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Duduk B, Stepanović J, Fránová J, Zwolińska A, Rekanović E, Stepanović M, Vučković N, Duduk N, Vico I. Geographical variations, prevalence, and molecular dynamics of fastidious phloem-limited pathogens infecting sugar beet across Central Europe. PLoS One 2024; 19:e0306136. [PMID: 38954690 PMCID: PMC11218978 DOI: 10.1371/journal.pone.0306136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 06/11/2024] [Indexed: 07/04/2024] Open
Abstract
In Europe, two fastidious phloem-limited pathogens, 'Candidatus Phytoplasma solani' (16SrXII-A) and 'Candidatus Arsenophonus phytopathogenicus', are associated with rubbery taproot disease (RTD) and syndrome basses richesses (SBR) of sugar beet, respectively. Both diseases can significantly reduce yield, especially when accompanied by root rot fungi. This study investigates the presence, geographic distribution and genetic traits of fastidious pathogens and the accompanying fungus, Macrophomina phaseolina, found on sugar beet across four geographically separated plains spanning seven countries in Central Europe. The survey revealed variable incidences of symptoms linked to these fastidious pathogens in the Pannonian and Wallachian Plains, sporadic occurrence in the North European Plain, and no symptomatic sugar beet in the Bohemian Plain. Molecular analyses unveiled the occurrence of both 'Ca. P. solani' and 'Ca. A. phytopathogenicus' throughout Central Europe, with a predominance of the phytoplasma. These fastidious pathogens were detected in all six countries surveyed within the Pannonian and Wallachian Plains, with only a limited presence of various phytoplasmas was found in the North European Plain, while no fastidious pathogens were detected in Bohemia, aligning with observed symptoms. While 16S rDNA sequences of 'Ca. P. solani' remained highly conserved, multi-locus characterization of two more variable loci (tuf and stamp) unveiled distinct variability patterns across the plains. Notably, the surprising lack of variability of tuf and stamp loci within Central Europe, particularly the Pannonian Plain, contrasted their high variability in Eastern and Western Europe, corresponding to epidemic and sporadic occurrence, respectively. The current study provides valuable insights into the genetic dynamics of 'Ca. P. solani' in Central Europe, and novel findings of the presence of 'Ca. A. phytopathogenicus' in five countries (Slovakia, Czech Republic, Austria, Serbia, and Romania) and M. phaseolina in sugar beet in Slovakia. These findings emphasize the need for further investigation of vector-pathogen(s)-plant host interactions and ecological drivers of disease outbreaks.
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Affiliation(s)
- Bojan Duduk
- Institute of Pesticides and Environmental Protection, Belgrade, Serbia
| | - Jelena Stepanović
- Institute of Pesticides and Environmental Protection, Belgrade, Serbia
| | - Jana Fránová
- Biology Centre, Czech Academy of Sciences, Institute of Plant Molecular Biology, Plant Virology, Ceske Budejovice, Czech Republic
| | - Agnieszka Zwolińska
- Department of Plant Physiology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Emil Rekanović
- Institute of Pesticides and Environmental Protection, Belgrade, Serbia
| | - Miloš Stepanović
- Institute of Pesticides and Environmental Protection, Belgrade, Serbia
| | - Nina Vučković
- University of Belgrade–Faculty of Agriculture, Belgrade, Serbia
| | - Nataša Duduk
- University of Belgrade–Faculty of Agriculture, Belgrade, Serbia
| | - Ivana Vico
- University of Belgrade–Faculty of Agriculture, Belgrade, Serbia
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Pierro R, Moussa A, Mori N, Marcone C, Quaglino F, Romanazzi G. Bois noir management in vineyard: a review on effective and promising control strategies. FRONTIERS IN PLANT SCIENCE 2024; 15:1364241. [PMID: 38601314 PMCID: PMC11004249 DOI: 10.3389/fpls.2024.1364241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Accepted: 03/07/2024] [Indexed: 04/12/2024]
Abstract
Among grapevine yellows, Bois noir (BN), associated with 'Candidatus Phytoplasma solani', represents the biggest threat in the main wine-growing areas worldwide, causing significant losses in berry quality and yields. BN epidemiology involves multiple plant hosts and several insect vectors, making considerably complex the development of effective management strategies. Since application of insecticides on the grapevine canopy is not effective to manage vectors, BN management includes an integrated approach based on treatments to the canopy to make the plant more resistant to the pathogen and/or inhibit the vector feeding, and actions on reservoir plants to reduce possibilities that the vector reaches the grapevine and transmit the phytoplasma. Innovative sustainable strategies developed in the last twenty years to improve the BN management are reviewed and discussed.
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Affiliation(s)
- Roberto Pierro
- Department of Pharmacy, University of Salerno, Fisciano, Salerno, Italy
| | - Abdelhameed Moussa
- Pests and Plant Protection Department, Agricultural & Biological Research Institute, National Research Centre, Cairo, Egypt
| | - Nicola Mori
- Department of Biotechnology, University of Verona, Verona, Italy
| | - Carmine Marcone
- Department of Pharmacy, University of Salerno, Fisciano, Salerno, Italy
| | - Fabio Quaglino
- Department of Agricultural and Environmental Sciences – Production, Landscape, Agroenergy, University of Milan, Milan, Italy
| | - Gianfranco Romanazzi
- Department of Agricultural, Food and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
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Kosovac A, Rekanović E, Ćurčić Ž, Stepanović J, Duduk B. Plants under Siege: Investigating the Relevance of ' Ca. P. solani' Cixiid Vectors through a Multi-Test Study. PLANTS (BASEL, SWITZERLAND) 2023; 12:4157. [PMID: 38140484 PMCID: PMC10748216 DOI: 10.3390/plants12244157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/08/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023]
Abstract
Crop losses caused by the plant pathogenic bacterium 'Candidatus Phytoplasma solani' (CaPsol) underscore the need to better understand its perplexing epidemiological pathways. Hyalesthes obsoletus (Hemiptera, Cixiidae) is a prominent CaPsol vector with three plant associations in Serbia (ex Urtica dioica/HobsUd; ex Convolvulus arvensis/HobsCa; ex Crepis foetida/HobsCf). Another cixiid planthopper, Reptalus quinquecostatus (Dufour), has been recently confirmed as a noteworthy CaPsol vector. A multi-test study assessed the relevance of H. obsoletus associations and R. quinquecostatus populations from Crataegus monogyna and Prunus spinosa in CaPsol occurrence in sugar beet, maize, and tobacco. Molecular typing of the CaPsol strains transmitted to test plants in experimental trials provided the first evidence of HobsUd transmitting CaPsol tuf-a type to sugar beet, HobsCa infecting maize and tobacco with tuf-b type, and HobsCf transmitting CaPsol tuf-b to maize. Affiliation of R. quinquecostatus with the specific CaPsol genotype, dSTOLg, was reaffirmed in this study. The possible involvement of R. quinquecostatus in maize redness disease and tobacco stolbur was suggested, given that this cixiid was identified as a vector of CaPsol to these crops. The obtained results indicate that the tested vectors pose a threat to cultivated plants in Serbia, underscoring the need to recognize their relevance in CaPsol disease occurrences.
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Affiliation(s)
- Andrea Kosovac
- Institute of Pesticides and Environmental Protection, 11080 Belgrade, Serbia; (E.R.); (J.S.); (B.D.)
| | - Emil Rekanović
- Institute of Pesticides and Environmental Protection, 11080 Belgrade, Serbia; (E.R.); (J.S.); (B.D.)
| | - Živko Ćurčić
- Institute of Field and Vegetable Crops, 21000 Novi Sad, Serbia;
| | - Jelena Stepanović
- Institute of Pesticides and Environmental Protection, 11080 Belgrade, Serbia; (E.R.); (J.S.); (B.D.)
| | - Bojan Duduk
- Institute of Pesticides and Environmental Protection, 11080 Belgrade, Serbia; (E.R.); (J.S.); (B.D.)
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Kosovac A, Ćurčić Ž, Stepanović J, Rekanović E, Duduk B. Epidemiological role of novel and already known 'Ca. P. solani' cixiid vectors in rubbery taproot disease of sugar beet in Serbia. Sci Rep 2023; 13:1433. [PMID: 36697493 PMCID: PMC9877035 DOI: 10.1038/s41598-023-28562-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 01/20/2023] [Indexed: 01/26/2023] Open
Abstract
Rubbery taproot disease (RTD) of sugar beet was recently associated with the plant pathogenic bacterium 'Candidatus Phytoplasma solani' (CaPsol) and reported throughout the Pannonian Plain with variations in severity. Tracing CaPsol epidemiological pathways was performed in the experimental sugar beet field in Rimski Šančevi (Serbia) in 2020-2021, where an RTD outbreak was recently recorded. A molecular epidemiology approach was applied to the study of three RTD occurrence scenarios: epidemic, non-epidemic and 'absence of RTD'. As a result, Hyalesthes obsoletus ex Convolvulus arvensis was detected as a CaPsol vector to sugar beet, while two other cixiids were identified for the first time as vectors of the CaPsol-induced plant disease in crops: Reptalus quinquecostatus and R. cuspidatus. R. quinquecostatus was proposed culpable for the 2020 RTD epidemic outbreak in Rimski Šančevi when dSTOLg CaPsol strain predominated in the RTD-affected sugar beet, whereas R. cuspidatus had a negligible role in RTD occurrence and displayed ambiguous involvement in CaPsol epidemiology on a wider scale. The temporal discrepancy of the offset of CaPsol dissemination and disease occurrence is the main obstacle in predicting CaPsol-induced diseases. Predicting disease occurrence and severity can only be achieved by gaining a better understanding of CaPsol epidemiological pathways and insect vectors involved in disease outbreaks.
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Affiliation(s)
- Andrea Kosovac
- Laboratory of Phytopathology, Institute of Pesticides and Environmental Protection, 11080, Belgrade, Serbia.
| | - Živko Ćurčić
- Sunflower Department, Institute of Field and Vegetable Crops, 21000, Novi Sad, Serbia
| | - Jelena Stepanović
- Laboratory of Phytopathology, Institute of Pesticides and Environmental Protection, 11080, Belgrade, Serbia
| | - Emil Rekanović
- Laboratory of Phytopathology, Institute of Pesticides and Environmental Protection, 11080, Belgrade, Serbia
| | - Bojan Duduk
- Laboratory of Phytopathology, Institute of Pesticides and Environmental Protection, 11080, Belgrade, Serbia
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Çağlar BK, Şimşek E. Detection and Multigene Typing of ' Candidatus Phytoplasma solani'-Related Strains Infecting Tomato and Potato Plants in Different Regions of Turkey. Pathogens 2022; 11:1031. [PMID: 36145463 PMCID: PMC9505192 DOI: 10.3390/pathogens11091031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/02/2022] [Accepted: 09/08/2022] [Indexed: 11/27/2022] Open
Abstract
'Candidatus Phytoplasma solani' ('Ca. P. solani') is a crop pathogen that is a member of the 16SrXII-A ribosomal subgroup. It is also known as stolbur phytoplasma and causes yield losses in several important crops, especially in Solanaceous crops. Different strains of the pathogen are regularly reported all over the world, particularly in the Mediterranean region. In this study, the determination of genetic diversity for the pathogen infecting tomatoes and potatoes was carried out by using multilocus sequence typing analysis for the Tuf, SecY, and Vmp1 genes to gain insight into the epidemiology of 'Ca. P. solani' in Turkey. Genetic diversity of the phytoplasmas was investigated by sequence-based phylogenetic analyses and in silico RFLP analysis of related genes. It was determined that all 'Ca. P. solani'-related strains infecting tomatoes and potatoes were tuf-b, which is linked to field bindweed (Convolvulus arvensis L.). Tomato or potato-infecting 'Ca. P. solani'-related strains showed similarities with each other; however, the isolates collected from different plants showed genetic differences in terms of the SecY gene. This study indicates that the highest genetic variability of collected samples was found in the Vmp1 gene. RsaI-RFLP analysis of TYPH10F/R amplicons showed that potato-infecting 'Ca. P. solani'-related strains were found to be similar to some existing V types. However, the V-type of tomato-infecting isolates is not similar to any previously reported V-type. The results indicate that there could be an important genetic diversity of 'Ca. P. solani'-related phytoplasmas in Turkey. This could indicate various ways in which the pathogen has adapted to the two host plants as a consequence of the various Vmp1 gene rearrangements seen in these two plant hosts. Obtained results also indicate that the epidemiology of 'Ca. P. solani'-related phytoplasmas in the tomato and potato agroecosystem may be better understood with the use of molecular data on the complex of vmp-types.
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Affiliation(s)
- Behçet Kemal Çağlar
- Department of Plant Protection, Faculty of Agriculture, Çukurova University, Adana 01330, Turkey
| | - Eray Şimşek
- Department of Plant Protection, Faculty of Agriculture, Harran University, Şanlıurfa 63290, Turkey
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In Silico Three-Dimensional (3D) Modeling of the SecY Protein of ‘Candidatus Phytoplasma Solani’ Strains Associated with Grapevine “Bois Noir” and Its Possible Relationship with Strain Virulence. INTERNATIONAL JOURNAL OF PLANT BIOLOGY 2022. [DOI: 10.3390/ijpb13020004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Grapevine “bois noir”, related to the presence of ‘Candidatus Phytoplasma solani’ (‘Ca. P. solani’), represents a serious threat in several vine-growing areas worldwide. In surveys conducted over two years, mild and/or moderate symptoms and lower pathogen titer were mainly associated with ‘Ca. P. solani’ strains harboring a secY gene sequence variant (secY52), whereas severe symptoms and higher titer were mainly observed in grapevines infected by phytoplasma strains carrying any one of another four variants. A comparison of amino acid sequences of the protein SecY of ‘Ca. P. solani’ strains revealed the presence of conservative and semi-conservative substitutions. The deduced three-dimensional (3D) protein analysis unveiled that one semi-conservative substitution identified in the sequence variant secY52 is responsible for a structural disordered region that probably confers a flexibility for binding to distinct molecular complexes. In fact, the other analyzed variants show an organized structure and the 3D in silico prediction allowed the identification of β-sheets. Thus, differences in symptom severity and pathogen concentration observed in grapevines infected by ‘Ca. P. solani’ strains carrying distinct secY gene sequence variants suggest a possible relationship between SecY protein structure and phytoplasma strain virulence.
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Contaldo N, Stepanović J, Pacini F, Bertaccini A, Duduk B. Molecular Variability and Host Distribution of ' Candidatus Phytoplasma solani' Strains from Different Geographic Origins. Microorganisms 2021; 9:microorganisms9122530. [PMID: 34946132 PMCID: PMC8705599 DOI: 10.3390/microorganisms9122530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 11/29/2021] [Accepted: 12/01/2021] [Indexed: 11/30/2022] Open
Abstract
The knowledge of phytoplasma genetic variability is a tool to study their epidemiology and to implement an effective monitoring and management of their associated diseases. ‘Candidatus Phytoplasma solani’ is associated with “bois noir” disease in grapevines, and yellowing and decline symptoms in many plant species, causing serious damages during the epidemic outbreaks. The epidemiology of the diseases associated with this phytoplasma is complex and related to numerous factors, such as interactions of the host plant and insect vectors and spreading through infected plant propagation material. The genetic variability of ‘Ca. P. solani’ strains in different host species and in different geographic areas during the last two decades was studied by RFLP analyses coupled with sequencing on vmp1, stamp, and tuf genes. A total of 119 strains were examined, 25 molecular variants were identified, and the variability of the studied genes was linked to both geographic distribution and year of infection. The crucial question in ‘Ca. P. solani’ epidemiology is to trace back the epidemic cycle of the infections. This study presents some relevant features about differential strain distribution useful for disease monitoring and forecasting, illustrating and comparing the phytoplasma molecular variants identified in various regions, host species, and time periods.
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Affiliation(s)
- Nicoletta Contaldo
- Department of Agricultural and Food Sciences, Alma Mater Studiorum-University of Bologna, 40127 Bologna, Italy; (F.P.); (A.B.)
- Correspondence:
| | - Jelena Stepanović
- Institute of Pesticides and Environmental Protection, 11080 Belgrade, Serbia; (J.S.); (B.D.)
| | - Francesco Pacini
- Department of Agricultural and Food Sciences, Alma Mater Studiorum-University of Bologna, 40127 Bologna, Italy; (F.P.); (A.B.)
| | - Assunta Bertaccini
- Department of Agricultural and Food Sciences, Alma Mater Studiorum-University of Bologna, 40127 Bologna, Italy; (F.P.); (A.B.)
| | - Bojan Duduk
- Institute of Pesticides and Environmental Protection, 11080 Belgrade, Serbia; (J.S.); (B.D.)
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Jović J, Marinković S, Jakovljević M, Krstić O, Cvrković T, Mitrović M, Toševski I. Symptomatology, (Co)occurrence and Differential Diagnostic PCR Identification of ' Ca. Phytoplasma solani' and ' Ca. Phytoplasma convolvuli' in Field Bindweed. Pathogens 2021; 10:pathogens10020160. [PMID: 33546447 PMCID: PMC7913610 DOI: 10.3390/pathogens10020160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 01/20/2021] [Accepted: 01/29/2021] [Indexed: 11/16/2022] Open
Abstract
Field bindweed (Convolvulus arvensis) is one of the major natural plant hosts and reservoirs of ‘Candidatus Phytoplasma solani’ (‘Ca. P. solani’), the causal agent of plant diseases in diverse agricultural crops, including Bois noir (BN) disease of grapevine. Phylogenetically, the most closely related phytoplasma to ‘Ca. P. solani’, the ‘Ca. P. convolvuli’, induces disease in field bindweed that is known by its symptoms as bindweed yellows (BY). The occurrence, coinfection and symptoms association of the two phytoplasmas in shared host plants were the subject of this study. Specific primers for the amplification of the elongation factor Tu gene (tuf) were developed for the identification of ‘Ca. P. convolvuli’ (by conventional nested PCR), as well as primers for simultaneous detection of ‘Ca. P. solani’ and ‘Ca. P. convolvuli’ by duplex SYBR Green real-time PCR. Among symptomatic bindweed plants, 25 and 41% were infected with a single phytoplasma species, ‘Ca. P. solani’ and ‘Ca. P. convolvuli’, respectively, while 34% were infected with both phytoplasmas. None of the non-symptomatic control plants carried phytoplasma, while non-symptomatic plants from our previous epidemiological studies in BN-affected vineyards were confirmed to be infected solely with ‘Ca. P. solani’. Stamp gene typing revealed Rqg50 and Rqg31 ‘Ca. P. solani’ genotypes in plants coinfected with ‘Ca. P. convolvuli’, while three diverse genotypes (Rqg50, GGY and Rpm35) were identified in a single locality with symptomatic bindweeds infected solely with ‘Ca. P. solani’. Variations in symptoms and their association with each of the phytoplasmas are described and documented. The symptom of bushy appearance could be single out as specific for ‘Ca. P. convolvuli’ infection, while occurrence of ‘Ca. P. solani’ could not be unequivocally associated with specific alterations in infected bindweeds. The results are discussed in the context of the epidemiological and ecological complexity of ‘Ca. P. solani’-induced diseases and the relationship between the two phytoplasma relatives in shared host plant.
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Affiliation(s)
- Jelena Jović
- Department of Plant Pests, Institute for Plant Protection and Environment, 11080 Zemun, Serbia; (S.M.); (M.J.); (O.K.); (T.C.); (M.M.); (I.T.)
- Correspondence: or
| | - Slavica Marinković
- Department of Plant Pests, Institute for Plant Protection and Environment, 11080 Zemun, Serbia; (S.M.); (M.J.); (O.K.); (T.C.); (M.M.); (I.T.)
| | - Miljana Jakovljević
- Department of Plant Pests, Institute for Plant Protection and Environment, 11080 Zemun, Serbia; (S.M.); (M.J.); (O.K.); (T.C.); (M.M.); (I.T.)
| | - Oliver Krstić
- Department of Plant Pests, Institute for Plant Protection and Environment, 11080 Zemun, Serbia; (S.M.); (M.J.); (O.K.); (T.C.); (M.M.); (I.T.)
| | - Tatjana Cvrković
- Department of Plant Pests, Institute for Plant Protection and Environment, 11080 Zemun, Serbia; (S.M.); (M.J.); (O.K.); (T.C.); (M.M.); (I.T.)
| | - Milana Mitrović
- Department of Plant Pests, Institute for Plant Protection and Environment, 11080 Zemun, Serbia; (S.M.); (M.J.); (O.K.); (T.C.); (M.M.); (I.T.)
| | - Ivo Toševski
- Department of Plant Pests, Institute for Plant Protection and Environment, 11080 Zemun, Serbia; (S.M.); (M.J.); (O.K.); (T.C.); (M.M.); (I.T.)
- CABI, 2800 Delémont, Switzerland
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Multilocus Genotyping Reveals New Molecular Markers for Differentiating Distinct Genetic Lineages among " Candidatus Phytoplasma Solani" Strains Associated with Grapevine Bois Noir. Pathogens 2020; 9:pathogens9110970. [PMID: 33233322 PMCID: PMC7700334 DOI: 10.3390/pathogens9110970] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 11/16/2022] Open
Abstract
Grapevine Bois noir (BN) is associated with infection by “Candidatus Phytoplasma solani” (CaPsol). In this study, an array of CaPsol strains was identified from 142 symptomatic grapevines in vineyards of northern, central, and southern Italy and North Macedonia. Molecular typing of the CaPsol strains was carried out by analysis of genes encoding 16S rRNA and translation elongation factor EF-Tu, as well as eight other previously uncharacterized genomic fragments. Strains of tuf-type a and b were found to be differentially distributed in the examined geographic regions in correlation with the prevalence of nettle and bindweed. Two sequence variants were identified in each of the four genomic segments harboring hlyC, cbiQ-glyA, trxA-truB-rsuA, and rplS-tyrS-csdB, respectively. Fifteen CaPsol lineages were identified based on distinct combinations of sequence variations within these genetic loci. Each CaPsol lineage exhibited a unique collective restriction fragment length polymorphism (RFLP) pattern and differed from each other in geographic distribution, probably in relation to the diverse ecological complexity of vineyards and their surroundings. This RFLP-based typing method could be a useful tool for investigating the ecology of CaPsol and the epidemiology of its associated diseases. Phylogenetic analyses highlighted that the sequence variants of the gene hlyC, which encodes a hemolysin III-like protein, separated into two clusters consistent with the separation of two distinct lineages on the basis of tufB gene sequences. Alignments of deduced full protein sequences of elongation factor-Tu (tufB gene) and hemolysin III-like protein (hlyC gene) revealed the presence of critical amino acid substitutions distinguishing CaPsol strains of tuf-type a and b. Findings from the present study provide new insights into the genetic diversity and ecology of CaPsol populations in vineyards.
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