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Sarkar P, Lin CY, Buritica JR, Killiny N, Levy A. Crossing the Gateless Barriers: Factors Involved in the Movement of Circulative Bacteria Within Their Insect Vectors. PHYTOPATHOLOGY 2023; 113:1805-1816. [PMID: 37160668 DOI: 10.1094/phyto-07-22-0249-ia] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Plant bacterial pathogens transmitted by hemipteran vectors pose a large threat to the agricultural industry worldwide. Although virus-vector relationships have been widely investigated, a significant gap exists in our understanding of the molecular interactions between circulative bacteria and their insect vectors, mainly leafhoppers and psyllids. In this review, we will describe how these bacterial pathogens adhere, invade, and proliferate inside their insect vectors. We will also highlight the different transmission routes and molecular factors of phloem-limited bacteria that maintain an effective relationship with the insect host. Understanding the pathogen-vector relationship at the molecular level will help in the management of vector-borne bacterial diseases.
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Affiliation(s)
- Poulami Sarkar
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850
| | - Chun-Yi Lin
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850
| | - Jacobo Robledo Buritica
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
| | - Nabil Killiny
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
| | - Amit Levy
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
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Sagouti T, Belabess Z, Rhallabi N, Barka EA, Tahiri A, Lahlali R. Citrus Stubborn Disease: Current Insights on an Enigmatic Problem Prevailing in Citrus Orchards. Microorganisms 2022; 10:183. [PMID: 35056632 PMCID: PMC8779666 DOI: 10.3390/microorganisms10010183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 01/05/2022] [Accepted: 01/12/2022] [Indexed: 12/29/2022] Open
Abstract
Citrus stubborn was initially observed in California in 1915 and was later proven as a graft-transmissible disease in 1942. In the field, diseased citrus trees have compressed and stunted appearances, and yield poor-quality fruits with little market value. The disease is caused by Spiroplasma citri, a phloem-restricted pathogenic mollicute, which belongs to the Spiroplasmataceae family (Mollicutes). S. citri has the largest genome of any Mollicutes investigated, with a genome size of roughly 1780 Kbp. It is a helical, motile mollicute that lacks a cell wall and peptidoglycan. Several quick and sensitive molecular-based and immuno-enzymatic pathogen detection technologies are available. Infected weeds are the primary source of transmission to citrus, with only a minor percentage of transmission from infected citrus to citrus. Several phloem-feeding leafhopper species (Cicadellidae, Hemiptera) support the natural spread of S. citri in a persistent, propagative manner. S. citri-free buds are used in new orchard plantings and bud certification, and indexing initiatives have been launched. Further, a quarantine system for newly introduced types has been implemented to limit citrus stubborn disease (CSD). The present state of knowledge about CSD around the world is summarized in this overview, where recent advances in S. citri detection, characterization, control and eradication were highlighted to prevent or limit disease spread through the adoption of best practices.
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Affiliation(s)
- Tourya Sagouti
- Laboratoire de Virologie, Microbiologie et Qualité/Ecotoxicologie et Biodiversité, Faculté des Sciences et Techniques de Mohammedia, Mohammedia 20650, Morocco; (T.S.); (N.R.)
| | - Zineb Belabess
- Plant Protection Laboratory, Regional Center of Agricultural Research of Oujda, National Institute of Agricultural Research, Avenue Mohamed VI, BP428 Oujda, Oujda 60000, Morocco;
| | - Naima Rhallabi
- Laboratoire de Virologie, Microbiologie et Qualité/Ecotoxicologie et Biodiversité, Faculté des Sciences et Techniques de Mohammedia, Mohammedia 20650, Morocco; (T.S.); (N.R.)
| | - Essaid Ait Barka
- Unité de Recherche Résistance Induite et Bio-Protection des Plantes-EA 4707, Université de Reims Champagne-Ardenne, 51100 Reims, France
| | - Abdessalem Tahiri
- Phytopathology Unit, Department of Plant Protection, Ecole Nationale d’Agriculture de Meknès, Meknes 50001, Morocco;
| | - Rachid Lahlali
- Phytopathology Unit, Department of Plant Protection, Ecole Nationale d’Agriculture de Meknès, Meknes 50001, Morocco;
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Rattner R, Thapa SP, Dang T, Osman F, Selvaraj V, Maheshwari Y, Pagliaccia D, Espindola AS, Hajeri S, Chen J, Coaker G, Vidalakis G, Yokomi R. Genome analysis of Spiroplasma citri strains from different host plants and its leafhopper vectors. BMC Genomics 2021; 22:373. [PMID: 34022804 PMCID: PMC8140453 DOI: 10.1186/s12864-021-07637-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 04/21/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Spiroplasma citri comprises a bacterial complex that cause diseases in citrus, horseradish, carrot, sesame, and also infects a wide array of ornamental and weed species. S. citri is transmitted in a persistent propagative manner by the beet leafhopper, Neoaliturus tenellus in North America and Circulifer haematoceps in the Mediterranean region. Leafhopper transmission and the pathogen's wide host range serve as drivers of genetic diversity. This diversity was examined in silico by comparing the genome sequences of seven S. citri strains from the United States (BR12, CC-2, C5, C189, LB 319, BLH-13, and BLH-MB) collected from different hosts and times with other publicly available spiroplasmas. RESULTS Phylogenetic analysis using 16S rRNA sequences from 39 spiroplasmas obtained from NCBI database showed that S. citri strains, along with S. kunkelii and S. phoeniceum, two other plant pathogenic spiroplasmas, formed a monophyletic group. To refine genetic relationships among S. citri strains, phylogenetic analyses with 863 core orthologous sequences were performed. Strains that clustered together were: CC-2 and C5; C189 and R8-A2; BR12, BLH-MB, BLH-13 and LB 319. Strain GII3-3X remained in a separate branch. Sequence rearrangements were observed among S. citri strains, predominantly in the center of the chromosome. One to nine plasmids were identified in the seven S. citri strains analyzed in this study. Plasmids were most abundant in strains isolated from the beet leafhopper, followed by strains from carrot, Chinese cabbage, horseradish, and citrus, respectively. All these S. citri strains contained one plasmid with high similarity to plasmid pSci6 from S. citri strain GII3-3X which is known to confer insect transmissibility. Additionally, 17 to 25 prophage-like elements were identified in these genomes, which may promote rearrangements and contribute to repetitive regions. CONCLUSIONS The genome of seven S. citri strains were found to contain a single circularized chromosome, ranging from 1.58 Mbp to 1.74 Mbp and 1597-2232 protein-coding genes. These strains possessed a plasmid similar to pSci6 from the GII3-3X strain associated with leafhopper transmission. Prophage sequences found in the S. citri genomes may contribute to the extension of its host range. These findings increase our understanding of S. citri genetic diversity.
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Affiliation(s)
- Rachel Rattner
- Crop Diseases, Pests, and Genetics Research Unit, San Joaquin Valley Agricultural Sciences Center, USDA Agricultural Research Service, Parlier, CA, 93648, USA
| | - Shree Prasad Thapa
- Department of Plant Pathology, University of California, Davis, CA, 95616, USA
| | - Tyler Dang
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
| | - Fatima Osman
- Department of Plant Pathology, University of California, Davis, CA, 95616, USA
| | - Vijayanandraj Selvaraj
- Crop Diseases, Pests, and Genetics Research Unit, San Joaquin Valley Agricultural Sciences Center, USDA Agricultural Research Service, Parlier, CA, 93648, USA
| | - Yogita Maheshwari
- Crop Diseases, Pests, and Genetics Research Unit, San Joaquin Valley Agricultural Sciences Center, USDA Agricultural Research Service, Parlier, CA, 93648, USA
| | - Deborah Pagliaccia
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
| | - Andres S Espindola
- Department of Entomology & Plant Pathology and Institute of Biosecurity and Microbial Forensics, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Subhas Hajeri
- Citrus Pest Detection Program, Central California Tristeza Eradication Agency, Tulare, CA, 93274, USA
| | - Jianchi Chen
- Crop Diseases, Pests, and Genetics Research Unit, San Joaquin Valley Agricultural Sciences Center, USDA Agricultural Research Service, Parlier, CA, 93648, USA
| | - Gitta Coaker
- Department of Plant Pathology, University of California, Davis, CA, 95616, USA
| | - Georgios Vidalakis
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
| | - Raymond Yokomi
- Crop Diseases, Pests, and Genetics Research Unit, San Joaquin Valley Agricultural Sciences Center, USDA Agricultural Research Service, Parlier, CA, 93648, USA.
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In Vitro Culture of the Insect Endosymbiont Spiroplasma poulsonii Highlights Bacterial Genes Involved in Host-Symbiont Interaction. mBio 2018; 9:mBio.00024-18. [PMID: 29559567 PMCID: PMC5874924 DOI: 10.1128/mbio.00024-18] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Endosymbiotic bacteria associated with eukaryotic hosts are omnipresent in nature, particularly in insects. Studying the bacterial side of host-symbiont interactions is, however, often limited by the unculturability and genetic intractability of the symbionts. Spiroplasma poulsonii is a maternally transmitted bacterial endosymbiont that is naturally associated with several Drosophila species. S. poulsonii strongly affects its host’s physiology, for example by causing male killing or by protecting it against various parasites. Despite intense work on this model since the 1950s, attempts to cultivate endosymbiotic Spiroplasma in vitro have failed so far. Here, we developed a method to sustain the in vitro culture of S. poulsonii by optimizing a commercially accessible medium. We also provide a complete genome assembly, including the first sequence of a natural plasmid of an endosymbiotic Spiroplasma species. Last, by comparing the transcriptome of the in vitro culture to the transcriptome of bacteria extracted from the host, we identified genes putatively involved in host-symbiont interactions. This work provides new opportunities to study the physiology of endosymbiotic Spiroplasma and paves the way to dissect insect-endosymbiont interactions with two genetically tractable partners. The discovery of insect bacterial endosymbionts (maternally transmitted bacteria) has revolutionized the study of insects, suggesting novel strategies for their control. Most endosymbionts are strongly dependent on their host to survive, making them uncultivable in artificial systems and genetically intractable. Spiroplasma poulsonii is an endosymbiont of Drosophila that affects host metabolism, reproduction, and defense against parasites. By providing the first reliable culture medium that allows a long-lasting in vitro culture of Spiroplasma and by elucidating its complete genome, this work lays the foundation for the development of genetic engineering tools to dissect endosymbiosis with two partners amenable to molecular study. Furthermore, the optimization method that we describe can be used on other yet uncultivable symbionts, opening new technical opportunities in the field of host-microbes interactions.
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Infection Function of Adhesin-Like Protein ALP609 from Spiroplasma melliferum CH-1. Curr Microbiol 2018; 75:701-708. [PMID: 29362879 DOI: 10.1007/s00284-018-1435-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Accepted: 01/05/2018] [Indexed: 10/18/2022]
Abstract
Spiroplasma melliferum is the causative agent of spiroplasmosis in honeybees. During infection, adhesion of spiroplasmas to the host cells through adhesion factors is a crucial step. In this study, we identified an adhesin-like protein (ALP609) in S. melliferum CH-1 and investigated its role in the infection. To determine whether ALP609 is an adhesion factor, we performed indirect immunofluorescence microscopy to visualize its adhesion properties. Subsequently, an infection model of S. melliferum CH-1 was established using primary midgut cells of Apis mellifera to examine the adhesion and invasion of spiroplasma using anti-ALP609 antibodies inhibition assays and competition assays with recombinant ALP609 in vitro. We found that anti-ALP609 antibodies could inhibit the adhesion and invasion of spiroplasma to the midgut cells of A. mellifera and reduce midgut cell invasion on increased exposure to recombinant ALP609. To the best of our knowledge, this is the first report identifying adhesion-related factors in S. melliferum. Our results suggested that ALP609 is an adhesin-like protein critical for invasion of S. melliferum CH-1 into midgut cells of A. mellifera.
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Dubrana MP, Guéguéniat J, Bertin C, Duret S, Arricau-Bouvery N, Claverol S, Lartigue C, Blanchard A, Renaudin J, Béven L. Proteolytic Post-Translational Processing of Adhesins in a Pathogenic Bacterium. J Mol Biol 2017; 429:1889-1902. [PMID: 28501585 DOI: 10.1016/j.jmb.2017.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 04/25/2017] [Accepted: 05/04/2017] [Indexed: 11/29/2022]
Abstract
Mollicutes, including mycoplasmas and spiroplasmas, have been considered as good representatives of the « minimal cell » concept: these wall-less bacteria are small in size and possess a minimal genome and restricted metabolic capacities. However, the recent discovery of the presence of post-translational modifications unknown so far, such as the targeted processing of membrane proteins of mycoplasma pathogens for human and swine, revealed a part of the hidden complexity of these microorganisms. In this study, we show that in the phytopathogen, insect-vectored Spiroplasma citri GII-3 adhesion-related protein (ScARP) adhesins are post-translationally processed through an ATP-dependent targeted cleavage. The cleavage efficiency could be enhanced in vitro when decreasing the extracellular pH or upon the addition of polyclonal antibodies directed against ScARP repeated units, suggesting that modification of the surface charge and/or ScARP conformational changes could initiate the cleavage. The two major sites for primary cleavage are localized within predicted disordered regions and do not fit any previously reported cleavage motif; in addition, the inhibition profile and the metal ion requirements indicate that this post-translational modification involves at least one non-conventional protease. Such a proteolytic process may play a role in S. citri colonization of cells of the host insect. Furthermore, our work indicates that post-translational cleavage of adhesins represents a common feature to mollicutes colonizing distinct hosts and that processing of surface antigens could represent a way to make the most out of a minimal genome.
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Affiliation(s)
| | - Julia Guéguéniat
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | - Clothilde Bertin
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | - Sybille Duret
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | | | | | - Carole Lartigue
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | - Alain Blanchard
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | - Joël Renaudin
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | - Laure Béven
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France.
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Dubrana MP, Béven L, Arricau-Bouvery N, Duret S, Claverol S, Renaudin J, Saillard C. Differential expression of Spiroplasma citri surface protein genes in the plant and insect hosts. BMC Microbiol 2016; 16:53. [PMID: 27005573 PMCID: PMC4804543 DOI: 10.1186/s12866-016-0666-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 03/07/2016] [Indexed: 11/10/2022] Open
Abstract
Background Spiroplasma citri is a cell wall-less, plant pathogenic bacteria that colonizes two distinct hosts, the leafhopper vector and the host plant. Given the absence of a cell wall, surface proteins including lipoproteins and transmembrane polypeptides are expected to play key roles in spiroplasma/host interactions. Important functions in spiroplasma/insect interactions have been shown for a few surface proteins such as the major lipoprotein spiralin, the transmembrane S. citri adhesion-related proteins (ScARPs) and the sugar transporter subunit Sc76. S. citri efficient transmission from the insect to the plant is expected to rely on its ability to adapt to the different environments and more specifically to regulate the expression of genes encoding surface-exposed proteins. Results Genes encoding S. citri lipoproteins and ScARPs were investigated for their expression level in axenic medium, in the leafhopper vector Circulifer haematoceps and in the host plant (periwinkle Catharanthus roseus) either insect-infected or graft-inoculated. The vast majority of the lipoprotein genes tested (25/28) differentially responded to the various host environments. Considering their relative expression levels in the different environments, the possible involvement of the targeted genes in spiroplasma host adaptation was discussed. In addition, two S. citri strains differing notably in their ability to express adhesin ScARP2b and pyruvate dehydrogenase E1 component differed in their capacity to multiply in the two hosts, the plant and the leafhopper vector. Conclusions This study provided us with a list of genes differentially expressed in the different hosts, leading to the identification of factors that are thought to be involved in the process of S. citri host adaptation. The identification of such factors is a key step for further understanding of S. citri pathogenesis. Moreover the present work highlights the high capacity of S. citri in tightly regulating the expression level of a large set of surface protein genes, despite the small size of its genome. Electronic supplementary material The online version of this article (doi:10.1186/s12866-016-0666-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marie-Pierre Dubrana
- UMR 1332 Biologie du Fruit et Pathologie, INRA, F-33882, Villenave d'Ornon, France.,UMR 1332 Biologie du Fruit et Pathologie, Université de Bordeaux, F-33882, Villenave d'Ornon, France
| | - Laure Béven
- UMR 1332 Biologie du Fruit et Pathologie, INRA, F-33882, Villenave d'Ornon, France. .,UMR 1332 Biologie du Fruit et Pathologie, Université de Bordeaux, F-33882, Villenave d'Ornon, France.
| | - Nathalie Arricau-Bouvery
- UMR 1332 Biologie du Fruit et Pathologie, INRA, F-33882, Villenave d'Ornon, France.,UMR 1332 Biologie du Fruit et Pathologie, Université de Bordeaux, F-33882, Villenave d'Ornon, France
| | - Sybille Duret
- UMR 1332 Biologie du Fruit et Pathologie, INRA, F-33882, Villenave d'Ornon, France.,UMR 1332 Biologie du Fruit et Pathologie, Université de Bordeaux, F-33882, Villenave d'Ornon, France
| | - Stéphane Claverol
- Plateforme Protéome, CGFB, Université de Bordeaux, F-33076, Bordeaux, France
| | - Joël Renaudin
- UMR 1332 Biologie du Fruit et Pathologie, INRA, F-33882, Villenave d'Ornon, France.,UMR 1332 Biologie du Fruit et Pathologie, Université de Bordeaux, F-33882, Villenave d'Ornon, France
| | - Colette Saillard
- UMR 1332 Biologie du Fruit et Pathologie, INRA, F-33882, Villenave d'Ornon, France.,UMR 1332 Biologie du Fruit et Pathologie, Université de Bordeaux, F-33882, Villenave d'Ornon, France
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Renaudin J, Béven L, Batailler B, Duret S, Desqué D, Arricau-Bouvery N, Malembic-Maher S, Foissac X. Heterologous expression and processing of the flavescence dorée phytoplasma variable membrane protein VmpA in Spiroplasma citri. BMC Microbiol 2015; 15:82. [PMID: 25879952 PMCID: PMC4392738 DOI: 10.1186/s12866-015-0417-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 03/18/2015] [Indexed: 11/21/2022] Open
Abstract
Background Flavescence dorée (FD) of grapevine is a phloem bacterial disease that threatens European vineyards. The disease is associated with a non-cultivable mollicute, a phytoplasma that is transmitted by the grapevine leafhopper Scaphoideus titanus in a persistent, propagative manner. The specificity of insect transmission is presumably mediated through interactions between the host tissues and phytoplasma surface proteins comprising the so-called variable membrane proteins (Vmps). Plant spiroplasmas and phytoplasmas share the same ecological niches, the phloem sieve elements of host plants and the hemocoel of insect vectors. Unlike phytoplasmas, however, spiroplasmas, and Spiroplasma citri in particular, can be grown in cell-free media and genetically engineered. As a new approach for studying phytoplasmas-insect cell interactions, we sought to mimic phytoplasmas through the construction of recombinant spiroplasmas exhibiting FD phytoplasma Vmps at the cell surface. Results Here, we report the expression of the FD phytoplasma VmpA in S. citri. Transformation of S. citri with plasmid vectors in which the vmpA coding sequence was under the control of the S. citri tuf gene promoter resulted in higher accumulation of VmpA than with the native promoter. Expression of VmpA at the spiroplasma surface was achieved by fusing the vmpA coding sequence to the signal peptide sequence of the S. citri adhesin ScARP3d, as revealed by direct colony immunoblotting and immunogold labelling electron microscopy. Anchoring of VmpA to the spiroplasma membrane was further demonstrated by Triton X-114 protein partitioning and Western immunoblotting. Using the same strategy, the secretion of free, functionally active β-lactamase (used as a model protein) into the culture medium by recombinant spiroplasmas was achieved. Conclusions Construction of recombinant spiroplasmas harbouring the FD phytoplasma variable membrane protein VmpA at their surface was achieved, which provides a new biological approach for studying interactions of phytoplasma surface proteins with host cells. Likewise, the secretion of functional β-lactamase by recombinant spiroplasmas established the considerable promise of the S. citri expression system for delivering phytoplasma effector proteins into host cells. Electronic supplementary material The online version of this article (doi:10.1186/s12866-015-0417-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Joël Renaudin
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
| | - Laure Béven
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
| | - Brigitte Batailler
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMS3420, Bordeaux Imaging Center, Bordeaux, France. .,CNRS, Bordeaux Imaging Center, UMS 3420, Bordeaux, France. .,INSERM, Bordeaux Imaging Center, US 004, Bordeaux, France.
| | - Sybille Duret
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
| | - Delphine Desqué
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
| | - Nathalie Arricau-Bouvery
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
| | - Sylvie Malembic-Maher
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
| | - Xavier Foissac
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
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The repetitive domain of ScARP3d triggers entry of Spiroplasma citri into cultured cells of the vector Circulifer haematoceps. PLoS One 2012; 7:e48606. [PMID: 23119070 PMCID: PMC3485318 DOI: 10.1371/journal.pone.0048606] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 09/27/2012] [Indexed: 11/19/2022] Open
Abstract
Spiroplasma citri is a plant pathogenic mollicute transmitted by the leafhopper vector Circulifer haematoceps. Successful transmission requires the spiroplasmas to cross the intestinal epithelium and salivary gland barriers through endocytosis mediated by receptor-ligand interactions. To characterize these interactions we studied the adhesion and invasion capabilities of a S. citri mutant using the Ciha-1 leafhopper cell line. S. citri GII3 wild-type contains 7 plasmids, 5 of which (pSci1 to 5) encode 8 related adhesins (ScARPs). As compared to the wild-type strain GII3, the S. citri mutant G/6 lacking pSci1 to 5 was affected in its ability to adhere and enter into the Ciha-1 cells. Proteolysis analyses, Triton X-114 partitioning and agglutination assays showed that the N-terminal part of ScARP3d, consisting of repeated sequences, was exposed to the spiroplasma surface whereas the C-terminal part was anchored into the membrane. Latex beads cytadherence assays showed the ScARP3d repeat domain (Rep3d) to be involved, and internalization of the Rep3d-coated beads to be actin-dependent. These data suggested that ScARP3d, via its Rep3d domain, was implicated in adhesion of S. citri GII3 to insect cells. Inhibition tests using anti-Rep3d antibodies and competitive assays with recombinant Rep3d both resulted in a decrease of insect cells invasion by the spiroplasmas. Unexpectedly, treatment of Ciha-1 cells with the actin polymerisation inhibitor cytochalasin D increased adhesion and consequently entry of S. citri GII3. For the ScARPs-less mutant G/6, only adhesion was enhanced though to a lesser extent following cytochalasin D treatment. All together these results strongly suggest a role of ScARPs, and particularly ScARP3d, in adhesion and invasion of the leafhopper cells by S. citri.
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Alexeev D, Kostrjukova E, Aliper A, Popenko A, Bazaleev N, Tyakht A, Selezneva O, Akopian T, Prichodko E, Kondratov I, Chukin M, Demina I, Galyamina M, Kamashev D, Vanyushkina A, Ladygina V, Levitskii S, Lazarev V, Govorun V. Application of Spiroplasma melliferum Proteogenomic Profiling for the Discovery of Virulence Factors and Pathogenicity Mechanisms in Host-associated Spiroplasmas. J Proteome Res 2011; 11:224-36. [DOI: 10.1021/pr2008626] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Dmitry Alexeev
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
- Moscow Institute of Physics and Technology - Bioinformatics Dolgoprudny,
Pervomayskaya 21 , Moscow 117303, Russian Federation
| | - Elena Kostrjukova
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Alexander Aliper
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Anna Popenko
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Nikolay Bazaleev
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Alexander Tyakht
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Oksana Selezneva
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
- Russian Research Centre Kurchatov Institute, pl. Akademika Kurchatova
1, Moscow 123182, Russian Federation
| | - Tatyana Akopian
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Elena Prichodko
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Ilya Kondratov
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Mikhail Chukin
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Irina Demina
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Maria Galyamina
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Dmitri Kamashev
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
- Russian Research Centre Kurchatov Institute, pl. Akademika Kurchatova
1, Moscow 123182, Russian Federation
| | - Anna Vanyushkina
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
- Russian Research Centre Kurchatov Institute, pl. Akademika Kurchatova
1, Moscow 123182, Russian Federation
| | - Valentina Ladygina
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Sergei Levitskii
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
- Russian Research Centre Kurchatov Institute, pl. Akademika Kurchatova
1, Moscow 123182, Russian Federation
| | - Vasily Lazarev
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
- Russian Research Centre Kurchatov Institute, pl. Akademika Kurchatova
1, Moscow 123182, Russian Federation
| | - Vadim Govorun
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
- Russian Research Centre Kurchatov Institute, pl. Akademika Kurchatova
1, Moscow 123182, Russian Federation
- M.M. Shemyakin–Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Ul. Miklukho-Maklaya,
16/10 , Moscow 117997, Russian Federation
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11
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Involvement of a minimal actin-binding region of Spiroplasma citri phosphoglycerate kinase in spiroplasma transmission by its leafhopper vector. PLoS One 2011; 6:e17357. [PMID: 21364953 PMCID: PMC3043095 DOI: 10.1371/journal.pone.0017357] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Accepted: 01/28/2011] [Indexed: 12/02/2022] Open
Abstract
Background Spiroplasma citri is a wall-less bacterium that colonizes phloem vessels of a large number of host plants. Leafhopper vectors transmit S. citri in a propagative and circulative manner, involving colonization and multiplication of bacteria in various insect organs. Previously we reported that phosphoglycerate kinase (PGK), the well-known glycolytic enzyme, bound to leafhopper actin and was unexpectedly implicated in the internalization process of S. citri into Circulifer haematoceps cells. Methodology/Principal Findings In an attempt to identify the actin-interacting regions of PGK, several overlapping PGK truncations were generated. Binding assays, using the truncations as probes on insect protein blots, revealed that the actin-binding region of PGK was located on the truncated peptide designated PGK-FL5 containing amino acids 49–154. To investigate the role of PGK-FL5-actin interaction, competitive spiroplasma attachment and internalization assays, in which His6-tagged PGK-FL5 was added to Ciha-1 cells prior to infection with S. citri, were performed. No effect on the efficiency of attachment of S. citri to leafhopper cells was observed while internalization was drastically reduced. The in vivo effect of PGK-FL5 was confirmed by competitive experimental transmission assays as injection of PGK-FL5 into S. citri infected leafhoppers significantly affected spiroplasmal transmission. Conclusion These results suggest that S. citri transmission by its insect vector is correlated to PGK ability to bind actin.
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12
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Breton M, Duret S, Béven L, Dubrana MP, Renaudin J. I-SceI-mediated plasmid deletion and intra-molecular recombination in Spiroplasma citri. J Microbiol Methods 2010; 84:216-22. [PMID: 21129414 DOI: 10.1016/j.mimet.2010.11.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 11/16/2010] [Accepted: 11/23/2010] [Indexed: 12/27/2022]
Abstract
S. citri wild-type strain GII3 carries six plasmids (pSci1 to -6) that are thought to encode determinants involved in the transmission of the spiroplasma by its leafhopper vector. In this study we report the use of meganuclease I-SceI for plasmid deletion in S. citri. Plasmids pSci1NT-I and pSci6PT-I, pSci1 and pSci6 derivatives that contain the tetM selection marker and a unique I-SceI recognition site were first introduced into S. citri strains 44 (having no plasmid) and GII3 (carrying pSci1-6), respectively. Due to incompatibility of homologous replication regions, propagation of the S. citri GII3 transformant in selective medium resulted in the replacement of the natural pSci6 by pSci6PT-I. The spiroplasmal transformants were further transformed by an oriC plasmid carrying the I-SceI gene under the control of the spiralin gene promoter. In the S. citri 44 transformant, expression of I-SceI resulted in rapid loss of pSciNT-I showing that expression of I-SceI can be used as a counter-selection tool in spiroplasmas. In the case of the S. citri GII3 transformant carrying pSci6PT-I, expression of I-SceI resulted in the deletion of plasmid fragments comprising the I-SceI site and the tetM marker. Delineating the I-SceI generated deletions proved they had occurred though recombination between homologous sequences. To our knowledge this is the first report of I-SceI mediated intra-molecular recombination in mollicutes.
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Affiliation(s)
- Marc Breton
- INRA, Génomique Diversité et Pouvoir Pathogéne, Villenave d'Ornon, France
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13
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Sequences essential for transmission of Spiroplasma citri by its leafhopper vector, Circulifer haematoceps, revealed by plasmid curing and replacement based on incompatibility. Appl Environ Microbiol 2010; 76:3198-205. [PMID: 20305023 DOI: 10.1128/aem.00181-10] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Spiroplasma citri GII3 contains highly related low-copy-number plasmids pSci1 to -6. Despite the strong similarities between their replication regions, these plasmids coexist in the spiroplasma cells, indicating that they are mutually compatible. The pSci1 to -6 plasmids encode the membrane proteins known as S. citri adhesion-related proteins (ScARPs) (pSci1 to -5) and the hydrophilic protein P32 (pSci6), which had been tentatively associated with insect transmission, as they were not detected in non-insect-transmissible strains. With the aim of further investigating the role of plasmid-encoded determinants in insect transmission, we have constructed S. citri mutant strains that differ in their plasmid contents by developing a plasmid curing/replacement strategy based on the incompatibility of plasmids having identical replication regions. Experimental transmission of these S. citri plasmid mutants through injection into the leafhopper vector Circulifer haematoceps revealed that pSci6, more precisely, the pSci6_06 coding sequence, encoding a protein of unknown function, was essential for transmission. In contrast, ScARPs and P32 were dispensable for both acquisition and transmission of the spiroplasmas by the leafhopper vector, even though S. citri mutants lacking pSci1 to -5 (encoding ScARPs) were acquired and transmitted at lower efficiencies than the wild-type strain GII3.
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14
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Gasparich GE. Spiroplasmas and phytoplasmas: microbes associated with plant hosts. Biologicals 2010; 38:193-203. [PMID: 20153217 DOI: 10.1016/j.biologicals.2009.11.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Accepted: 11/12/2009] [Indexed: 02/01/2023] Open
Abstract
This review will focus on two distinct genera, Spiroplasma and 'Candidatus Phytoplasma,' within the class Mollicutes (which also includes the genus Mycoplasma, a concern for animal-based cell culture). As members of the Mollicutes, both are cell wall-less microbes which have a characteristic small size (1-2 microM in diameter) and small genome size (530 Kb-2220 Kb). These two genera contain microbes which have a dual host cycle in which they can replicate in their leafhopper or psyllid insect vectors as well as in the sieve tubes of their plant hosts. Major distinctions between the two genera are that most spiroplasmas are cultivable in nutrient rich media, possess a very characteristic helical morphology, and are motile, while the phytoplasmas remain recalcitrant to cultivation attempts to date and exhibit a pleiomorphic or filamentous shape. This review article will provide a historical over view of their discovery, a brief review of taxonomical characteristics, diversity, host interactions (with a focus on plant hosts), phylogeny, and current detection and elimination techniques.
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Affiliation(s)
- Gail E Gasparich
- Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD 21252, USA.
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15
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Entry of Spiroplasma citri into Circulifer haematoceps cells involves interaction between spiroplasma phosphoglycerate kinase and leafhopper actin. Appl Environ Microbiol 2010; 76:1879-86. [PMID: 20118377 DOI: 10.1128/aem.02384-09] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transmission of the phytopathogenic mollicutes, spiroplasmas, and phytoplasmas by their insect vectors mainly depends on their ability to pass through gut cells, to multiply in various tissues, and to traverse the salivary gland cells. The passage of these different barriers suggests molecular interactions between the plant mollicute and the insect vector that regulate transmission. In the present study, we focused on the interaction between Spiroplasma citri and its leafhopper vector, Circulifer haematoceps. An in vitro protein overlay assay identified five significant binding activities between S. citri proteins and insect host proteins from salivary glands. One insect protein involved in one binding activity was identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) as actin. Confocal microscopy observations of infected salivary glands revealed that spiroplasmas colocated with the host actin filaments. An S. citri actin-binding protein of 44 kDa was isolated by affinity chromatography and identified by LC-MS/MS as phosphoglycerate kinase (PGK). To investigate the role of the PGK-actin interaction, we performed competitive binding and internalization assays on leafhopper cultured cell lines (Ciha-1) in which His(6)-tagged PGK from S. citri or purified PGK from Saccharomyces cerevisiae was added prior to the addition of S. citri inoculum. The results suggested that exogenous PGK has no effect on spiroplasmal attachment to leafhopper cell surfaces but inhibits S. citri internalization, demonstrating that the process leading to internalization of S. citri in eukaryotic cells requires the presence of PGK. PGK, regardless of origin, reduced the entry of spiroplasmas into Ciha-1 cells in a dose-dependent manner.
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16
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Duret S, Batailler B, Danet JL, Béven L, Renaudin J, Arricau-Bouvery N. Infection of the Circulifer haematoceps cell line Ciha-1 by Spiroplasma citri: the non-insect-transmissible strain 44 is impaired in invasion. MICROBIOLOGY-SGM 2009; 156:1097-1107. [PMID: 20019079 DOI: 10.1099/mic.0.035063-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Successful transmission of Spiroplasma citri by its leafhopper vector requires a specific interaction between the spiroplasma surface and the insect cells. With the aim of studying these interactions at the cellular and molecular levels, a cell line, named Ciha-1, was established using embryonic tissues from the eggs of the S. citri natural vector Circulifer haematoceps. This is the first report, to our knowledge, of a cell line for this leafhopper species and of its successful infection by the insect-transmissible strain S. citri GII3. Adherence of the spiroplasmas to the cultured Ciha-1 cells was studied by c.f.u. counts and by electron microscopy. Entry of the spiroplasmas into the insect cells was analysed quantitatively by gentamicin protection assays and qualitatively by double immunofluorescence microscopy. Spiroplasmas were detected within the cell cytoplasm as early as 1 h after inoculation and survived at least 2 days inside the cells. Comparing the insect-transmissible GII3 and non-insect-transmissible 44 strains revealed that adherence to and entry into Ciha-1 cells of S. citri 44 were significantly less efficient than those of S. citri GII3.
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Affiliation(s)
- Sybille Duret
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, Centre de Bordeaux-Aquitaine, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Brigitte Batailler
- Plateau Technique Imagerie/Cytologie, INRA, Centre de Bordeaux-Aquitaine, F-33883 Villenave d'Ornon, France.,Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, Centre de Bordeaux-Aquitaine, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Jean-Luc Danet
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, Centre de Bordeaux-Aquitaine, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Laure Béven
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, Centre de Bordeaux-Aquitaine, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Joël Renaudin
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, Centre de Bordeaux-Aquitaine, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Nathalie Arricau-Bouvery
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, Centre de Bordeaux-Aquitaine, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
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17
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Ishii Y, Oshima K, Kakizawa S, Hoshi A, Maejima K, Kagiwada S, Yamaji Y, Namba S. Process of reductive evolution during 10 years in plasmids of a non-insect-transmissible phytoplasma. Gene 2009; 446:51-7. [PMID: 19631261 DOI: 10.1016/j.gene.2009.07.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2009] [Revised: 07/01/2009] [Accepted: 07/14/2009] [Indexed: 11/18/2022]
Abstract
A non-insect-transmissible phytoplasma strain (OY-NIM) was obtained from insect-transmissible strain OY-M by plant grafting using no insect vectors. In this study, we analyzed for the gene structure of plasmids during its maintenance in plant tissue culture for 10 years. OY-M strain has one plasmid encoding orf3 gene which is thought to be involved in insect transmissibility. The gradual loss of OY-NIM plasmid sequence was observed in subsequent steps: first, the promoter region of orf3 was lost, followed by the loss of then a large region including orf3, and finally the entire plasmid was disappeared. In contrast, no mutation was found in a pseudogene on OY-NIM chromosome in the same period, indicating that OY-NIM plasmid evolved more rapidly than the chromosome-encoded gene tested. Results revealed an actual evolutionary process of OY plasmid, and provide a model for the stepwise process in reductive evolution of plasmids by environmental adaptation. Furthermore, this study indicates the great plasticity of plasmids throughout the evolution of phytoplasma.
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Affiliation(s)
- Yoshiko Ishii
- Department of Agricultural and Environmental Biology, The University of Tokyo, Yayoi, Bunkyo-ku, Japan
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18
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Ishii Y, Kakizawa S, Hoshi A, Maejima K, Kagiwada S, Yamaji Y, Oshima K, Namba S. In the non-insect-transmissible line of onion yellows phytoplasma (OY-NIM), the plasmid-encoded transmembrane protein ORF3 lacks the major promoter region. Microbiology (Reading) 2009; 155:2058-2067. [DOI: 10.1099/mic.0.027409-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
‘Candidatus Phytoplasma asteris’, onion yellows strain (OY), a mildly pathogenic line (OY-M), is a phytopathogenic bacterium transmitted by Macrosteles striifrons leafhoppers. OY-M contains two types of plasmids (EcOYM and pOYM), each of which possesses a gene encoding the putative transmembrane protein, ORF3. A non-insect-transmissible line of this phytoplasma (OY-NIM) has the corresponding plasmids (EcOYNIM and pOYNIM), but pOYNIM lacks orf3. Here we show that in OY-M, orf3 is transcribed from two putative promoters and that on EcOYNIM, one of the promoter sequences is mutated and the other deleted. We also show by immunohistochemical analysis that ORF3 is not expressed in OY-NIM-infected plants. Moreover, ORF3 protein seems to be preferentially expressed in OY-M-infected insects rather than in plants. We speculate that ORF3 may play a role in the interactions of OY with its insect host.
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Affiliation(s)
- Yoshiko Ishii
- 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 113-8657, Japan
| | - Shigeyuki Kakizawa
- 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 113-8657, Japan
| | - Ayaka Hoshi
- 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 113-8657, Japan
| | - Kensaku Maejima
- 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 113-8657, Japan
| | - 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
- 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 113-8657, Japan
| | - Kenro Oshima
- Laboratory of Clinical Plant Science, 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
- Laboratory of Clinical Plant Science, 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
- 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 113-8657, Japan
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19
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Bai X, Correa VR, Toruño TY, Ammar ED, Kamoun S, Hogenhout SA. AY-WB phytoplasma secretes a protein that targets plant cell nuclei. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2009; 22:18-30. [PMID: 19061399 DOI: 10.1094/mpmi-22-1-0018] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The fully sequenced genome of aster yellows phytoplasma strain witches' broom (AY-WB; Candidatus Phytoplasma asteris) was mined for the presence of genes encoding secreted proteins based on the presence of N-terminal signal peptides (SP). We identified 56 secreted AY-WB proteins (SAP). These SAP are candidate effector proteins potentially involved in interaction with plant and insect cell components. One of these SAP, SAP11, contains an N-terminal SP sequence and a eukaryotic bipartite nuclear localization signal (NLS). Transcripts for SAP11 were detected in AY-WB-infected plants. Yellow fluorescence protein (YFP)-tagged SAP11 accumulated in Nicotiana benthamiana cell nuclei, whereas the nuclear targeting of YFP-tagged SAP11 mutants with disrupted NLS was inhibited. The nuclear transport of YFP-SAP11 was also inhibited in N. benthamiana plants in which the expression of importin alpha was knocked down using virus-induced gene silencing (VIGS). Furthermore, SAP11 was detected by immunocytology in nuclei of young sink tissues of China aster plants infected with AY-WB. In summary, this work shows that AY-WB phytoplasma produces a protein that targets the nuclei of plant host cells; this protein is a potential phytoplasma effector that may alter plant cell physiology.
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Affiliation(s)
- Xiaodong Bai
- Department of Entomology, The Ohio State University-OARDC, Wooster 44691, USA
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20
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Breton M, Duret S, Arricau-Bouvery N, Béven L, Renaudin J. Characterizing the replication and stability regions of Spiroplasma citri plasmids identifies a novel replication protein and expands the genetic toolbox for plant-pathogenic spiroplasmas. MICROBIOLOGY-SGM 2008; 154:3232-3244. [PMID: 18832328 DOI: 10.1099/mic.0.2008/019562-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Spiroplasma citri strain GII3 contains seven plasmids, pSciA and pSci1-6, that share extensive regions of sequence homology and display a mosaic gene organization. Plasmid pSci2 comprises 12 coding sequences (CDS), three of which encode polypeptides homologous to proteins Soj/ParA, involved in chromosome partitioning, and TrsE and Mob/TraG, implicated in the type IV secretion pathway. One CDS encodes the adhesin-like protein ScARP3d whereas the other eight encode polypeptides with no homology to known proteins. The pSci2 CDS pE and soj have counterparts in all seven plasmids. Through successive deletions, various pSci2 derivatives were constructed and assessed for their ability to replicate by transformation of S. citri 44, a strain which has no plasmid. The smallest functional replicon was found to contain a single CDS (pE) and its flanking intergenic regions. Shuttle (S. citri/Escherichia coli) plasmids, in which CDS pE was disrupted, failed to replicate in S. citri, suggesting that PE is the replication protein of the S. citri plasmids. Successive propagations of pSci2-derived transformed spiroplasmas, in the absence of selection pressure, revealed that only pSci2 derivatives having an intact soj gene were stably maintained, indicating that the soj-encoded polypeptide is most likely involved in plasmid partitioning. Upon transformation, pSci2 derivatives, including shuttle (S. citri/E. coli) plasmids, were shown to replicate in all S. citri strains tested regardless of whether the strain possesses endogenous plasmids, such as strain GII3, or not, such as strain R8A2. In addition, the pSci replicons were introduced efficiently into the plant-pathogenic spiroplasmas Spiroplasma kunkelii and Spiroplasma phoeniceum, the transformation of which had never, to our knowledge, been described before. These studies show that, besides their implications for the biology of S. citri, the pSci plasmids hold considerable promise as vectors of general use for genetic studies of plant-pathogenic spiroplasmas. As an example, a HA-tagged S. citri protein was expressed in S. kunkelii. Detection of pE-hybridizing sequences in various group I spiroplasma species indicated that pE replicating plasmids were not restricted to the three plant-pathogenic spiroplasmas.
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Affiliation(s)
- Marc Breton
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Sybille Duret
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Nathalie Arricau-Bouvery
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Laure Béven
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Joël Renaudin
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
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21
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Hogenhout SA, Oshima K, Ammar ED, Kakizawa S, Kingdom HN, Namba S. Phytoplasmas: bacteria that manipulate plants and insects. MOLECULAR PLANT PATHOLOGY 2008; 9:403-23. [PMID: 18705857 PMCID: PMC6640453 DOI: 10.1111/j.1364-3703.2008.00472.x] [Citation(s) in RCA: 177] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
TAXONOMY Superkingdom Prokaryota; Kingdom Monera; Domain Bacteria; Phylum Firmicutes (low-G+C, Gram-positive eubacteria); Class Mollicutes; Candidatus (Ca.) genus Phytoplasma. HOST RANGE Ca. Phytoplasma comprises approximately 30 distinct clades based on 16S rRNA gene sequence analyses of approximately 200 phytoplasmas. Phytoplasmas are mostly dependent on insect transmission for their spread and survival. The phytoplasma life cycle involves replication in insects and plants. They infect the insect but are phloem-limited in plants. Members of Ca. Phytoplasma asteris (16SrI group phytoplasmas) are found in 80 monocot and dicot plant species in most parts of the world. Experimentally, they can be transmitted by approximately 30, frequently polyphagous insect species, to 200 diverse plant species. DISEASE SYMPTOMS In plants, phytoplasmas induce symptoms that suggest interference with plant development. Typical symptoms include: witches' broom (clustering of branches) of developing tissues; phyllody (retrograde metamorphosis of the floral organs to the condition of leaves); virescence (green coloration of non-green flower parts); bolting (growth of elongated stalks); formation of bunchy fibrous secondary roots; reddening of leaves and stems; generalized yellowing, decline and stunting of plants; and phloem necrosis. Phytoplasmas can be pathogenic to some insect hosts, but generally do not negatively affect the fitness of their major insect vector(s). In fact, phytoplasmas can increase fecundity and survival of insect vectors, and may influence flight behaviour and plant host preference of their insect hosts. DISEASE CONTROL The most common practices are the spraying of various insecticides to control insect vectors, and removal of symptomatic plants. Phytoplasma-resistant cultivars are not available for the vast majority of affected crops.
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Affiliation(s)
- Saskia A Hogenhout
- Department of Disease and Stress Biology, The John Innes Centre, Norwich Research Park, Colney Lane, Colney, Norwich, Norfolk NR4 7UH, UK.
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Saillard C, Carle P, Duret-Nurbel S, Henri R, Killiny N, Carrère S, Gouzy J, Bové JM, Renaudin J, Foissac X. The abundant extrachromosomal DNA content of the Spiroplasma citri GII3-3X genome. BMC Genomics 2008; 9:195. [PMID: 18442384 PMCID: PMC2386487 DOI: 10.1186/1471-2164-9-195] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Accepted: 04/28/2008] [Indexed: 11/24/2022] Open
Abstract
Background Spiroplama citri, the causal agent of citrus stubborn disease, is a bacterium of the class Mollicutes and is transmitted by phloem-feeding leafhopper vectors. In order to characterize candidate genes potentially involved in spiroplasma transmission and pathogenicity, the genome of S. citri strain GII3-3X is currently being deciphered. Results Assembling 20,000 sequencing reads generated seven circular contigs, none of which fit the 1.8 Mb chromosome map or carried chromosomal markers. These contigs correspond to seven plasmids: pSci1 to pSci6, with sizes ranging from 12.9 to 35.3 kbp and pSciA of 7.8 kbp. Plasmids pSci were detected as multiple copies in strain GII3-3X. Plasmid copy numbers of pSci1-6, as deduced from sequencing coverage, were estimated at 10 to 14 copies per spiroplasma cell, representing 1.6 Mb of extrachromosomal DNA. Genes encoding proteins of the TrsE-TraE, Mob, TraD-TraG, and Soj-ParA protein families were predicted in most of the pSci sequences, in addition to members of 14 protein families of unknown function. Plasmid pSci6 encodes protein P32, a marker of insect transmissibility. Plasmids pSci1-5 code for eight different S. citri adhesion-related proteins (ScARPs) that are homologous to the previously described protein P89 and the S. kunkelii SkARP1. Conserved signal peptides and C-terminal transmembrane alpha helices were predicted in all ScARPs. The predicted surface-exposed N-terminal region possesses the following elements: (i) 6 to 8 repeats of 39 to 42 amino acids each (sarpin repeats), (ii) a central conserved region of 330 amino acids followed by (iii) a more variable domain of about 110 amino acids. The C-terminus, predicted to be cytoplasmic, consists of a 27 amino acid stretch enriched in arginine and lysine (KR) and an optional 23 amino acid stretch enriched in lysine, aspartate and glutamate (KDE). Plasmids pSci mainly present a linear increase of cumulative GC skew except in regions presenting conserved hairpin structures. Conclusion The genome of S. citri GII3-3X is characterized by abundant extrachromosomal elements. The pSci plasmids could not only be vertically inherited but also horizontally transmitted, as they encode proteins usually involved in DNA element partitioning and cell to cell DNA transfer. Because plasmids pSci1-5 encode surface proteins of the ScARP family and pSci6 was recently shown to confer insect transmissibility, diversity and abundance of S. citri plasmids may essentially aid the rapid adaptation of S. citri to more efficient transmission by different insect vectors and to various plant hosts.
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Affiliation(s)
- Colette Saillard
- Université Victor Ségalen Bordeaux 2, UMR 1090 Génomique Diversité Pouvoir Pathogène, BP 81, F-33883 Villenave d'Ornon, France.
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Yokomi RK, Mello AFS, Saponari M, Fletcher J. Polymerase Chain Reaction-Based Detection of Spiroplasma citri Associated with Citrus Stubborn Disease. PLANT DISEASE 2008; 92:253-260. [PMID: 30769379 DOI: 10.1094/pdis-92-2-0253] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Polymerase chain reaction (PCR)-based detection of citrus stubborn disease was improved using primers based on sequences of the P89 putative adhesin gene and the P58 putative adhesin multigene of Spiroplasma citri. Real-time PCR also was developed with detection limits estimated to be between 10-4 and 10-4 ng by serial dilution of a recombinant S. citri plasmid into DNA extracts from healthy Madam Vinous sweet orange. PCR for the detection of S. citri by these new primers was validated by comparing culturing of the pathogen, the traditional method of diagnosis, with PCR assays from samples taken from two citrus plots in Kern County, CA. Fruit columella was collected from 384 and 377 individual trees in each of two fields, respectively; one portion was used for culturing and the other for DNA extraction and PCR. PCR results matched those of culturing 85 to 100% of the time depending on the primers used. More importantly, PCR detected S. citri from culture-negative trees in 5 to 15% of the cases, suggesting that PCR performed as well or better than culturing for detection of S. citri in field samples. Real-time PCR proved to be the best method for detection. Differential reaction of the samples to the P58 primer pairs suggested that two populations of S. citri occur in historical and present-day field isolates. Citrus stubborn disease incidence was estimated to be 58.3 and 3.7% in the two orchards. The results presented here support the use of PCR for reliable detection of S. citri in field trees.
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Affiliation(s)
- Raymond K Yokomi
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Parlier, CA 93648
| | - Alexandre F S Mello
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Parlier, CA 93648
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Brown DR, Whitcomb RF, Bradbury JM. Revised minimal standards for description of new species of the class Mollicutes (division Tenericutes). Int J Syst Evol Microbiol 2008; 57:2703-2719. [PMID: 17978244 DOI: 10.1099/ijs.0.64722-0] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Minimal standards for novel species of the class Mollicutes (trivial term, mollicutes), last published in 1995, require revision. The International Committee on Systematics of Prokaryotes Subcommittee on the Taxonomy of Mollicutes proposes herein revised standards that reflect recent advances in molecular systematics and the species concept for prokaryotes. The mandatory requirements are: (i) deposition of the type strain into two recognized culture collections, preferably located in different countries; (ii) deposition of the 16S rRNA gene sequence into a public database, and a phylogenetic analysis of the relationships among the 16S rRNA gene sequences of the novel species and its neighbours; (iii) deposition of antiserum against the type strain into a recognized collection; (iv) demonstration, by using the combination of 16S rRNA gene sequence analyses, serological analyses and supplementary phenotypic data, that the type strain differs significantly from all previously named species; and (v) assignment to an order, a family and a genus in the class, with an appropriate specific epithet. The 16S rRNA gene sequence provides the primary basis for assignment to hierarchical rank, and may also constitute evidence of species novelty, but serological and supplementary phenotypic data must be presented to substantiate this. Serological methods have been documented to be congruent with DNA-DNA hybridization data and with 16S rRNA gene placements. The novel species must be tested serologically to the greatest extent that the investigators deem feasible against all neighbouring species whose 16S rRNA gene sequences show >0.94 similarity. The investigator is responsible for justifying which characters are most meaningful for assignment to the part of the mollicute phylogenetic tree in which a novel species is located, and for providing the means by which novel species can be identified by other investigators. The publication of the description should appear in a journal having wide circulation. If the journal is not the International Journal of Systematic and Evolutionary Microbiology, copies of the publication must be submitted to that journal so that the name may be considered for inclusion in a Validation List as required by the International Code of Bacteriological Nomenclature (the Bacteriological Code). Updated informal descriptions of the class Mollicutes and some of its constituent higher taxa are available as supplementary material in IJSEM Online.
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Affiliation(s)
- Daniel R Brown
- Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610-0880, USA
| | - Robert F Whitcomb
- Collaborator, Vegetable Laboratory, Beltsville Agricultural Research Center, US Department of Agriculture, Beltsville, MD 20705, USA
| | - Janet M Bradbury
- Department of Veterinary Pathology, University of Liverpool, Leahurst, Neston, CH64 7TE, UK
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Berho N, Duret S, Danet JL, Renaudin J. Plasmid pSci6 from Spiroplasma citri GII-3 confers insect transmissibility to the non-transmissible strain S. citri 44. Microbiology (Reading) 2006; 152:2703-2716. [PMID: 16946265 DOI: 10.1099/mic.0.29085-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The insect-transmissible strain GII-3 of Spiroplasma citri contains plasmids pSci1–6, five of which (pSci1–5) encode adhesin-like proteins and one (pSci6) encodes protein P32, which has been associated with insect transmissibility. In contrast, S. citri strains ASP-1 and 44, which cannot be transmitted via injection into the leafhopper vector Circulifer haematoceps, lack these proteins and also do not carry plasmids pSci1–6. To further study the apparent relationship between the presence of plasmids and insect transmissibility, plasmids from S. citri GII-3 were introduced into the insect-non-transmissible S. citri strain 44 by electrotransformation using the tetM gene as the selection marker. Tetracycline-resistant transformants were shown to carry one, two or three distinct plasmids. Plasmids pSci1–6 were all detected in the transformants, pSci1 being the most frequently found, alone or together with other plasmids. Selected S. citri 44 transformants having distinct plasmid contents were submitted, separately or in combination, to experimental transmission to periwinkle (Catharanthus roseus) plants via injection into the leafhopper vector. The occurrence of symptomatic plants indicated that, in contrast to S. citri 44, spiroplasmal transformants were transmitted to the host plant, in which they multiplied. Spiroplasma cultures isolated from these infected plants all contained pSci6, leading to the conclusion that, under the experimental conditions used, transformation by pSci6 conferred insect transmissibility to S. citri strain 44. This is believed to be the first report of a phenotypic change associated with transformation of S. citri by natural plasmids.
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Affiliation(s)
- Nathalie Berho
- UMR 1090 Génomique Développement et Pouvoir Pathogène, INRA, Université de Bordeaux 2, Centre INRA de Bordeaux, 71 avenue Edouard Bourlaux, BP 81, 33883 Villenave d'Ornon Cedex, France
| | - Sybille Duret
- UMR 1090 Génomique Développement et Pouvoir Pathogène, INRA, Université de Bordeaux 2, Centre INRA de Bordeaux, 71 avenue Edouard Bourlaux, BP 81, 33883 Villenave d'Ornon Cedex, France
| | - Jean-Luc Danet
- UMR 1090 Génomique Développement et Pouvoir Pathogène, INRA, Université de Bordeaux 2, Centre INRA de Bordeaux, 71 avenue Edouard Bourlaux, BP 81, 33883 Villenave d'Ornon Cedex, France
| | - Joël Renaudin
- UMR 1090 Génomique Développement et Pouvoir Pathogène, INRA, Université de Bordeaux 2, Centre INRA de Bordeaux, 71 avenue Edouard Bourlaux, BP 81, 33883 Villenave d'Ornon Cedex, France
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