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Tokuda R, Iwabuchi N, Kitazawa Y, Nijo T, Suzuki M, Maejima K, Oshima K, Namba S, Yamaji Y. Potential mobile units drive the horizontal transfer of phytoplasma effector phyllogen genes. Front Genet 2023; 14:1132432. [PMID: 37252660 PMCID: PMC10210161 DOI: 10.3389/fgene.2023.1132432] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 04/03/2023] [Indexed: 05/31/2023] Open
Abstract
Phytoplasmas are obligate intracellular plant pathogenic bacteria that can induce phyllody, which is a type of abnormal floral organ development. Phytoplasmas possess phyllogens, which are effector proteins that cause phyllody in plants. Phylogenetic comparisons of phyllogen and 16S rRNA genes have suggested that phyllogen genes undergo horizontal transfer between phytoplasma species and strains. However, the mechanisms and evolutionary implications of this horizontal gene transfer are unclear. Here, we analyzed synteny in phyllogen flanking genomic regions from 17 phytoplasma strains that were related to six 'Candidatus' species, including three strains newly sequenced in this study. Many of the phyllogens were flanked by multicopy genes within potential mobile units (PMUs), which are putative transposable elements found in phytoplasmas. The multicopy genes exhibited two distinct patterns of synteny that correlated with the linked phyllogens. The low level of sequence identities and partial truncations found among these phyllogen flanking genes indicate that the PMU sequences are deteriorating, whereas the highly conserved sequences and functions (e.g., inducing phyllody) of the phyllogens suggest that the latter are important for phytoplasma fitness. Furthermore, although their phyllogens were similar, PMUs in strains related to 'Ca. P. asteris' were often located in different regions of the genome. These findings strongly indicate that PMUs drive the horizontal transfer of phyllogens among phytoplasma species and strains. These insights improve our understanding of how symptom-determinant genes have been shared among phytoplasmas.
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Affiliation(s)
- Ryosuke Tokuda
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Nozomu Iwabuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yugo Kitazawa
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Takamichi Nijo
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Masato Suzuki
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kensaku Maejima
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kenro Oshima
- Faculty of Bioscience and Applied Chemistry, Hosei University, Tokyo, Japan
| | - Shigetou Namba
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yasuyuki Yamaji
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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Iwabuchi N, Kitazawa Y, Maejima K, Koinuma H, Miyazaki A, Matsumoto O, Suzuki T, Nijo T, Oshima K, Namba S, Yamaji Y. Functional variation in phyllogen, a phyllody-inducing phytoplasma effector family, attributable to a single amino acid polymorphism. Mol Plant Pathol 2020; 21:1322-1336. [PMID: 32813310 PMCID: PMC7488466 DOI: 10.1111/mpp.12981] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/25/2020] [Accepted: 07/05/2020] [Indexed: 05/08/2023]
Abstract
Flower malformation represented by phyllody is a common symptom of phytoplasma infection induced by a novel family of phytoplasma effectors called phyllogens. Despite the accumulation of functional and structural phyllogen information, the molecular mechanisms of phyllody have not yet been integrated with their evolutionary aspects due to the limited data on their homologs across diverse phytoplasma lineages. Here, we developed a novel universal PCR-based approach to identify 25 phytoplasma phyllogens related to nine "Candidatus Phytoplasma" species, including four species whose phyllogens have not yet been identified. Phylogenetic analyses showed that the phyllogen family consists of four groups (phyl-A, -B, -C, and -D) and that the evolutionary relationships of phyllogens were significantly distinct from those of phytoplasmas, suggesting that phyllogens were transferred horizontally among phytoplasma strains and species. Although phyllogens belonging to the phyl-A, -C, and -D groups induced phyllody, the phyl-B group lacked the ability to induce phyllody. Comparative functional analyses of phyllogens revealed that a single amino acid polymorphism in phyl-B group phyllogens prevented interactions between phyllogens and A- and E-class MADS domain transcription factors (MTFs), resulting in the inability to degrade several MTFs and induce phyllody. Our finding of natural variation in the function of phytoplasma effectors provides new insights into molecular mechanisms underlying the aetiology of phytoplasma diseases.
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Affiliation(s)
- Nozomu Iwabuchi
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Yugo Kitazawa
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Kensaku Maejima
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Hiroaki Koinuma
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Akio Miyazaki
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Ouki Matsumoto
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Takumi Suzuki
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Takamichi Nijo
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | | | - Shigetou Namba
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Yasuyuki Yamaji
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
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Tanno K, Maejima K, Miyazaki A, Koinuma H, Iwabuchi N, Kitazawa Y, Nijo T, Hashimoto M, Yamaji Y, Namba S. Comprehensive screening of antimicrobials to control phytoplasma diseases using an in vitro plant-phytoplasma co-culture system. Microbiology (Reading) 2018; 164:1048-1058. [PMID: 29952745 DOI: 10.1099/mic.0.000681] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Phytoplasmas are plant-pathogenic bacteria that infect many important crops and cause serious economic losses worldwide. However, owing to an inability to culture phytoplasmas, screening of antimicrobials on media is difficult. The only antimicrobials being used to control phytoplasmas are tetracycline-class antibiotics. In this study, we developed an accurate and efficient screening method to evaluate the effects of antimicrobials using an in vitro plant-phytoplasma co-culture system. We tested 40 antimicrobials, in addition to tetracycline, and four of these (doxycycline, chloramphenicol, thiamphenicol and rifampicin) decreased the accumulation of 'Candidatus (Ca.) Phytoplasma asteris'. The phytoplasma was eliminated from infected plants by the application of both tetracycline and rifampicin. We also compared nucleotide sequences of rRNAs and amino acid sequences of proteins targeted by antimicrobials between phytoplasmas and other bacteria. Since antimicrobial target sequences were conserved among various phytoplasma species, the antimicrobials that decreased accumulation of 'Ca. P. asteris' may also have been effective against other phytoplasma species. These approaches will provide new strategies for phytoplasma disease management.
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Affiliation(s)
- Kazuyuki Tanno
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kensaku Maejima
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Akio Miyazaki
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hiroaki Koinuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Nozomu Iwabuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yugo Kitazawa
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Takamichi Nijo
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Masayoshi Hashimoto
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yasuyuki Yamaji
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Shigetou Namba
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Nijo T, Okano Y, Kondo M, Okuhara H, Sekimura H, Fujimoto Y, Hosoe N, Maejima K, Yamaji Y, Namba S. Complete Genome Sequence of a Lily virus X Isolate from Japan. Genome Announc 2018; 6:e01462-17. [PMID: 29371349 PMCID: PMC5786675 DOI: 10.1128/genomea.01462-17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 12/15/2017] [Indexed: 11/20/2022]
Abstract
The complete genome sequence of Lily virus X (LVX), which infects lilies, was determined for the first time from lilies in Japan. As with previous reports, the genome of the Japanese LVX isolate lacked an AUG start codon for the triple gene block protein 3-like region.
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Affiliation(s)
- Takamichi Nijo
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yukari Okano
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Masayoshi Kondo
- Biotechnology Division, Niigata Agricultural Research Institute, Niigata, Japan
| | - Hiroaki Okuhara
- Biotechnology Division, Niigata Agricultural Research Institute, Niigata, Japan
| | - Hiroyo Sekimura
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yuji Fujimoto
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Naoi Hosoe
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kensaku Maejima
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yasuyuki Yamaji
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Shigetou Namba
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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5
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Miyazaki A, Shigaki T, Koinuma H, Iwabuchi N, Rauka GB, Kembu A, Saul J, Watanabe K, Nijo T, Maejima K, Yamaji Y, Namba S. ‘Candidatus Phytoplasma noviguineense’, a novel taxon associated with Bogia coconut syndrome and banana wilt disease on the island of New Guinea. Int J Syst Evol Microbiol 2018; 68:170-175. [DOI: 10.1099/ijsem.0.002480] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- Akio Miyazaki
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Toshiro Shigaki
- National Agricultural Research Institute, PO Box 1639, Lae, Morobe Province 411, Papua New Guinea
| | - Hiroaki Koinuma
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Nozomu Iwabuchi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Gou Bue Rauka
- National Agricultural Research Institute, PO Box 1639, Lae, Morobe Province 411, Papua New Guinea
| | - Alfred Kembu
- Cocoa Coconut Institute Stewart Research Station, PO Box 642, Madang, Madang Province, Papua New Guinea
| | - Josephine Saul
- Cocoa Coconut Institute Stewart Research Station, PO Box 642, Madang, Madang Province, Papua New Guinea
| | - Kiyoto Watanabe
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Takamichi Nijo
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kensaku Maejima
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yasuyuki Yamaji
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Shigetou Namba
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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6
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Nijo T, Neriya Y, Koinuma H, Iwabuchi N, Kitazawa Y, Tanno K, Okano Y, Maejima K, Yamaji Y, Oshima K, Namba S. Genome-Wide Analysis of the Transcription Start Sites and Promoter Motifs of Phytoplasmas. DNA Cell Biol 2017; 36:1081-1092. [PMID: 29039971 DOI: 10.1089/dna.2016.3616] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Phytoplasmas are obligate intracellular parasitic bacteria that infect both plants and insects. We previously identified the sigma factor RpoD-dependent consensus promoter sequence of phytoplasma. However, the genome-wide landscape of RNA transcripts, including non-coding RNAs (ncRNAs) and RpoD-independent promoter elements, was still unknown. In this study, we performed an improved RNA sequencing analysis for genome-wide identification of the transcription start sites (TSSs) and the consensus promoter sequences. We constructed cDNA libraries using a random adenine/thymine hexamer primer, in addition to a conventional random hexamer primer, for efficient sequencing of 5'-termini of AT-rich phytoplasma RNAs. We identified 231 TSSs, which were classified into four categories: mRNA TSSs, internal sense TSSs, antisense TSSs (asTSSs), and orphan TSSs (oTSSs). The presence of asTSSs and oTSSs indicated the genome-wide transcription of ncRNAs, which might act as regulatory ncRNAs in phytoplasmas. This is the first description of genome-wide phytoplasma ncRNAs. Using a de novo motif discovery program, we identified two consensus motif sequences located upstream of the TSSs. While one was almost identical to the RpoD-dependent consensus promoter sequence, the other was an unidentified novel motif, which might be recognized by another transcription initiation factor. These findings are valuable for understanding the regulatory mechanism of phytoplasma gene expression.
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Affiliation(s)
- Takamichi Nijo
- 1 Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo, Japan
| | - Yutaro Neriya
- 1 Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo, Japan
| | - Hiroaki Koinuma
- 1 Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo, Japan
| | - Nozomu Iwabuchi
- 1 Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo, Japan
| | - Yugo Kitazawa
- 1 Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo, Japan
| | - Kazuyuki Tanno
- 1 Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo, Japan
| | - Yukari Okano
- 1 Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo, Japan
| | - Kensaku Maejima
- 1 Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo, Japan
| | - Yasuyuki Yamaji
- 1 Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo, Japan
| | - Kenro Oshima
- 2 Department of Clinical Plant Science, Faculty of Bioscience and Applied Chemistry, Hosei University , Tokyo, Japan
| | - Shigetou Namba
- 1 Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo, Japan
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Kitazawa Y, Iwabuchi N, Himeno M, Sasano M, Koinuma H, Nijo T, Tomomitsu T, Yoshida T, Okano Y, Yoshikawa N, Maejima K, Oshima K, Namba S. Phytoplasma-conserved phyllogen proteins induce phyllody across the Plantae by degrading floral MADS domain proteins. J Exp Bot 2017; 68:2799-2811. [PMID: 28505304 PMCID: PMC5853863 DOI: 10.1093/jxb/erx158] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 04/13/2017] [Indexed: 05/21/2023]
Abstract
ABCE-class MADS domain transcription factors (MTFs) are key regulators of floral organ development in angiosperms. Aberrant expression of these genes can result in abnormal floral traits such as phyllody. Phyllogen is a virulence factor conserved in phytoplasmas, plant pathogenic bacteria of the class Mollicutes. It triggers phyllody in Arabidopsis thaliana by inducing degradation of A- and E-class MTFs. However, it is still unknown whether phyllogen can induce phyllody in plants other than A. thaliana, although phytoplasma-associated phyllody symptoms are observed in a broad range of angiosperms. In this study, phyllogen was shown to cause phyllody phenotypes in several eudicot species belonging to three different families. Moreover, phyllogen can interact with MTFs of not only angiosperm species including eudicots and monocots but also gymnosperms and a fern, and induce their degradation. These results suggest that phyllogen induces phyllody in angiosperms and inhibits MTF function in diverse plant species.
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Affiliation(s)
- Yugo Kitazawa
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Nozomu Iwabuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Misako Himeno
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Momoka Sasano
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Hiroaki Koinuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Takamichi Nijo
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Tatsuya Tomomitsu
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Tetsuya Yoshida
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Yukari Okano
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Nobuyuki Yoshikawa
- Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka-shi, Iwate, Japan
| | - Kensaku Maejima
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Kenro Oshima
- Faculty of Bioscience, Hosei University, 3-7-2 Kajino-cho, Koganei-shi, Tokyo, Japan
| | - Shigetou Namba
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
- Correspondence:
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Miura C, Komatsu K, Maejima K, Nijo T, Kitazawa Y, Tomomitsu T, Yusa A, Himeno M, Oshima K, Namba S. Functional characterization of the principal sigma factor RpoD of phytoplasmas via an in vitro transcription assay. Sci Rep 2015; 5:11893. [PMID: 26150080 PMCID: PMC4493692 DOI: 10.1038/srep11893] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 06/09/2015] [Indexed: 02/07/2023] Open
Abstract
Phytoplasmas (class, Mollicutes) are insect-transmissible and plant-pathogenic bacteria that multiply intracellularly in both plants and insects through host switching. Our previous study revealed that phytoplasmal sigma factor rpoD of OY-M strain (rpoDOY) could be a key regulator of host switching, because the expression level of rpoDOY was higher in insect hosts than in plant hosts. In this study, we developed an in vitro transcription assay system to identify RpoDOY-dependent genes and the consensus promoter elements. The assay revealed that RpoDOY regulated some housekeeping, virulence, and host–phytoplasma interaction genes of OY-M strain. The upstream region of the transcription start sites of these genes contained conserved –35 and –10 promoter sequences, which were similar to the typical bacterial RpoD-dependent promoter elements, while the –35 promoter elements were variable. In addition, we searched putative RpoD-dependent genes based on these promoter elements on the whole genome sequence of phytoplasmas using in silico tools. The phytoplasmal RpoD seems to mediate the transcription of not only many housekeeping genes as the principal sigma factor, but also the virulence- and host-phytoplasma interaction-related genes exhibiting host-specific expression patterns. These results indicate that more complex mechanisms exist than previously thought regarding gene regulation enabling phytoplasmas to switch hosts.
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Affiliation(s)
- Chihiro Miura
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Ken Komatsu
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan
| | - Kensaku Maejima
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Takamichi Nijo
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Yugo Kitazawa
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Tatsuya Tomomitsu
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Akira Yusa
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Misako Himeno
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Kenro Oshima
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Shigetou Namba
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
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9
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Neriya Y, Maejima K, Nijo T, Tomomitsu T, Yusa A, Himeno M, Netsu O, Hamamoto H, Oshima K, Namba S. Onion yellow phytoplasma P38 protein plays a role in adhesion to the hosts. FEMS Microbiol Lett 2014; 361:115-22. [PMID: 25302654 DOI: 10.1111/1574-6968.12620] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 10/03/2014] [Accepted: 10/03/2014] [Indexed: 11/29/2022] Open
Abstract
Adhesins are microbial surface proteins that mediate the adherence of microbial pathogens to host cell surfaces. In Mollicutes, several adhesins have been reported in mycoplasmas and spiroplasmas. Adhesins P40 of Mycoplasma agalactiae and P89 of Spiroplasma citri contain a conserved amino acid sequence known as the Mollicutes adhesin motif (MAM), whose function in the host cell adhesion remains unclear. Here, we show that phytoplasmas, which are plant-pathogenic mollicutes transmitted by insect vectors, possess an adhesion-containing MAM that was identified in a putative membrane protein, PAM289 (P38), of the 'Candidatus Phytoplasma asteris,' OY strain. P38 homologs and their MAMs were highly conserved in related phytoplasma strains. While P38 protein was expressed in OY-infected insect and plant hosts, binding assays showed that P38 interacts with insect extract, and weakly with plant extract. Interestingly, the interaction of P38 with the insect extract depended on MAM. These results suggest that P38 is a phytoplasma adhesin that interacts with the hosts. In addition, the MAM of adhesins is important for the interaction between P38 protein and hosts.
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Affiliation(s)
- Yutaro Neriya
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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10
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Komatsu K, Hashimoto M, Okano Y, Keima T, Kitazawa Y, Nijo T, Takahashi S, Maejima K, Yamaji Y, Namba S. Construction of an infectious cDNA clone of radish mosaic virus, a crucifer-infecting comovirus. Arch Virol 2013; 158:1579-82. [PMID: 23447094 DOI: 10.1007/s00705-013-1635-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 01/05/2013] [Indexed: 11/28/2022]
Abstract
Radish mosaic virus (RaMV) is a crucifer-infecting comovirus that has been detected worldwide. Here, we report the successful construction of a full-length infectious cDNA clone of RaMV. The full-length cDNA clones corresponding to RNA1 and RNA2 of a Japanese isolate of RaMV were cloned into the pBlueScript plasmid or the binary vector pCAMBIA1301 downstream of the cauliflower mosaic virus 35S promoter. Mechanical inoculation or agroinoculation of Nicotiana benthamiana with these vectors resulted in systemic RaMV infections causing symptoms similar to those caused by the wild-type parental virus. The presence of progeny virus was verified by western blot analysis and electron microscopy.
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Affiliation(s)
- Ken Komatsu
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
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