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Moll L, Giralt N, Planas M, Feliu L, Montesinos E, Bonaterra A, Badosa E. Prunus dulcis response to novel defense elicitor peptides and control of Xylella fastidiosa infections. PLANT CELL REPORTS 2024; 43:190. [PMID: 38976088 PMCID: PMC11231009 DOI: 10.1007/s00299-024-03276-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Accepted: 06/27/2024] [Indexed: 07/09/2024]
Abstract
KEY MESSAGE New defense elicitor peptides have been identified which control Xylella fastidiosa infections in almond. Xylella fastidiosa is a plant pathogenic bacterium that has been introduced in the European Union (EU), threatening the agricultural economy of relevant Mediterranean crops such as almond (Prunus dulcis). Plant defense elicitor peptides would be promising to manage diseases such as almond leaf scorch, but their effect on the host has not been fully studied. In this work, the response of almond plants to the defense elicitor peptide flg22-NH2 was studied in depth using RNA-seq, confirming the activation of the salicylic acid and abscisic acid pathways. Marker genes related to the response triggered by flg22-NH2 were used to study the effect of the application strategy of the peptide on almond plants and to depict its time course. The application of flg22-NH2 by endotherapy triggered the highest number of upregulated genes, especially at 6 h after the treatment. A library of peptides that includes BP100-flg15, HpaG23, FV7, RIJK2, PIP-1, Pep13, BP16-Pep13, flg15-BP100 and BP16 triggered a stronger defense response in almond plants than flg22-NH2. The best candidate, FV7, when applied by endotherapy on almond plants inoculated with X. fastidiosa, significantly reduced levels of the pathogen and decreased disease symptoms. Therefore, these novel plant defense elicitors are suitable candidates to manage diseases caused by X. fastidiosa, in particular almond leaf scorch.
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Affiliation(s)
- Luis Moll
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV, University of Girona, Campus Montilivi, 17003, Girona, Spain
| | - Núria Giralt
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV, University of Girona, Campus Montilivi, 17003, Girona, Spain
| | - Marta Planas
- LIPPSO, Department of Chemistry, University of Girona, Campus Montilivi, 17003, Girona, Spain
| | - Lidia Feliu
- LIPPSO, Department of Chemistry, University of Girona, Campus Montilivi, 17003, Girona, Spain
| | - Emilio Montesinos
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV, University of Girona, Campus Montilivi, 17003, Girona, Spain
| | - Anna Bonaterra
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV, University of Girona, Campus Montilivi, 17003, Girona, Spain
| | - Esther Badosa
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV, University of Girona, Campus Montilivi, 17003, Girona, Spain.
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Giménez-Romero A, Galván J, Montesinos M, Bauzà J, Godefroid M, Fereres A, Ramasco JJ, Matías MA, Moralejo E. Global predictions for the risk of establishment of Pierce's disease of grapevines. Commun Biol 2022; 5:1389. [PMID: 36539523 PMCID: PMC9768138 DOI: 10.1038/s42003-022-04358-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 12/09/2022] [Indexed: 12/24/2022] Open
Abstract
The vector-borne bacterium Xylella fastidiosa is responsible for Pierce's disease (PD), a lethal grapevine disease that originated in the Americas. The international plant trade is expanding the geographic range of this pathogen, posing a new threat to viticulture worldwide. To assess the potential incidence of PD, we have built a dynamic epidemiological model based on the response of 36 grapevine varieties to the pathogen in inoculation assays and on the vectors' distribution when this information is available. Key temperature-driven epidemiological processes, such as PD symptom development and recovery, are mechanistically modelled. Integrating into the model high-resolution spatiotemporal climatic data from 1981 onward and different infectivity (R0) scenarios, we show how the main wine-producing areas thrive mostly in non-risk, transient, or epidemic-risk zones with potentially low growth rates in PD incidence. Epidemic-risk zones with moderate to high growth rates are currently marginal outside the US. However, a global expansion of epidemic-risk zones coupled with small increments in the disease growth rate is projected for 2050. Our study globally downscales the risk of PD establishment while highlighting the importance of considering climate variability, vector distribution, and an invasive criterion as factors to obtain better PD risk maps.
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Affiliation(s)
- Alex Giménez-Romero
- grid.507629.f0000 0004 1768 3290Instituto de Física Interdisciplinar y Sistemas Complejos, (IFISC-UIB-CSIC), Campus UIB, 07122 Palma de Mallorca, Spain
| | - Javier Galván
- grid.507629.f0000 0004 1768 3290Instituto de Física Interdisciplinar y Sistemas Complejos, (IFISC-UIB-CSIC), Campus UIB, 07122 Palma de Mallorca, Spain
| | | | - Joan Bauzà
- grid.9563.90000 0001 1940 4767Departamento de Geografía, Universidad de las Islas Baleares, Campus UIB, 07122 Palma de Mallorca, Spain
| | - Martin Godefroid
- grid.4711.30000 0001 2183 4846Instituto de Ciencias Agrarias, Consejo Superior de Investigaciones Científicas, ICA-CSIC, 28006 Madrid, Spain
| | - Alberto Fereres
- grid.4711.30000 0001 2183 4846Instituto de Ciencias Agrarias, Consejo Superior de Investigaciones Científicas, ICA-CSIC, 28006 Madrid, Spain
| | - José J. Ramasco
- grid.507629.f0000 0004 1768 3290Instituto de Física Interdisciplinar y Sistemas Complejos, (IFISC-UIB-CSIC), Campus UIB, 07122 Palma de Mallorca, Spain
| | - Manuel A. Matías
- grid.507629.f0000 0004 1768 3290Instituto de Física Interdisciplinar y Sistemas Complejos, (IFISC-UIB-CSIC), Campus UIB, 07122 Palma de Mallorca, Spain
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3
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Vectors as Sentinels: Rising Temperatures Increase the Risk of Xylella fastidiosa Outbreaks. BIOLOGY 2022; 11:biology11091299. [PMID: 36138778 PMCID: PMC9495951 DOI: 10.3390/biology11091299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/26/2022] [Accepted: 08/27/2022] [Indexed: 11/17/2022]
Abstract
Global change is expected to modify the threat posed by pathogens to plants. However, little is known regarding how a changing climate will influence the epidemiology of generalist vector-borne diseases. We developed a high-throughput screening method to test for the presence of a deadly plant pathogen, Xylella fastidiosa, in its insect vectors. Then, using data from a four-year survey in climatically distinct areas of Corsica (France), we demonstrated a positive correlation between the proportion of vectors positive to X. fastidiosa and temperature. Notably, a higher prevalence corresponded with milder winters. Our projections up to 2100 indicate an increased risk of outbreaks. While the proportion of vectors that carry the pathogen should increase, the climate conditions will remain suitable for the bacterium and its main vector, with possible range shifts towards a higher elevation. Besides calling for research efforts to limit the incidence of plant diseases in the temperate zone, this work reveals that recent molecular technologies could and should be used for massive screening of pathogens in vectors to scale-up surveillance and management efforts.
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Thidiazuron: New Trends and Future Perspectives to Fight Xylella fastidiosa in Olive Trees. Antibiotics (Basel) 2022; 11:antibiotics11070947. [PMID: 35884201 PMCID: PMC9312276 DOI: 10.3390/antibiotics11070947] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/11/2022] [Accepted: 07/13/2022] [Indexed: 11/25/2022] Open
Abstract
These days, most of our attention has been focused on the COVID-19 pandemic, and we have often neglected what is happening in the environment. For instance, the bacterium Xylella fastidiosa re-emerged as a plant pathogen of global importance in 2013 when it was first associated with an olive tree disease epidemic in Italy, called Olive Quick Decline Syndrome (OQDS), specifically caused by X. fastidiosa subspecies pauca ST53, which affects the Salento olive trees (Apulia, South-East Italy). This bacterium, transmitted by the insect Philaenus spumarius, is negatively reshaping the Salento landscape and has had a very high impact in the production of olives, leading to an increase of olive oil prices, thus new studies to curb this bacterium are urgently needed. Thidiazuron (TDZ), a diphenylurea (N-phenyl-1,2,3-thiadiazol-5-yl urea), has gained considerable attention in recent decades due to its efficient role in plant cell and tissue culture, being the most suitable growth regulator for rapid and effective plant production in vitro. Its biological activity against bacteria, fungi and biofilms has also been described, and the use of this low-cost compound to fight OQDS may be an intriguing idea.
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5
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de Souza Pacheco I, Doss ALA, Vindiola BG, Brown DJ, Ettinger CL, Stajich JE, Redak RA, Walling LL, Atkinson PW. Efficient CRISPR/Cas9-mediated genome modification of the glassy-winged sharpshooter Homalodisca vitripennis (Germar). Sci Rep 2022; 12:6428. [PMID: 35440677 PMCID: PMC9018754 DOI: 10.1038/s41598-022-09990-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 03/28/2022] [Indexed: 12/26/2022] Open
Abstract
CRISPR/Cas9 technology enables the extension of genetic techniques into insect pests previously refractory to genetic analysis. We report the establishment of genetic analysis in the glassy-winged sharpshooter (GWSS), Homalodisca vitripennis, which is a significant leafhopper pest of agriculture in California. We use a novel and simple approach of embryo microinjection in situ on the host plant and obtain high frequency mutagenesis, in excess of 55%, of the cinnabar and white eye pigmentation loci. Through pair matings, we obtained 100% transmission of w and cn alleles to the G3 generation and also established that both genes are located on autosomes. Our analysis of wing phenotype revealed an unexpected discovery of the participation of pteridine pigments in wing and wing-vein coloration, indicating a role for these pigments beyond eye color. We used amplicon sequencing to examine the extent of off-target mutagenesis in adults arising from injected eggs, which was found to be negligible or non-existent. Our data show that GWSS can be easily developed as a genetic model system for the Hemiptera, enabling the study of traits that contribute to the success of invasive pests and vectors of plant pathogens. This will facilitate novel genetic control strategies.
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Affiliation(s)
| | - Anna-Louise A Doss
- Department of Entomology, University of California, Riverside, CA, 92521, USA
| | - Beatriz G Vindiola
- Department of Entomology, University of California, Riverside, CA, 92521, USA
| | - Dylan J Brown
- Department of Entomology, University of California, Riverside, CA, 92521, USA
| | - Cassandra L Ettinger
- Department of Microbiology & Plant Pathology, University of California, Riverside, CA, 92521, USA
| | - Jason E Stajich
- Department of Microbiology & Plant Pathology, University of California, Riverside, CA, 92521, USA.,Institute for Integrative Genome Biology, University of California, Riverside, CA, 92521, USA
| | - Richard A Redak
- Department of Entomology, University of California, Riverside, CA, 92521, USA
| | - Linda L Walling
- Department of Botany & Plant Sciences, University of California, Riverside, CA, 92521, USA. .,Institute for Integrative Genome Biology, University of California, Riverside, CA, 92521, USA.
| | - Peter W Atkinson
- Department of Entomology, University of California, Riverside, CA, 92521, USA. .,Institute for Integrative Genome Biology, University of California, Riverside, CA, 92521, USA.
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6
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Falsini S, Tani C, Sambuco G, Papini A, Faraoni P, Campigli S, Ghelardini L, Bleve G, Rizzo D, Ricciolini M, Scarpelli I, Drosera L, Gnerucci A, Hand FP, Marchi G, Schiff S. Anatomical and biochemical studies of Spartium junceum infected by Xylella fastidiosa subsp. multiplex ST 87. PROTOPLASMA 2022; 259:103-115. [PMID: 33860374 PMCID: PMC8752565 DOI: 10.1007/s00709-021-01640-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 03/29/2021] [Indexed: 06/12/2023]
Abstract
Spartium junceum L. is a typical species of Mediterranean shrubland areas, also grown in gardens and parks as an ornamental. In recent years in Europe, S. junceum has been recurrently found to be infected by different subspecies and genotypes of the quarantine regulated bacterium Xylella fastidiosa (Xf). This work presents for the first time the anatomy of S. junceum plants that we found, by means of genetic and immunochemistry analysis, to be naturally infected by Xf subsp. multiplex ST87 (XfmST87) in Monte Argentario (Grosseto, Tuscany, Italy), a new outbreak area within the EU. Our anatomical observations showed that bacteria colonized exclusively the xylem conductive elements and moved horizontally to adjacent vessels through pits. Interestingly, a pink/violet matrix was observed with Toluidine blue staining in infected conduits indicating a high content of acidic polysaccharides. In particular, when this pink-staining matrix was observed, bacterial cells were either absent or degenerated, suggesting that the matrix was produced by the host plant as a defense response against bacterial spread. In addition, a blue-staining phenolic material was found in the vessels and, at high concentration, in the pits and inter-vessels. SEM micrographs confirmed that polysaccharide and phenolic components showed different structures, which appear to be related to two different morphologies: fibrillary and granular, respectively. Moreover, our LM observations revealed bacterial infection in xylem conductive elements of green shoots and leaves only, and not in those of other plant organs such as roots and flowers.
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Affiliation(s)
- S Falsini
- Dipartimento di Biologia, Università degli studi di Firenze, via P.A. Micheli 3, 50121, Firenze, Italy.
| | - C Tani
- Dipartimento di Biologia, Università degli studi di Firenze, via P.A. Micheli 3, 50121, Firenze, Italy
| | - G Sambuco
- Dipartimento di Biologia, Università degli studi di Firenze, via P.A. Micheli 3, 50121, Firenze, Italy
| | - A Papini
- Dipartimento di Biologia, Università degli studi di Firenze, via P.A. Micheli 3, 50121, Firenze, Italy
| | - P Faraoni
- Dipartimento di Scienze Biomediche, Sperimentali e Cliniche, Università degli Studi di Firenze, viale G. Pieraccini 6, 50139, Firenze, Italy
| | - S Campigli
- Dipartimento di Scienze delle Produzioni Agroalimentari e dell'Ambiente, Università degli Studi di Firenze, Piazzale delle Cascine 28, 50100, Firenze, Italy
| | - L Ghelardini
- Dipartimento di Scienze delle Produzioni Agroalimentari e dell'Ambiente, Università degli Studi di Firenze, Piazzale delle Cascine 28, 50100, Firenze, Italy
| | - G Bleve
- Istituto di Scienze delle Produzioni Alimentari, Consiglio Nazionale delle Ricerche, Lecce, Italy
| | - D Rizzo
- Regione Toscana, Servizio Fitosanitario Regionale e di Vigilanza e Controllo Agroforestale, Via A. Manzoni 16, 50121, Firenze, Italy
| | - M Ricciolini
- Regione Toscana, Servizio Fitosanitario Regionale e di Vigilanza e Controllo Agroforestale, Via A. Manzoni 16, 50121, Firenze, Italy
| | - I Scarpelli
- Regione Toscana, Servizio Fitosanitario Regionale e di Vigilanza e Controllo Agroforestale, Via A. Manzoni 16, 50121, Firenze, Italy
| | - L Drosera
- Regione Toscana, Servizio Fitosanitario Regionale e di Vigilanza e Controllo Agroforestale, Via A. Manzoni 16, 50121, Firenze, Italy
| | - A Gnerucci
- Dipartimento di Scienze Biomediche, Sperimentali e Cliniche, Università degli Studi di Firenze, viale G. Pieraccini 6, 50139, Firenze, Italy
- Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, 50019, Sesto Fiorentino, (FI), Italy
| | - F Peduto Hand
- Department of Plant Pathology, Ohio State University, Columbus, OH, 43220, USA
| | - G Marchi
- Dipartimento di Scienze delle Produzioni Agroalimentari e dell'Ambiente, Università degli Studi di Firenze, Piazzale delle Cascine 28, 50100, Firenze, Italy
| | - S Schiff
- Dipartimento di Biologia, Università degli studi di Firenze, via P.A. Micheli 3, 50121, Firenze, Italy.
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Moll L, Badosa E, Planas M, Feliu L, Montesinos E, Bonaterra A. Antimicrobial Peptides With Antibiofilm Activity Against Xylella fastidiosa. Front Microbiol 2021; 12:753874. [PMID: 34819923 PMCID: PMC8606745 DOI: 10.3389/fmicb.2021.753874] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 10/04/2021] [Indexed: 11/26/2022] Open
Abstract
Xylella fastidiosa is a plant pathogen that was recently introduced in Europe and is causing havoc to its agriculture. This Gram-negative bacterium invades the host xylem, multiplies, and forms biofilm occluding the vessels and killing its host. In spite of the great research effort, there is no method that effectively prevents or cures hosts from infections. The main control strategies up to now are eradication, vector control, and pathogen-free plant material. Antimicrobial peptides have arisen as promising candidates to combat this bacterium due to their broad spectrum of activity and low environmental impact. In this work, peptides previously reported in the literature and newly designed analogs were studied for its bactericidal and antibiofilm activity against X. fastidiosa. Also, their hemolytic activity and effect on tobacco leaves when infiltrated were determined. To assess the activity of peptides, the strain IVIA 5387.2 with moderate growth, able to produce biofilm and susceptible to antimicrobial peptides, was selected among six representative strains found in the Mediterranean area (DD1, CFBP 8173, Temecula, IVIA 5387.2, IVIA 5770, and IVIA 5901.2). Two interesting groups of peptides were identified with bactericidal and/or antibiofilm activity and low-moderate toxicity. The peptides 1036 and RIJK2 with dual (bactericidal–antibiofilm) activity against the pathogen and moderate toxicity stand out as the best candidates to control X. fastidiosa diseases. Nevertheless, peptides with only antibiofilm activity and low toxicity are also promising agents as they could prevent the occlusion of xylem vessels caused by the pathogen. The present work contributes to provide novel compounds with antimicrobial and antibiofilm activity that could lead to the development of new treatments against diseases caused by X. fastidiosa.
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Affiliation(s)
- Luís Moll
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Girona, Spain
| | - Esther Badosa
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Girona, Spain
| | - Marta Planas
- LIPPSO, Department of Chemistry, University of Girona, Girona, Spain
| | - Lidia Feliu
- LIPPSO, Department of Chemistry, University of Girona, Girona, Spain
| | - Emilio Montesinos
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Girona, Spain
| | - Anna Bonaterra
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Girona, Spain
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Bodino N, Demichelis S, Simonetto A, Volani S, Saladini MA, Gilioli G, Bosco D. Phenology, Seasonal Abundance, and Host-Plant Association of Spittlebugs (Hemiptera: Aphrophoridae) in Vineyards of Northwestern Italy. INSECTS 2021; 12:insects12111012. [PMID: 34821812 PMCID: PMC8624594 DOI: 10.3390/insects12111012] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/05/2021] [Accepted: 11/07/2021] [Indexed: 12/05/2022]
Abstract
Simple Summary Spittlebugs are the most abundant and widespread xylem-sap feeder insects in Europe. They are also the only proven vectors of the notorious bacterium Xylella fastidiosa (Xf) in the Old World. Xf inhabits the xylem of hundreds of plant species and is the causal agent of severe diseases to several crop plants, including grapevines. Since the spread of Xf depends on insect transmission, the study of vector abundance and ecology in the vineyard is of key importance in assessing the risk of disease spread to grapevines. The aim of this work was to gain information on Xf vector ecology and abundance in the vineyard agroecosystem. Herbaceous cover of inter-rows and headlands was colonized in spring by nymphs and in late summer/autumn by adults for oviposition, while woody hosts (grapevines and trees in the surroundings) represented a refuge during summer. Three spittlebug species were collected: Philaenus spumarius, Neophilaenus campestris, and Aphrophora alni, but the latter two species were very rare on the grapevine canopy. The presence of P. spumarius for an extended period on the grapevine canopy, together with its known ability to transmit Xf to grapevine, underlines the importance of preventing the introduction of Xf in Xf-free areas and of monitoring health conditions of grapevines in the Xf-infected areas of Europe. Abstract Spittlebugs (Hemiptera: Aphrophoridae) are the vectors of the bacterium Xylella fastidiosa (Xf) in Europe. Xf may cause severe epidemics in cultivated plants, including grapevines. To assess the threat represented by the bacterium to grapevines, detailed information on the vectors’ phenology, density, and ecology in vineyards is needed. The aim of the present work was to describe spittlebug diversity, phenology, and host-plant association in the vineyard agroecosystem. Two separate field surveys of nymphal and adult spittlebug populations, i.e., a two-year survey of a single site and a one-year survey of three sites, were performed in vineyards of northwestern Italy in three consecutive years. Philaenus spumarius was the most common species, reaching average nymph densities on herbaceous cover up to 60–130 nymphs/m2. Adults were sampled on grapevines from May to September, with a peak in June (up to 0.43 insects/sweep). Herbaceous cover was colonized after egg hatching and in late summer for oviposition, while wild woody hosts represented a refuge during summer. The results show that spittlebugs can reach high population levels in vineyards, at least in the areas where the ground is covered by herbaceous plants for the whole season and the use of insecticides is moderate. The extended presence of P. spumarius adults on grapevines represents a serious risk factor for the spread of Xf. The scenarios of Xf establishment in vineyards in northwestern Italy and Europe are discussed in relation to the abundance, phenology, and plant association of spittlebugs.
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Affiliation(s)
- Nicola Bodino
- CNR–Istituto per la Protezione Sostenibile delle Piante, Strada delle Cacce, 73, 10135 Torino, Italy;
| | - Stefano Demichelis
- Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università degli Studi di Torino, Largo Paolo Braccini, 2, 10095 Grugliasco, Italy; (S.D.); (M.A.S.)
| | - Anna Simonetto
- Agrofood Lab, Dipartimento di Ingegneria Civile, Architettura, Territorio, Ambiente e di Matematica, Università degli Studi di Brescia, 25123 Brescia, Italy; (A.S.); (G.G.)
| | - Stefania Volani
- Agrofood Lab, Dipartimento di Medicina Molecolare e Traslazionale, Università degli Studi di Brescia, 25123 Brescia, Italy;
| | - Matteo Alessandro Saladini
- Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università degli Studi di Torino, Largo Paolo Braccini, 2, 10095 Grugliasco, Italy; (S.D.); (M.A.S.)
| | - Gianni Gilioli
- Agrofood Lab, Dipartimento di Ingegneria Civile, Architettura, Territorio, Ambiente e di Matematica, Università degli Studi di Brescia, 25123 Brescia, Italy; (A.S.); (G.G.)
| | - Domenico Bosco
- CNR–Istituto per la Protezione Sostenibile delle Piante, Strada delle Cacce, 73, 10135 Torino, Italy;
- Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università degli Studi di Torino, Largo Paolo Braccini, 2, 10095 Grugliasco, Italy; (S.D.); (M.A.S.)
- Correspondence:
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9
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Baró A, Montesinos L, Badosa E, Montesinos E. Aggressiveness of Spanish Isolates of Xylella fastidiosa to Almond Plants of Different Cultivars Under Greenhouse Conditions. PHYTOPATHOLOGY 2021; 111:1994-2001. [PMID: 33749331 DOI: 10.1094/phyto-02-21-0049-r] [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: 06/12/2023]
Abstract
The aggressiveness of Spanish isolates of Xylella fastidiosa, representing different sequence types, were studied in almond plants of several cultivars by means of the dynamics of the population levels and symptoms, colonization and spread, and dose-effect relationships. Pathogen dynamics in almond plants under greenhouse conditions showed doubling times of 2.1 to 2.5 days during the exponential growth phase, with a maximum population size of about 35 days postinoculation (dpi). Differences in patterns in population dynamics were observed between sap and xylem tissue after the exponential growth, as population levels in the xylem tissue remained stable while viable cells in sap decreased. Population levels were higher in two upward zones than in the downward zone with respect to the inoculation area. The first symptoms were observed between 20 and 60 dpi, and disease severity increased over time at doubling times of 30 days, with a maximum observed at 120 dpi. Strains tested showed differences in population levels in the cultivars studied and were able to spread with different intensity from contaminated plant parts to new growing shoots after pruning. Two almond isolates showed different performance in dose-effect relationships when inoculated in cultivar Avijor. Whereas IVIA 5387.2 reached high population levels but showed high median effective dose (ED50) and minimal infective dose (MID) values, IVIA 5901.2 showed low population levels and low ED50 and MID values. This study has implications for the epidemiology of X. fastidiosa in almond crops, estimating doubling times of the pathogen in planta and of symptom development and showing differences in aggressiveness between strains.
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Affiliation(s)
- Aina Baró
- Institute of Food and Agricultural Technology-XaRTA-CIDSAV, University of Girona, 17003 Girona, Spain
| | - Laura Montesinos
- Institute of Food and Agricultural Technology-XaRTA-CIDSAV, University of Girona, 17003 Girona, Spain
| | - Esther Badosa
- Institute of Food and Agricultural Technology-XaRTA-CIDSAV, University of Girona, 17003 Girona, Spain
| | - Emilio Montesinos
- Institute of Food and Agricultural Technology-XaRTA-CIDSAV, University of Girona, 17003 Girona, Spain
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10
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Zlatkov N, Nadeem A, Uhlin BE, Wai SN. Eco-evolutionary feedbacks mediated by bacterial membrane vesicles. FEMS Microbiol Rev 2021; 45:fuaa047. [PMID: 32926132 PMCID: PMC7968517 DOI: 10.1093/femsre/fuaa047] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 09/11/2020] [Indexed: 12/27/2022] Open
Abstract
Bacterial membrane vesicles (BMVs) are spherical extracellular organelles whose cargo is enclosed by a biological membrane. The cargo can be delivered to distant parts of a given habitat in a protected and concentrated manner. This review presents current knowledge about BMVs in the context of bacterial eco-evolutionary dynamics among different environments and hosts. BMVs may play an important role in establishing and stabilizing bacterial communities in such environments; for example, bacterial populations may benefit from BMVs to delay the negative effect of certain evolutionary trade-offs that can result in deleterious phenotypes. BMVs can also perform ecosystem engineering by serving as detergents, mediators in biochemical cycles, components of different biofilms, substrates for cross-feeding, defense systems against different dangers and enzyme-delivery mechanisms that can change substrate availability. BMVs further contribute to bacteria as mediators in different interactions, with either other bacterial species or their hosts. In short, BMVs extend and deliver phenotypic traits that can have ecological and evolutionary value to both their producers and the ecosystem as a whole.
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Affiliation(s)
- Nikola Zlatkov
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187 Umeå, Sweden
| | - Aftab Nadeem
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187 Umeå, Sweden
| | - Bernt Eric Uhlin
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187 Umeå, Sweden
| | - Sun Nyunt Wai
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187 Umeå, Sweden
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11
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Jeger MJ. The Epidemiology of Plant Virus Disease: Towards a New Synthesis. PLANTS (BASEL, SWITZERLAND) 2020; 9:E1768. [PMID: 33327457 PMCID: PMC7764944 DOI: 10.3390/plants9121768] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/07/2020] [Accepted: 12/10/2020] [Indexed: 02/07/2023]
Abstract
Epidemiology is the science of how disease develops in populations, with applications in human, animal and plant diseases. For plant diseases, epidemiology has developed as a quantitative science with the aims of describing, understanding and predicting epidemics, and intervening to mitigate their consequences in plant populations. Although the central focus of epidemiology is at the population level, it is often necessary to recognise the system hierarchies present by scaling down to the individual plant/cellular level and scaling up to the community/landscape level. This is particularly important for diseases caused by plant viruses, which in most cases are transmitted by arthropod vectors. This leads to range of virus-plant, virus-vector and vector-plant interactions giving a distinctive character to plant virus epidemiology (whilst recognising that some fungal, oomycete and bacterial pathogens are also vector-borne). These interactions have epidemiological, ecological and evolutionary consequences with implications for agronomic practices, pest and disease management, host resistance deployment, and the health of wild plant communities. Over the last two decades, there have been attempts to bring together these differing standpoints into a new synthesis, although this is more apparent for evolutionary and ecological approaches, perhaps reflecting the greater emphasis on shorter often annual time scales in epidemiological studies. It is argued here that incorporating an epidemiological perspective, specifically quantitative, into this developing synthesis will lead to new directions in plant virus research and disease management. This synthesis can serve to further consolidate and transform epidemiology as a key element in plant virus research.
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Affiliation(s)
- Michael J Jeger
- Department of Life Sciences, Imperial College London, Silwood Park, Ascot SL5 7PY, UK
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12
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Di Genova D, Lewis KJ, Oliver JE. Natural Infection of Southern Highbush Blueberry ( Vaccinium corymbosum Interspecific Hybrids) by Xylella fastidiosa subsp. fastidiosa. PLANT DISEASE 2020; 104:2598-2605. [PMID: 32795247 DOI: 10.1094/pdis-11-19-2477-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Xylella fastidiosa (Xf) is an emerging insect-vectored, xylem-limited bacterium that can cause disease on several economically important fruit and tree crops including almond, blueberry, citrus, grapevine, peach, and pecan. On blueberry, Xf causes bacterial leaf scorch (BLS), which is prevalent in the southeastern United States. This disease, previously reported to be caused by Xf subsp. multiplex (Xfm), can result in rapid plant decline and death of southern highbush (SHB) blueberry cultivars. In 2017, a survey of blueberry plantings in southern Georgia (U.S.A.) confirmed the presence of Xf-infected plants in eight of nine sites examined, and seven isolates were cultured from infected plants. Genetic characterization of these isolates through single-locus and multilocus sequence analysis revealed that three isolates from two sites belonged to Xf subsp. fastidiosa (Xff), with significant similarity to isolates from grapevine. After these three isolates were artificially inoculated onto greenhouse-grown SHB blueberries (cv. 'Rebel'), symptoms typical of BLS developed, and Xff infection was confirmed through genetic characterization and reisolation of the bacterium to fulfill Koch's postulates. Because all previously reported Xf isolates from blueberry have been characterized as Xfm, this is the first time that isolation of Xff has been reported from naturally infected blueberry plantings. The potential impact of Xff isolates on disease management in blueberry requires further exploration. Furthermore, given that isolates from both Xfm and Xff were obtained within a single naturally infected blueberry planting, blueberry in southern Georgia may provide opportunities for intersubspecific recombination between Xff and Xfm isolates.
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Affiliation(s)
- Dario Di Genova
- Department of Crop and Soil Sciences, University of Georgia, Tifton Campus, Tifton, GA 31793, U.S.A
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, 35020 Legnaro, Italy
| | - Kippy J Lewis
- Department of Plant Pathology, University of Georgia, Tifton Campus, Tifton, GA 31793, U.S.A
| | - Jonathan E Oliver
- Department of Plant Pathology, University of Georgia, Tifton Campus, Tifton, GA 31793, U.S.A
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13
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Vergine M, Nicolì F, Sabella E, Aprile A, De Bellis L, Luvisi A. Secondary Metabolites in Xylella fastidiosa-Plant Interaction. Pathogens 2020; 9:pathogens9090675. [PMID: 32825425 PMCID: PMC7559865 DOI: 10.3390/pathogens9090675] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/12/2020] [Accepted: 08/18/2020] [Indexed: 12/24/2022] Open
Abstract
During their evolutionary history, plants have evolved the ability to synthesize and accumulate small molecules known as secondary metabolites. These compounds are not essential in the primary cell functions but play a significant role in the plants’ adaptation to environmental changes and in overcoming stress. Their high concentrations may contribute to the resistance of the plants to the bacterium Xylella fastidiosa, which has recently re-emerged as a plant pathogen of global importance. Although it is established in several areas globally and is considered one of the most dangerous plant pathogens, no cure has been developed due to the lack of effective bactericides and the difficulties in accessing the xylem vessels where the pathogen grows and produces cell aggregates and biofilm. This review highlights the role of secondary metabolites in the defense of the main economic hosts of X. fastidiosa and identifies how knowledge about biosynthetic pathways could improve our understanding of disease resistance. In addition, current developments in non-invasive techniques and strategies of combining molecular and physiological techniques are examined, in an attempt to identify new metabolic engineering options for plant defense.
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14
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Baró A, Badosa E, Montesinos L, Feliu L, Planas M, Montesinos E, Bonaterra A. Screening and identification of BP100 peptide conjugates active against Xylella fastidiosa using a viability-qPCR method. BMC Microbiol 2020; 20:229. [PMID: 32727358 PMCID: PMC7392676 DOI: 10.1186/s12866-020-01915-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 07/20/2020] [Indexed: 12/16/2022] Open
Abstract
Background Xylella fastidiosa is one of the most harmful bacterial plant pathogens worldwide, causing a variety of diseases, with huge economic impact to agriculture and environment. Although it has been extensively studied, there are no therapeutic solutions to suppress disease development in infected plants. In this context, antimicrobial peptides represent promising alternatives to traditional compounds due to their activity against a wide range of plant pathogens, their low cytotoxicity, their mode of action that make resistance more difficult and their availability for being expressed in plants. Results Peptide conjugates derived from the lead peptide BP100 and fragments of cecropin, magainin or melittin were selected and tested against the plant pathogenic bacteria X. fastidiosa. In order to screen the activity of these antimicrobials, and due to the fastidious nature of the pathogen, a methodology consisting of a contact test coupled with the viability-quantitative PCR (v-qPCR) method was developed. The nucleic acid-binding dye PEMAX was used to selectively quantify viable cells by v-qPCR. In addition, the primer set XF16S-3 amplifying a 279 bp fragment was selected as the most suitable for v-qPCR. The performance of the method was assessed by comparing v-qPCR viable cells estimation with conventional qPCR and plate counting. When cells were treated with peptide conjugates derived from BP100, the observed differences between methods suggested that, in addition to cell death due to the lytic effect of the peptides, there was an induction of the viable but non-culturable state in cells. Notably, a contact test coupled to v-qPCR allowed fast and accurate screening of antimicrobial peptides, and led to the identification of new peptide conjugates active against X. fastidiosa. Conclusions Antimicrobial peptides active against X. fastidiosa have been identified using an optimized methodology that quantifies viable cells without a cultivation stage, avoiding underestimation or false negative detection of the pathogen due to the viable but non-culturable state, and overestimation of the viable population observed using qPCR. These findings provide new alternative compounds for being tested in planta for the control of X. fastidiosa, and a methodology that enables the fast screening of a large amount of antimicrobials against this plant pathogenic bacterium.
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Affiliation(s)
- Aina Baró
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Girona, Spain
| | - Esther Badosa
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Girona, Spain
| | - Laura Montesinos
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Girona, Spain
| | - Lidia Feliu
- LIPPSO, Department of Chemistry, University of Girona, Girona, Spain
| | - Marta Planas
- LIPPSO, Department of Chemistry, University of Girona, Girona, Spain
| | - Emilio Montesinos
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Girona, Spain
| | - Anna Bonaterra
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Girona, Spain.
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15
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Mazzaglia A, Rahi YJ, Taratufolo MC, Tatì M, Turco S, Ciarroni S, Tagliavento V, Valentini F, D'Onghia AM, Balestra GM. A new inclusive MLVA assay to investigate genetic variability of Xylella fastidiosa with a specific focus on the Apulian outbreak in Italy. Sci Rep 2020; 10:10856. [PMID: 32616824 PMCID: PMC7331650 DOI: 10.1038/s41598-020-68072-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 06/16/2020] [Indexed: 12/04/2022] Open
Abstract
The Olive Quick Decline Syndrome by Xylella fastidiosa subspecies pauca is among the most severe phytopathological emergencies nowadays. In few years, the outbreak devastated olive groves in Apulia (Italy), potentially endangering the entire Mediterranean basin. This research aimed to develop a multiple locus VNTR analysis assay, a molecular tool to differentiate between populations of the pathogen. It has already been successfully applied to different X. fastidiosa subspecies from various plant hosts. The previously published TR loci, together with a set of new design, have been tested in silico on the genome of the Apulian De Donno strain. The resulting selection of 37 TR loci was amplified on the genomic DNAs of the Apulian strains AND from representatives of X. fastidiosa subspecies, and directly on DNA extracted from infected plants. The assay clearly discerned among subspecies or even sequence types (ST), but also pointed out variants within the same ST so as to provide more detailed information on the dynamics and pathogen diffusion pathways. Its effective application even on total DNAs extracted from infected tissues of different host plants makes it particularly useful for large-scale screening of infection and for the strengthening of containment measures.
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Affiliation(s)
- Angelo Mazzaglia
- Dipartimento di Scienze Agrarie e Forestali (DAFNE), Università della Tuscia, 01100, Viterbo, Italy.
| | - Yaseen Jundi Rahi
- Dipartimento di Scienze Agrarie e Forestali (DAFNE), Università della Tuscia, 01100, Viterbo, Italy
- CIHEAM-Mediterranean Agronomic Institute of Bari, 70010, Valenzano, BA, Italy
| | - Maria Claudia Taratufolo
- Dipartimento di Scienze Agrarie e Forestali (DAFNE), Università della Tuscia, 01100, Viterbo, Italy
| | - Marta Tatì
- Dipartimento di Scienze Agrarie e Forestali (DAFNE), Università della Tuscia, 01100, Viterbo, Italy
| | - Silvia Turco
- Dipartimento di Scienze Agrarie e Forestali (DAFNE), Università della Tuscia, 01100, Viterbo, Italy
| | | | | | - Franco Valentini
- CIHEAM-Mediterranean Agronomic Institute of Bari, 70010, Valenzano, BA, Italy
| | - Anna Maria D'Onghia
- CIHEAM-Mediterranean Agronomic Institute of Bari, 70010, Valenzano, BA, Italy
| | - Giorgio Mariano Balestra
- Dipartimento di Scienze Agrarie e Forestali (DAFNE), Università della Tuscia, 01100, Viterbo, Italy
- Phytoparasite Diagnostics s.r.l., 01100, Viterbo, Italy
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16
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Baró A, Mora I, Montesinos L, Montesinos E. Differential Susceptibility of Xylella fastidiosa Strains to Synthetic Bactericidal Peptides. PHYTOPATHOLOGY 2020; 110:1018-1026. [PMID: 31985337 DOI: 10.1094/phyto-12-19-0477-r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The kinetics of cell inactivation and the susceptibility of Xylella fastidiosa subspecies fastidiosa, multiplex, and pauca to synthetic antimicrobial peptides from two libraries (CECMEL11 and CYCLO10) were studied. The bactericidal effect was dependent on the relative concentrations of peptide and bacterial cells, and was influenced by the diluent, either buffer or sap. The most bactericidal and lytic peptide was BP178, an enlarged derivative of the amphipathic cationic linear undecapeptide BP100. The maximum reduction in survivors after BP178 treatment occurred within the first 10 to 20 min of contact and at micromolar concentrations (<10 μM), resulting in pore formation in cell membranes, abundant production of outer membrane vesicles, and lysis. A threshold ratio of 109 molecules of peptide per bacterial cell was estimated to be necessary to initiate cell inactivation. There was a differential susceptibility to BP178 among strains, with DD1 being the most resistant and CFBP 8173 the most susceptible. Moreover, strains showed a proportion of cells under the viable but nonculturable state, which was highly variable among strains. These findings may have implications for managing the diseases caused by X. fastidiosa.
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Affiliation(s)
- Aina Baró
- Institute of Food and Agricultural Technology-XaRTA-CIDSAV, University of Girona, C/ Maria Aurèlia Capmany 61, 17003 Girona, Spain
| | - Isabel Mora
- Institute of Food and Agricultural Technology-XaRTA-CIDSAV, University of Girona, C/ Maria Aurèlia Capmany 61, 17003 Girona, Spain
| | - Laura Montesinos
- Institute of Food and Agricultural Technology-XaRTA-CIDSAV, University of Girona, C/ Maria Aurèlia Capmany 61, 17003 Girona, Spain
| | - Emilio Montesinos
- Institute of Food and Agricultural Technology-XaRTA-CIDSAV, University of Girona, C/ Maria Aurèlia Capmany 61, 17003 Girona, Spain
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17
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Schneider K, van der Werf W, Cendoya M, Mourits M, Navas-Cortés JA, Vicent A, Oude Lansink A. Impact of Xylella fastidiosa subspecies pauca in European olives. Proc Natl Acad Sci U S A 2020; 117:9250-9259. [PMID: 32284411 PMCID: PMC7196823 DOI: 10.1073/pnas.1912206117] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Xylella fastidiosa is the causal agent of plant diseases that cause massive economic damage. In 2013, a strain of the bacterium was, for the first time, detected in the European territory (Italy), causing the Olive Quick Decline Syndrome. We simulate future spread of the disease based on climatic-suitability modeling and radial expansion of the invaded territory. An economic model is developed to compute impact based on discounted foregone profits and losses in investment. The model projects impact for Italy, Greece, and Spain, as these countries account for around 95% of the European olive oil production. Climatic suitability modeling indicates that, depending on the suitability threshold, 95.5 to 98.9%, 99.2 to 99.8%, and 84.6 to 99.1% of the national areas of production fall into suitable territory in Italy, Greece, and Spain, respectively. For Italy, across the considered rates of radial range expansion the potential economic impact over 50 y ranges from 1.9 billion to 5.2 billion Euros for the economic worst-case scenario, in which production ceases after orchards die off. If replanting with resistant varieties is feasible, the impact ranges from 0.6 billion to 1.6 billion Euros. Depending on whether replanting is feasible, between 0.5 billion and 1.3 billion Euros can be saved over the course of 50 y if disease spread is reduced from 5.18 to 1.1 km per year. The analysis stresses the necessity to strengthen the ongoing research on cultivar resistance traits and application of phytosanitary measures, including vector control and inoculum suppression, by removing host plants.
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Affiliation(s)
- Kevin Schneider
- Business Economics Group, Wageningen University, 6700 EW, Wageningen, Netherlands;
| | - Wopke van der Werf
- Centre for Crop Systems Analysis, Wageningen University, 6700 AK, Wageningen, Netherlands
| | - Martina Cendoya
- Centre de Protecció Vegetal i Biotecnología, Institut Valencià d'Investigacions Agràries, 46113 Moncada (Valencia), Spain
| | - Monique Mourits
- Business Economics Group, Wageningen University, 6700 EW, Wageningen, Netherlands
| | - Juan A Navas-Cortés
- Institute for Sustainable Agriculture, Spanish National Research Council (CSIC), 14004 Córdoba, Spain
| | - Antonio Vicent
- Centre de Protecció Vegetal i Biotecnología, Institut Valencià d'Investigacions Agràries, 46113 Moncada (Valencia), Spain
| | - Alfons Oude Lansink
- Business Economics Group, Wageningen University, 6700 EW, Wageningen, Netherlands
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18
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Landa BB, Castillo AI, Giampetruzzi A, Kahn A, Román-Écija M, Velasco-Amo MP, Navas-Cortés JA, Marco-Noales E, Barbé S, Moralejo E, Coletta-Filho HD, Saldarelli P, Saponari M, Almeida RPP. Emergence of a Plant Pathogen in Europe Associated with Multiple Intercontinental Introductions. Appl Environ Microbiol 2020; 86:e01521-19. [PMID: 31704683 PMCID: PMC6974645 DOI: 10.1128/aem.01521-19] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 11/05/2019] [Indexed: 11/20/2022] Open
Abstract
Pathogen introductions have led to numerous disease outbreaks in naive regions of the globe. The plant pathogen Xylella fastidiosa has been associated with various recent epidemics in Europe affecting agricultural crops, such as almond, grapevine, and olive, but also endemic species occurring in natural forest landscapes and ornamental plants. We compared whole-genome sequences of X. fastidiosa subspecies multiplex from America and strains associated with recent outbreaks in southern Europe to infer their likely origins and paths of introduction within and between the two continents. Phylogenetic analyses indicated multiple introductions of X. fastidiosa subspecies multiplex into Italy, Spain, and France, most of which emerged from a clade with limited genetic diversity with a likely origin in California, USA. The limited genetic diversity observed in X. fastidiosa subspecies multiplex strains originating from California is likely due to the clade itself being an introduction from X. fastidiosa subspecies multiplex populations in the southeastern United States, where this subspecies is most likely endemic. Despite the genetic diversity found in some areas in Europe, there was no clear evidence of recombination occurring among introduced X. fastidiosa strains in Europe. Sequence type taxonomy, based on multilocus sequence typing (MLST), was shown, at least in one case, to not lead to monophyletic clades of this pathogen; whole-genome sequence data were more informative in resolving the history of introductions than MLST data. Although additional data are necessary to carefully tease out the paths of these recent dispersal events, our results indicate that whole-genome sequence data should be considered when developing management strategies for X. fastidiosa outbreaks.IMPORTANCEXylella fastidiosa is an economically important plant-pathogenic bacterium that has emerged as a pathogen of global importance associated with a devastating epidemic in olive trees in Italy associated with X. fastidiosa subspecies pauca and other outbreaks in Europe, such as X. fastidiosa subspecies fastidiosa and X. fastidiosa subspecies multiplex in Spain and X. fastidiosa subspecies multiplex in France. We present evidence of multiple introductions of X. fastidiosa subspecies multiplex, likely from the United States, into Spain, Italy, and France. These introductions illustrate the risks associated with the commercial trade of plant material at global scales and the need to develop effective policy to limit the likelihood of pathogen pollution into naive regions. Our study demonstrates the need to utilize whole-genome sequence data to study X. fastidiosa introductions at outbreak stages, since a limited number of genetic markers does not provide sufficient phylogenetic resolution to determine dispersal paths or relationships among strains that are of biological and quarantine relevance.
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Affiliation(s)
- Blanca B Landa
- Institute for Sustainable Agriculture, Consejo Superior de Investigaciones Científicas (IAS-CSIC), Córdoba, Spain
| | - Andreina I Castillo
- Department of Environmental Science, Policy and Management, University of California, Berkeley, Berkeley, California, USA
| | - Annalisa Giampetruzzi
- Dipartimento di Scienze del Suolo della Pianta e degli Alimenti, Universit à degli Studi di Bari Aldo Moro, Bari, Italy
| | - Alexandra Kahn
- Department of Environmental Science, Policy and Management, University of California, Berkeley, Berkeley, California, USA
| | - Miguel Román-Écija
- Institute for Sustainable Agriculture, Consejo Superior de Investigaciones Científicas (IAS-CSIC), Córdoba, Spain
| | - María Pilar Velasco-Amo
- Institute for Sustainable Agriculture, Consejo Superior de Investigaciones Científicas (IAS-CSIC), Córdoba, Spain
| | - Juan A Navas-Cortés
- Institute for Sustainable Agriculture, Consejo Superior de Investigaciones Científicas (IAS-CSIC), Córdoba, Spain
| | - Ester Marco-Noales
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), Moncada, Spain
| | - Silvia Barbé
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), Moncada, Spain
| | - Eduardo Moralejo
- Tragsa, Empresa de Transformación Agraria, Delegación de Baleares, Palma de Mallorca, Spain
| | | | | | - Maria Saponari
- Istituto per la Protezione Sostenibile delle Piante, CNR, Bari, Italy
| | - Rodrigo P P Almeida
- Department of Environmental Science, Policy and Management, University of California, Berkeley, Berkeley, California, USA
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19
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Cattò C, De Vincenti L, Cappitelli F, D’Attoma G, Saponari M, Villa F, Forlani F. Non-Lethal Effects of N-Acetylcysteine on Xylella fastidiosa Strain De Donno Biofilm Formation and Detachment. Microorganisms 2019; 7:E656. [PMID: 31817370 PMCID: PMC6955915 DOI: 10.3390/microorganisms7120656] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/28/2019] [Accepted: 12/03/2019] [Indexed: 01/03/2023] Open
Abstract
This study investigated in-vitro the non-lethal effects of N-acetylcysteine (NAC) on Xylella fastidiosa subspecies pauca strain De Donno (Xf-DD) biofilm. This strain was isolated from the olive trees affected by the olive quick decline syndrome in southern Italy. Xf-DD was first exposed to non-lethal concentrations of NAC from 0.05 to 1000 µM. Cell surface adhesion was dramatically reduced at 500 µM NAC (-47%), hence, this concentration was selected for investigating the effects of pre-, post- and co-treatments on biofilm physiology and structural development, oxidative homeostasis, and biofilm detachment. Even though 500 µM NAC reduced bacterial attachment to surfaces, compared to the control samples, it promoted Xf-DD biofilm formation by increasing: (i) biofilm biomass by up to 78% in the co-treatment, (ii) matrix polysaccharides production by up to 72% in the pre-treatment, and (iii) reactive oxygen species levels by 3.5-fold in the co-treatment. Xf-DD biofilm detachment without and with NAC was also investigated. The NAC treatment did not increase biofilm detachment, compared to the control samples. All these findings suggested that, at 500 µM, NAC diversified the phenotypes in Xf-DD biofilm, promoting biofilm formation (hyper-biofilm-forming phenotype) and discouraging biofilm detachment (hyper-attachment phenotype), while increasing oxidative stress level in the biofilm.
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Affiliation(s)
- Cristina Cattò
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy; (C.C.); (L.D.V.); (F.C.); (F.F.)
| | - Luca De Vincenti
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy; (C.C.); (L.D.V.); (F.C.); (F.F.)
| | - Francesca Cappitelli
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy; (C.C.); (L.D.V.); (F.C.); (F.F.)
| | - Giusy D’Attoma
- Institute for Sustainable Plant Protection, Consiglio Nazionale delle Ricerche, via Amendola 165/A, 70126 Bari, Italy (M.S.)
| | - Maria Saponari
- Institute for Sustainable Plant Protection, Consiglio Nazionale delle Ricerche, via Amendola 165/A, 70126 Bari, Italy (M.S.)
| | - Federica Villa
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy; (C.C.); (L.D.V.); (F.C.); (F.F.)
| | - Fabio Forlani
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy; (C.C.); (L.D.V.); (F.C.); (F.F.)
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20
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Lessons from One Fastidious Bacterium to Another: What Can We Learn about Liberibacter Species from Xylella fastidiosa. INSECTS 2019; 10:insects10090300. [PMID: 31527458 PMCID: PMC6780969 DOI: 10.3390/insects10090300] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/11/2019] [Accepted: 09/12/2019] [Indexed: 02/06/2023]
Abstract
Huanglongbing is causing economic devastation to the citrus industry in Florida, and threatens the industry everywhere the bacterial pathogens in the Candidatus Liberibacter genus and their insect vectors are found. Bacteria in the genus cannot be cultured and no durable strategy is available for growers to control plant infection or pathogen transmission. However, scientists and grape growers were once in a comparable situation after the emergence of Pierce’s disease, which is caused by Xylella fastidiosa and spread by its hemipteran insect vector. Proactive quarantine and vector control measures coupled with interdisciplinary data-driven science established control of this devastating disease and pushed the frontiers of knowledge in the plant pathology and vector biology fields. Our review highlights the successful strategies used to understand and control X. fastidiosa and their potential applicability to the liberibacters associated with citrus greening, with a focus on the interactions between bacterial pathogen and insect vector. By placing the study of Candidatus Liberibacter spp. within the current and historical context of another fastidious emergent plant pathogen, future basic and applied research to develop control strategies can be prioritized.
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Novelli S, Gismondi A, Di Marco G, Canuti L, Nanni V, Canini A. Plant defense factors involved in Olea europaea resistance against Xylella fastidiosa infection. JOURNAL OF PLANT RESEARCH 2019; 132:439-455. [PMID: 30993555 DOI: 10.1007/s10265-019-01108-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 04/09/2019] [Indexed: 06/09/2023]
Abstract
Olive quick decline syndrome (OQDS) is a dangerous plant disease, caused by the bacterium Xylella fastidiosa, which targets olive (Olea europaea). Since field observations suggested that some olive cultivars (i.e. Leccino) were more resistant to OQDS than others (i.e. Cellina di Nardò), the plant defense strategies adopted by olive to contrast X. fastidiosa infection were investigated. In the present study, ELISA and genetic approaches were used to confirm plant infection, while microbial colonization mechanism and distribution in host plant tissues and reactive oxygen species (ROS) levels were examined by light, scanning electron and confocal microscopy analyses. Spectrophotometric and chromatographic techniques were performed to measure secondary metabolites content and qPCR assay was carried out for monitoring plant gene expression variation. Our analysis showed that X. fastidiosa caused accumulation of ROS in Leccino samples compared to Cellina di Nardò. Moreover, the infection induced the up-regulation of defense-related genes, such as NADPH oxidase, some protein kinases, pathogen plant response factors and metabolic enzymes. We also found that Leccino plants enhanced the production of specific antioxidant and antimicrobial molecules, to fight the pathogen and avoid its spreading into xylem vessels. We provided new information on OQDS resistance mechanism applied by Leccino cultivar. In particular, we evidenced that high concentrations of ROS, switching on plant defence signalling pathways, may represent a key factor in fighting X. fastidiosa infection.
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Affiliation(s)
- Silvia Novelli
- Department of Biology, University of Rome "Tor Vergata", via della Ricerca Scientifica 1, Rome, 00133, Italy
| | - Angelo Gismondi
- Department of Biology, University of Rome "Tor Vergata", via della Ricerca Scientifica 1, Rome, 00133, Italy
| | - Gabriele Di Marco
- Department of Biology, University of Rome "Tor Vergata", via della Ricerca Scientifica 1, Rome, 00133, Italy
| | - Lorena Canuti
- Department of Biology, University of Rome "Tor Vergata", via della Ricerca Scientifica 1, Rome, 00133, Italy
| | - Valentina Nanni
- Department of Biology, University of Rome "Tor Vergata", via della Ricerca Scientifica 1, Rome, 00133, Italy
| | - Antonella Canini
- Department of Biology, University of Rome "Tor Vergata", via della Ricerca Scientifica 1, Rome, 00133, Italy.
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Bragard C, Dehnen-Schmutz K, Di Serio F, Gonthier P, Jacques MA, Jaques Miret JA, Justesen AF, MacLeod A, Magnusson CS, Milonas P, Navas-Cortés JA, Potting R, Reignault PL, Thulke HH, van der Werf W, Vicent Civera A, Yuen J, Zappalà L, Boscia D, Chapman D, Gilioli G, Krugner R, Mastin A, Simonetto A, Spotti Lopes JR, White S, Abrahantes JC, Delbianco A, Maiorano A, Mosbach-Schulz O, Stancanelli G, Guzzo M, Parnell S. Update of the Scientific Opinion on the risks to plant health posed by Xylella fastidiosa in the EU territory. EFSA J 2019; 17:e05665. [PMID: 32626299 PMCID: PMC7009223 DOI: 10.2903/j.efsa.2019.5665] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
EFSA was asked to update the 2015 EFSA risk assessment on Xylella fastidiosa for the territory of the EU. In particular, EFSA was asked to focus on potential establishment, short- and long-range spread, the length of the asymptomatic period, the impact of X. fastidiosa and an update on risk reduction options. EFSA was asked to take into account the different subspecies and Sequence Types of X. fastidiosa. This was attempted throughout the scientific opinion but several issues with data availability meant that this could only be partially achieved. Models for risk of establishment showed most of the EU territory may be potentially suitable for X. fastidiosa although southern EU is most at risk. Differences in estimated areas of potential establishment were evident among X. fastidiosa subspecies, particularly X. fastidiosa subsp. multiplex which demonstrated areas of potential establishment further north in the EU. The model of establishment could be used to develop targeted surveys by Member States. The asymptomatic period of X. fastidiosa varied significantly for different host and pathogen subspecies combinations, for example from a median of approximately 1 month in ornamental plants and up to 10 months in olive, for pauca. This variable and long asymptomatic period is a considerable limitation to successful detection and control, particularly where surveillance is based on visual inspection. Modelling suggested that local eradication (e.g. within orchards) is possible, providing sampling intensity is sufficient for early detection and effective control measures are implemented swiftly (e.g. within 30 days). Modelling of long-range spread (e.g. regional scale) demonstrated the important role of long-range dispersal and the need to better understand this. Reducing buffer zone width in both containment and eradication scenarios increased the area infected. Intensive surveillance for early detection, and consequent plant removal, of new outbreaks is crucial for both successful eradication and containment at the regional scale, in addition to effective vector control. The assessment of impacts indicated that almond and Citrus spp. were at lower impact on yield compared to olive. Although the lowest impact was estimated for grapevine, and the highest for olive, this was based on several assumptions including that the assessment considered only Philaenus spumarius as a vector. If other xylem-feeding insects act as vectors the impact could be different. Since the Scientific Opinion published in 2015, there are still no risk reduction options that can remove the bacterium from the plant in open field conditions. Short- and long-range spread modelling showed that an early detection and rapid application of phytosanitary measures, consisting among others of plant removal and vector control, are essential to prevent further spread of the pathogen to new areas. Further data collection will allow a reduction in uncertainty and facilitate more tailored and effective control given the intraspecific diversity of X. fastidiosa and wide host range.
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Girelli CR, Angilè F, Del Coco L, Migoni D, Zampella L, Marcelletti S, Cristella N, Marangi P, Scortichini M, Fanizzi FP. 1H-NMR Metabolite Fingerprinting Analysis Reveals a Disease Biomarker and a Field Treatment Response in Xylella fastidiosa subsp. pauca-Infected Olive Trees. PLANTS (BASEL, SWITZERLAND) 2019; 8:E115. [PMID: 31035723 PMCID: PMC6571561 DOI: 10.3390/plants8050115] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 04/24/2019] [Accepted: 04/26/2019] [Indexed: 12/16/2022]
Abstract
Xylella fastidiosa subsp. pauca is a xylem-limited bacterial phytopathogen currently found associated on many hectares with the "olive quick decline syndrome" in the Apulia region (Southern Italy), and the cultivars Ogliarola salentina and Cellina di Nardò result in being particularly sensitive to the disease. In order to find compounds showing the capability of reducing the population cell density of the pathogen within the leaves, we tested, in some olive orchards naturally-infected by the bacterium, a zinc-copper-citric acid biocomplex, namely Dentamet®, by spraying it to the crown, once per month, during spring and summer. The occurrence of the pathogen in the four olive orchards chosen for the trial was molecularly assessed. A 1H NMR metabolomic approach, in conjunction with a multivariate statistical analysis, was applied to investigate the metabolic pattern of both infected and treated adult olive cultivars, Ogliarola salentina and Cellina di Nardò trees, in two sampling periods, performed during the first year of the trial. For both cultivars and sampling periods, the orthogonal partial least squares discriminant analysis (OPLS-DA) gave good models of separation according to the treatment application. In both cultivars, some metabolites such as quinic acid, the aldehydic form of oleoeuropein, ligstroside and phenolic compounds, were consistently found as discriminative for the untreated olive trees in comparison with the Dentamet®-treated trees. Quinic acid, a precursor of lignin, was confirmed as a disease biomarker for the olive trees infected by X. fastidiosa subsp. pauca. When treated with Dentamet®, the two cultivars showed a distinct response. A consistent increase in malic acid was observed for the Ogliarola salentina trees, whereas in the Cellina di Nardò trees the treatments attenuate the metabolic response to the infection. To note that in Cellina di Nardò trees at the first sampling, an increase in γ-aminobutyric acid (GABA) was observed. This study highlights how the infection incited by X. fastidiosa subsp. pauca strongly modifies the overall metabolism of olive trees, and how a zinc-copper-citric acid biocomplex can induce an early re-programming of the metabolic pathways in the infected trees.
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Affiliation(s)
- Chiara Roberta Girelli
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Prov.le Lecce-Monteroni, I-73100 Lecce, Italy.
| | - Federica Angilè
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Prov.le Lecce-Monteroni, I-73100 Lecce, Italy.
| | - Laura Del Coco
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Prov.le Lecce-Monteroni, I-73100 Lecce, Italy.
| | - Danilo Migoni
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Prov.le Lecce-Monteroni, I-73100 Lecce, Italy.
| | - Luigi Zampella
- Council for Agricultural research and Economics-Research Centre for Olive, Fruit Trees and Citrus, Via Torrino, 3, I-81100, Caserta, Italy.
| | - Simone Marcelletti
- Council for Agricultural research and Economics-Research Centre for Olive, Fruit Trees and Citrus, Via Torrino, 3, I-81100, Caserta, Italy.
| | - Nicola Cristella
- Studio Agro-Ambientale ed Ingegneria Terranostra srls, Via XXIV Maggio, 10, I-74020 Lizzano (TA), Italy.
| | - Paolo Marangi
- Studio Agro-Ambientale ed Ingegneria Terranostra srls, Via XXIV Maggio, 10, I-74020 Lizzano (TA), Italy.
| | - Marco Scortichini
- Council for Agricultural research and Economics-Research Centre for Olive, Fruit Trees and Citrus, Via Torrino, 3, I-81100, Caserta, Italy.
| | - Francesco Paolo Fanizzi
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Prov.le Lecce-Monteroni, I-73100 Lecce, Italy.
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Safady NG, Lopes JRS, Francisco CS, Coletta-Filho HD. Distribution and Genetic Diversity of Xylella fastidiosa subsp. pauca Associated with Olive Quick Syndrome Symptoms in Southeastern Brazil. PHYTOPATHOLOGY 2019; 109:257-264. [PMID: 30457432 DOI: 10.1094/phyto-07-18-0273-fi] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In Brazil, the host expansion of Xylella fastidiosa subsp. pauca was recently demonstrated with the report of diseased olive trees (Olea europaea), whose symptoms were associated with olive quick decline syndrome previously described in southern Italy. We employed both polymerase chain reaction-based techniques and culture medium isolation to investigate the geographic distribution of X. fastidiosa as well as the genetic signatures of 21 strains isolated from 11 olive orchards in both São Paulo and Minas Gerais States in Brazil. X. fastidiosa subsp. pauca was detected in 83% of the orchards examined in the region, and was positively diagnosed in 43.7% of all sampled plants with typical scorching symptoms. Of the 21 strains characterized with fast-evolving microsatellite (single sequence repeat [SSR]) markers, 20 different multilocus microsatellite genotypes were observed with the overall allelic diversity of HNei = 0.38. Principal component analysis using the SSR markers clustered all strains, except for three, in one cluster demonstrating a limited range of genetic diversity. Multilocus sequence typing analysis showed the prevalence of a sequence type (ST16) in 75% of the samples; three other novel STs (84, 85, and 86), were detected, all belonging to the X. fastidiosa subsp. pauca cluster. These results show that genetically diverse strains of X. fastidiosa subsp. pauca are widely present in olive orchards in southeastern Brazil, which is consistent with the long history of this bacterium in that region.
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Affiliation(s)
- Nágela Gomes Safady
- First and fourth authors: IAC-Centro de Citricultura 'Sylvio Moreira', Cordeirópolis, São Paulo, 13490-970, Brasil; first author: UFSCaR-Universidade de São Carlos, PGPVBA, Araras, São Paulo, 13600-970, Brasil; second author: Departamento de Entomologia e Acarologia, 'Escola Superior de Agricultura Luiz de Queiroz', Universidade de São Paulo, Piracicaba, São Paulo, 13418-900, Brasil; and third author: Plant Pathology, Institute of Integrative Biology, ETH Zürich, CH-8092 Zürich, Switzerland
| | - João R S Lopes
- First and fourth authors: IAC-Centro de Citricultura 'Sylvio Moreira', Cordeirópolis, São Paulo, 13490-970, Brasil; first author: UFSCaR-Universidade de São Carlos, PGPVBA, Araras, São Paulo, 13600-970, Brasil; second author: Departamento de Entomologia e Acarologia, 'Escola Superior de Agricultura Luiz de Queiroz', Universidade de São Paulo, Piracicaba, São Paulo, 13418-900, Brasil; and third author: Plant Pathology, Institute of Integrative Biology, ETH Zürich, CH-8092 Zürich, Switzerland
| | - Carolina S Francisco
- First and fourth authors: IAC-Centro de Citricultura 'Sylvio Moreira', Cordeirópolis, São Paulo, 13490-970, Brasil; first author: UFSCaR-Universidade de São Carlos, PGPVBA, Araras, São Paulo, 13600-970, Brasil; second author: Departamento de Entomologia e Acarologia, 'Escola Superior de Agricultura Luiz de Queiroz', Universidade de São Paulo, Piracicaba, São Paulo, 13418-900, Brasil; and third author: Plant Pathology, Institute of Integrative Biology, ETH Zürich, CH-8092 Zürich, Switzerland
| | - Helvécio Della Coletta-Filho
- First and fourth authors: IAC-Centro de Citricultura 'Sylvio Moreira', Cordeirópolis, São Paulo, 13490-970, Brasil; first author: UFSCaR-Universidade de São Carlos, PGPVBA, Araras, São Paulo, 13600-970, Brasil; second author: Departamento de Entomologia e Acarologia, 'Escola Superior de Agricultura Luiz de Queiroz', Universidade de São Paulo, Piracicaba, São Paulo, 13418-900, Brasil; and third author: Plant Pathology, Institute of Integrative Biology, ETH Zürich, CH-8092 Zürich, Switzerland
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Jeger M, Bragard C. The Epidemiology of Xylella fastidiosa; A Perspective on Current Knowledge and Framework to Investigate Plant Host-Vector-Pathogen Interactions. PHYTOPATHOLOGY 2019; 109:200-209. [PMID: 30365394 DOI: 10.1094/phyto-07-18-0239-fi] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Insect-transmitted plant diseases caused by viruses, phytoplasmas, and bacteria share many features in common regardless of the causal agent. This perspective aims to show how a model framework, developed originally for plant virus diseases, can be modified for the case of diseases incited by Xylella fastidiosa. In particular, the model framework enables the specification of a simple but quite general invasion criterion defined in terms of key plant, pathogen, and vector parameters and, importantly, their interactions, which determine whether or not an incursion or isolated outbreak of a pathogen will lead to establishment, persistence, and subsequent epidemic development. Hence, this approach is applicable to the wide range of X. fastidiosa-incited diseases that have recently emerged in southern Europe, each with differing host plant, pathogen subspecies, and vector identities. Of particular importance are parameters relating to vector abundance and activity, transmission characteristics, and behavior in relation to preferences for host infection status. Some gaps in knowledge with regard to the developing situation in Europe are noted.
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Affiliation(s)
- Michael Jeger
- First author: Centre for Environmental Policy, Imperial College London, Silwood Park Campus, Ascot SL7 9LU, United Kingdom; and second author: Earth and Life Institute, UCLouvain, B-1348 Louvain-la-Neuve, Belgium
| | - Claude Bragard
- First author: Centre for Environmental Policy, Imperial College London, Silwood Park Campus, Ascot SL7 9LU, United Kingdom; and second author: Earth and Life Institute, UCLouvain, B-1348 Louvain-la-Neuve, Belgium
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Martinetti D, Soubeyrand S. Identifying Lookouts for Epidemio-Surveillance: Application to the Emergence of Xylella fastidiosa in France. PHYTOPATHOLOGY 2019; 109:265-276. [PMID: 30457431 DOI: 10.1094/phyto-07-18-0237-fi] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Recent detections of Xylella fastidiosa in Corsica Island, France, has raised concerns on its possible spread to mainland France and the rest of the Mediterranean Basin. Early detection of infected plants is paramount to prevent the spread of the bacteria, but little is known about this pathosystem in European environments, hence standard surveillance strategies may be ineffective. We present a new methodological approach for the design of risk-based surveillance strategies, adapted to the emerging risk caused by X. fastidiosa. Our proposal is based on a combination of machine learning techniques and network analysis that aims at understanding the main abiotic drivers of the infection, produce risk maps and identify lookouts for the design of future surveillance plans. The identified drivers coincide with known results in laboratory studies about the correlation between environmental variables, such as water stress and temperature, and the presence of the bacterium in plants. Furthermore, the produced risk maps overlap nicely with detected foci of infection, while they also highlight other susceptible regions where X. fastidiosa has not been found yet. We conclude the paper presenting a list of recommended regions for a risk-based surveillance campaign based on the predicted spread and probability of early detection of the disease.
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Colella C, Carradore R, Cerroni A. Problem Setting and Problem Solving in the Case of Olive Quick Decline Syndrome in Apulia, Italy: A Sociological Approach. PHYTOPATHOLOGY 2019; 109:187-199. [PMID: 30589371 DOI: 10.1094/phyto-07-18-0247-fi] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This article gives an account of the social construction of phytopathological knowledge in the case of olive quick decline syndrome (OQDS) in Apulia, Italy. Due to the economic, cultural, and social importance of the olive crop, the spread of this disease has been characterized by a social debate over the implementation of mandatory phytosanitary policies, the etiological role played by the bacterium Xylella fastidiosa, the role of scientific experts, and the unexplored research trajectories ("undone science") proposed by social and environmental movements. We examine how the disease has generated different approaches to problem setting and problem solving, one focused on OQDS as a complex of symptoms uniquely caused by X. fastidiosa, and the other framing the study of "complesso del disseccamento rapido dell'olivo" (CoDiRO) as a complex of causes. Drawing on a 2-year ethnographic study among researchers, policymakers, agricultural stakeholders, and social movements, this article uses theoretical concepts from the sociology of knowledge, sociology of scientific knowledge, and sociology of ignorance to examine the case and to reconstruct the 360° approach proposed by social movements as an alternative to the epistemic and political reductionism of official phytosanitary and science policies.
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Affiliation(s)
- Christian Colella
- Department of Sociology and Social Research, University of Milano-Bicocca, Milan, 20126, Italy
| | - Roberto Carradore
- Department of Sociology and Social Research, University of Milano-Bicocca, Milan, 20126, Italy
| | - Andrea Cerroni
- Department of Sociology and Social Research, University of Milano-Bicocca, Milan, 20126, Italy
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Cruaud A, Gonzalez AA, Godefroid M, Nidelet S, Streito JC, Thuillier JM, Rossi JP, Santoni S, Rasplus JY. Using insects to detect, monitor and predict the distribution of Xylella fastidiosa: a case study in Corsica. Sci Rep 2018; 8:15628. [PMID: 30353142 PMCID: PMC6199265 DOI: 10.1038/s41598-018-33957-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 10/03/2018] [Indexed: 11/18/2022] Open
Abstract
We sampled ca 2500 specimens of Philaenus spumarius (Hemiptera: Aphrophoridae) throughout Corsica without a priori knowledge on the presence of symptoms on plants. We screened 448 specimens for the presence of Xylella fastidiosa (Xf) using qPCR and a custom nested PCR. qPCR appeared versatile and under-estimated the prevalence of Xf. Nested PCR showed that Xf was present in all populations. Molecular results were validated by prediction on the distribution of Xf made from tests conducted on plants, which shows the pertinence of using vectors in risk assessment studies. Xf was detected in tenerals and adults. Thus, P. spumarius could acquire Xf from its host plant, mostly Cistus monspeliensis in Corsica, which may act as reservoir for the next season. This contrasts with other observations and suggests that management strategies may have to be adapted on a case-by-case basis. At least two genetic entities and several variants of Xf not yet identified on plants were present in the insects, which suggests ancient introductions of Xf and a probable underestimation of the current diversity of the strains present in Corsica. Interestingly 6% of the specimens carried two subspecies of Xf. Studies are required to better characterize the strains present in Corsica and to determine how the disease was introduced, spread and why no sign of a potential epidemic was detected earlier. This study shows that, when sensitive enough methods are implemented, spittlebugs (and more specifically P. spumarius for which species distribution modelling shows it could be a good sentinel for Europe) can be used to predict and better assess the exact distribution of Xf. Furthermore, Xf multiply only in their foregut and does not become circulative, which facilitates its detection.
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Affiliation(s)
- Astrid Cruaud
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, University Montpellier, Montpellier, France.
| | - Anne-Alicia Gonzalez
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, University Montpellier, Montpellier, France
- INRA, UMR1334 AGAP, F-34398, Montpellier, France
| | - Martin Godefroid
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, University Montpellier, Montpellier, France
| | - Sabine Nidelet
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, University Montpellier, Montpellier, France
| | - Jean-Claude Streito
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, University Montpellier, Montpellier, France
| | - Jean-Marc Thuillier
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, University Montpellier, Montpellier, France
| | - Jean-Pierre Rossi
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, University Montpellier, Montpellier, France
| | | | - Jean-Yves Rasplus
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, University Montpellier, Montpellier, France
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Kyrkou I, Pusa T, Ellegaard-Jensen L, Sagot MF, Hansen LH. Pierce's Disease of Grapevines: A Review of Control Strategies and an Outline of an Epidemiological Model. Front Microbiol 2018; 9:2141. [PMID: 30258423 PMCID: PMC6143690 DOI: 10.3389/fmicb.2018.02141] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 08/21/2018] [Indexed: 11/13/2022] Open
Abstract
Xylella fastidiosa is a notorious plant pathogenic bacterium that represents a threat to crops worldwide. Its subspecies, Xylella fastidiosa subsp. fastidiosa is the causal agent of Pierce's disease of grapevines. Pierce's disease has presented a serious challenge for the grapevine industry in the United States and turned into an epidemic in Southern California due to the invasion of the insect vector Homalodisca vitripennis. In an attempt to minimize the effects of Xylella fastidiosa subsp. fastidiosa in vineyards, various studies have been developing and testing strategies to prevent the occurrence of Pierce's disease, i.e., prophylactic strategies. Research has also been undertaken to investigate therapeutic strategies to cure vines infected by Xylella fastidiosa subsp. fastidiosa. This report explicitly reviews all the strategies published to date and specifies their current status. Furthermore, an epidemiological model of Xylella fastidiosa subsp. fastidiosa is proposed and key parameters for the spread of Pierce's disease deciphered in a sensitivity analysis of all model parameters. Based on these results, it is concluded that future studies should prioritize therapeutic strategies, while investments should only be made in prophylactic strategies that have demonstrated promising results in vineyards.
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Affiliation(s)
- Ifigeneia Kyrkou
- Laboratory of Environmental Microbiology and Biotechnology, Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - Taneli Pusa
- INRIA Grenoble Rhône-Alpes, Montbonnot-Saint-Martin, France
- Laboratoire de Biométrie et Biologie Évolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon 1, Villeurbanne, France
- Department of Computer, Automatic and Management Engineering, Sapienza University of Rome, Rome, Italy
| | - Lea Ellegaard-Jensen
- Laboratory of Environmental Microbiology and Biotechnology, Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - Marie-France Sagot
- INRIA Grenoble Rhône-Alpes, Montbonnot-Saint-Martin, France
- Laboratoire de Biométrie et Biologie Évolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon 1, Villeurbanne, France
| | - Lars Hestbjerg Hansen
- Laboratory of Environmental Microbiology and Biotechnology, Department of Environmental Science, Aarhus University, Roskilde, Denmark
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Abstract
Following a request from the European Commission, EFSA periodically updates the database on the host plants of Xylella spp. While previous editions of the database (2015 and 2016) dealt with the species Xylella fastidiosa only, this database version addresses the whole genus Xylella, including therefore both species X. fastidiosa and Xylella taiwanensis. The database now includes information on host plants of Xylella spp. retrieved from scientific literature up to November 2017 and from EUROPHYT notifications up to May 2018. An extensive literature search was performed to screen the scientific and technical literature published between the previous database update conducted in December 2015 and December 2017. The literature screening was supported by the DistillerSR software platform. The applied protocol for the extensive literature review and extensive information search, together with examples of data extraction, are described in detail in this report. This report also includes published information on resistance or tolerance of plant varieties to Xylella spp. The current database includes 563 plant species reported to be infected by X. fastidiosa, of which for 312 plant species the infection has been determined with at least two different detection methods. These species cover hundreds of host plant genera in 82 botanical families (61 botanical families when considering only records with at least two different detection methods). The update of this database of host plants of Xylella spp. reported world-wide provides a key tool for risk management, risk assessment and research on this polyphagous bacterial plant pathogen.
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Sicard A, Zeilinger AR, Vanhove M, Schartel TE, Beal DJ, Daugherty MP, Almeida RPP. Xylella fastidiosa: Insights into an Emerging Plant Pathogen. ANNUAL REVIEW OF PHYTOPATHOLOGY 2018; 56:181-202. [PMID: 29889627 DOI: 10.1146/annurev-phyto-080417-045849] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The bacterium Xylella fastidiosa re-emerged as a plant pathogen of global importance in 2013 when it was first associated with an olive tree disease epidemic in Italy. The current threat to Europe and the Mediterranean basin, as well as other world regions, has increased as multiple X. fastidiosa genotypes have now been detected in Italy, France, and Spain. Although X. fastidiosa has been studied in the Americas for more than a century, there are no therapeutic solutions to suppress disease development in infected plants. Furthermore, because X. fastidiosa is an obligatory plant and insect vector colonizer, the epidemiology and dynamics of each pathosystem are distinct. They depend on the ecological interplay of plant, pathogen, and vector and on how interactions are affected by biotic and abiotic factors, including anthropogenic activities and policy decisions. Our goal with this review is to stimulate discussion and novel research by contextualizing available knowledge on X. fastidiosa and how it may be applicable to emerging diseases.
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Affiliation(s)
- Anne Sicard
- Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720, USA;
- Biologie et Génétique des Interactions Plant-Parasite, UMR 0385, Centre de Coopération Internationale en Recherche Agronomique pour le Développement-Institut National de la Recherche Agronomique-Montpellier SupAgro, Campus International de Baillarguet, 34398 Montpellier CEDEX 05, France
| | - Adam R Zeilinger
- Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720, USA;
| | - Mathieu Vanhove
- Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720, USA;
| | - Tyler E Schartel
- Department of Entomology, University of California, Riverside, California 92521, USA
| | - Dylan J Beal
- Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720, USA;
| | - Matthew P Daugherty
- Department of Entomology, University of California, Riverside, California 92521, USA
| | - Rodrigo P P Almeida
- Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720, USA;
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Arora AK, Pesko KN, Quintero-Hernández V, Possani LD, Miller TA, Durvasula RV. A paratransgenic strategy to block transmission of Xylella fastidiosa from the glassy-winged sharpshooter Homalodisca vitripennis. BMC Biotechnol 2018; 18:50. [PMID: 30134885 PMCID: PMC6104007 DOI: 10.1186/s12896-018-0460-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 08/02/2018] [Indexed: 01/08/2023] Open
Abstract
Background Arthropod-borne diseases remain a leading cause of human morbidity and mortality and exact an enormous toll on global agriculture. The practice of insecticide-based control is fraught with issues of excessive cost, human and environmental toxicity, unwanted impact on beneficial insects and selection of resistant insects. Efforts to modulate insects to eliminate pathogen transmission have gained some traction and remain future options for disease control. Results Here, we report a paratransgenic strategy that targets transmission of Xylella fastidiosa, a leading bacterial pathogen of agriculture, by the Glassy-Winged Sharpshooter (GWSS), Homalodisca vitripennis. Earlier, we identified Pantoea agglomerans, a bacterial symbiont of the GWSS as the paratransgenic control agent. We genetically engineered P. agglomerans to express two antimicrobial peptides (AMP)-melittin and scorpine-like molecule (SLM). Melittin and SLM were chosen as the effector molecules based on in vitro studies, which showed that both molecules have anti-Xylella activity at concentrations that did not kill P. agglomerans. Using these AMP-expressing strains of P. agglomerans, we demonstrated disruption of pathogen transmission from insects to grape plants below detectable levels. Conclusion This is the first report of halting pathogen transmission from paratransgenically modified insects. It is also the first demonstration of paratransgenic control in an agriculturally important insect vector. Electronic supplementary material The online version of this article (10.1186/s12896-018-0460-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Arinder K Arora
- Department of Biology, University of New Mexico, Albuquerque, NM-87131, USA.,Department of Entomology, Cornell University, Ithaca, NY-48153, USA
| | - Kendra N Pesko
- Molecular Biology, Scientific Laboratory Division, New Mexico Dept. of Health, Albuquerque, NM-87102, USA
| | - Verónica Quintero-Hernández
- Departamento de Medicina Molecular, Instituto de Biotecnologia, Universidad Nacional Autonoma de Mexico, Av. Universidad, 2001, Colonia Chamilpa, 62210, Cuernavaca, Morelos, Mexico.,CONACYT-Laboratorio de Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas-Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, Col. San Manuel, C.P. 72570, Puebla, Puebla, Mexico
| | - Lourival D Possani
- Departamento de Medicina Molecular, Instituto de Biotecnologia, Universidad Nacional Autonoma de Mexico, Av. Universidad, 2001, Colonia Chamilpa, 62210, Cuernavaca, Morelos, Mexico
| | - Thomas A Miller
- Department of Entomology, University of California, Riverside, CA-92521, USA
| | - Ravi V Durvasula
- Present Address: Department of Medicine, Loyola University Stritch School of Medicine, Maywood, IL-60153, USA.
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Soubeyrand S, de Jerphanion P, Martin O, Saussac M, Manceau C, Hendrikx P, Lannou C. Inferring pathogen dynamics from temporal count data: the emergence of Xylella fastidiosa in France is probably not recent. THE NEW PHYTOLOGIST 2018; 219:824-836. [PMID: 29689134 PMCID: PMC6032966 DOI: 10.1111/nph.15177] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 03/16/2018] [Indexed: 05/08/2023]
Abstract
Unravelling the ecological structure of emerging plant pathogens persisting in multi-host systems is challenging. In such systems, observations are often heterogeneous with respect to time, space and host species, and may lead to biases of perception. The biased perception of pathogen ecology may be exacerbated by hidden fractions of the whole host population, which may act as infection reservoirs. We designed a mechanistic-statistical approach to help understand the ecology of emerging pathogens by filtering out some biases of perception. This approach, based on SIR (Susceptible-Infected-Removed) models and a Bayesian framework, disentangles epidemiological and observational processes underlying temporal counting data. We applied our approach to French surveillance data on Xylella fastidiosa, a multi-host pathogenic bacterium recently discovered in Corsica, France. A model selection led to two diverging scenarios: one scenario without a hidden compartment and an introduction around 2001, and the other with a hidden compartment and an introduction around 1985. Thus, Xylella fastidiosa was probably introduced into Corsica much earlier than its discovery, and its control could be arduous under the hidden compartment scenario. From a methodological perspective, our approach provides insights into the dynamics of emerging plant pathogens and, in particular, the potential existence of infection reservoirs.
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Affiliation(s)
| | | | | | - Mathilde Saussac
- Unit of Coordination and Support to SurveillanceANSES69364LyonFrance
| | | | - Pascal Hendrikx
- Unit of Coordination and Support to SurveillanceANSES69364LyonFrance
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Martinelli F, Marchese A, Giovino A, Marra FP, Della Noce I, Caruso T, Dandekar AM. In-Field and Early Detection of Xylella fastidiosa Infections in Olive Using a Portable Instrument. FRONTIERS IN PLANT SCIENCE 2018; 9:2007. [PMID: 30713547 PMCID: PMC6345699 DOI: 10.3389/fpls.2018.02007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 12/31/2018] [Indexed: 05/04/2023]
Affiliation(s)
- Federico Martinelli
- Department of Agricultural Food Forest Sciences, University of Palermo, Palermo, Italy
- *Correspondence: Federico Martinelli
| | - Annalisa Marchese
- Department of Agricultural Food Forest Sciences, University of Palermo, Palermo, Italy
| | - Antonio Giovino
- Council for Agricultural Research and Economics (CREA), Research Centre for Plant Protection and Certification (CREA-DC), Bagheria, Italy
| | - Francesco Paolo Marra
- Department of Agricultural Food Forest Sciences, University of Palermo, Palermo, Italy
| | | | - Tiziano Caruso
- Department of Agricultural Food Forest Sciences, University of Palermo, Palermo, Italy
| | - Abhaya M. Dandekar
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
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Medrano EG, Grauke LJ, Stanford RL, Thompson TE. Evidence for the presence of a bacterial endosymbiont in the pecan scab pathogen Venturia effusa (basyonym: Fusicladium effusum). J Appl Microbiol 2017; 123:491-497. [PMID: 28561954 DOI: 10.1111/jam.13503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 05/10/2017] [Accepted: 05/15/2017] [Indexed: 11/29/2022]
Abstract
AIMS To determine whether Venturia effusa, the causative fungal agent of pecan scab, harbours a bacterial symbiont. METHODS AND RESULTS Venturia effusa isolates were maintained on potato dextrose agar amended with antibiotics (chloramphenicol (100 μg ml-1 ) and tetracycline 100 (μg ml-1 )). Genomic DNA extracted from mycelia was used to target eubacterial 16S rDNA. A 1·4-kbp PCR amplified product using 16S rDNA degenerate primers was cloned, sequenced and found to have 99% identities with Actinobacteria representatives. Attempts to culture the detected bacteria apart from the fungus following agitation and fungal cell lysis were unsuccessful using standard bacteriological media under either aerobic or anaerobic conditions. Fungal structures were visualized using scanning electron microscopy and putative bacterial formations associated with the fungal mycelia were observed. Fluorescence in situ hybridization using 16S rDNA oligonucleotides illuminated spores and portions of the hyphae. CONCLUSIONS This is the first report to provide both molecular microbiological and microscopic evidence in support of the hypothesis that V. effusa harbours endosymbiotic bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY Findings from this research contribute fundamental information regarding the biology of the fungus that may ultimately lead to identifying a target of the pathogen for use in management and/or avoidance strategies.
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Affiliation(s)
- E G Medrano
- Insect Control and Cotton Disease Research Unit, College Station, TX, USA
| | - L J Grauke
- Crop Germplasm Research Unit, College Station, TX, USA
| | - R L Stanford
- Crop Germplasm Research Unit, College Station, TX, USA
| | - T E Thompson
- Crop Germplasm Research Unit, College Station, TX, USA
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Baldi P, La Porta N. Xylella fastidiosa: Host Range and Advance in Molecular Identification Techniques. FRONTIERS IN PLANT SCIENCE 2017; 8:944. [PMID: 28642764 PMCID: PMC5462928 DOI: 10.3389/fpls.2017.00944] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 05/22/2017] [Indexed: 05/05/2023]
Abstract
In the never ending struggle against plant pathogenic bacteria, a major goal is the early identification and classification of infecting microorganisms. Xylella fastidiosa, a Gram-negative bacterium belonging to the family Xanthmonadaceae, is no exception as this pathogen showed a broad range of vectors and host plants, many of which may carry the pathogen for a long time without showing any symptom. Till the last years, most of the diseases caused by X. fastidiosa have been reported from North and South America, but recently a widespread infection of olive quick decline syndrome caused by this fastidious pathogen appeared in Apulia (south-eastern Italy), and several cases of X. fastidiosa infection have been reported in other European Countries. At least five different subspecies of X. fastidiosa have been reported and classified: fastidiosa, multiplex, pauca, sandyi, and tashke. A sixth subspecies (morus) has been recently proposed. Therefore, it is vital to develop fast and reliable methods that allow the pathogen detection during the very early stages of infection, in order to prevent further spreading of this dangerous bacterium. To this purpose, the classical immunological methods such as ELISA and immunofluorescence are not always sensitive enough. However, PCR-based methods exploiting specific primers for the amplification of target regions of genomic DNA have been developed and are becoming a powerful tool for the detection and identification of many species of bacteria. The aim of this review is to illustrate the application of the most commonly used PCR approaches to X. fastidiosa study, ranging from classical PCR, to several PCR-based detection methods: random amplified polymorphic DNA (RAPD), quantitative real-time PCR (qRT-PCR), nested-PCR (N-PCR), immunocapture PCR (IC-PCR), short sequence repeats (SSRs, also called VNTR), single nucleotide polymorphisms (SNPs) and multilocus sequence typing (MLST). Amplification and sequence analysis of specific targets is also mentioned. The fast progresses achieved during the last years in the DNA-based classification of this pathogen are described and discussed and specific primers designed for the different methods are listed, in order to provide a concise and useful tool to all the researchers working in the field.
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Affiliation(s)
- Paolo Baldi
- IASMA Research and Innovation Centre, Fondazione Edmund MachTrento, Italy
| | - Nicola La Porta
- IASMA Research and Innovation Centre, Fondazione Edmund MachTrento, Italy
- MOUNTFOR Project Centre, European Forest InstituteTrento, Italy
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Marcelletti S, Scortichini M. Xylella fastidiosa CoDiRO strain associated with the olive quick decline syndrome in southern Italy belongs to a clonal complex of the subspecies pauca that evolved in Central America. Microbiology (Reading) 2016; 162:2087-2098. [DOI: 10.1099/mic.0.000388] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Simone Marcelletti
- Council for Agricultural Research and Analysis of Agricultural Economics (CREA), Research Centre for Fruit Trees, Via di Fioranello 52, I-00134 Roma, Italy
| | - Marco Scortichini
- Council for Agricultural Research and Analysis of Agricultural Economics (CREA), Research Centre for Fruit Trees, Via Torrino 3, I-81100 Caserta, Italy
- Council for Agricultural Research and Analysis of Agricultural Economics (CREA), Research Centre for Fruit Trees, Via di Fioranello 52, I-00134 Roma, Italy
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Perilla-Henao LM, Casteel CL. Vector-Borne Bacterial Plant Pathogens: Interactions with Hemipteran Insects and Plants. FRONTIERS IN PLANT SCIENCE 2016; 7:1163. [PMID: 27555855 PMCID: PMC4977473 DOI: 10.3389/fpls.2016.01163] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 07/20/2016] [Indexed: 05/22/2023]
Abstract
Hemipteran insects are devastating pests of crops due to their wide host range, rapid reproduction, and ability to transmit numerous plant-infecting pathogens as vectors. While the field of plant-virus-vector interactions has flourished in recent years, plant-bacteria-vector interactions remain poorly understood. Leafhoppers and psyllids are by far the most important vectors of bacterial pathogens, yet there are still significant gaps in our understanding of their feeding behavior, salivary secretions, and plant responses as compared to important viral vectors, such as whiteflies and aphids. Even with an incomplete understanding of plant-bacteria-vector interactions, some common themes have emerged: (1) all known vector-borne bacteria share the ability to propagate in the plant and insect host; (2) particular hemipteran families appear to be incapable of transmitting vector-borne bacteria; (3) all known vector-borne bacteria have highly reduced genomes and coding capacity, resulting in host-dependence; and (4) vector-borne bacteria encode proteins that are essential for colonization of specific hosts, though only a few types of proteins have been investigated. Here, we review the current knowledge on important vector-borne bacterial pathogens, including Xylella fastidiosa, Spiroplasma spp., Liberibacter spp., and 'Candidatus Phytoplasma spp.'. We then highlight recent approaches used in the study of vector-borne bacteria. Finally, we discuss the application of this knowledge for control and future directions that will need to be addressed in the field of vector-plant-bacteria interactions.
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Affiliation(s)
| | - Clare L. Casteel
- Department of Plant Pathology, University of California at Davis, Davis, CAUSA
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Giampetruzzi A, Morelli M, Saponari M, Loconsole G, Chiumenti M, Boscia D, Savino VN, Martelli GP, Saldarelli P. Transcriptome profiling of two olive cultivars in response to infection by the CoDiRO strain of Xylella fastidiosa subsp. pauca. BMC Genomics 2016; 17:475. [PMID: 27350531 PMCID: PMC4924284 DOI: 10.1186/s12864-016-2833-9] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 06/13/2016] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND The recent Xylella fastidiosa subsp. pauca (Xfp) outbreak in olive (Olea europaea) groves in southern Italy is causing a destructive disease denoted Olive Quick Decline Syndrome (OQDS). Field observations disclosed that Xfp-infected plants of cv. Leccino show much milder symptoms, than the more widely grown and highly susceptible cv. Ogliarola salentina. To determine whether these field observations underlie a tolerant condition of cv. Leccino, which could be exploited for lessening the economic impact of the disease on the local olive industry, transcriptional changes occurring in plants of the two cultivars affected by Xfp were investigated. RESULTS A global quantitative transcriptome profiling comparing susceptible (Ogliarola salentina) and tolerant (Leccino) olive cultivars, infected or not by Xfp, was done on messenger RNA (mRNAs) extracted from xylem tissues. The study revealed that 659 and 447 genes were differentially regulated in cvs Leccino and Ogliarola upon Xfp infection, respectively, whereas 512 genes were altered when the transcriptome of both infected cultivars was compared. Analysis of these differentially expressed genes (DEGs) shows that the presence of Xfp is perceived by the plants of both cultivars, in which it triggers a differential response strongly involving the cell wall. Up-regulation of genes encoding receptor-like kinases (RLK) and receptor-like proteins (RLP) is the predominant response of cv. Leccino, which is missing in cv. Ogliarola salentina. Moreover, both cultivars react with a strong re-modelling of cell wall proteins. These data suggest that Xfp elicits a different transcriptome response in the two cultivars, which determines a lower pathogen concentration in cv. Leccino and indicates that this cultivar may harbor genetic constituents and/or regulatory elements which counteract Xfp infection. CONCLUSIONS Collectively these findings suggest that cv. Leccino is endowed with an intrinsic tolerance to Xfp, which makes it eligible for further studies aiming at investigating molecular basis and pathways modulating its different defense response.
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Affiliation(s)
- Annalisa Giampetruzzi
- />Dipartimento di Scienze del Suolo della Pianta e degli Alimenti, Università degli Studi di Bari Aldo Moro, via Amendola 165/A, Bari, Italy
| | - Massimiliano Morelli
- />Consiglio Nazionale delle Ricerche, Istituto per la Protezione Sostenibile delle Piante, SS Bari, via Amendola 122/D, Bari, Italy
| | - Maria Saponari
- />Consiglio Nazionale delle Ricerche, Istituto per la Protezione Sostenibile delle Piante, SS Bari, via Amendola 122/D, Bari, Italy
| | - Giuliana Loconsole
- />Dipartimento di Scienze del Suolo della Pianta e degli Alimenti, Università degli Studi di Bari Aldo Moro, via Amendola 165/A, Bari, Italy
| | - Michela Chiumenti
- />Consiglio Nazionale delle Ricerche, Istituto per la Protezione Sostenibile delle Piante, SS Bari, via Amendola 122/D, Bari, Italy
| | - Donato Boscia
- />Consiglio Nazionale delle Ricerche, Istituto per la Protezione Sostenibile delle Piante, SS Bari, via Amendola 122/D, Bari, Italy
| | - Vito N. Savino
- />Dipartimento di Scienze del Suolo della Pianta e degli Alimenti, Università degli Studi di Bari Aldo Moro, via Amendola 165/A, Bari, Italy
| | - Giovanni P. Martelli
- />Dipartimento di Scienze del Suolo della Pianta e degli Alimenti, Università degli Studi di Bari Aldo Moro, via Amendola 165/A, Bari, Italy
| | - Pasquale Saldarelli
- />Consiglio Nazionale delle Ricerche, Istituto per la Protezione Sostenibile delle Piante, SS Bari, via Amendola 122/D, Bari, Italy
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Bosso L, Di Febbraro M, Cristinzio G, Zoina A, Russo D. Shedding light on the effects of climate change on the potential distribution of Xylella fastidiosa in the Mediterranean basin. Biol Invasions 2016. [DOI: 10.1007/s10530-016-1118-1] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Almeida RPP, Nunney L. How Do Plant Diseases Caused by Xylella fastidiosa Emerge? PLANT DISEASE 2015; 99:1457-1467. [PMID: 30695952 DOI: 10.1094/pdis-02-15-0159-fe] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Emerging plant diseases frequently have significant economic, environmental, cultural, and social impacts. The prediction of new disease emergence, associated with new pathogens or not, remains a difficult and controversial topic. The main factors driving epidemics are often only identified several years after outbreaks, generally revealing that a limited number of factors are associated with the emergence of specific groups of pathogens. This pattern is illustrated in the insect-borne xylem-limited bacterium Xylella fastidiosa, an organism associated with several new plant diseases in different regions of the globe. Research during the last decade focusing on several severe disease outbreaks has led to substantial changes in our understanding of X. fastidiosa biology, ecology, and evolution. This new information has not only led to new insights into aspects of the biology of this bacterium and its interactions with plant and insect hosts, but also made available a phylogenetic framework that has allowed for better inferences concerning factors leading to the emergence of diseases. Here we identify and discuss these main pathways leading to epidemics caused by X. fastidiosa. Our ultimate goal was to raise critical questions and issues for academics and regulatory agencies alike, since the information generated during the last decade has both raised new questions but also clarified old ones.
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Affiliation(s)
- Rodrigo P P Almeida
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720
| | - Leonard Nunney
- Department of Biology, University of California, Riverside, CA 92521
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Lamichhane JR, Venturi V. Synergisms between microbial pathogens in plant disease complexes: a growing trend. FRONTIERS IN PLANT SCIENCE 2015; 6:385. [PMID: 26074945 PMCID: PMC4445244 DOI: 10.3389/fpls.2015.00385] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 05/13/2015] [Indexed: 05/20/2023]
Abstract
Plant diseases are often thought to be caused by one species or even by a specific strain. Microbes in nature, however, mostly occur as part of complex communities and this has been noted since the time of van Leeuwenhoek. Interestingly, most laboratory studies focus on single microbial strains grown in pure culture; we were therefore unaware of possible interspecies and/or inter-kingdom interactions of pathogenic microbes in the wild. In human and animal infections, it is now being recognized that many diseases are the result of multispecies synergistic interactions. This increases the complexity of the disease and has to be taken into consideration in the development of more effective control measures. On the other hand, there are only a few reports of synergistic pathogen-pathogen interactions in plant diseases and the mechanisms of interactions are currently unknown. Here we review some of these reports of synergism between different plant pathogens and their possible implications in crop health. Finally, we briefly highlight the recent technological advances in diagnostics as these are beginning to provide important insights into the microbial communities associated with complex plant diseases. These examples of synergistic interactions of plant pathogens that lead to disease complexes might prove to be more common than expected and understanding the underlying mechanisms might have important implications in plant disease epidemiology and management.
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Affiliation(s)
| | - Vittorio Venturi
- International Centre for Genetic Engineering and BiotechnologyTrieste, Italy
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Scientific Opinion on the risks to plant health posed byXylella fastidiosain the EU territory, with the identification and evaluation of risk reduction options. EFSA J 2015. [DOI: 10.2903/j.efsa.2015.3989] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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45
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Statement of EFSA on host plants, entry and spread pathways and risk reduction options for Xylella fastidiosa Wells et al. EFSA J 2013. [DOI: 10.2903/j.efsa.2013.3468] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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