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Zecharia N, Miri V, Dror O, Hatib K, Holland D, Dani S, Bahar O. Seasonal Dynamics and Distribution of Xylella fastidiosa in Infected Almond Trees. PHYTOPATHOLOGY 2024:PHYTO07230240R. [PMID: 38105220 DOI: 10.1094/phyto-07-23-0240-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
This research focused on studying the dynamics of the bacterial pathogen Xylella fastidiosa in almond trees across different developmental stages. The objective was to understand the seasonal distribution and concentration of X. fastidiosa within almond trees. Different tree organs, including leaves, shoots, branches, fruits, flowers, and roots, from 10 X. fastidiosa-infected almond trees were sampled over 2 years. The incidence and concentration of X. fastidiosa were determined using qPCR and isolation. Throughout the study, X. fastidiosa was consistently absent from fruits, flowers, and roots, whereas it was detected in leaves as well as in shoots and branches. We demonstrate that the absence of X. fastidiosa in the roots is likely linked to the inability of this isolate to infect the peach-almond hybrid rootstock GF677. X. fastidiosa incidence in shoots and branches remained consistent throughout the year, whereas in leaf petioles, it varied across developmental stages, with lower detection during the early and late stages of the season. Similarly, viable X. fastidiosa cells were isolated from shoots and branches at all developmental stages, but no successful isolations were achieved from leaf petioles during the vegetative and nut growth stage. Studying the progression of almond leaf scorch symptoms in trees with initial infections showed that once symptoms emerged on one branch, symptomless branches were likely already infected by the bacterium. Therefore, selectively pruning symptomatic branches is unlikely to cure the tree. This study enhances our understanding of X. fastidiosa dynamics in almond trees and may have practical applications for its detection and control.
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Affiliation(s)
- Noa Zecharia
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
- The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Vanunu Miri
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
- The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Orit Dror
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Kamel Hatib
- Newe Ya'ar Research Center, Agricultural Research Organization, Volcani Center, Ramat Yishay, Israel
| | - Doron Holland
- Newe Ya'ar Research Center, Agricultural Research Organization, Volcani Center, Ramat Yishay, Israel
| | - Shtienberg Dani
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Ofir Bahar
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
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Serio F, Imbriani G, Girelli CR, Miglietta PP, Scortichini M, Fanizzi FP. A Decade after the Outbreak of Xylella fastidiosa subsp. pauca in Apulia (Southern Italy): Methodical Literature Analysis of Research Strategies. PLANTS (BASEL, SWITZERLAND) 2024; 13:1433. [PMID: 38891241 PMCID: PMC11175074 DOI: 10.3390/plants13111433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/17/2024] [Accepted: 05/20/2024] [Indexed: 06/21/2024]
Abstract
In 2013, an outbreak of Xylella fastidiosa (Xf) was identified for the first time in Europe, in the extreme south of Italy (Apulia, Salento territory). The locally identified subspecies pauca turned out to be lethal for olive trees, starting an unprecedented phytosanitary emergency for one of the most iconic cultivations of the Mediterranean area. Xf pauca (Xfp) is responsible for a severe disease, the olive quick decline syndrome (OQDS), spreading epidemically and with dramatic impact on the agriculture, the landscape, the tourism and the cultural heritage of this region. The bacterium, transmitted by insects that feed on xylem sap, causes rapid wilting in olive trees due to biofilm formation, which obstructs the plant xylematic vessels. The aim of this review is to perform a thorough analysis that offers a general overview of the published work, from 2013 to December 2023, related to the Xfp outbreak in Apulia. This latter hereto has killed millions of olive trees and left a ghostly landscape with more than 8000 square kilometers of infected territory, that is 40% of the region. The majority of the research efforts made to date to combat Xfp in olive plants are listed in the present review, starting with the early attempts to identify the bacterium, the investigations to pinpoint and possibly control the vector, the assessment of specific diagnostic techniques and the pioneered therapeutic approaches. Interestingly, according to the general set criteria for the preliminary examination of the accessible scientific literature related to the Xfp outbreak on Apulian olive trees, fewer than 300 papers can be found over the last decade. Most of them essentially emphasize the importance of developing diagnostic tools that can identify the disease early, even when infected plants are still asymptomatic, in order to reduce the risk of infection for the surrounding plants. On the other hand, in the published work, the diagnostic focus (57%) overwhelmingly encompasses all other possible investigation goals such as vectors, impacts and possible treatments. Notably, between 2013 and 2023, only 6.3% of the literature reports addressing the topic of Xfp in Apulia were concerned with the application of specific treatments against the bacterium. Among them, those reporting field trials on infected plants, including simple pruning indications, were further limited (6%).
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Affiliation(s)
- Francesca Serio
- Department of Biological and Environmental Sciences and Technology, University of Salento, 73100 Lecce, Italy; (F.S.); (G.I.); (C.R.G.); (P.P.M.)
| | - Giovanni Imbriani
- Department of Biological and Environmental Sciences and Technology, University of Salento, 73100 Lecce, Italy; (F.S.); (G.I.); (C.R.G.); (P.P.M.)
| | - Chiara Roberta Girelli
- Department of Biological and Environmental Sciences and Technology, University of Salento, 73100 Lecce, Italy; (F.S.); (G.I.); (C.R.G.); (P.P.M.)
| | - Pier Paolo Miglietta
- Department of Biological and Environmental Sciences and Technology, University of Salento, 73100 Lecce, Italy; (F.S.); (G.I.); (C.R.G.); (P.P.M.)
| | - Marco Scortichini
- Council for Agricultural Research and Economics (CREA)-Research Centre for Olive, Fruit and Citrus Crops, Via di Fioranello, 52, 00134 Roma, Italy;
| | - Francesco Paolo Fanizzi
- Department of Biological and Environmental Sciences and Technology, University of Salento, 73100 Lecce, Italy; (F.S.); (G.I.); (C.R.G.); (P.P.M.)
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Bodino N, Cavalieri V, Dongiovanni C, Saponari M, Bosco D. Bioecological Traits of Spittlebugs and Their Implications for the Epidemiology and Control of the Xylella fastidiosa Epidemic in Apulia (Southern Italy). PHYTOPATHOLOGY 2023; 113:1647-1660. [PMID: 36945728 DOI: 10.1094/phyto-12-22-0460-ia] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Spatial-temporal dynamics of spittlebug populations, together with transmission biology, are of major importance to outline the disease epidemiology of Xylella fastidiosa subsp. pauca in Apulian olive groves. The spread rate of X. fastidiosa is mainly influenced by (i) the pathogen colonization of the host plant; (ii) the acquisition of the pathogen by the vector from an infected plant, and its inoculation to healthy plants; (iii) the vector population dynamics and abundance at different spatial scales; and (iv) the dispersal of the vector. In this contribution we summarize the recent advances in research on insect vectors' traits-points ii, iii, and iv-focusing on those most relevant to X. fastidiosa epidemic in Apulia. Among the vectors' bioecological traits influencing the X. fastidiosa epidemic in olive trees, we emphasize the following: natural infectivity and transmission efficiency, phenological timing of both nymphal and adult stage, the role of seminatural vegetation as a vector reservoir in the agroecosystem and landscape, and preferential and directional dispersal capabilities. Despite the research on X. fastidiosa vectors carried out in Europe in the last decade, key uncertainties on insect vectors remain, hampering a thorough understanding of pathogen epidemiology and the development of effective and targeted management strategies. Our goal is to provide a structured and contextualized review of knowledge on X. fastidiosa vectors' key traits in the Apulian epidemic, highlighting information gaps and stimulating novel research pathways on X. fastidiosa pathosystems in Europe. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Nicola Bodino
- CNR-Istituto per la Protezione Sostenibile delle Piante, 10135 Torino, Italy
| | - Vincenzo Cavalieri
- CNR-Istituto per la Protezione Sostenibile delle Piante, SS Bari, 70126 Bari, Italy
| | - Crescenza Dongiovanni
- CRSFA-Centro di Ricerca, Sperimentazione e Formazione in Agricoltura Basile Caramia, 70010 Locorotondo (BA), Italy
| | - Maria Saponari
- CNR-Istituto per la Protezione Sostenibile delle Piante, SS Bari, 70126 Bari, Italy
| | - Domenico Bosco
- CNR-Istituto per la Protezione Sostenibile delle Piante, 10135 Torino, Italy
- Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università degli Studi di Torino, 10095 Grugliasco (TO), Italy
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Kahn AK, Sicard A, Cooper ML, Daugherty MP, Donegan MA, Almeida RPP. Progression of Xylella fastidiosa Infection in Grapevines Under Field Conditions. PHYTOPATHOLOGY 2023; 113:1465-1473. [PMID: 37080548 DOI: 10.1094/phyto-01-23-0008-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The pathogen Xylella fastidiosa subsp. fastidiosa has circulated through California's vineyards since its introduction from Central America in the 1800s. This pathogen is responsible for a bacterial disease called Pierce's disease (PD) of grapevine. With no known cure, PD has had devastating effects on some vineyards. Important factors that impact disease severity and persistence include: the presence of insect vectors, grapevine cultivar, management, ecology, and winter temperatures. Removal of infected vines is critical for reducing pathogen spread but relies on accurate and rapid pathogen detection. In this study, we foster a greater understanding of disease symptom emergence by way of a 3-year field inoculation project in Napa Valley. Although PD emergence and symptom progression have been studied in greenhouse and experimental plots, there is a large knowledge gap in quantifying disease progression under commercial conditions. After inoculating 80 mature Vitis vinifera vines in April 2017, we measured bacterial populations and six symptom types at four locations within each plant throughout the subsequent three growing seasons. The main foci of the project were understanding X. fastidiosa movement through the plants, infection, overwinter curing, and symptom development. We observed greater winter recovery than expected, and shriveled grape clusters proved to be a more reliable early indication of infection than other more commonly used symptoms. Although there were differences among wine grape cultivars, this work suggests that disease progression in the field may not fit the paradigm of predominant leaf scorch and low recovery rates as neatly as has been previously believed.
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Affiliation(s)
- Alexandra K Kahn
- Department of Environmental Science, Policy, and Management, University of California Berkeley, CA 94720
| | - Anne Sicard
- Department of Environmental Science, Policy, and Management, University of California Berkeley, CA 94720
| | - Monica L Cooper
- Division of Agriculture and Natural Resources, University of California, Cooperative Extension, Napa, CA 94559
| | | | - Monica A Donegan
- Department of Environmental Science, Policy, and Management, University of California Berkeley, CA 94720
| | - Rodrigo P P Almeida
- Department of Environmental Science, Policy, and Management, University of California Berkeley, CA 94720
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Roddee J, Backus EA, Cervantes FA, Hanboonsong Y. Xylella fastidiosa inoculation behaviors (EPG X wave) are performed differently by blue-green sharpshooters based on infection status of prior probing host. JOURNAL OF ECONOMIC ENTOMOLOGY 2023; 116:697-712. [PMID: 36988102 DOI: 10.1093/jee/toad043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 12/22/2022] [Accepted: 02/17/2023] [Indexed: 06/14/2023]
Abstract
Does Xylella fastidiosa, a bacterial plant pathogen with noncirculative foregut-borne transmission, manipulate behavior of its sharpshooter vector to facilitate its own inoculation? To answer this question, blue-green sharpshooters, Graphocephala atropunctata (Signoret), were reared on basil to clean their foreguts, then removed from the colony and given one of four pre-electropenetrography (EPG) treatments: i) old colony adults on basil, ii) young colony adults on basil, iii) young colony adults held on healthy grapevine for 4 days, and iv) young colony adults held on Xf-infected (symptomatic) grapevine for 4 days. After treatments, stylet probing behaviors were recorded on healthy grapevine via AC-DC electropenetrography. Waveforms representing putative Xf inoculation (XB1 [salivation and rinsing egestion] and XC1 [discharging egestion]) and other behaviors were statistically compared among treatments. Mean number of events per insect and 'total' duration per insect of XB1 and XC1 were highest for insects from healthy grape, lowest for basil (regardless of insect age), and intermediate for Xf-infected grape. The surprising results showed that prior exposure to healthy grapevines had a stronger effect on subsequent performance of inoculation behaviors on healthy grapevine than did prior exposure to Xf-infected grapevine. It is hypothesized that non-Xf microbes were acquired from healthy grapevine, causing greater clogging of the precibarium, leading to more performance of inoculation behaviors. This study shows for the first time that presence of noncirculative, foregut-borne microbes can directly manipulate a vector's behavior to increase inoculation. Also, EPG can uniquely visualize the dynamic interactions between vectors and the microbes they carry.
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Affiliation(s)
- Jariya Roddee
- Department of Entomology and Plant Pathology, Faculty of Agriculture, Khon Kaen University, 40002, Khon Kaen, Thailand
| | - Elaine A Backus
- USDA Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Avenue, Parlier, CA 93648 - 9757, USA
| | - Felix A Cervantes
- USDA Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Avenue, Parlier, CA 93648 - 9757, USA
| | - Yupa Hanboonsong
- Department of Entomology and Plant Pathology, Faculty of Agriculture, Khon Kaen University, 40002, Khon Kaen, Thailand
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Zecharia N, Krasnov H, Vanunu M, Siri AC, Haberman A, Dror O, Vakal L, Almeida RPP, Blank L, Shtienberg D, Bahar O. Xylella fastidiosa Outbreak in Israel: Population Genetics, Host Range, and Temporal and Spatial Distribution Analysis. PHYTOPATHOLOGY 2022; 112:2296-2309. [PMID: 35778787 DOI: 10.1094/phyto-03-22-0105-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Diseases caused by the insect-transmitted bacterium Xylella fastidiosa have been reported in the Americas since the 19th century, causing diseases such as Pierce's disease of grapevine, almond leaf scorch (ALS), and citrus variegated chlorosis. In the last decade X. fastidiosa was reported from different parts of the world, most notably from southern Italy, infecting olives. In 2017, X. fastidiosa was reported to be associated with ALS symptoms in Israel. Here, we investigated the causal agent of ALS in Israel, its genetic diversity, and host range, and we characterized the temporal and spatial distribution of the disease. X. fastidiosa subsp. fastidiosa sequence type 1 was isolated from symptomatic almond trees and was used to infect almond and grapevine by mechanical inoculation. The pathogen, however, did not infect olive, peach, cherry, plum, nectarine, clementine, and grapefruit plants. Genomic analysis of local isolates revealed that the local population is derived from a single introduction and that they are closely related to X. fastidiosa strains from grapevines in California. Distribution analyses revealed that ALS did not expand from 2017 to 2019; however, since 2020, newly symptomatic trees appeared in the tested orchards. Symptomatic trees were located primarily in clusters, and symptoms tended to spread within rows. Our study confirms that X. fastidiosa is the causal agent of ALS in Israel and describes its genetic and host range characteristics. Although there is no clear evidence yet for the identity of the vectors in Israel, ALS spread continues to threat the almond and grapevine industries in Israel.
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Affiliation(s)
- Noa Zecharia
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
- The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Helena Krasnov
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
| | - Miri Vanunu
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
- The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Andreina Castillo Siri
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA, U.S.A
| | - Ami Haberman
- The Plant Protection and Inspection Services, Ministry of Agriculture and Rural Development, Rishon LeZion, Israel
| | - Orit Dror
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
| | - Lera Vakal
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
| | - Rodrigo P P Almeida
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA, U.S.A
| | - Lior Blank
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
| | - Dani Shtienberg
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
| | - Ofir Bahar
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
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Sicard A, Saponari M, Vanhove M, Castillo AI, Giampetruzzi A, Loconsole G, Saldarelli P, Boscia D, Neema C, Almeida RPP. Introduction and adaptation of an emerging pathogen to olive trees in Italy. Microb Genom 2021; 7. [PMID: 34904938 PMCID: PMC8767334 DOI: 10.1099/mgen.0.000735] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The invasive plant pathogen Xylella fastidiosa currently threatens European flora through the loss of economically and culturally important host plants. This emerging vector-borne bacterium, native to the Americas, causes several important diseases in a wide range of plants including crops, ornamentals, and trees. Previously absent from Europe, and considered a quarantine pathogen, X. fastidiosa was first detected in Apulia, Italy in 2013 associated with a devastating disease of olive trees (Olive Quick Decline Syndrome, OQDS). OQDS has led to significant economic, environmental, cultural, as well as political crises. Although the biology of X. fastidiosa diseases have been studied for over a century, there is still no information on the determinants of specificity between bacterial genotypes and host plant species, which is particularly relevant today as X. fastidiosa is expanding in the naive European landscape. We analysed the genomes of 79 X. fastidiosa samples from diseased olive trees across the affected area in Italy as well as genomes of the most genetically closely related strains from Central America. We provided insights into the ecological and evolutionary emergence of this pathogen in Italy. We first showed that the outbreak in Apulia is due to a single introduction from Central America that we estimated to have occurred in 2008 [95 % HPD: 1930–2016]. By using a combination of population genomic approaches and evolutionary genomics methods, we further identified a short list of genes that could play a major role in the adaptation of X. fastidiosa to this new environment. We finally provided experimental evidence for the adaptation of the strain to this new environment.
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Affiliation(s)
- Anne Sicard
- UC Berkeley, Department of Environmental Science, Policy, and Management, Berkeley, CA 94720, U.S.A.,PHIM Plant Health Institute, Univ Montpellier, INRAE, Institut Agro, CIRAD, IRD, Montpellier, France
| | - Maria Saponari
- National Research Council (CNR), Institute for Sustainable Plant Protection, Via Amendola 122/D, 70126 Bari, Italy
| | - Mathieu Vanhove
- UC Berkeley, Department of Environmental Science, Policy, and Management, Berkeley, CA 94720, U.S.A
| | - Andreina I Castillo
- UC Berkeley, Department of Environmental Science, Policy, and Management, Berkeley, CA 94720, U.S.A
| | - Annalisa Giampetruzzi
- University of Bari Aldo Moro, Department of Soil, Plant and Food Sciences, Piazza Umberto I, 70121 Bari, Italy
| | - Giuliana Loconsole
- National Research Council (CNR), Institute for Sustainable Plant Protection, Via Amendola 122/D, 70126 Bari, Italy
| | - Pasquale Saldarelli
- National Research Council (CNR), Institute for Sustainable Plant Protection, Via Amendola 122/D, 70126 Bari, Italy
| | - Donato Boscia
- National Research Council (CNR), Institute for Sustainable Plant Protection, Via Amendola 122/D, 70126 Bari, Italy
| | - Claire Neema
- PHIM Plant Health Institute, Univ Montpellier, INRAE, Institut Agro, CIRAD, IRD, Montpellier, France
| | - Rodrigo P P Almeida
- UC Berkeley, Department of Environmental Science, Policy, and Management, Berkeley, CA 94720, U.S.A
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Picciotti U, Lahbib N, Sefa V, Porcelli F, Garganese F. Aphrophoridae Role in Xylella fastidiosa subsp. pauca ST53 Invasion in Southern Italy. Pathogens 2021; 10:1035. [PMID: 34451499 PMCID: PMC8399165 DOI: 10.3390/pathogens10081035] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 12/03/2022] Open
Abstract
The Philaenus spumarius L. (Hemiptera Aphrophoridae) is a xylem-sap feeder vector that acquires Xylella fastidiosa subsp. pauca ST53 during feeding on infected plants. The bacterium is the plant pathogen responsible for olive quick decline syndrome that has decimated olive trees in Southern Italy. Damage originates mainly from the insect vector attitude that multiplies the pathogen potentialities propagating Xf in time and space. The principal action to manage insect-borne pathogens and to contain the disease spread consists in vector and transmission control. The analysis of an innovative and sustainable integrated pest management quantitative strategy that targets the vector and the infection by combining chemical and physical control means demonstrates that it is possible to stop the Xylella invasion. This review updates the available topics addressing vectors' identification, bionomics, infection management, and induced disease by Xylella invasion to discuss major available tools to mitigate the damage consequent to the disease.
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Affiliation(s)
- Ugo Picciotti
- Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari Aldo Moro, 70126 Bari, Italy; (U.P.); (N.L.); (V.S.); (F.G.)
- Department of Marine Science and Applied Biology, Laboratory of Plant Pathology, University of Alicante, 03080 Alicante, Spain
| | - Nada Lahbib
- Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari Aldo Moro, 70126 Bari, Italy; (U.P.); (N.L.); (V.S.); (F.G.)
- Faculty of Sciences of Tunis, University of Tunis El-Manar, Tunis 1068, Tunisia
- INRAT—National Institute of Agronomic Research of Tunisia, Laboratory of Plant Protection, Rue Hédi Karray, Ariana 2049, Tunisia
| | - Valdete Sefa
- Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari Aldo Moro, 70126 Bari, Italy; (U.P.); (N.L.); (V.S.); (F.G.)
| | - Francesco Porcelli
- Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari Aldo Moro, 70126 Bari, Italy; (U.P.); (N.L.); (V.S.); (F.G.)
- CIHEAM—Centre International de Hautes Etudes Agronomiques Méditerranéennes, Mediterranean Agronomic Institute of Bari, 70010 Valenzano, BA, Italy
| | - Francesca Garganese
- Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari Aldo Moro, 70126 Bari, Italy; (U.P.); (N.L.); (V.S.); (F.G.)
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Zeilinger AR, Wallis CM, Beal D, Sicard A, Walker MA, Almeida RPP. Plant defense against a pathogen drives nonlinear transmission dynamics through both vector preference and acquisition. Ecosphere 2021. [DOI: 10.1002/ecs2.3505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Adam R. Zeilinger
- Department of Environmental Science, Policy, and Management University of California Berkeley Berkeley California94720USA
| | - Christopher M. Wallis
- Crop Diseases, Pests and Genetics Research Unit USDA‐ARS San Joaquin Valley Agricultural Sciences Center 9611 South Riverbend Avenue Parlier California93648USA
| | - Dylan Beal
- Department of Environmental Science, Policy, and Management University of California Berkeley Berkeley California94720USA
| | - Anne Sicard
- Department of Environmental Science, Policy, and Management University of California Berkeley Berkeley California94720USA
| | - M. Andrew Walker
- Department of Viticulture and Enology University of California Davis Davis California95616USA
| | - Rodrigo P. P. Almeida
- Department of Environmental Science, Policy, and Management University of California Berkeley Berkeley California94720USA
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Beal DJ, Cooper M, Daugherty MP, Purcell AH, Almeida RPP. Seasonal Abundance and Infectivity of Philaenus spumarius (Hemiptera: Aphrophoridae), a Vector of Xylella fastidiosa in California Vineyards. ENVIRONMENTAL ENTOMOLOGY 2021; 50:467-476. [PMID: 33399197 DOI: 10.1093/ee/nvaa178] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Indexed: 06/12/2023]
Abstract
The meadow spittlebug, Philaenus spumarius (Linnaeus) (Hemiptera: Aphrophoridae), is a vector of the plant pathogen Xylella fastidiosa; however, its role in recent outbreaks of Pierce's disease of grapevine (PD) in California is unclear. While the phenology and ecology of P. spumarius can help determine its contributions to PD epidemics, both remain poorly described in the North Coast vineyards of California. We assessed the phenology of P. spumarius in the region. Spittlemasses were first observed in February or March, while the emergence of adult spittlebugs did not occur until April or May depending on the year. Analysis of sweep and trap data from 2016 to 2018 revealed significant effects of survey month, vineyard site, and year on adult abundance in sweep and trap surveys. Spittlebug adults were present in the vineyards from April until December, with the greatest number of adults by sweep net in May or June, whereas adults on traps peaked between July and November. Analysis of natural infectivity in groups of field-collected spittlebug adults showed significant difference in transmission rates among months. Spittlebugs successfully transmitted Xylella fastidiosa (Wells) (Xanthomonadales: Xanthomonadaceae) to potted grapevines between July and December. The greatest risk of X. fastidiosa transmission by P. spumarius was in December (60%) followed by October (30%). However, the infectivity patterns of the meadow spittlebug did not align with the historical paradigm of California North Coast PD. We discuss alternative hypotheses in which P. spumarius could play a role in the epidemiology of this disease.
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Affiliation(s)
- Dylan J Beal
- Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA
| | - Monica Cooper
- Division of Agriculture and Natural Resources, University of California, Cooperative Extension, Napa, CA
| | - Matthew P Daugherty
- Department of Entomology, University of California, Riverside, Riverside, CA
| | - Alexander H Purcell
- Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA
| | - Rodrigo P P Almeida
- Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA
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Lopes SA, Raiol-Júnior LL, Torres SCZ, Martins EC, Prado SS, Beriam LOS. Differential Responses of Tobacco to the Citrus Variegated Chlorosis and Coffee Stem Atrophy Strains of Xylella fastidiosa. PHYTOPATHOLOGY 2020; 110:567-573. [PMID: 31750792 DOI: 10.1094/phyto-10-19-0374-r] [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: 06/10/2023]
Abstract
Xylella fastidiosa comprises a diverse group of xylem-limited, insect-transmitted bacterial pathogens. In Brazil, the citrus variegated chlorosis (CVC) and coffee stem atrophy (CSA) diseases are caused by X. fastidiosa subspecies pauca transmitted by common insect vectors. No simple protocol allowing strain discrimination exists, making epidemiological studies, which are important for devising control measures, difficult to undertake. Here, we show that both strains can easily be distinguished based on the pattern of leaf symptoms that they induce on pin prick-inoculated tobacco seedlings, namely small orange lesions and large necrotic lesions induced by the CVC and CSA strains, respectively. These differential responses allowed us to investigate whether mixed strain infections would occur in citrus or coffee trees in the field. Seedlings were individually inoculated with X. fastidiosa colonies recovered from citrus or coffee plants from various locations at three different times. No mixed infections were detected. In two experiments, the citrus and coffee strains infected only their original hosts as well as tobacco. The usefulness of this tobacco bioassay as a tool to study X. fastidiosa spread was demonstrated. It provided evidence that, over the years, the CVC and CSA pathogens have remained limited to their original hosts, despite crop proximity and the presence of sharpshooter vectors that favor transmission of the bacteria to and between both host species.
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Affiliation(s)
- Silvio A Lopes
- Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil
- Fundo de Defesa da Citricultura, Araraquara, São Paulo, Brazil
| | - Laudecir L Raiol-Júnior
- Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil
- Fundo de Defesa da Citricultura, Araraquara, São Paulo, Brazil
| | | | | | - Simone S Prado
- Empresa Brasileira de Pesquisa Agropecuária, Jaguariuna, São Paulo, Brazil
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12
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Burbank LP, Sisterson MS, O'Leary ML. Infection of Blueberry Cultivar 'Emerald' with a California Pierce's Disease Strain of Xylella fastidiosa and Acquisition by Glassy-Winged Sharpshooter. PLANT DISEASE 2020; 104:154-160. [PMID: 31697223 DOI: 10.1094/pdis-05-19-1126-re] [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: 06/10/2023]
Abstract
Bacterial leaf scorch disease caused by Xylella fastidiosa occurs in southern highbush blueberry varieties in the southeastern United States. Susceptibility to X. fastidiosa varies by blueberry cultivar, and these interactions are often strain-specific. Xylella fastidiosa subsp. fastidiosa is the causal agent of Pierce's disease in grapevines, and it has been problematic in the San Joaquin Valley of California since the introduction of the glassy-winged sharpshooter (Homalodisca vitripennis). The glassy-winged sharpshooter is known to feed on blueberry, a crop that is expanding in the San Joaquin Valley. Currently, little is known about the potential for the spread of X. fastidiosa between grape and blueberry in this region. The ability of a Pierce's disease strain of X. fastidiosa from the San Joaquin Valley to cause disease in southern highbush blueberry and the potential for the glassy-winged sharpshooter to transmit X. fastidiosa between blueberry and grapevine were investigated. Experimental inoculations showed that the X. fastidiosa subsp. fastidiosa strain Bakersfield-1 can cause disease in blueberry cv. Emerald, and that the glassy-winged sharpshooter can acquire X. fastidiosa from artificially inoculated blueberry plants under laboratory conditions. Understanding the possibility for X. fastidiosa strains from the San Joaquin Valley to infect multiple crops grown in proximity is important for area-wide pest and disease management.
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Affiliation(s)
- Lindsey P Burbank
- United States Department of Agriculture, Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648
| | - Mark S Sisterson
- United States Department of Agriculture, Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648
| | - Michael L O'Leary
- United States Department of Agriculture, Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648
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13
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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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14
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Daugherty MP, Almeida RPP. Understanding How an Invasive Vector Drives Pierce's Disease Epidemics: Seasonality and Vine-to-Vine Spread. PHYTOPATHOLOGY 2019; 109:277-285. [PMID: 30451633 DOI: 10.1094/phyto-07-18-0217-fi] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
For vector-borne plant pathogens, disease epidemics may be attributable to multiple mechanisms, including introduction of a novel vector whose epidemiological role differs from that of native vectors. In such cases, understanding an exotic vector's ability to drive an epidemic is central to mitigating its impact. We studied how the invasive glassy-winged sharpshooter (Homalodisca vitripennis Germar) can drive Pierce's disease outbreaks in vineyards, focusing on its potential to promote vine-to-vine (i.e., secondary) spread of Xylella fastidiosa relative to potential constraints stemming from seasonality in the pathosystem. First, we developed a general vector-borne disease model to understand the consequences for disease dynamics of (i) seasonal acquisition efficiency and (ii) seasonal host recovery from infection. Results of the modeling indicate that these two sources of seasonality could constrain disease incidence, particularly when working in concert. Next, we established a field cage experiment to determine whether H. vitripennis promotes vine-to-vine spread, and looked for evidence of seasonality in spread. Broadly, results from the experiment supported assumptions of the model; there was modest to significant increase in the frequency of pathogen spread over the first season, and those new infections that occurred later in the season were more likely to recover during winter. Ultimately, by the end of the second season, there was not evidence of significant secondary spread, likely due to a combination of seasonal constraints and low transmission efficiency by H. vitripennis. Collectively, these results suggest that, although H. vitripennis may be able to promote vine-to-vine spread in certain contexts, it may not be the key factor explaining its impact. Rather, the ability of H. vitripennis to drive epidemics is likely to be more directly related to its potential to reach higher population densities than native vectors.
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Affiliation(s)
- Matthew P Daugherty
- Department of Entomology, University of California, Riverside 92521 and Department of Environmental Science, Policy and Management, University of California, Berkeley 94720
| | - Rodrigo P P Almeida
- Department of Entomology, University of California, Riverside 92521 and Department of Environmental Science, Policy and Management, University of California, Berkeley 94720
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15
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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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16
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Esteves MB, Kleina HT, Sales TDM, Oliveira TP, de Lara IAR, Almeida RPP, Coletta-Filho HD, Lopes JRS. Transmission Efficiency of Xylella fastidiosa subsp. pauca Sequence Types by Sharpshooter Vectors after In Vitro Acquisition. PHYTOPATHOLOGY 2019; 109:286-293. [PMID: 30451635 DOI: 10.1094/phyto-07-18-0254-fi] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Xylella fastidiosa subsp. pauca is genetically diverse and has many vector species. However, there is limited information on vector specificity and efficiency for different sequence types (STs) within the pathogen subspecies. Both STs of X. fastidiosa and vectors differ in their associations with plants; therefore, assessment of vector competence should include the standardized vector acquisition ability of bacteria from artificial diets. This work aimed to adapt and validate an in vitro acquisition system for strains of X. fastidiosa that cause citrus variegated chlorosis, and to compare the transmission efficiency of STs of subsp. pauca by different species of sharpshooter vector. First, acquisition and transmission of ST13 by Bucephalogonia xanthophis and Macugonalia leucomelas was tested using an artificial diet with bacteria grown on minimum defined medium (X. fastidiosa medium) with or without 1% galacturonic acid (GA). Subsequently, four sharpshooter species (B. xanthophis, M. leucomelas, M. cavifrons, and Sibovia sagata) were compared as vectors of ST13 acquired from artificial diets, and four STs of subsp. pauca (11, 13, 65, and 70) were tested for acquisition and transmission by M. leucomelas. The artificial system allowed efficient acquisition and transmission of ST13 to plants, with no differences between the media tested. ST13 was transmitted more efficiently by B. xanthophis and M. leucomelas when compared with M. cavifrons and S. sagata. Different STs influenced acquisition and transmission rates by M. leucomelas. The differences in vector competence, despite the standardized acquisition system, suggest that ST-vector foregut or vector-plant interactions may influence bacterial acquisition, retention and inoculation by the insect.
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Affiliation(s)
- Mariana B Esteves
- First and eighth authors: Departamento de Entomologia e Acarologia, Escola Superior de Agricultura "Luiz de Queiroz" (Esalq), Universidade de São Paulo (USP), Piracicaba, São Paulo (SP), 13418-900, Brazil; second author: Departamento de Fitotecnia e Fitossanitarismo, Universidade Federal do Paraná, Curitiba, Paraná, 80035-050, Brazil; third author: Instituto Federal do Pará, Castanhal, Pará, 68740-970, Brazil; fourth and fifth authors: Departamento de Ciências Exatas, Esalq, USP; sixth author: Department of Environmental Science, Policy, and Management, University of California, Berkeley 94720-3114, USA; and seventh author: Centro de Citricultura "Sylvio Moreira", Instituto Agronômico, Cordeirópolis, SP, 13490-970, Brazil
| | - Heloisa T Kleina
- First and eighth authors: Departamento de Entomologia e Acarologia, Escola Superior de Agricultura "Luiz de Queiroz" (Esalq), Universidade de São Paulo (USP), Piracicaba, São Paulo (SP), 13418-900, Brazil; second author: Departamento de Fitotecnia e Fitossanitarismo, Universidade Federal do Paraná, Curitiba, Paraná, 80035-050, Brazil; third author: Instituto Federal do Pará, Castanhal, Pará, 68740-970, Brazil; fourth and fifth authors: Departamento de Ciências Exatas, Esalq, USP; sixth author: Department of Environmental Science, Policy, and Management, University of California, Berkeley 94720-3114, USA; and seventh author: Centro de Citricultura "Sylvio Moreira", Instituto Agronômico, Cordeirópolis, SP, 13490-970, Brazil
| | - Tiago de Melo Sales
- First and eighth authors: Departamento de Entomologia e Acarologia, Escola Superior de Agricultura "Luiz de Queiroz" (Esalq), Universidade de São Paulo (USP), Piracicaba, São Paulo (SP), 13418-900, Brazil; second author: Departamento de Fitotecnia e Fitossanitarismo, Universidade Federal do Paraná, Curitiba, Paraná, 80035-050, Brazil; third author: Instituto Federal do Pará, Castanhal, Pará, 68740-970, Brazil; fourth and fifth authors: Departamento de Ciências Exatas, Esalq, USP; sixth author: Department of Environmental Science, Policy, and Management, University of California, Berkeley 94720-3114, USA; and seventh author: Centro de Citricultura "Sylvio Moreira", Instituto Agronômico, Cordeirópolis, SP, 13490-970, Brazil
| | - Thiago P Oliveira
- First and eighth authors: Departamento de Entomologia e Acarologia, Escola Superior de Agricultura "Luiz de Queiroz" (Esalq), Universidade de São Paulo (USP), Piracicaba, São Paulo (SP), 13418-900, Brazil; second author: Departamento de Fitotecnia e Fitossanitarismo, Universidade Federal do Paraná, Curitiba, Paraná, 80035-050, Brazil; third author: Instituto Federal do Pará, Castanhal, Pará, 68740-970, Brazil; fourth and fifth authors: Departamento de Ciências Exatas, Esalq, USP; sixth author: Department of Environmental Science, Policy, and Management, University of California, Berkeley 94720-3114, USA; and seventh author: Centro de Citricultura "Sylvio Moreira", Instituto Agronômico, Cordeirópolis, SP, 13490-970, Brazil
| | - Idemauro A R de Lara
- First and eighth authors: Departamento de Entomologia e Acarologia, Escola Superior de Agricultura "Luiz de Queiroz" (Esalq), Universidade de São Paulo (USP), Piracicaba, São Paulo (SP), 13418-900, Brazil; second author: Departamento de Fitotecnia e Fitossanitarismo, Universidade Federal do Paraná, Curitiba, Paraná, 80035-050, Brazil; third author: Instituto Federal do Pará, Castanhal, Pará, 68740-970, Brazil; fourth and fifth authors: Departamento de Ciências Exatas, Esalq, USP; sixth author: Department of Environmental Science, Policy, and Management, University of California, Berkeley 94720-3114, USA; and seventh author: Centro de Citricultura "Sylvio Moreira", Instituto Agronômico, Cordeirópolis, SP, 13490-970, Brazil
| | - Rodrigo P P Almeida
- First and eighth authors: Departamento de Entomologia e Acarologia, Escola Superior de Agricultura "Luiz de Queiroz" (Esalq), Universidade de São Paulo (USP), Piracicaba, São Paulo (SP), 13418-900, Brazil; second author: Departamento de Fitotecnia e Fitossanitarismo, Universidade Federal do Paraná, Curitiba, Paraná, 80035-050, Brazil; third author: Instituto Federal do Pará, Castanhal, Pará, 68740-970, Brazil; fourth and fifth authors: Departamento de Ciências Exatas, Esalq, USP; sixth author: Department of Environmental Science, Policy, and Management, University of California, Berkeley 94720-3114, USA; and seventh author: Centro de Citricultura "Sylvio Moreira", Instituto Agronômico, Cordeirópolis, SP, 13490-970, Brazil
| | - Helvécio D Coletta-Filho
- First and eighth authors: Departamento de Entomologia e Acarologia, Escola Superior de Agricultura "Luiz de Queiroz" (Esalq), Universidade de São Paulo (USP), Piracicaba, São Paulo (SP), 13418-900, Brazil; second author: Departamento de Fitotecnia e Fitossanitarismo, Universidade Federal do Paraná, Curitiba, Paraná, 80035-050, Brazil; third author: Instituto Federal do Pará, Castanhal, Pará, 68740-970, Brazil; fourth and fifth authors: Departamento de Ciências Exatas, Esalq, USP; sixth author: Department of Environmental Science, Policy, and Management, University of California, Berkeley 94720-3114, USA; and seventh author: Centro de Citricultura "Sylvio Moreira", Instituto Agronômico, Cordeirópolis, SP, 13490-970, Brazil
| | - João R S Lopes
- First and eighth authors: Departamento de Entomologia e Acarologia, Escola Superior de Agricultura "Luiz de Queiroz" (Esalq), Universidade de São Paulo (USP), Piracicaba, São Paulo (SP), 13418-900, Brazil; second author: Departamento de Fitotecnia e Fitossanitarismo, Universidade Federal do Paraná, Curitiba, Paraná, 80035-050, Brazil; third author: Instituto Federal do Pará, Castanhal, Pará, 68740-970, Brazil; fourth and fifth authors: Departamento de Ciências Exatas, Esalq, USP; sixth author: Department of Environmental Science, Policy, and Management, University of California, Berkeley 94720-3114, USA; and seventh author: Centro de Citricultura "Sylvio Moreira", Instituto Agronômico, Cordeirópolis, SP, 13490-970, Brazil
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17
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Del Cid C, Krugner R, Zeilinger AR, Daugherty MP, Almeida RPP. Plant Water Stress and Vector Feeding Preference Mediate Transmission Efficiency of a Plant Pathogen. ENVIRONMENTAL ENTOMOLOGY 2018; 47:1471-1478. [PMID: 30247531 DOI: 10.1093/ee/nvy136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Indexed: 06/08/2023]
Abstract
Pathogen spread by arthropod vectors is the outcome of pathogen-vector-plant interactions, as well as how these interactions are impacted by abiotic and biotic factors. While plant water stress impacts each component of the Pierce's disease pathosystem (Xylella fastidiosa Wells et al., insect vectors, and grapevines), the outcome of interactions in relation to pathogen spread is unknown. The objectives of this study were 1) to determine the role of plant water stress on vector acquisition and inoculation of X. fastidiosa under choice and no-choice conditions for source or recipient vines, and 2) to provide insights into the effects of vineyard irrigation regimes on spread of X. fastidiosa by using a host-vector epidemic model. Under no-choice conditions, pathogen acquisition increased as water stress increased in source plants, while inoculation was not affected by water status of recipient vines. Thus, under no-choice conditions, plant water stress increased transmission of X. fastidiosa. However, when vectors had a choice of an uninfected well-watered versus an infected water-stressed grapevine, transmission efficiency declined as water stress levels increased. While our experimental results produced wide uncertainty estimates, the epidemiological modeling suggested a non-linear relationship between water stress and pathogen spread: moderate water stress enhances pathogen spread but severe or no stress produce equivalent spread. In summary, both host plant condition and vector host preference interacted to determine transmission efficiency of X. fastidiosa.
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Affiliation(s)
- Celia Del Cid
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA
| | - Rodrigo Krugner
- United States Department of Agriculture, Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA
| | - Adam R Zeilinger
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA
| | | | - Rodrigo P P Almeida
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA
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Zeilinger AR, Turek D, Cornara D, Sicard A, Lindow SE, Almeida RPP. Bayesian vector transmission model detects conflicting interactions from transgenic disease‐resistant grapevines. Ecosphere 2018. [DOI: 10.1002/ecs2.2494] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Adam R. Zeilinger
- Department of Environmental Science, Policy, and Management University of California 130 Mulford Hall Berkeley California 94720 USA
| | - Daniel Turek
- Department of Mathematics and Statistics Williams College Williamstown Massachusetts 01267 USA
| | - Daniele Cornara
- Instituto de Ciencias Agrarias Consejo Superior de Investigaciones Cientificas ICA‐CSIC Calle Serrano 115 dpdo Madrid 28006 Spain
| | - Anne Sicard
- Department of Environmental Science, Policy, and Management University of California 130 Mulford Hall Berkeley California 94720 USA
| | - Steven E. Lindow
- Department of Plant and Microbial Biology University of California Berkeley Berkeley California 94720 USA
| | - Rodrigo P. P. Almeida
- Department of Environmental Science, Policy, and Management University of California 130 Mulford Hall Berkeley California 94720 USA
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19
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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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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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Jeger M, Caffier D, Candresse T, Chatzivassiliou E, Dehnen-Schmutz K, Gilioli G, Grégoire JC, Jaques Miret JA, MacLeod A, Navajas Navarro M, Niere B, Parnell S, Potting R, Rafoss T, Rossi V, Urek G, Van Bruggen A, Van der Werf W, West J, Winter S, Almeida R, Bosco D, Jacques MA, Landa B, Purcell A, Saponari M, Czwienczek E, Delbianco A, Stancanelli G, Bragard C. Updated pest categorisation of Xylella fastidiosa. EFSA J 2018; 16:e05357. [PMID: 32625990 PMCID: PMC7009507 DOI: 10.2903/j.efsa.2018.5357] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Following a request from the European Commission, the EFSA Plant Health Panel updated its pest categorisation of Xylella fastidiosa, previously delivered as part of the pest risk assessment published in 2015. X. fastidiosa is a Gram‐negative bacterium, responsible for various plant diseases, including Pierce's disease, phony peach disease, citrus variegated chlorosis, olive quick decline syndrome, almond leaf scorch and various other leaf scorch diseases. The pathogen is endemic in the Americas and is present in Iran. In the EU, it is reported in southern Apulia in Italy, on the island of Corsica and in the Provence‐Alpes‐Côte d'Azur region in France, as well as in the Autonomous region of Madrid, the province of Alicante and the Balearic Islands in Spain. The reported status is ‘transient, under eradication’, except for the Balearic Islands, Corsica and southern of Apulia, where the status is ‘present with a restricted distribution, under containment’. The pathogen is regulated under Council Directive 2000/29/EC and through emergency measures under http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32015D0789 (as amended http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32017D2352). The pest could enter the EU via host plants for planting and via infectious insect vectors. The host range includes hundreds of host species listed in the EFSA host plant database. In the EU, host plants are widely distributed and climatic conditions are favourable for its establishment. X. fastidiosa can spread by movement of host plants for planting and infectious insect vectors. X. fastidiosa is known to cause severe direct damage to major crops including almonds, citrus, grapevines, olives, stone fruits and also forest trees, landscape and ornamental trees, with high impacts. The criteria assessed by the Panel for consideration as a potential Union quarantine pest are met (the pathogen is present in the EU, but it has a restricted distribution and is under official control). X. fastidiosa is not considered as a regulated non‐quarantine pest (RNQP) as the pathogen may spread also via insect vector transmission.
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Rapicavoli J, Ingel B, Blanco‐Ulate B, Cantu D, Roper C. Xylella fastidiosa: an examination of a re-emerging plant pathogen. MOLECULAR PLANT PATHOLOGY 2018; 19:786-800. [PMID: 28742234 PMCID: PMC6637975 DOI: 10.1111/mpp.12585] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Revised: 07/13/2017] [Accepted: 07/19/2017] [Indexed: 05/10/2023]
Abstract
UNLABELLED Xylella fastidiosa is a Gram-negative bacterial plant pathogen with an extremely wide host range. This species has recently been resolved into subspecies that correlate with host specificity. This review focuses on the status of X. fastidiosa pathogenic associations in plant hosts in which the bacterium is either endemic or has been recently introduced. Plant diseases associated with X. fastidiosa have been documented for over a century, and much about what is known in the context of host-pathogen interactions is based on these hosts, such as grape and citrus, in which this pathogen has been well described. Recent attention has focused on newly emerging X. fastidiosa diseases, such as in olives. TAXONOMY Bacteria; Gammaproteobacteria; family Xanthomonadaceae; genus Xylella; species fastidiosa. MICROBIOLOGICAL PROPERTIES Gram-negative rod (0.25-0.35 × 0.9-3.5 μm), non-flagellate, motile via Type IV pili-mediated twitching, fastidious. HOST RANGE Xylella fastidiosa has a broad host range that includes ornamental, ecological and agricultural plants belonging to over 300 different species in 63 different families. To date, X. fastidiosa has been found to be pathogenic in over 100 plant species. In addition, it can establish non-symptomatic associations with many plants as a commensal endophyte. Here, we list the four distinct subspecies of X. fastidiosa and some of the agriculturally relevant diseases caused by them: X. fastidiosa ssp. fastidiosa causes Pierce's disease (PD) of grapevine (Vitis vinifera); X. fastidiosa ssp. multiplex causes almond leaf scorch (ALS) and diseases on other nut and shade tree crops; X. fastidiosa ssp. pauca causes citrus variegated chlorosis (CVC) (Citrus spp.), coffee leaf scorch and olive quick decline syndrome (OQDS) (Olea europaea); X. fastidiosa ssp. sandyi causes oleander leaf scorch (OLS) (Nerium oleander). Significant host specificity seemingly exists for some of the subspecies, although this could be a result of technical biases based on the limited number of plants tested, whereas some subspecies are not as stringent in their host range and can infect several plant hosts. DISEASE SYMPTOMS Most X. fastidiosa-related diseases appear as marginal leaf necrosis and scorching of the leaves. In the case of PD, X. fastidiosa can also cause desiccation of berries (termed 'raisining'), irregular periderm development and abnormal abscission of petioles. In olive trees affected with OQDS, leaves exhibit marginal necrosis and defoliation, and overall tree decline occurs. Plants with ALS and OLS also exhibit the characteristic leaf scorch symptoms. Not all X. fastidiosa-related diseases exhibit the typical leaf scorch symptoms. These include CVC and Phony Peach disease, amongst others. In the case of CVC, symptoms include foliar wilt and interveinal chlorosis on the upper surfaces of the leaves (similar to zinc deficiency), which correspond to necrotic, gum-like regions on the undersides of the leaves. Additional symptoms of CVC include defoliation, dieback and hardening of fruits. Plants infected with Phony Peach disease exhibit a denser, more compact canopy (as a result of shortened internodes, darker green leaves and delayed leaf senescence), premature bloom and reduced fruit size. Some occlusions occur in the xylem vessels, but there are no foliar wilting, chlorosis or necrosis symptoms . USEFUL WEBSITES: http://www.piercesdisease.org/; https://pubmlst.org/xfastidiosa/; http://www.xylella.lncc.br/; https://nature.berkeley.edu/xylella/; https://ec.europa.eu/food/plant/plant_health_biosecurity/legislation/emergency_measures/xylella-fastidiosa_en.
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Affiliation(s)
- Jeannette Rapicavoli
- Department of Plant Pathology and MicrobiologyUniversity of CaliforniaRiversideCA 92521USA
| | - Brian Ingel
- Department of Plant Pathology and MicrobiologyUniversity of CaliforniaRiversideCA 92521USA
| | | | - Dario Cantu
- Department of Viticulture and EnologyUniversity of CaliforniaDavisCA 95616USA
| | - Caroline Roper
- Department of Plant Pathology and MicrobiologyUniversity of CaliforniaRiversideCA 92521USA
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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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Baù A, Delbianco A, Stancanelli G, Tramontini S. Susceptibility of Olea europaea L. varieties to Xylella fastidiosa subsp. pauca ST53: systematic literature search up to 24 March 2017. EFSA J 2017; 15:e04772. [PMID: 32625470 PMCID: PMC7009984 DOI: 10.2903/j.efsa.2017.4772] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
EFSA was requested by the European Commission to produce a report on the susceptibility of olive varieties to the Apulian strain of Xylella fastidiosa (subsp. pauca strain CoDiRO, ST53). A systematic literature search identified 21 references providing results of primary research studies on olive plants infected (naturally or artificially) by ST53. From experimental infectivity studies and from surveys in olive orchards, converging lines of evidence indicate tolerance of the Leccino variety to ST53 infections, although no long-term observations on yield are available yet. While the variety Leccino can become infected with the pathogen, it develops milder symptoms compared to those observed on susceptible varieties (e.g. Cellina di Nardò, Ogliarola salentina). Also, the size of the X. fastidiosa bacterial populations measured in Leccino-infected plants is lower compared to susceptible olive varieties. Preliminary results show that tolerance or resistance traits can also be found in other olive varieties. New research is now in place in the EU to study the level of susceptibility of many olive varieties to ST53 infections, therefore more relevant results will become available in the coming years.
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Wen JT, Viravathana P, Ingel B, Roper C, Tsutsui H. Polydiacetylene-Coated Sensor Strip for Immunochromatic Detection of Xylella fastidiosa subsp. fastidiosa. SLAS Technol 2017; 22:406-412. [PMID: 28378611 DOI: 10.1177/2472630316689286] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This study presents a sensor strip for user-friendly, naked-eye detection of Xylella fasitdiosa, the bacterial causal agent of Pierce's disease in grapevine. This sensor uses anti- X. fastidiosa antibodies conjugated to a polydiacetylene layer on a polyvinylidene fluoride strip to generate specific color transitions and discriminate levels of the pathogen. The detection limit of the sensor is 0.8 × 108 cells/mL, which is similar to bacterial load in grapevine 18 days following bacterial inoculation. This sensor enables equipment-free detection that is highly desirable for in-field diagnostic tools in resource-limited settings.
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Affiliation(s)
- Jessica T Wen
- 1 Department of Mechanical Engineering, University of California, Riverside, CA, USA.,2 Department of Bioengineering, University of California, Riverside, CA, USA
| | - Polrit Viravathana
- 3 Department of Plant Pathology and Microbiology, University of California, Riverside, CA, USA
| | - Brian Ingel
- 3 Department of Plant Pathology and Microbiology, University of California, Riverside, CA, USA
| | - Caroline Roper
- 3 Department of Plant Pathology and Microbiology, University of California, Riverside, CA, USA
| | - Hideaki Tsutsui
- 1 Department of Mechanical Engineering, University of California, Riverside, CA, USA.,2 Department of Bioengineering, University of California, Riverside, CA, USA
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26
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Cornara D, Sicard A, Zeilinger AR, Porcelli F, Purcell AH, Almeida RPP. Transmission of Xylella fastidiosa to Grapevine by the Meadow Spittlebug. PHYTOPATHOLOGY 2016; 106:1285-1290. [PMID: 27392174 DOI: 10.1094/phyto-05-16-0202-r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
There is little information available on Xylella fastidiosa transmission by spittlebugs (Hemiptera, Cercopoidea). This group of insect vectors may be of epidemiological relevance in certain diseases, so it is important to better understand the basic parameters of X. fastidiosa transmission by spittlebugs. We used grapevines as a host plant and the aphrophorid Philaenus spumarius as a vector to estimate the effect of plant access time on X. fastidiosa transmission to plants; in addition, bacterial population estimates in the heads of vectors were determined and correlated with plant infection status. Results show that transmission efficiency of X. fastidiosa by P. spumarius increased with plant access time, similarly to insect vectors in another family (Hemiptera, Cicadellidae). Furthermore, a positive correlation between pathogen populations in P. spumarius and transmission to plants was observed. Bacterial populations in insects were one to two orders of magnitude lower than those observed in leafhopper vectors, and population size peaked within 3 days of plant access period. These results suggest that P. spumarius has either a limited number of sites in the foregut that may be colonized, or that fluid dynamics in the mouthparts of these insects is different from that in leafhoppers. Altogether our results indicate that X. fastidiosa transmission by spittlebugs is similar to that by leafhoppers. In addition, the relationship between cell numbers in vectors and plant infection may have under-appreciated consequences to pathogen spread.
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Affiliation(s)
- D Cornara
- First and fourth authors: DiSSPA, sez. Zoologia ed Entomologia, Università degli Studi di Bari Aldo Moro, via Amendola 165/A, 70126 Bari; and second, third, fifth, and sixth authors: ESPM, University of California-Berkeley, 130 Mulford Hall 3114, Berkeley, CA 94720
| | - A Sicard
- First and fourth authors: DiSSPA, sez. Zoologia ed Entomologia, Università degli Studi di Bari Aldo Moro, via Amendola 165/A, 70126 Bari; and second, third, fifth, and sixth authors: ESPM, University of California-Berkeley, 130 Mulford Hall 3114, Berkeley, CA 94720
| | - A R Zeilinger
- First and fourth authors: DiSSPA, sez. Zoologia ed Entomologia, Università degli Studi di Bari Aldo Moro, via Amendola 165/A, 70126 Bari; and second, third, fifth, and sixth authors: ESPM, University of California-Berkeley, 130 Mulford Hall 3114, Berkeley, CA 94720
| | - F Porcelli
- First and fourth authors: DiSSPA, sez. Zoologia ed Entomologia, Università degli Studi di Bari Aldo Moro, via Amendola 165/A, 70126 Bari; and second, third, fifth, and sixth authors: ESPM, University of California-Berkeley, 130 Mulford Hall 3114, Berkeley, CA 94720
| | - A H Purcell
- First and fourth authors: DiSSPA, sez. Zoologia ed Entomologia, Università degli Studi di Bari Aldo Moro, via Amendola 165/A, 70126 Bari; and second, third, fifth, and sixth authors: ESPM, University of California-Berkeley, 130 Mulford Hall 3114, Berkeley, CA 94720
| | - R P P Almeida
- First and fourth authors: DiSSPA, sez. Zoologia ed Entomologia, Università degli Studi di Bari Aldo Moro, via Amendola 165/A, 70126 Bari; and second, third, fifth, and sixth authors: ESPM, University of California-Berkeley, 130 Mulford Hall 3114, Berkeley, CA 94720
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Jeger M, Bragard C, Caffier D, Chatzivassiliou E, Dehnen-Schmutz K, Gilioli G, Grégoire JC, Jaques Miret JA, MacLeod A, Navajas Navarro M, Niere B, Parnell S, Potting R, Rafoss T, Rossi V, Urek G, Van Bruggen A, Van Der Werf W, West J, Winter S, De La Fuente L, Spotti Lopes JR, Tramontini S, Andueza M, Candresse T. Susceptibility of Citrusspp., Quercus ilexand Vitisspp. to Xylella fastidiosastrain CoDiRO. EFSA J 2016. [DOI: 10.2903/j.efsa.2016.4601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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28
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Jeger M, Bragard C, Caffier D, Chatzivassiliou E, Dehnen-Schmutz K, Gilioli G, Grégoire JC, Jaques Miret JA, MacLeod A, Navajas Navarro M, Niere B, Parnell S, Potting R, Rafoss T, Rossi V, Urek G, Van Bruggen A, Van Der Werf W, West J, Winter S, Tramontini S, Andueza M, Candresse T. Susceptibility of Phoenix roebeleniito Xylella fastidiosa. EFSA J 2016. [DOI: 10.2903/j.efsa.2016.4600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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29
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Cornara D, Saponari M, Zeilinger AR, de Stradis A, Boscia D, Loconsole G, Bosco D, Martelli GP, Almeida RPP, Porcelli F. Spittlebugs as vectors of Xylella fastidiosa in olive orchards in Italy. JOURNAL OF PEST SCIENCE 2016; 90:521-530. [PMID: 28275326 PMCID: PMC5320020 DOI: 10.1007/s10340-016-0793-0] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 06/14/2016] [Accepted: 06/28/2016] [Indexed: 05/08/2023]
Abstract
The recent introduction of Xylella fastidiosa in Europe and its involvement in the Olive Quick Decline Syndrome (OQDS) in Apulia (Salento, Lecce district, South Italy) led us to investigate the biology and transmission ability of the meadow spittlebug, Philaenus spumarius, which was recently demonstrated to transmit X. fastidiosa to periwinkle plants. Four xylem-sap-feeding insect species were found within and bordering olive orchards across Salento during a survey carried out from October 2013 to December 2014: P. spumarius was the most abundant species on non-olive vegetation in olive orchards as well as on olive foliage and was the only species that consistently tested positive for the presence of X. fastidiosa using real-time PCR. P. spumarius, whose nymphs develop within spittle on weeds during the spring, are likely to move from weeds beneath olive trees to olive canopy during the dry period (May to October 2014). The first X. fastidiosa-infective P. spumarius were collected in May from olive canopy: all the individuals previously collected on weeds tested negative for the bacterium. Experiments demonstrated that P. spumarius transmitted X. fastidiosa from infected to uninfected olive plants. Moreover, P. spumarius acquired X. fastidiosa from several host plant species in the field, with the highest acquisition rate from olive, polygala and acacia. Scanning electron microscopy (SEM) revealed bacterial cells resembling X. fastidiosa in the foreguts of adult P. spumarius. The data presented here are essential to plan an effective IPM strategy and limit further spread of the fastidious bacterium.
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Affiliation(s)
- Daniele Cornara
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Maria Saponari
- Institute for Sustainable Plant Protection, National Research Council (CNR), Bari, Italy
| | - Adam R. Zeilinger
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA USA
| | - Angelo de Stradis
- Institute for Sustainable Plant Protection, National Research Council (CNR), Bari, Italy
| | - Donato Boscia
- Institute for Sustainable Plant Protection, National Research Council (CNR), Bari, Italy
| | - Giuliana Loconsole
- Institute for Sustainable Plant Protection, National Research Council (CNR), Bari, Italy
| | - Domenico Bosco
- Department of Agriculture, Forestry and Food Sciences, University of Turin, Grugliasco, Italy
| | - Giovanni P. Martelli
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Rodrigo P. P. Almeida
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA USA
| | - Francesco Porcelli
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Bari, Italy
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Labroussaa F, Zeilinger AR, Almeida RPP. Blocking the Transmission of a Noncirculative Vector-Borne Plant Pathogenic Bacterium. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2016; 29:535-544. [PMID: 27049684 DOI: 10.1094/mpmi-02-16-0032-r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The successful control of insect-borne plant pathogens is often difficult to achieve due to the ecologically complex interactions among pathogens, vectors, and host plants. Disease management often relies on pesticides and other approaches that have limited long-term sustainability. To add a new tool to control vector-borne diseases, we attempted to block the transmission of a bacterial insect-transmitted pathogen, the bacterium Xylella fastidiosa, by disrupting bacteria-insect vector interactions. X. fastidiosa is known to attach to and colonize the cuticular surface of the mouthparts of vectors; a set of recombinant peptides was generated and the chemical affinities of these peptides to chitin and related carbohydrates was assayed in vitro. Two candidates, the X. fastidiosa hypothetical protein PD1764 and an N-terminal region of the hemagglutinin-like protein B (HxfB) showed affinity for these substrates. These proteins were provided to vectors via an artificial diet system in which insects acquire X. fastidiosa, followed by an inoculation access period on plants under greenhouse conditions. Both PD1764 and HxfAD1-3 significantly blocked transmission. Furthermore, bacterial populations within insects over a 10-day period demonstrated that these peptides inhibited cell adhesion to vectors but not bacterial multiplication, indicating that the mode of action of these peptides is restricted to limiting cell adhesion to insects, likely via competition for adhesion sites. These results open a new venue in the search for sustainable disease-control strategies that are pathogen specific and may have limited nontarget effects.
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Affiliation(s)
- Fabien Labroussaa
- Department of Environmental Science, Policy and Management, 130 Mulford Hall, University of California, Berkeley, CA 94720, U.S.A
| | - Adam R Zeilinger
- Department of Environmental Science, Policy and Management, 130 Mulford Hall, University of California, Berkeley, CA 94720, U.S.A
| | - Rodrigo P P Almeida
- Department of Environmental Science, Policy and Management, 130 Mulford Hall, University of California, Berkeley, CA 94720, U.S.A
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Tuan SJ, Hu FT, Chang HY, Chang PW, Chen YH, Huang TP. Xylella fastidiosa Transmission and Life History of Two Cicadellinae Sharpshooters, Kolla paulula and Bothrogonia ferruginea (Hemiptera: Cicadellidae), in Taiwan. JOURNAL OF ECONOMIC ENTOMOLOGY 2016; 109:1034-1040. [PMID: 26875741 DOI: 10.1093/jee/tow016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 01/21/2016] [Indexed: 06/05/2023]
Abstract
Xylella fastidiosa causes Pierce's disease (PD) and is transmitted by xylem-sap-feeding insects. While X. fastidiosa -infected grapevines have been detected, the transmission vectors reported have never been recorded in Taiwan. Previous studies have suggested that Kolla paulula (Walker) and Bothrogonia ferruginea (F.) are candidate vectors in Taiwan. Here, we explored the life history of these two leafhoppers, evaluated the transmission efficiency of X. fastidiosa by the vectors, and investigated the genetic identity of three collected X. fastidiosa strains, namely, GMb, BQa, and BQ7f from the grapevine cultivars Golden Muscat (GM) and Black Queen (BQ), and one previously extracted strain GV148 from Kyoho (GV) showing PD symptoms in local vineyards. The results showed that all four strains were 100% identical to X. fastidiosa isolate Temecula1 from a naturally infected grapevine in the United States based on sequence analyses of 16S rRNA and 16S-23S ITS. The acquisition rates by K. paulula and B. ferruginea from the symptomatic cultivar Golden Muscat were 83.3 and 70.0% per individual, and the transmission rates to healthy grapevines were 13.3 and 6.7%, respectively. The acquisition rates by the groups of three K. paulula from the symptomatic cultivars Golden Muscat and Black Queen were 54.7 and 49.6%, respectively. Additionally, the transmission rates by K. paulula from and to each of these two grapevine cultivars were not significantly different. In view of their acquisition from infected grapevines and the effective transmission of X. fastidiosa to healthy grapevines, these two sharpshooter species are vectors of X. fastidiosa in Taiwan.
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Overall LM, Rebek EJ. Seasonal Abundance and Natural Inoculativity of Insect Vectors of Xylella fastidiosa in Oklahoma Tree Nurseries and Vineyards. JOURNAL OF ECONOMIC ENTOMOLOGY 2015; 108:2536-2545. [PMID: 26331482 DOI: 10.1093/jee/tov261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Accepted: 08/09/2015] [Indexed: 06/05/2023]
Abstract
Xylella fastidiosa is the causative agent of diseases of perennial plants including peach, plum, elm, oak, pecan, and grape. This bacterial pathogen is transmitted by xylem-feeding insects. In recent years, Pierce's disease of grape has been detected in 10 counties in central and northeastern Oklahoma, prompting further investigation of the disease epidemiology in this state. We surveyed vineyards and tree nurseries in Oklahoma for potential insect vectors to determine species composition, infectivity, and natural inoculativity of commonly captured insect vectors. Yellow sticky cards were used to sample insect fauna at each location. Insects were removed from sticky cards and screened for X. fastidiosa using immunocapture-PCR to determine their infectivity. A second objective was to test the natural inoculativity of insect vectors that are found in vineyards. Graphocephala versuta (Say), Graphocephala coccinea (Forster), Paraulacizes irrorata (F.), Oncometopia orbona (F.), Cuerna costalis (F.), and Entylia carinata Germar were collected from vineyards and taken back to the lab to determine their natural inoculativity. Immunocapture-PCR was used to test plant and insect samples for presence of X. fastidiosa. The three most frequently captured species from vineyards and tree nurseries were G. versuta, Clastoptera xanthocephala Germar, and O. orbona. Of those insects screened for X. fastidiosa, 2.4% tested positive for the bacterium. Field-collected G. versuta were inoculative to both ragweed and alfalfa. Following a 7-d inoculation access period, a higher percentage of alfalfa became infected than ragweed. Results from this study provide insight into the epidemiology of X. fastidiosa in Oklahoma.
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Affiliation(s)
- Lisa M Overall
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078.
| | - Eric J Rebek
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078
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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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Harris JL, Di Bello PL, Lear M, Balci Y. Bacterial Leaf Scorch in the District of Columbia: Distribution, Host Range, and Presence of Xylella fastidiosa Among Urban Trees. PLANT DISEASE 2014; 98:1611-1618. [PMID: 30703881 DOI: 10.1094/pdis-02-14-0158-sr] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A survey of urban trees affected by bacterial leaf scorch (BLS) caused by Xylella fastidiosa was conducted in the District of Columbia during 2011 and 2012. Over 20 species of urban trees were evaluated at 95 sites. Symptomatic and asymptomatic foliage from trees with BLS symptoms and foliage from neighboring asymptomatic trees were sampled. An X. fastidiosa-specific enzyme-linked immunosorbent assay (ELISA) and a polymerase chain reaction assay were used to detect and identify the strains from environmental samples. Symptomatic trees testing ELISA-positive for X. fastidiosa occurred most frequently with Quercus palustris, Q. rubra, Ulmus americana, and Platanus occidentalis. The bacterium was also less frequently identified on eight other symptomatic and five asymptomatic tree species. On infected trees, the bacterium was also detected on the asymptomatic portion of seven tree species. All strains were identified as the X. fastidiosa subsp. multiplex genotype ALSII except on Morus alba, where the genotype ALSI and the subsp. sandyi were detected. The occurrence of crown dieback was found significantly associated with X. fastidiosa-infection on Q. palustris, Q. rubra, U. americana, and P. occidentalis. Because this pathogen continues to perpetuate uncontrolled in urban environments, there is a pressing need to identify long-term management strategies that abate disease.
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Affiliation(s)
- Jordan L Harris
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park 20742
| | - Patrick L Di Bello
- Cell and Molecular Biology Program, Department of Plant Pathology, University of Arkansas, Fayetteville 72701
| | - Monica Lear
- District Department of Transportation, Urban Forestry Administration, Washington, DC 20003
| | - Yilmaz Balci
- Department of Plant Science and Landscape Architecture, University of Maryland
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Pierce BK, Voegel T, Kirkpatrick BC. The Xylella fastidiosa PD1063 protein is secreted in association with outer membrane vesicles. PLoS One 2014; 9:e113504. [PMID: 25426629 PMCID: PMC4245136 DOI: 10.1371/journal.pone.0113504] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 10/27/2014] [Indexed: 11/18/2022] Open
Abstract
Xylella fastidiosa is a gram-negative, xylem-limited plant pathogenic bacterium that causes disease in a variety of economically important agricultural crops including Pierce's disease of grapevines. Xylella fastidiosa biofilms formed in the xylem vessels of plants play a key role in early colonization and pathogenicity by providing a protected niche and enhanced cell survival. Here we investigate the role of Xylella fastidiosa PD1063, the predicted ortholog of Xanthomonas oryzae pv. oryzae PXO_03968, which encodes an outer membrane protein. To assess the function of the Xylella fastidiosa ortholog, we created Xylella fastidiosa mutants deleted for PD1063 and then assessed biofilm formation, cell-cell aggregation and cell growth in vitro. We also assessed disease severity and pathogen titers in grapevines mechanically inoculated with the Xylella fastidiosa PD1063 mutant. We found a significant decrease in cell-cell aggregation among PD1063 mutants but no differences in cell growth, biofilm formation, disease severity or titers in planta. Based on the demonstration that Xanthomonas oryzae pv. oryzae PXO_03968 encodes an outer membrane protein, secreted in association with outer membrane vesicles, we predicted that PD1063 would also be secreted in a similar manner. Using anti-PD1063 antibodies, we found PD1063 in the supernatant and secreted in association with outer membrane vesicles. PD1063 purified from the supernatant, outer membrane fractions and outer membrane vesicles was 19.2 kD, corresponding to the predicted size of the processed protein. Our findings suggest Xylella fastidiosa PD1063 is not essential for development of Pierce's disease in Vitis vinifera grapevines although further research is required to determine the function of the PD1063 outer membrane protein in Xylella fastidiosa.
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Affiliation(s)
- Brittany K. Pierce
- Department of Plant Pathology, University of California Davis, Davis, California, United States of America
| | - Tanja Voegel
- Department of Biology, University of British Columbia, Okanagan, Kelowna, BC, Canada
| | - Bruce C. Kirkpatrick
- Department of Plant Pathology, University of California Davis, Davis, California, United States of America
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Coletta-Filho HD, Daugherty MP, Ferreira C, Lopes JRS. Temporal progression of 'Candidatus Liberibacter asiaticus' infection in citrus and acquisition efficiency by Diaphorina citri. PHYTOPATHOLOGY 2014; 104:416-21. [PMID: 24620723 DOI: 10.1094/phyto-06-13-0157-r] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Over the last decade, the plant disease huanglongbing (HLB) has emerged as a primary threat to citrus production worldwide. HLB is associated with infection by phloem-limited bacteria ('Candidatus Liberibacter' spp.) that are transmitted by the Asian citrus psyllid, Diaphorina citri. Transmission efficiency varies with vector-related aspects (e.g., developmental stage and feeding periods) but there is no information on the effects of host-pathogen interactions. Here, acquisition efficiency of 'Candidatus Liberibacter asiaticus' by D. citri was evaluated in relation to temporal progression of infection and pathogen titer in citrus. We graft inoculated sweet orange trees with 'Ca. L. asiaticus'; then, at different times after inoculation, we inspected plants for HLB symptoms, measured bacterial infection levels (i.e., titer or concentration) in plants, and measured acquisition by psyllid adults that were confined on the trees. Plant infection levels increased rapidly over time, saturating at uniformly high levels (≈10(8) copy number of 16S ribosomal DNA/g of plant tissue) near 200 days after inoculation-the same time at which all infected trees first showed disease symptoms. Pathogen acquisition by vectors was positively associated with plant infection level and time since inoculation, with acquisition occurring as early as the first measurement, at 60 days after inoculation. These results suggest that there is ample potential for psyllids to acquire the pathogen from trees during the asymptomatic phase of infection. If so, this could limit the effectiveness of tree rouging as a disease management tool and would likely explain the rapid spread observed for this disease in the field.
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Killiny N, Almeida RPP. Factors affecting the initial adhesion and retention of the plant pathogen Xylella fastidiosa in the foregut of an insect vector. Appl Environ Microbiol 2014; 80:420-6. [PMID: 24185853 PMCID: PMC3910991 DOI: 10.1128/aem.03156-13] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 10/29/2013] [Indexed: 11/20/2022] Open
Abstract
Vector transmission of bacterial plant pathogens involves three steps: pathogen acquisition from an infected host, retention within the vector, and inoculation of cells into susceptible tissue of an uninfected plant. In this study, a combination of plant and artificial diet systems were used to determine the importance of several genes on the initial adhesion and retention of the bacterium Xylella fastidiosa to an efficient insect vector. Mutant strains included fimbrial (fimA and pilB) and afimbrial (hxfA and hxfB) adhesins and three loci involved in regulatory systems (rpfF, rpfC, and cgsA). Transmission assays with variable retention time indicated that HxfA and HxfB were primarily important for early adhesion to vectors, while FimA was necessary for both adhesion and retention. The long pilus protein PilB was not deficient in initial adhesion but may be important for retention. Genes upregulated under the control of rpfF are important for both initial adhesion and retention, as transmission rates of this mutant strain were initially low and decreased over time, while disruption of rpfC and cgsA yielded trends similar to that shown by the wild-type control. Because induction of an X. fastidiosa transmissible state requires pectin, a series of experiments were used to test the roles of a polygalacturonase (pglA) and the pectin and galacturonic acid carbohydrates on the transmission of X. fastidiosa. Results show that galacturonic acid, or PglA activity breaking pectin into its major subunit (galacturonic acid), is required for X. fastidiosa vector transmission using an artificial diet system. This study shows that early adhesion and retention of X. fastidiosa are mediated by different factors. It also illustrates that the interpretation of results of vector transmission experiments, in the context of vector-pathogen interaction studies, is highly dependent on experimental design.
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Affiliation(s)
- Nabil Killiny
- Citrus Research and Education Center, Department of Entomology and Nematology, University of Florida, IFAS, Lake Alfred, Florida, USA
| | - Rodrigo P. P. Almeida
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, California, USA
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Zeilinger AR, Daugherty MP. Vector preference and host defense against infection interact to determine disease dynamics. OIKOS 2013. [DOI: 10.1111/j.1600-0706.2013.01074.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Killiny N, Martinez RH, Dumenyo CK, Cooksey DA, Almeida RPP. The exopolysaccharide of Xylella fastidiosa is essential for biofilm formation, plant virulence, and vector transmission. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:1044-1053. [PMID: 23678891 DOI: 10.1094/mpmi-09-12-0211-r] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Exopolysaccharides (EPS) synthesized by plant-pathogenic bacteria are generally essential for virulence. The role of EPS produced by the vector-transmitted bacterium Xylella fastidiosa was investigated by knocking out two genes implicated in the EPS biosynthesis, gumD and gumH. Mutant strains were affected in growth characteristics in vitro, including adhesion to surfaces and biofilm formation. In addition, different assays were used to demonstrate that the mutant strains produced significantly less EPS compared with the wild type. Furthermore, gas chromatography-mass spectrometry showed that both mutant strains did not produce oligosaccharides. Biologically, the mutants were deficient in movement within plants, resulting in an avirulent phenotype. Additionally, mutant strains were affected in transmission by insects: they were very poorly transmitted by and retained within vectors. The gene expression profile indicated upregulation of genes implicated in cell-to-cell signaling and adhesins while downregulation in genes was required for within-plant movement in EPS-deficient strains. These results suggest an essential role for EPS in X. fastidiosa interactions with both plants and insects.
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Affiliation(s)
- N Killiny
- Department of Entomology and Nematology, Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850, USA.
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Voegel TM, Doddapaneni H, Cheng DW, Lin H, Stenger DC, Kirkpatrick BC, Roper MC. Identification of a response regulator involved in surface attachment, cell-cell aggregation, exopolysaccharide production and virulence in the plant pathogen Xylella fastidiosa. MOLECULAR PLANT PATHOLOGY 2013; 14:256-264. [PMID: 23186359 PMCID: PMC6638743 DOI: 10.1111/mpp.12004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Xylella fastidiosa, the causal agent of Pierce's disease of grapevine, possesses several two-component signal transduction systems that allow the bacterium to sense and respond to changes in its environment. Signals are perceived by sensor kinases that autophosphorylate and transfer the phosphate to response regulators (RRs), which direct an output response, usually by acting as transcriptional regulators. In the X. fastidiosa genome, 19 RRs were found. A site-directed knockout mutant in one unusual RR, designated XhpT, composed of a receiver domain and a histidine phosphotransferase output domain, was constructed. The resulting mutant strain was analysed for changes in phenotypic traits related to biofilm formation and gene expression using microarray analysis. We found that the xhpT mutant was altered in surface attachment, cell-cell aggregation, exopolysaccharide (EPS) production and virulence in grapevine. In addition, this mutant had an altered transcriptional profile when compared with wild-type X. fastidiosa in genes for several biofilm-related traits, such as EPS production and haemagglutinin adhesins.
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Affiliation(s)
- Tanja M Voegel
- Department of Plant Pathology, University of California, Davis, CA 95616, USA
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Rashed A, Kwan J, Baraff B, Ling D, Daugherty MP, Killiny N, Almeida RPP. Relative susceptibility of Vitis vinifera cultivars to vector-borne Xylella fastidiosa through time. PLoS One 2013; 8:e55326. [PMID: 23424629 PMCID: PMC3570562 DOI: 10.1371/journal.pone.0055326] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 12/21/2012] [Indexed: 11/19/2022] Open
Abstract
Understanding the interactions between pathogen, crop and vector are necessary for the development of disease control practices of vector-borne pathogens. For instance, resistant plant genotypes can help constrain disease symptoms due to infections and limit pathogen spread by vectors. On the other hand, genotypes susceptible to infection may increase pathogen spread owing to their greater pathogen quantity, regardless of their symptom status. In this study, we evaluated under greenhouse conditions the relative levels of resistance (i.e. relatively lower pathogen quantity) versus tolerance (i.e. less symptom severity) of 10 commercial grapevine (Vitis vinifera) cultivars to Pierce's disease etiological agent, the bacterium Xylella fastidiosa. Overall, no correlation was detected between pathogen quantity and disease severity, indicating the existence of among-cultivar variation in plant response to infection. Thompson Seedless and Barbera were the two most susceptible among 10 evaluated cultivars. Rubired showed the least severe disease symptoms and was categorized as one of the most resistant genotypes in this study. However, within each cultivar the degree of resistance/tolerance was not consistent across sampling dates. These cultivar and temporal differences in susceptibility to infection may have important consequences for disease epidemiology and the effectiveness of management protocols.
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Affiliation(s)
- Arash Rashed
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, United States of America.
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Abstract
The history of advances in research on Xylella fastidiosa provides excellent examples of how paradigms both advance and limit our scientific understanding of plant pathogens and the plant diseases they cause. I describe this from a personal perspective, having been directly involved with many persons who made paradigm-changing discoveries, beginning with the discovery that a bacterium, not a virus, causes Pierce's disease of grape and other plant diseases in numerous plant species, including important crop and forest species.
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Affiliation(s)
- Alexander Purcell
- Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720-3114, USA.
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Rathé AA, Pilkington LJ, Gurr GM, Hoddle MS, Daugherty MP, Constable FE, Luck JE, Powell KS, Fletcher MJ, Edwards OR. Incursion preparedness: anticipating the arrival of an economically important plant pathogenXylella fastidiosaWells (Proteobacteria: Xanthomonadaceae) and the insect vectorHomalodisca vitripennis(Germar) (Hemiptera: Cicadellidae) in Australia. ACTA ACUST UNITED AC 2011. [DOI: 10.1111/j.1440-6055.2011.00856.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Rashed A, Daugherty MP, Almeida RPP. Grapevine genotype susceptibility to Xylella fastidiosa does not predict vector transmission success. ENVIRONMENTAL ENTOMOLOGY 2011; 40:1192-1199. [PMID: 22251730 DOI: 10.1603/en11108] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
For vector-borne diseases, interactions between vector, host, and pathogen can influence patterns of disease spread. In particular, previous studies suggest that host genotype may influence disease dynamics because of differences in susceptibility to the pathogen and, therefore, subsequent vector transmission efficiency from these plants. We tested this hypothesis by using the pathogenic bacterium Xylella fastidiosa, the etiological agent of Pierce's disease in grapevines, and its leafhopper vector Homalodisca vitripennis (Germar). Pathogen infection level and transmission efficiency among several widely cultivated red and white wine, table, and raisin grape cultivars, were compared with the expectation that vector transmission rate would differ among cultivars, because of underlying differences in susceptibility to infection. The 14 grapevine genotypes evaluated showed significant differences among cultivars in the populations of X. fastidiosa that developed in petioles. 'Flame seedless' hosted the highest bacterial populations, between 1.81 and 2.05 times higher than the least susceptible 'Merlot', 'Crimson seedless', 'Grenache Noir', and 'Rubired'. Although the transmission rate of X. fastidiosa by H. vitripennis varied substantially (zero to 33%), it was not significantly different among cultivars. These results suggest that either the relationship between vine infection level and transmission is weaker than previously reported, or innate differences in vector preference among cultivars confounded any effects of vine susceptibility to infection.
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Affiliation(s)
- Arash Rashed
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, USA
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Nadarasah G, Stavrinides J. Insects as alternative hosts for phytopathogenic bacteria. FEMS Microbiol Rev 2011; 35:555-75. [DOI: 10.1111/j.1574-6976.2011.00264.x] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Daane KM, Wistrom CM, Shapland EB, Sisterson MS. Seasonal abundance of Draeculacephala minerva and other Xylella fastidiosa vectors in California almond orchards and vineyards. JOURNAL OF ECONOMIC ENTOMOLOGY 2011; 104:367-374. [PMID: 21510181 DOI: 10.1603/ec10226] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Almond leaf scorch (ALS) disease is caused by the bacterium Xylella fastidiosa and transmitted by xylem-feeding insects. Reports of increased incidence of ALS-diseased trees in California prompted surveys in three almond [Prunus dulcis (Mill.) D. A. Webb]-growing regions, from June 2003 to September 2005, to determine insect vector species composition and abundance. For comparison, sampling in and near vineyards in the San Joaquin Valley, California, also was completed. Sampling in or near almond orchards collected >42,000 Cicadomorpha of which 4.8% were xylem feeders, including 1912 grass sharpshooter, Draeculacephala minerva Ball; five Xyphon fulgida Nottingham; and a single spittlebug, Philaenus spumarius L. The most abundant vector was D. minerva. Season-long sampling indicated that D. minerva was a year-round resident in and/or near almonds in the Sacramento Valley, but not in the San Joaquin Valley. Similarly, D. minerca was rare in vineyards in the San Joaquin Valley, but was abundant in irrigated pastures near vineyards. D. minerva was most frequently collected along orchard margins, and peak densities were observed in summer, the period of time when bacterial titers are reported to increase in infected trees. Screening of D. minerva for presence of X.fastidiosa found that 1.1% of insects collected near almond orchards and 4.5% of insects collected from pastures tested positive. The X. fastidiosa subspecies and genotype detected in insects collected from orchards matched those collected from ALS-diseased almond trees in the same orchard. Of the few X. fulgida and P. spumarius collected, none tested positive for X. fastidiosa. Results are discussed with respect to X. fastidiosa vector control and detection methods.
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Affiliation(s)
- Kent M Daane
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720-3114, USA.
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Sisterson MS, Thammiraju SR, Lynn-Patterson K, Groves RL, Daane KM. Epidemiology of Diseases Caused by Xylella fastidiosa in California: Evaluation of Alfalfa as a Source of Vectors and Inocula. PLANT DISEASE 2010; 94:827-834. [PMID: 30743547 DOI: 10.1094/pdis-94-7-0827] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Pierce's disease and almond leaf scorch disease have been chronic problems for California grape and almond growers, respectively. Both diseases are caused by the xylem-limited, bacterial pathogen Xylella fastidiosa, which is transmitted by xylem-feeding insects. We evaluated the potential for alfalfa to serve as a source of vectors and inocula in California. Analysis of Geographic Information Systems maps on the distribution and abundance of grape, almond, and alfalfa plantings determined that 94,521 ha of almond and grape were planted within 1.6 km of an alfalfa field. Seasonal trends of X. fastidiosa detection were monitored outdoors and in the greenhouse in five needle-inoculated alfalfa cultivars (CUF101, Moapa69, WL342, WL530HQ, and WL625HQ) over 2 years. Results suggest that cool winter temperatures reduced X. fastidiosa populations to undetectable levels but did not eliminate infections. Sampling of alfalfa fields to assess incidence of X. fastidiosa corroborated this result, with positive samples detected in summer only. Incidence of X. fastidiosa in alfalfa during summer was low, with only 6 positive samples out of 1,156 samples collected over 3 years. Insect trapping in alfalfa fields over 3 years found that the green sharpshooter (Draeculacephala minerva) was the most abundant vector. Within alfalfa fields, green sharpshooter abundance was highest in weedy areas, suggesting a preference for weeds over alfalfa. These results confirm that weedy alfalfa fields can serve as an important source of vectors. Incidence of X. fastidiosa in alfalfa was low, possibly due to preference of vectors for weeds over alfalfa.
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Affiliation(s)
- Mark S Sisterson
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648
| | - Shyamala R Thammiraju
- Department of Environmental Science, Policy and Management, University of California, Berkeley 94720-3114
| | - Kris Lynn-Patterson
- Division of Agriculture and Natural Resources, University of California, Kearney Agricultural Center, Parlier 93648
| | | | - Kent M Daane
- Department of Environmental Science, Policy and Management, University of California, Berkeley
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Sanderlin RS, Melanson RA. Insect Transmission of Xylella fastidiosa to Pecan. PLANT DISEASE 2010; 94:465-470. [PMID: 30754516 DOI: 10.1094/pdis-94-4-0465] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Pecan bacterial leaf scorch (PBLS), caused by the bacterium Xylella fastidiosa, can cause economically significant crop loss to some pecan (Carya illinoinensis) cultivars in the southeastern United States. X. fastidiosa is typically vectored by spittlebugs (Cercopidae) and leafhoppers (Cicadellidae). Because no vector species had been reported for pecan, an attempt was made to identify potential vectors that are capable of acquiring the bacterium from infected pecan trees and transmitting to pecan. Several spittlebug and leafhopper species collected from various sources, including sorghum and pecan, were tested as potential vectors of the pathogen from pecan to pecan. When tested in groups, the pecan spittlebug, Clastoptera achatina; the Johnson-grass sharpshooter, Homalodisca insolita; and the glassy-winged sharpshooter (GWSS), Homalodisca vitripennis, had transmission rates to pecan of 11.4, 19.3, and 4%, respectively, following a pathogen acquisition period on infected pecan terminals. The pecan spittlebug is common in pecan orchards in the southeastern United States, and the GWSS was observed on young vigorous pecan shoots. Limited testing with the diamond-backed spittlebug, Lepyronia quadrangularis, and the lateral-lined sharpshooter, Cuerna costalis, suggested that these could be occasional vectors of X. fastidiosa to pecan. There is a need for studies on the identification and population dynamics of Cicadellidae that inhabit pecan orchards to determine if management of vectors is needed in commercial pecan production to reduce the spread of PBLS.
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Affiliation(s)
- R S Sanderlin
- Louisiana State University Agricultural Center Pecan Research-Extension Station, P.O. Box 5519, Shreveport 71135
| | - R A Melanson
- Louisiana State University Agricultural Center Plant Pathology and Crop Physiology Department, Baton Rouge 70803
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