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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] [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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2
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Bertaccini A. Plants and Phytoplasmas: When Bacteria Modify Plants. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11111425. [PMID: 35684198 PMCID: PMC9182842 DOI: 10.3390/plants11111425] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 05/18/2022] [Accepted: 05/24/2022] [Indexed: 05/14/2023]
Abstract
Plant pathogen presence is very dangerous for agricultural ecosystems and causes huge economic losses. Phytoplasmas are insect-transmitted wall-less bacteria living in plants, only in the phloem tissues and in the emolymph of their insect vectors. They are able to manipulate several metabolic pathways of their hosts, very often without impairing their life. The molecular diversity described (49 'Candidatus Phytoplasma' species and about 300 ribosomal subgroups) is only in some cases related to their associated symptomatology. As for the other plant pathogens, it is necessary to verify their identity and recognize the symptoms associated with their presence to appropriately manage the diseases. However, the never-ending mechanism of patho-adaptation and the copresence of other pathogens makes this management difficult. Reducing the huge impact of phytoplasma-associated diseases in all the main crops and wild species is, however, relevant, in order to reduce their effects that are jeopardizing plant biodiversity.
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Affiliation(s)
- Assunta Bertaccini
- Department of Agricultural and Food Sciences, Alma Mater Studiorum-University of Bologna, 40127 Bologna, Italy
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3
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Huang W, MacLean AM, Sugio A, Maqbool A, Busscher M, Cho ST, Kamoun S, Kuo CH, Immink RGH, Hogenhout SA. Parasitic modulation of host development by ubiquitin-independent protein degradation. Cell 2021; 184:5201-5214.e12. [PMID: 34536345 PMCID: PMC8525514 DOI: 10.1016/j.cell.2021.08.029] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 07/14/2021] [Accepted: 08/24/2021] [Indexed: 01/08/2023]
Abstract
Certain obligate parasites induce complex and substantial phenotypic changes in their hosts in ways that favor their transmission to other trophic levels. However, the mechanisms underlying these changes remain largely unknown. Here we demonstrate how SAP05 protein effectors from insect-vectored plant pathogenic phytoplasmas take control of several plant developmental processes. These effectors simultaneously prolong the host lifespan and induce witches' broom-like proliferations of leaf and sterile shoots, organs colonized by phytoplasmas and vectors. SAP05 acts by mediating the concurrent degradation of SPL and GATA developmental regulators via a process that relies on hijacking the plant ubiquitin receptor RPN10 independent of substrate ubiquitination. RPN10 is highly conserved among eukaryotes, but SAP05 does not bind insect vector RPN10. A two-amino-acid substitution within plant RPN10 generates a functional variant that is resistant to SAP05 activities. Therefore, one effector protein enables obligate parasitic phytoplasmas to induce a plethora of developmental phenotypes in their hosts.
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Affiliation(s)
- Weijie Huang
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Allyson M MacLean
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Akiko Sugio
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Abbas Maqbool
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Marco Busscher
- Laboratory of Molecular Biology, Wageningen University and Research, Wageningen 6708 PB, the Netherlands; Plant Developmental Systems, Bioscience, Wageningen University and Research, Wageningen 6708 PB, the Netherlands
| | - Shu-Ting Cho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Chih-Horng Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Richard G H Immink
- Laboratory of Molecular Biology, Wageningen University and Research, Wageningen 6708 PB, the Netherlands; Plant Developmental Systems, Bioscience, Wageningen University and Research, Wageningen 6708 PB, the Netherlands
| | - Saskia A Hogenhout
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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4
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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. MOLECULAR PLANT PATHOLOGY 2020; 21:1322-1336. [PMID: 32813310 PMCID: PMC7488466 DOI: 10.1111/mpp.12981] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [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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5
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NAMBA S. Molecular and biological properties of phytoplasmas. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2019; 95:401-418. [PMID: 31406061 PMCID: PMC6766451 DOI: 10.2183/pjab.95.028] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Phytoplasmas, a large group of plant-pathogenic, phloem-inhabiting bacteria were discovered by Japanese scientists in 1967. They are transmitted from plant to plant by phloem-feeding insect hosts and cause a variety of symptoms and considerable damage in more than 1,000 plant species. In the first quarter century following the discovery of phytoplasmas, their tiny cell size and the difficulty in culturing them hampered their biological classification and restricted research to ecological studies such as detection by electron microscopy and identification of insect vectors. In the 1990s, however, tremendous advances in molecular biology and related technologies encouraged investigation of phytoplasmas at the molecular level. In the last quarter century, molecular biology has revealed important properties of phytoplasmas. This review summarizes the history and current status of phytoplasma research, focusing on their discovery, molecular classification, diagnosis of phytoplasma diseases, reductive evolution of their genomes, characteristic features of their plasmids, molecular mechanisms of insect transmission, virulence factors, and chemotherapy.
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Affiliation(s)
- Shigetou NAMBA
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- Correspondence should be addressed: S. Namba, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan (e-mail: )
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6
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Abstract
Phytoplasmas are associated with diseases in several hundreds of cultivated herbaceous and woody plants. Their impact in agriculture and the periodical outbreak of worrying epidemics make very important, besides precise laboratory-based diagnosis, the direct in-field recognition of phytoplasma disease symptoms. Even if some symptoms are typical of this kind of pathogens, in-field diagnosis requires the knowledge of the host plant, strong field experience, and awareness of the symptom variability of the various organs of the plant during different seasons and under various environmental conditions. It is therefore very important to be familiar with factors like environmental conditions, agronomical features, and disease progression that influence symptom expression. Therefore, a satisfactory diagnosis should be based on repeated and complete observations scored over the entire plant and across different times of the year. A more suitable diagnosis is possible if the observer is able to recognize and distinguish the symptoms of other biotic or abiotic diseases. A general rule is to observe three different symptoms, at least, and to seek input from the grower about the initial development, frequency, diffusion, and particular characteristics of the disease.After a short introduction the following symptoms are presented: the most common and representative symptoms caused by phytoplasmas; the most common symptoms of phytoplasma diseases occurring in particular plant organs, with some references to specific diseases; phytoplasma symptoms on the model plant periwinkle (Vinca rosea or Catharanthus roseus); the main factors influencing phytoplasma symptoms expression; and several practical procedures that should be followed for suitable diagnosis. A series of original photos have been included to illustrate typical symptoms.
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Affiliation(s)
- Paolo Ermacora
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy.
| | - Ruggero Osler
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
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7
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Tomkins M, Kliot A, Marée AF, Hogenhout SA. A multi-layered mechanistic modelling approach to understand how effector genes extend beyond phytoplasma to modulate plant hosts, insect vectors and the environment. CURRENT OPINION IN PLANT BIOLOGY 2018; 44:39-48. [PMID: 29547737 DOI: 10.1016/j.pbi.2018.02.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/05/2018] [Accepted: 02/06/2018] [Indexed: 05/13/2023]
Abstract
Members of the Candidatus genus Phytoplasma are small bacterial pathogens that hijack their plant hosts via the secretion of virulence proteins (effectors) leading to a fascinating array of plant phenotypes, such as witch's brooms (stem proliferations) and phyllody (retrograde development of flowers into vegetative tissues). Phytoplasma depend on insect vectors for transmission, and interestingly, these insect vectors were found to be (in)directly attracted to plants with these phenotypes. Therefore, phytoplasma effectors appear to reprogram plant development and defence to lure insect vectors, similarly to social engineering malware, which employs tricks to lure people to infected computers and webpages. A multi-layered mechanistic modelling approach will enable a better understanding of how phytoplasma effector-mediated modulations of plant host development and insect vector behaviour contribute to phytoplasma spread, and ultimately to predict the long reach of phytoplasma effector genes.
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Affiliation(s)
- Melissa Tomkins
- Department of Computational and Systems Biology, The John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Adi Kliot
- Department of Crop Genetics, The John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Athanasius Fm Marée
- Department of Computational and Systems Biology, The John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom.
| | - Saskia A Hogenhout
- Department of Crop Genetics, The John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom.
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8
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Wambua L, Schneider B, Okwaro A, Wanga JO, Imali O, Wambua PN, Agutu L, Olds C, Jones CS, Masiga D, Midega C, Khan Z, Jores J, Fischer A. Development of field-applicable tests for rapid and sensitive detection of Candidatus Phytoplasma oryzae. Mol Cell Probes 2017. [PMID: 28647581 DOI: 10.1016/j.mcp.2017.06.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Napier grass Stunt Disease (NSD) is a severe disease of Napier grass (Pennisetum purpureum) in Eastern Africa, caused by the leafhopper-transmitted bacterium Candidatus Phytoplasma oryzae. The pathogen severely impairs the growth of Napier grass, the major fodder for dairy cattle in Eastern Africa. NSD is associated with biomass losses of up to 70% of infected plants. Diagnosis of NSD is done by nested PCR targeting the phytoplasma DNA, which is difficult to perform in developing countries with little infrastructure. We report the development of an easy to use, rapid, sensitive and specific molecular assay for field diagnosis of NSD. The procedure is based on recombinase polymerase amplification and targets the imp gene encoding a pathogen-specific immunodominant membrane protein. Therefore we followed a two-step process. First we developed an isothermal DNA amplification method for real time fluorescence application and then transferred this assay to a lateral flow format. The limit of detection for both procedures was estimated to be 10 organisms. We simplified the template preparation procedure by using freshly squeezed phloem sap from Napier grass. Additionally, we developed a laboratory serological assay with the potential to be converted to a lateral flow assay. Two murine monoclonal antibodies with high affinity and specificity to the immunodominant membrane protein IMP of Candidatus Phytoplasma oryzae were generated. Both antibodies specifically reacted with the denatured or native 17 kDa IMP protein. In dot blot experiments of extracts from infected plant, phytoplasmas were detected in as little as 12,5 μg of fresh plant material.
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Affiliation(s)
- Lillian Wambua
- International Centre of Insect Physiology and Ecology, P.O Box 30772, 00100 Nairobi, Kenya; School of Biological Sciences, University of Nairobi, P.O Box 30197, 00100 Nairobi, Kenya
| | - Bernd Schneider
- Julius Kühn Institute, Federal Research Centre for Cultivated Plants, Institute for Plant Protection in Fruit Crops and Viticulture, 69221 Dossenheim, Germany
| | - Allan Okwaro
- International Centre of Insect Physiology and Ecology, P.O Box 30772, 00100 Nairobi, Kenya; Department of Biochemistry & Biotechnology, Kenyatta University, P.O. Box 43844, 00100 Nairobi, Kenya
| | - Joseph Odhiambo Wanga
- International Centre of Insect Physiology and Ecology, P.O Box 30772, 00100 Nairobi, Kenya
| | - Olive Imali
- International Centre of Insect Physiology and Ecology, P.O Box 30772, 00100 Nairobi, Kenya
| | - Peninah Nduku Wambua
- International Centre of Insect Physiology and Ecology, P.O Box 30772, 00100 Nairobi, Kenya; School of Biological Sciences, University of Nairobi, P.O Box 30197, 00100 Nairobi, Kenya
| | - Lavender Agutu
- International Centre of Insect Physiology and Ecology, P.O Box 30772, 00100 Nairobi, Kenya
| | - Cassandra Olds
- Washington State University, Pullman, WA, USA; International Livestock Research Institute, P.O Box 30709, 00100 Nairobi, Kenya
| | - Chris Stephen Jones
- International Livestock Research Institute, P.O Box 30709, 00100 Nairobi, Kenya
| | - Daniel Masiga
- International Centre of Insect Physiology and Ecology, P.O Box 30772, 00100 Nairobi, Kenya
| | - Charles Midega
- International Centre of Insect Physiology and Ecology, P.O Box 30772, 00100 Nairobi, Kenya
| | - Zeyaur Khan
- International Centre of Insect Physiology and Ecology, P.O Box 30772, 00100 Nairobi, Kenya
| | - Joerg Jores
- International Livestock Research Institute, P.O Box 30709, 00100 Nairobi, Kenya; Institute of Veterinary Bacteriology, University of Bern, 3012 Bern, Switzerland
| | - Anne Fischer
- International Centre of Insect Physiology and Ecology, P.O Box 30772, 00100 Nairobi, Kenya.
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9
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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. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:2799-2811. [PMID: 28505304 PMCID: PMC5853863 DOI: 10.1093/jxb/erx158] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [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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10
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Konnerth A, Krczal G, Boonrod K. Immunodominant membrane proteins of phytoplasmas. MICROBIOLOGY-SGM 2016; 162:1267-1273. [PMID: 27384683 DOI: 10.1099/mic.0.000331] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Phytoplasmas are plant-pathogenic, phloem-colonizing, cell wall-less microorganisms that are primarily dependent on insect transmission for their spread and survival. The life cycle of phytoplasmas involves replication in insects and host plants. Until recently, phytoplasmas have resisted all attempts at cultivation in cell-free media, making these pathogens poorly characterized on a physiological and biochemical basis. However, host-pathogen relationships can be studied by investigating immunodominant membrane proteins (IDPs), which are located on the exterior surfaces of phytoplasma cells and are the most abundant proteins of the cell membrane. These membrane proteins come in direct contact with both insect and plant hosts and are thought to play a crucial role in phytoplasma spread both within the plant and by insect vectors. Therefore, there is great interest in studying this class of proteins. We summarize and discuss important investigations about these membrane proteins, which have already provided a better understanding of the host-phytoplasma relationship.
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Affiliation(s)
- Alisa Konnerth
- RLP-AgroScience GmbH, AlPlanta-Institute for Plant Research, Breitenweg 71, 67435 Neustadt, Germany
| | - Gabriele Krczal
- RLP-AgroScience GmbH, AlPlanta-Institute for Plant Research, Breitenweg 71, 67435 Neustadt, Germany
| | - Kajohn Boonrod
- RLP-AgroScience GmbH, AlPlanta-Institute for Plant Research, Breitenweg 71, 67435 Neustadt, Germany
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11
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Wei W, Davis RE, Suo X, Zhao Y. Occurrence, distribution and possible functional roles of simple sequence repeats in phytoplasma genomes. Int J Syst Evol Microbiol 2015; 65:2748-2760. [DOI: 10.1099/ijs.0.000273] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Phytoplasmas are unculturable, cell-wall-less bacteria that parasitize plants and insects. This transkingdom life cycle requires rapid responses to vastly different environments, including transitions from plant phloem sieve elements to various insect tissues and alternations among diverse plant hosts. Features that enable such flexibility in other microbes include simple sequence repeats (SSRs) — mutation-prone, phase-variable short DNA tracts that function as ‘evolutionary rheostats’ and enhance rapid adaptations. To gain insights into the occurrence, distribution and potentially functional roles of SSRs in phytoplasmas, we performed computational analysis on the genomes of five completely sequenced phytoplasma strains, ‘Candidatus Phytoplasma asteris’-related strains OYM and AYWB, ‘Candidatus Phytoplasma australiense’-related strains CBWB and SLY and ‘Candidatus Phytoplasma mali’-related strain AP-AT. The overall density of SSRs in phytoplasma genomes was higher than in representative strains of other prokaryotes. While mono- and trinucleotide SSRs were significantly overrepresented in the phytoplasma genomes, dinucleotide SSRs and other higher-order SSRs were underrepresented. The occurrence and distribution of long SSRs in the prophage islands and phytoplasma-unique genetic loci indicated that SSRs played a role in compounding the complexity of sequence mosaics in individual genomes and in increasing allelic diversity among genomes. Findings from computational analyses were further complemented by an examination of SSRs in varied additional phytoplasma strains, with a focus on potential contingency genes. Some SSRs were located in regions that could profoundly alter the regulation of transcription and translation of affected genes and/or the composition of protein products.
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Affiliation(s)
- Wei Wei
- Molecular Plant Pathology Laboratory, USDA-Agricultural Research Service, Beltsville, MD, 20705, USA
| | - Robert E. Davis
- Molecular Plant Pathology Laboratory, USDA-Agricultural Research Service, Beltsville, MD, 20705, USA
| | - Xiaobing Suo
- Molecular Plant Pathology Laboratory, USDA-Agricultural Research Service, Beltsville, MD, 20705, USA
| | - Yan Zhao
- Molecular Plant Pathology Laboratory, USDA-Agricultural Research Service, Beltsville, MD, 20705, USA
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12
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Murolo S, Romanazzi G. In-vineyard population structure of 'Candidatus Phytoplasma solani' using multilocus sequence typing analysis. INFECTION GENETICS AND EVOLUTION 2015; 31:221-30. [PMID: 25660034 DOI: 10.1016/j.meegid.2015.01.028] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 01/28/2015] [Accepted: 01/29/2015] [Indexed: 11/28/2022]
Abstract
'Candidatus Phytoplasma solani' is a phytoplasma of the stolbur group (16SrXII subgroup A) that is associated with 'Bois noir' and causes heavy damage to the quality and quantity of grapevine yields in several European countries, and particularly in the Mediterranean area. Analysis of 'Ca. P. solani' genetic diversity was carried out for strains infecting a cv. 'Chardonnay' vineyard, through multilocus sequence typing analysis for the vmp1, stamp and secY genes. Several types per gene were detected: seven out of 20 types for vmp1, six out of 17 for stamp, and four out of 16 for secY. High correlations were seen among the vmp1, stamp and secY typing with the tuf typing. However, no correlations were seen among the tuf and vmp1 types and the Bois noir severity in the surveyed grapevines. Grouping the 'Ca. P. solani' sequences on the basis of their origins (i.e., study vineyard, Italian regions, Euro-Mediterranean countries), dN/dS ratio analysis revealed overall positive selection for stamp (3.99, P=0.019) and vmp1 (2.28, P=0.001). For secY, the dN/dS ratio was 1.02 (P=0.841), showing neutral selection across this gene. Using analysis of the nucleotide sequencing by a Bayesian approach, we determined the population structure of 'Ca. P. solani', which appears to be structured in 3, 5 and 6 subpopulations, according to the secY, stamp and vmp1 genes, respectively. The high genetic diversity of 'Ca. P. solani' from a single vineyard reflects the population structure across wider geographical scales. This information is useful to trace inoculum source and movement of pathogen strains at the local level and over long distances.
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Affiliation(s)
- Sergio Murolo
- Department of Agricultural, Food and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
| | - Gianfranco Romanazzi
- Department of Agricultural, Food and Environmental Sciences, Marche Polytechnic University, Ancona, Italy.
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Bertaccini A, Duduk B, Paltrinieri S, Contaldo N. Phytoplasmas and Phytoplasma Diseases: A Severe Threat to Agriculture. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/ajps.2014.512191] [Citation(s) in RCA: 218] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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14
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Neriya Y, Sugawara K, Maejima K, Hashimoto M, Komatsu K, Minato N, Miura C, Kakizawa S, Yamaji Y, Oshima K, Namba S. Cloning, expression analysis, and sequence diversity of genes encoding two different immunodominant membrane proteins in poinsettia branch-inducing phytoplasma (PoiBI). FEMS Microbiol Lett 2011; 324:38-47. [PMID: 22092762 DOI: 10.1111/j.1574-6968.2011.02384.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 07/25/2011] [Accepted: 08/08/2011] [Indexed: 11/26/2022] Open
Abstract
Poinsettia branch-inducing phytoplasma (PoiBI) is a phytopathogenic bacterium that infects poinsettia, and is associated with the free-branching morphotype (characterized by many axillary shoots and flowers) of many commercially grown poinsettias. The major membrane proteins of phytoplasmas are classified into three general types, that is, immunodominant membrane protein (Imp), immunodominant membrane protein A (IdpA), and antigenic membrane protein (Amp). These membrane proteins are often used as targets for the production of antibodies used in phytoplasma detection. Herein, we cloned and sequenced the imp and idpA genes of PoiBI strains from 26 commercial poinsettia cultivars. Although the amino acid sequences of the encoded IdpA proteins were invariant, those of the encoded Imp varied among the PoiBI isolates, with no synonymous nucleotide substitution. Western blotting and immunohistochemical analyses revealed that the amount of Imp expressed exceeded that of IdpA, in contrast to the case of a related phytoplasma-disease, western X-disease, for which the major membrane protein appears to be IdpA, not Imp. These results suggest that even phylogenetically close phytoplasmas express different types of major membrane proteins.
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Affiliation(s)
- Yutaro Neriya
- Laboratory of Plant Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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15
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Himeno M, Neriya Y, Minato N, Miura C, Sugawara K, Ishii Y, Yamaji Y, Kakizawa S, Oshima K, Namba S. Unique morphological changes in plant pathogenic phytoplasma-infected petunia flowers are related to transcriptional regulation of floral homeotic genes in an organ-specific manner. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 67:971-979. [PMID: 21605209 DOI: 10.1111/j.1365-313x.2011.04650.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Abnormal flowers are often induced by infection of certain plant pathogens, e.g. phytoplasma, but the molecular mechanisms underlying these malformations have remained poorly understood. Here, we show that infection with OY-W phytoplasma (Candidatus Phytoplasma asteris, onion yellows phytoplasma strain, line OY-W) affects the expression of the floral homeotic genes of petunia plants in an organ-specific manner. Upon infection with OY-W phytoplasma, floral morphological changes, including conversion to leaf-like structures, were observed in sepals, petals and pistils, but not in stamens. As the expression levels of homeotic genes differ greatly between floral organs, we examined the expression levels of homeotic genes in each floral organ infected by OY-W phytoplasma, compared with healthy plants. The expression levels of several homeotic genes required for organ development, such as PFG, PhGLO1 and FBP7, were significantly downregulated by the phytoplasma infection in floral organs, except the stamens, suggesting that the unique morphological changes caused by the phytoplasma infection might result from the significant decrease in expression of some crucial homeotic genes. Moreover, the expression levels of TER, ALF and DOT genes, which are known to participate in floral meristem identity, were significantly downregulated in the phytoplasma-infected petunia meristems, implying that phytoplasma would affect an upstream signaling pathway of floral meristem identity. Our results suggest that phytoplasma infection may have complex effects on floral development, resulting in the unique phenotypes that were clearly distinct from the mutant flower phenotypes produced by the knock-out or the overexpression of certain homeotic genes.
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Affiliation(s)
- Misako Himeno
- Department of Agricultural and Environmental Biology, Laboratory of Plant Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
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Seemüller E, Kiss E, Sule S, Schneider B. Multiple infection of apple trees by distinct strains of 'Candidatus Phytoplasma mali' and its pathological relevance. PHYTOPATHOLOGY 2010; 100:863-870. [PMID: 20701483 DOI: 10.1094/phyto-100-9-0863] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Forty-eight apple trees infected by 'Candidatus Phytoplasma mali' were examined using single-strand conformation polymorphism (SSCP) and sequence analysis of a variable hflB gene fragment and the immunodominant membrane protein-encoding imp gene. SSCP analysis of polymerase chain reaction-amplified hflB gene fragments revealed diverse profiles, differing in number and position of the bands. The 'Ca. P. mali' content of a single infected apple tree was termed an accession. Cloning of fragments from accessions that yielded fewer bands resulted in clone populations showing uniform or moderately polymorphic SSCP patterns and largely homogenous nucleotide sequences. In contrast, inserts from accessions yielding more bands were heterogeneous and formed two to four distinct groups of profiles. DNA fragments from such accessions were diverse and clustered distantly when subjected to phylogenetic analysis, mostly as two homogenous groups plus one or a few other sequences. Similar results were obtained upon imp gene examination. The collective data indicate that accessions exhibiting more complex patterns were composed of two or three distinct 'Ca. P. mali' strains. There is evidence that multiple infections are of pathological relevance due to strain interactions leading to shifts in the populations. In triply infected trees of one accession, no specific symptoms were induced by the presence of two of the strains. The rare appearance of pronounced symptoms was associated with a separate strain that possessed a unique SSCP profile and a unique hflB sequence. The two mild strains from this apple accession also induced only mild symptoms on periwinkle and tobacco and occurred specifically in one of these plants.
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Affiliation(s)
- Erich Seemüller
- Federal Research Centre for Cultivated Plants, Institute for plant protection in Fruit Crops and Viticulture, Dossenheim, German.
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Hoshi A, Oshima K, Kakizawa S, Ishii Y, Ozeki J, Hashimoto M, Komatsu K, Kagiwada S, Yamaji Y, Namba S. A unique virulence factor for proliferation and dwarfism in plants identified from a phytopathogenic bacterium. Proc Natl Acad Sci U S A 2009; 106:6416-21. [PMID: 19329488 PMCID: PMC2669400 DOI: 10.1073/pnas.0813038106] [Citation(s) in RCA: 157] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2008] [Indexed: 01/05/2023] Open
Abstract
One of the most important themes in agricultural science is the identification of virulence factors involved in plant disease. Here, we show that a single virulence factor, tengu-su inducer (TENGU), induces witches' broom and dwarfism and is a small secreted protein of the plant-pathogenic bacterium, phytoplasma. When tengu was expressed in Nicotiana benthamiana plants, these plants showed symptoms of witches' broom and dwarfism, which are typical of phytoplasma infection. Transgenic Arabidopsis thaliana lines expressing tengu exhibited similar symptoms, confirming the effects of tengu expression on plants. Although the localization of phytoplasma was restricted to the phloem, TENGU protein was detected in apical buds by immunohistochemical analysis, suggesting that TENGU was transported from the phloem to other cells. Microarray analyses showed that auxin-responsive genes were significantly down-regulated in the tengu-transgenic plants compared with GUS-transgenic control plants. These results suggest that TENGU inhibits auxin-related pathways, thereby affecting plant development.
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Affiliation(s)
- Ayaka Hoshi
- 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; and
| | - Kenro Oshima
- 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; and
| | - Shigeyuki Kakizawa
- 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; and
| | - Yoshiko Ishii
- 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; and
| | - Johji Ozeki
- 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; and
| | - 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; and
| | - Ken Komatsu
- 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; and
| | - Satoshi Kagiwada
- Department of Clinical Plant Science, Faculty of Bioscience and Applied Chemistry, Hosei University, 3-7-2 Kajinocho, Koganei, Tokyo 184-8584, 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; and
| | - 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; and
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