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan
| | - Nobuaki Ishihama
- Plant Immunity Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan
| | - Ken Shirasu
- Plant Immunity Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan
- Graduate School of Science, The University of Tokyo, Tokyo 113-8657, Japan
| | - Hidenori Matsui
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
| | - Kazuhiro Toyoda
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
| | - Yuki Ichinose
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
| | - Tetsuya Hayashi
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Akira Kawaguchi
- Western Region Agricultural Research Center (WARC), National Agricultural and Food Research Organization (NARO), Fukuyama, Hiroshima 721-8514, Japan
| | - Yoshiteru Noutoshi
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
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Ishiga T, Sakata N, Usuki G, Nguyen VT, Gomi K, Ishiga Y. Large-Scale Transposon Mutagenesis Reveals Type III Secretion Effector HopR1 Is a Major Virulence Factor in Pseudomonas syringae pv. actinidiae. PLANTS (BASEL, SWITZERLAND) 2022; 12:plants12010141. [PMID: 36616271 PMCID: PMC9823363 DOI: 10.3390/plants12010141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/11/2022] [Accepted: 12/16/2022] [Indexed: 05/27/2023]
Abstract
Bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae (Psa) is a serious threat to kiwifruit production worldwide. Four biovars (Psa biovar 1; Psa1, Psa biovar 3; Psa3, Psa biovar 5; Psa5, and Psa biovar 6; Psa6) were reported in Japan, and virulent Psa3 strains spread rapidly to kiwifruit production areas worldwide. Therefore, there is an urgent need to develop critical management strategies for bacterial canker based on dissecting the dynamic interactions between Psa and kiwifruit. To investigate the molecular mechanism of Psa3 infection, we developed a rapid and reliable high-throughput flood-inoculation method using kiwifruit seedlings. Using this inoculation method, we screened 3000 Psa3 transposon insertion mutants and identified 91 reduced virulence mutants and characterized the transposon insertion sites in these mutants. We identified seven type III secretion system mutants, and four type III secretion effectors mutants including hopR1. Mature kiwifruit leaves spray-inoculated with the hopR1 mutant showed significantly reduced virulence compared to Psa3 wild-type, indicating that HopR1 has a critical role in Psa3 virulence. Deletion mutants of hopR1 in Psa1, Psa3, Psa5, and Psa6 revealed that the type III secretion effector HopR1 is a major virulence factor in these biovars. Moreover, hopR1 mutants of Psa3 failed to reopen stomata on kiwifruit leaves, suggesting that HopR1 facilitates Psa entry through stomata into plants. Furthermore, defense related genes were highly expressed in kiwifruit plants inoculated with hopR1 mutant compared to Psa wild-type, indicating that HopR1 suppresses defense-related genes of kiwifruit. These results suggest that HopR1 universally contributes to virulence in all Psa biovars by overcoming not only stomatal-based defense, but also apoplastic defense.
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Affiliation(s)
- Takako Ishiga
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572, Ibaraki, Japan
| | - Nanami Sakata
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572, Ibaraki, Japan
| | - Giyu Usuki
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572, Ibaraki, Japan
| | - Viet Tru Nguyen
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572, Ibaraki, Japan
- Western Highlands Agriculture and Forestry Science Institute, 53 Nguyen Luong Bang Street, Buon Ma Thuot City 630000, Vietnam
| | - Kenji Gomi
- Faculty of Agriculture, Kagawa University, Miki 761-0795, Kagawa, Japan
| | - Yasuhiro Ishiga
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572, Ibaraki, Japan
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Huang MY, Wang WY, Liang ZZ, Huang YC, Yi Y, Niu FX. Enhancing the Production of Pinene in Escherichia coli by Using a Combination of Shotgun, Product-Tolerance and I-SceI Cleavage Systems. BIOLOGY 2022; 11:biology11101484. [PMID: 36290388 PMCID: PMC9598909 DOI: 10.3390/biology11101484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 09/23/2022] [Accepted: 10/04/2022] [Indexed: 11/05/2022]
Abstract
Simple Summary The limit screening method (LMS method) and product-tolerance engineering was proposed and applied. AcrB, flgFG, motB and ndk were found to be associated with an enhanced tolerance of E. coli to pinene. Using the I-SceI cleavage system, the promoters of acrB, flgFG, and ndk genes were replaced with P37, and pinene production was eventually increased 2.1 times. In general, a combination of shotgun, product-tolerance, and I-SceI cleavage systems provides a more convenient and efficient way of enhancing the synthesis of target products in a host strain. Abstract Tolerance breeding through genetic engineering, sequence and omics analyses, and gene identification processes are widely used to synthesize biofuels. The majority of related mechanisms have been shown to yield endogenous genes with high expression. However, the process was time-consuming and labor-intensive, meaning there is a need to address the problems associated with the low-throughput screening method and significant time and money consumption. In this study, a combination of the limit screening method (LMS method) and product-tolerance engineering was proposed and applied. The Escherichia coli MG1655 genomic DNA library was constructed using the shotgun method. Then, the cultures were incubated at concentrations of 0.25%, 0.5%, 0.75% and 1.0% of pinene with different inhibitory effects. Finally, the genes acrB, flgFG, motB and ndk were found to be associated with the enhanced tolerance of E. coli to pinene. Using the I-SceI cleavage system, the promoters of acrB, flgFG and ndk genes were replaced with P37. The final strain increased the production of pinene from glucose by 2.1 times.
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Affiliation(s)
- Ming-Yue Huang
- Guangxi Key Laboratory of Green Processing of Sugar Resources, Guangxi University of Science and Technology, Liuzhou 545006, China
- Department of Basic Medicine, Guangxi University of Science and Technology, Liuzhou 545006, China
| | - Wei-Yang Wang
- Guangxi Key Laboratory of Green Processing of Sugar Resources, Guangxi University of Science and Technology, Liuzhou 545006, China
| | - Zhen-Zhen Liang
- Guangxi Key Laboratory of Green Processing of Sugar Resources, Guangxi University of Science and Technology, Liuzhou 545006, China
| | - Yu-Chen Huang
- Guangxi Key Laboratory of Green Processing of Sugar Resources, Guangxi University of Science and Technology, Liuzhou 545006, China
| | - Yi Yi
- Guangxi Key Laboratory of Green Processing of Sugar Resources, Guangxi University of Science and Technology, Liuzhou 545006, China
- Correspondence: (Y.Y.); (F.-X.N.)
| | - Fu-Xing Niu
- Guangxi Key Laboratory of Green Processing of Sugar Resources, Guangxi University of Science and Technology, Liuzhou 545006, China
- Correspondence: (Y.Y.); (F.-X.N.)
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Nguyen VT, Sakata N, Usuki G, Ishiga T, Hashimoto Y, Ishiga Y. Multiple virulence factors regulated by AlgU contribute to the pathogenicity of Pseudomonas savastanoi pv. glycinea in soybean. PeerJ 2021; 9:e12405. [PMID: 34760389 PMCID: PMC8559602 DOI: 10.7717/peerj.12405] [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: 06/21/2021] [Accepted: 10/08/2021] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas savastanoi pv. glycinea (Psg) causes bacterial blight of soybean. To identify candidate virulence factors, transposon-mediated mutational analysis of Psg was carried out. We syringe-inoculated soybean leaves with Psg transposon mutants and identified 28 mutants which showed reduced virulence from 1,000 mutants screened. Next, we spray-inoculated soybean leaves with these mutants and demonstrated that the algU mutant showed significantly reduced virulence together with reduced bacterial populations in planta. Expression profiles comparison between the Psg wild-type (WT) and algU mutant in HSC broth revealed that expression of coronatine (COR)-related genes (including cmaA and corR) were down-regulated in the algU mutant compared with Psg WT. Moreover, we also showed that COR production were reduced in the algU mutant compared with WT. We also demonstrated that algD, which is related to alginate biosynthesis, showed reduced expression and biofilm formation was significantly suppressed in the algU mutant. Furthermore, hrpL also showed less expression in the algU mutant. These results indicate that AlgU plays a critical role in promoting Psg pathogenesis by regulating multiple virulence factors.
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Affiliation(s)
- Viet Tru Nguyen
- Western Highlands Agriculture and Forestry Science Institute, Buon Ma Thuot, Daklak, Vietnam.,Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Nanami Sakata
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Giyu Usuki
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Takako Ishiga
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yoshiteru Hashimoto
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.,Microbiology Research Center for Sustainability (MiCS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yasuhiro Ishiga
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
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Alav I, Kobylka J, Kuth MS, Pos KM, Picard M, Blair JMA, Bavro VN. Structure, Assembly, and Function of Tripartite Efflux and Type 1 Secretion Systems in Gram-Negative Bacteria. Chem Rev 2021; 121:5479-5596. [PMID: 33909410 PMCID: PMC8277102 DOI: 10.1021/acs.chemrev.1c00055] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Indexed: 12/11/2022]
Abstract
Tripartite efflux pumps and the related type 1 secretion systems (T1SSs) in Gram-negative organisms are diverse in function, energization, and structural organization. They form continuous conduits spanning both the inner and the outer membrane and are composed of three principal components-the energized inner membrane transporters (belonging to ABC, RND, and MFS families), the outer membrane factor channel-like proteins, and linking the two, the periplasmic adaptor proteins (PAPs), also known as the membrane fusion proteins (MFPs). In this review we summarize the recent advances in understanding of structural biology, function, and regulation of these systems, highlighting the previously undescribed role of PAPs in providing a common architectural scaffold across diverse families of transporters. Despite being built from a limited number of basic structural domains, these complexes present a staggering variety of architectures. While key insights have been derived from the RND transporter systems, a closer inspection of the operation and structural organization of different tripartite systems reveals unexpected analogies between them, including those formed around MFS- and ATP-driven transporters, suggesting that they operate around basic common principles. Based on that we are proposing a new integrated model of PAP-mediated communication within the conformational cycling of tripartite systems, which could be expanded to other types of assemblies.
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Affiliation(s)
- Ilyas Alav
- Institute
of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Jessica Kobylka
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Miriam S. Kuth
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Klaas M. Pos
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Martin Picard
- Laboratoire
de Biologie Physico-Chimique des Protéines Membranaires, CNRS
UMR 7099, Université de Paris, 75005 Paris, France
- Fondation
Edmond de Rothschild pour le développement de la recherche
Scientifique, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Jessica M. A. Blair
- Institute
of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Vassiliy N. Bavro
- School
of Life Sciences, University of Essex, Colchester, CO4 3SQ United Kingdom
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Sakata N, Ishiga T, Ishiga Y. Pseudmonas cannabina pv. alisalensis TrpA Is Required for Virulence in Multiple Host Plants. Front Microbiol 2021; 12:659734. [PMID: 33959115 PMCID: PMC8093880 DOI: 10.3389/fmicb.2021.659734] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/22/2021] [Indexed: 11/13/2022] Open
Abstract
Pseudomonas cannabina pv. alisalensis (Pcal) causes bacterial leaf spot and blight of Brassicaceae and Poaceae. We previously identified several potential Pcal virulence factors with transposon mutagenesis. Among these a trpA mutant disrupted the tryptophan synthase alpha chain, and had an effect on disease symptom development and bacterial multiplication. To assess the importance of TrpA in Pcal virulence, we characterized the trpA mutant based on inoculation test and Pcal gene expression profiles. The trpA mutant showed reduced virulence when dip- and syringe-inoculated on cabbage and oat. Moreover, epiphytic bacterial populations of the trpA mutant were also reduced compared to the wild-type (WT). These results suggest that TrpA contributes to bacterial multiplication on the leaf surface and in the apoplast, and disease development. Additionally, several Brassicaceae (including Japanese radish, broccoli, and Chinese cabbage) also exhibited reduced symptom development when inoculated with the trpA mutant. Moreover, trpA disruption led to downregulation of bacterial virulence genes, including type three effectors (T3Es) and the phytotoxin coronatine (COR), and to upregulation of tryptophan biosynthesis genes. These results indicate that a trade-off between virulence factor production and Pcal multiplication with tryptophan might be regulated in the infection processes.
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Affiliation(s)
- Nanami Sakata
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Takako Ishiga
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yasuhiro Ishiga
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
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Quorum Sensing Regulation in Phytopathogenic Bacteria. Microorganisms 2021; 9:microorganisms9020239. [PMID: 33498890 PMCID: PMC7912708 DOI: 10.3390/microorganisms9020239] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 11/17/2022] Open
Abstract
Quorum sensing is a type of chemical communication by which bacterial populations control expression of their genes in a coordinated manner. This regulatory mechanism is commonly used by pathogens to control the expression of genes encoding virulence factors and that of genes involved in the bacterial adaptation to variations in environmental conditions. In phytopathogenic bacteria, several mechanisms of quorum sensing have been characterized. In this review, we describe the different quorum sensing systems present in phytopathogenic bacteria, such as those using the signal molecules named N-acyl-homoserine lactone (AHL), diffusible signal factor (DSF), and the unknown signal molecule of the virulence factor modulating (VFM) system. We focus on studies performed on phytopathogenic bacteria of major importance, including Pseudomonas, Ralstonia, Agrobacterium, Xanthomonas, Erwinia, Xylella,Dickeya, and Pectobacterium spp. For each system, we present the mechanism of regulation, the functions targeted by the quorum sensing system, and the mechanisms by which quorum sensing is regulated.
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Ichinose Y, Nishimura T, Harada M, Kashiwagi R, Yamamoto M, Noutoshi Y, Toyoda K, Taguchi F, Takemoto D, Matsui H. Role of Two Sets of RND-Type Multidrug Efflux Pump Transporter Genes, mexAB-oprM and mexEF-oprN, in Virulence of Pseudomonas syringae pv. tabaci 6605. THE PLANT PATHOLOGY JOURNAL 2020; 36:148-156. [PMID: 32296294 PMCID: PMC7143514 DOI: 10.5423/ppj.oa.11.2019.0273] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 02/09/2020] [Accepted: 03/06/2020] [Indexed: 05/11/2023]
Abstract
Pseudomonas syringae pv. tabaci 6605 has two multidrug resistance (MDR) efflux pump transporters, MexAB-OprM and MexEF-OprN. To understand the role of these MDR efflux pumps in virulence, we generated deletion mutants, ∆mexB, ∆mexF, and ∆mexB∆mexF, and investigated their sensitivity to plant-derived antimicrobial compounds, antibiotics, and virulence. Growth inhibition assays with KB soft agar plate showed that growth of the wild-type (WT) was inhibited by 5 µl of 1 M catechol and 1 M coumarin but not by other plant-derived potential antimicrobial compounds tested including phytoalexins. The sensitivity to these compounds tended to increase in ∆mexB and ∆mexB∆mexF mutants. The ∆mexB∆mexF mutant was also sensitive to 2 M acetovanillone. The mexAB-oprM was constitutively expressed, and activated in the ∆mexF and ∆mexB∆mexF mutant strains. The swarming and swimming motilities were impaired in ∆mexF and ∆mexB∆mexF mutants. The flood inoculation test indicated that bacterial populations in all mutant strains were significantly lower than that of WT, although all mutants and WT caused similar disease symptoms. These results indicate that MexAB-OprM extrudes plant-derived catechol, acetovanillone, or coumarin, and contributes to bacterial virulence. Furthermore, MexAB-OprM and MexEF-OprN complemented each other's functions to some extent.
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Affiliation(s)
- Yuki Ichinose
- Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
- Corresponding author. Phone/FAX) +81-86-251-8308, E-mail)
| | - Takafumi Nishimura
- Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan
| | - Minori Harada
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
| | - Ryota Kashiwagi
- Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan
| | - Mikihiro Yamamoto
- Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
| | - Yoshiteru Noutoshi
- Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
| | - Kazuhiro Toyoda
- Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
| | - Fumiko Taguchi
- Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan
| | - Daigo Takemoto
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Hidenori Matsui
- Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
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Ishiga T, Sakata N, Nguyen VT, Ishiga Y. Flood inoculation of seedlings on culture medium to study interactions between Pseudomonas syringae pv. actinidiae and kiwifruit. JOURNAL OF GENERAL PLANT PATHOLOGY : JGPP 2020; 86:257-265. [PMID: 32412555 PMCID: PMC7222055 DOI: 10.1007/s10327-020-00916-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 12/12/2019] [Indexed: 06/01/2023]
Abstract
Bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae (Psa) is a serious threat to kiwifruit production. Highly virulent strains of Psa biovar3 (Psa3) have spread rapidly to kiwifruit production areas worldwide. Therefore, there is an urgent need to develop critical management strategies for bacterial canker based on dissecting the interactions between Psa and kiwifruit. Here, we developed a rapid and reliable flood-inoculation method using kiwifruit seedlings grown on Murashige and Skoog medium. This method has several advantages over inoculation of conventional soil-grown plants. We demonstrated the utility of a kiwifruit seedling assay to study the virulence of Psa biovars and Psa3 virulence factors, including the type III secretion system (T3SS). Kiwifruit seedlings inoculated with Psa3 developed severe necrosis within 1 week, whereas those inoculated with a T3SS-deficient hrcN mutant of Psa3 did not. This method was also useful for analyzing expression profiles of genes involved in Psa3 virulence during infection, and revealed that the expression of genes encoding the T3SS and type III secreted effectors were strongly induced in planta. Our results indicate that the T3SS has an important role in Psa3 virulence, and the flood-inoculation assay using kiwifruit seedling is suitable for analyzing Psa and kiwifruit interactions.
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Affiliation(s)
- Takako Ishiga
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 Japan
| | - Nanami Sakata
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 Japan
| | - Viet Tru Nguyen
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 Japan
| | - Yasuhiro Ishiga
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 Japan
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10
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Sakata N, Ishiga T, Saito H, Nguyen VT, Ishiga Y. Transposon mutagenesis reveals Pseudomonas cannabina pv. alisalensis optimizes its virulence factors for pathogenicity on different hosts. PeerJ 2019; 7:e7698. [PMID: 31579596 PMCID: PMC6756136 DOI: 10.7717/peerj.7698] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 08/19/2019] [Indexed: 11/30/2022] Open
Abstract
Pseudomonas cannabina pv. alisalensis (Pcal), which causes bacterial blight disease of Brassicaceae, is an economically important pathogen worldwide. To identify Pcal genes involved in pathogenesis, we conducted a screen for 1,040 individual Pcal KB211 Tn5 mutants with reduced virulence on cabbage plants using a dip-inoculation method. We isolated 53 reduced virulence mutants and identified several potential virulence factors involved in Pcal virulence mechanisms such as the type III secretion system, membrane transporters, transcription factors, and amino acid metabolism. Importantly, Pcal is pathogenic on a range of monocotyledonous and dicotyledonous plants. Therefore, we also carried out the inoculation test on oat plants, which are cultivated after cabbage cultivation as green manure crops. Interestingly among the 53 mutants, 31 mutants also exhibited reduced virulence on oat seedlings, indicating that Pcal optimizes its virulence factors for pathogenicity on different host plants. Our results highlight the importance of revealing the virulence factors for each plant host-bacterial interaction, and will provide new insights into Pcal virulence mechanisms.
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Affiliation(s)
- Nanami Sakata
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Takako Ishiga
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Haruka Saito
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Viet Tru Nguyen
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yasuhiro Ishiga
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
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