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Surano A, del Grosso C, Musio B, Todisco S, Giampetruzzi A, Altamura G, Saponari M, Gallo V, Mastrorilli P, Boscia D, Saldarelli P. Exploring the xylem-sap to unravel biological features of Xylella fastidiosa subspecies pauca ST53 in immune, resistant and susceptible crop species through metabolomics and in vitro studies. FRONTIERS IN PLANT SCIENCE 2024; 14:1343876. [PMID: 38312355 PMCID: PMC10834688 DOI: 10.3389/fpls.2023.1343876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 12/28/2023] [Indexed: 02/06/2024]
Abstract
Xylella fastidiosa subsp. pauca ST53 (Xfp) is a pathogenic bacterium causing one of the most severe plant diseases currently threatening the olive-growing areas of the Mediterranean, the Olive Quick Decline Syndrome (OQDS). The majority of the olive cultivars upon infections more or less rapidly develop severe desiccation phenomena, while few are resistant (e.g. Leccino and FS17), being less impacted by the infections. The present study contributes to elucidating the basis of the resistance phenomenon by investigating the influence of the composition of the xylem sap of plant species on the rate of bacterial multiplication. Xylem saps from Xfp host and non-host species were used for growing the bacterium in vitro, monitoring bacterial growth, biofilm formation, and the expression of specific genes. Moreover, species-specific metabolites, such as mannitol, quinic acid, tartaric acid, and choline were identified by non-targeted NMR-based metabolomic analysis in olive, grapevine, and citrus. In general, the xylem saps of immune species, including grapevine and citrus, were richer in amino acids, organic acids, and glucose. The results showed greater bacterial growth in the olive cultivar notoriously susceptible to Xfp (Cellina di Nardò), compared to that recorded in the resistant cultivar Leccino. Conversely, higher biofilm formation occurred in Leccino compared to Cellina di Nardò. Using the xylem saps of two Xfp-immune species (citrus and grapevine), a divergent bacterial behavior was recorded: low planktonic growth and biofilm production were detected in citrus compared to the grapevine. A parallel evaluation of the expression of 15 genes showed that Xfp directs its molecular functions mainly to virulence. Overall, the results gained through this multidisciplinary study contribute to extending the knowledge on the host-pathogen interaction, while confirming that the host response and resistance mechanism have a multifactorial basis, most likely with a cumulative effect on the phenotype.
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Affiliation(s)
- Antony Surano
- Institute for Sustainable Plant Protection, National Research Council (CNR), Bari, Italy
| | - Carmine del Grosso
- Institute for Sustainable Plant Protection, National Research Council (CNR), Bari, Italy
| | - Biagia Musio
- Department of Civil, Environmental, Land, Building Engineering and Chemistry (DICATECh), Polytechnic University of Bari, Bari, Italy
| | - Stefano Todisco
- Department of Civil, Environmental, Land, Building Engineering and Chemistry (DICATECh), Polytechnic University of Bari, Bari, Italy
| | - Annalisa Giampetruzzi
- Institute for Sustainable Plant Protection, National Research Council (CNR), Bari, Italy
| | - Giuseppe Altamura
- CRSFA-Centro Ricerca, Sperimentazione e Formazione in Agricoltura Basile Caramia, Locorotondo, Italy
| | - Maria Saponari
- Institute for Sustainable Plant Protection, National Research Council (CNR), Bari, Italy
| | - Vito Gallo
- Department of Civil, Environmental, Land, Building Engineering and Chemistry (DICATECh), Polytechnic University of Bari, Bari, Italy
- Innovative Solutions S.r.l.—Spin-Off Company of Polytechnic University of Bari, Noci, Italy
| | - Piero Mastrorilli
- Department of Civil, Environmental, Land, Building Engineering and Chemistry (DICATECh), Polytechnic University of Bari, Bari, Italy
- Innovative Solutions S.r.l.—Spin-Off Company of Polytechnic University of Bari, Noci, Italy
| | - Donato Boscia
- Institute for Sustainable Plant Protection, National Research Council (CNR), Bari, Italy
| | - Pasquale Saldarelli
- Institute for Sustainable Plant Protection, National Research Council (CNR), Bari, Italy
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Orfei B, Moretti C, Loreti S, Tatulli G, Onofri A, Scotti L, Aceto A, Buonaurio R. Silver nanoclusters with Ag 2+/3+ oxidative states are a new highly effective tool against phytopathogenic bacteria. Appl Microbiol Biotechnol 2023:10.1007/s00253-023-12596-z. [PMID: 37289240 DOI: 10.1007/s00253-023-12596-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 05/03/2023] [Accepted: 05/09/2023] [Indexed: 06/09/2023]
Abstract
The main measure worldwide adopted to manage plant bacterial diseases is based on the application of copper compounds, which are often partially efficacious for the frequent appearance of copper-resistant bacterial strains and have raised concerns for their toxicity to the environment and humans. Therefore, there is an increasing need to develop new environmentally friendly, efficient, and reliable strategies for controlling plant bacterial diseases, and among them, the use of nanoparticles seems promising. The present study aimed to evaluate the feasibility of protecting plants against attacks of gram-negative and gram-positive phytopathogenic bacteria by using electrochemically synthesized silver ultra nanoclusters (ARGIRIUM‑SUNCs®) with an average size of 1.79 nm and characterized by rare oxidative states (Ag2+/3+). ARGIRIUM‑SUNCs strongly inhibited the in vitro growth (effective concentration, EC50, less than 1 ppm) and biofilm formation of Pseudomonas syringae pv. tomato and of quarantine bacteria Xanthomonas vesicatoria, Xylella fastidiosa subsp. pauca, and Clavibacter michiganensis subsp. michiganensis. In addition, treatments with ARGIRIUM‑SUNCs also provoked the eradication of biofilm for P. syringae pv. tomato, X. vesicatoria, and C. michiganensis subsp. michiganensis. Treatment of tomato plants via root absorption with ARGIRIUM‑SUNCs (10 ppm) is not phytotoxic and protected (80%) the plants against P. syringae pv. tomato attacks. ARGIRIUM‑SUNCs at low doses induced hormetic effects on P. syringae pv. tomato, X. vesicatoria, and C. michiganensis subsp. michiganensis as well as on tomato root growth. The use of ARGIRIUM‑SUNCs in protecting plants against phytopathogenic bacteria is a possible alternative control measure. KEY POINTS: • ARGIRIUM‑SUNC has strong antimicrobial activities against phytopathogenic bacteria; • ARGIRIUM‑SUNC inhibits biofilm formation at low doses; • ARGIRIUM‑SUNC protects tomato plants against bacterial speck disease.
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Affiliation(s)
- Benedetta Orfei
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, Perugia, Italy
| | - Chiaraluce Moretti
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, Perugia, Italy.
| | - Stefania Loreti
- Council for Agricultural Research and Economics (CREA), Research Centre for Plant Protection and Certification, Roma, Italy
| | - Giuseppe Tatulli
- Council for Agricultural Research and Economics (CREA), Research Centre for Plant Protection and Certification, Roma, Italy
| | - Andrea Onofri
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, Perugia, Italy
| | - Luca Scotti
- Department of Medical, Oral and Biotechnological Sciences, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy.
| | - Antonio Aceto
- Department of Medical, Oral and Biotechnological Sciences, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy
| | - Roberto Buonaurio
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, Perugia, Italy
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Román-Écija M, Navas-Cortés JA, Velasco-Amo MP, Arias-Giraldo LF, Gómez LM, Fuente LDL, Landa BB. Two Xylella fastidiosa subsp. multiplex Strains Isolated from Almond in Spain Differ in Plasmid Content and Virulence Traits. PHYTOPATHOLOGY 2023; 113:960-974. [PMID: 36576402 DOI: 10.1094/phyto-06-22-0234-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The plant-pathogenic bacterium Xylella fastidiosa is a major threat to agriculture and the environment worldwide. Recent devastating outbreaks in Europe highlight the potential of this pathogen to cause emergent diseases. X. fastidiosa subsp. multiplex ESVL and IVIA5901 strains that belong to sequence type 6 were isolated from almond orchards within the outbreak area in Alicante province (Spain). Both strains share more than 99% of the chromosomal sequences (average nucleotide identity), but the ESVL strain harbors two plasmids (pXF64-Hb_ESVL and pUCLA-ESVL). Here, virulence phenotypes and genome content were compared between both strains, using three strains from the United States as a reference for the phenotypic analyses. Experiments in microfluidic chambers, used as a simulation of xylem vessels, showed that twitching motility was absent in the IVIA5901 strain, whereas the ESVL strain had reduced twitching motility. In general, both Spanish strains had less biofilm formation, less cell aggregation, and lower virulence in tobacco compared with U.S. reference strains. Genome analysis of the two plasmids from ESVL revealed 51 unique coding sequences that were absent in the chromosome of IVIA5901. Comparison of the chromosomes of both strains showed some unique coding sequences and single-nucleotide polymorphisms in each strain, with potential deleterious mutations. Genomic differences found in genes previously associated with adhesion and motility might explain the differences in the phenotypic traits studied. Although additional studies are necessary to infer the potential role of X. fastidiosa plasmids, our results indicate that the presence of plasmids should be considered in the study of the mechanisms of pathogenicity and adaptation in X. fastidiosa to new environments. [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)
- M Román-Écija
- Department of Crop Protection, Institute for Sustainable Agriculture, Consejo Superior de Investigaciones Científicas, Córdoba, Spain
| | - J A Navas-Cortés
- Department of Crop Protection, Institute for Sustainable Agriculture, Consejo Superior de Investigaciones Científicas, Córdoba, Spain
| | - M P Velasco-Amo
- Department of Crop Protection, Institute for Sustainable Agriculture, Consejo Superior de Investigaciones Científicas, Córdoba, Spain
| | - L F Arias-Giraldo
- Department of Crop Protection, Institute for Sustainable Agriculture, Consejo Superior de Investigaciones Científicas, Córdoba, Spain
| | - L M Gómez
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, U.S.A
| | - L De La Fuente
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, U.S.A
| | - B B Landa
- Department of Crop Protection, Institute for Sustainable Agriculture, Consejo Superior de Investigaciones Científicas, Córdoba, Spain
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Synthetic Peptides against Plant Pathogenic Bacteria. Microorganisms 2022; 10:microorganisms10091784. [PMID: 36144386 PMCID: PMC9504393 DOI: 10.3390/microorganisms10091784] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 08/31/2022] [Accepted: 09/01/2022] [Indexed: 11/16/2022] Open
Abstract
The control of plant diseases caused by bacteria that seriously compromise crop productivity around the world is still one of the most important challenges in food security. Integrated approaches for disease control generally lack plant protection products with high efficacy and low environmental and health adverse effects. Functional peptides, either from natural sources or synthetic, are considered as novel candidates to develop biopesticides. Synthetic peptides can be obtained based on the structure of natural compounds or de novo designed, considering the features of antimicrobial peptides. The advantage of this approach is that analogues can be conveniently prepared, enabling the identification of sequences with improved biological properties. Several peptide libraries have been designed and synthetized, and the best sequences showed strong bactericidal activity against important plant pathogenic bacteria, with a good profile of biodegradability and low toxicity. Among these sequences, there are bacteriolytic or antibiofilm peptides that work against the target bacteria, plant defense elicitor peptides, and multifunctional peptides that display several of these properties. Here, we report the research performed by our groups during the last twenty years, as well as our ongoing work. We also highlight those peptides that can be used as candidates to develop novel biopesticides, and the main challenges and prospects.
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Feitosa-Junior OR, Souza APS, Zaini PA, Baccari C, Ionescu M, Pierry PM, Uceda-Campos G, Labroussaa F, Almeida RPP, Lindow SE, da Silva AM. The XadA Trimeric Autotransporter Adhesins in Xylella fastidiosa Differentially Contribute to Cell Aggregation, Biofilm Formation, Insect Transmission and Virulence to Plants. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2022; 35:857-866. [PMID: 35704683 DOI: 10.1094/mpmi-05-22-0108-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Surface adhesion strategies are widely employed by bacterial pathogens during establishment and systemic spread in their host. A variety of cell-surface appendages such as pili, fimbriae, and afimbrial adhesins are involved in these processes. The phytopathogen Xylella fastidiosa employs several of these structures for efficient colonization of its insect and plant hosts. Among the adhesins encoded in the X. fastidiosa genome, three afimbrial adhesins, XadA1, Hsf/XadA2, and XadA3, are predicted to be trimeric autotransporters with a C-terminal YadA-anchor membrane domain. We analyzed the individual contributions of XadA1, XadA2, and XadA3 to various cellular behaviors both in vitro and in vivo. Using isogenic X. fastidiosa mutants, we found that cell-cell aggregation and biofilm formation were severely impaired in the absence of XadA3. No significant reduction of cell-surface attachment was found with any mutant under flow conditions. Acquisition by insect vectors and transmission to grapevines were reduced in the XadA3 deletion mutant. While the XadA3 mutant was hypervirulent in grapevines, XadA1 or XadA2 deletion mutants conferred lower disease severity than the wild-type strain. This insight of the importance of these adhesive proteins and their individual contributions to different aspects of X. fastidiosa biology should guide new approaches to reduce pathogen transmission and disease development. [Formula: see text] Copyright © 2022 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)
- Oseias R Feitosa-Junior
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Ana Paula S Souza
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Paulo A Zaini
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
- Department of Plant Sciences, University of California, Davis, CA, U.S.A
| | - Clelia Baccari
- Department of Plant and Microbial Biology, University of California, Berkeley, U.S.A
| | - Michael Ionescu
- Department of Plant and Microbial Biology, University of California, Berkeley, U.S.A
| | - Paulo M Pierry
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Guillermo Uceda-Campos
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Fabien Labroussaa
- Department of Environmental Science, Policy and Management, University of California, Berkeley, U.S.A
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Rodrigo P P Almeida
- Department of Environmental Science, Policy and Management, University of California, Berkeley, U.S.A
| | - Steven E Lindow
- Department of Plant and Microbial Biology, University of California, Berkeley, U.S.A
| | - Aline M da Silva
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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Krugner R, Rogers EE, Burbank LP, Wallis CM, Ledbetter CA. Insights Regarding Resistance of 'Nemaguard' Rootstock to the Bacterium Xylella fastidiosa. PLANT DISEASE 2022; 106:2074-2081. [PMID: 35253489 DOI: 10.1094/pdis-01-22-0136-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: 06/14/2023]
Abstract
'Nemaguard' is a commonly used rootstock for almond and stone fruits due to resistance to nematodes and enhanced scion vigor. Nemaguard also happens to be resistant to strains of Xylella fastidiosa that cause almond leaf scorch disease. Previous research showed that prior to June-budding, this rootstock can prevent infection of almond nursery stock by X. fastidiosa. Further, the rootstock also promotes recovery from infection in susceptible almond scions. Objectives of this study were to 1) compare movement and bacterial populations of X. fastidiosa in almond and Nemaguard, 2) determine whether the metabolic profile of infected versus noninfected plants of each species correspond with differences in pathogen distribution, and 3) evaluate the impact of feeding on Nemaguard on transmission efficiency and pathogen populations in insects. Results showed limited or no movement of X. fastidiosa beyond the point of mechanical inoculation in Nemaguard, whereas X. fastidiosa was detected in susceptible almond and isolated from plant samples distal to the point of inoculation. Large differences in the concentration of phenolic compounds between Nemaguard and almond were also found, although this was not impacted by infection status. After acquiring X. fastidiosa from infected plants, vector access periods of up to 14 days on Nemaguard neither reduced pathogen populations in vectors nor reduced transmission efficiency of X. fastidiosa to susceptible plants when compared with similar vector-access periods on susceptible grapevines. Results suggest Nemaguard, in spite of having high phenolic concentrations in its xylem, does not directly impact X. fastidiosa survival and that future research should focus on identification of potential physical traits that prevent bacterial attachment, multiplication, or movement within the plant.
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Affiliation(s)
- Rodrigo Krugner
- USDA-Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648
| | - Elizabeth E Rogers
- USDA-Agricultural Research Service, Foreign Disease-Weed Science Research Unit, Fort Detrick, MD 21702-5023
| | - Lindsey P Burbank
- USDA-Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648
| | - Christopher M Wallis
- USDA-Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648
| | - Craig A Ledbetter
- USDA-Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648
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Host-specific signal perception by PsaR2 LuxR solo induces Pseudomonas syringae pv. actinidiae virulence traits. Microbiol Res 2022; 260:127048. [DOI: 10.1016/j.micres.2022.127048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/23/2022] [Accepted: 04/19/2022] [Indexed: 11/19/2022]
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Moll L, Badosa E, Planas M, Feliu L, Montesinos E, Bonaterra A. Antimicrobial Peptides With Antibiofilm Activity Against Xylella fastidiosa. Front Microbiol 2021; 12:753874. [PMID: 34819923 PMCID: PMC8606745 DOI: 10.3389/fmicb.2021.753874] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 10/04/2021] [Indexed: 11/26/2022] Open
Abstract
Xylella fastidiosa is a plant pathogen that was recently introduced in Europe and is causing havoc to its agriculture. This Gram-negative bacterium invades the host xylem, multiplies, and forms biofilm occluding the vessels and killing its host. In spite of the great research effort, there is no method that effectively prevents or cures hosts from infections. The main control strategies up to now are eradication, vector control, and pathogen-free plant material. Antimicrobial peptides have arisen as promising candidates to combat this bacterium due to their broad spectrum of activity and low environmental impact. In this work, peptides previously reported in the literature and newly designed analogs were studied for its bactericidal and antibiofilm activity against X. fastidiosa. Also, their hemolytic activity and effect on tobacco leaves when infiltrated were determined. To assess the activity of peptides, the strain IVIA 5387.2 with moderate growth, able to produce biofilm and susceptible to antimicrobial peptides, was selected among six representative strains found in the Mediterranean area (DD1, CFBP 8173, Temecula, IVIA 5387.2, IVIA 5770, and IVIA 5901.2). Two interesting groups of peptides were identified with bactericidal and/or antibiofilm activity and low-moderate toxicity. The peptides 1036 and RIJK2 with dual (bactericidal–antibiofilm) activity against the pathogen and moderate toxicity stand out as the best candidates to control X. fastidiosa diseases. Nevertheless, peptides with only antibiofilm activity and low toxicity are also promising agents as they could prevent the occlusion of xylem vessels caused by the pathogen. The present work contributes to provide novel compounds with antimicrobial and antibiofilm activity that could lead to the development of new treatments against diseases caused by X. fastidiosa.
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Affiliation(s)
- Luís Moll
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Girona, Spain
| | - Esther Badosa
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Girona, Spain
| | - Marta Planas
- LIPPSO, Department of Chemistry, University of Girona, Girona, Spain
| | - Lidia Feliu
- LIPPSO, Department of Chemistry, University of Girona, Girona, Spain
| | - Emilio Montesinos
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Girona, Spain
| | - Anna Bonaterra
- Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Girona, Spain
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Dong CL, Lu MX, Du YZ. Transcriptomic analysis of pre-diapause larvae of Chilo suppressalis (Walker) (Lepidoptera: Pyralidae) in natural populations. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2021; 40:100903. [PMID: 34455148 DOI: 10.1016/j.cbd.2021.100903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 08/12/2021] [Accepted: 08/15/2021] [Indexed: 11/27/2022]
Abstract
Chilo suppressalis Walker is a devastating pest of rice in Asia and exhibits facultative diapause in the larval stage. Most prior experiments on diapausing and non-diapausing C. suppressalis were conducted in the laboratory. In this study, transcriptome analyses were performed on pre-diapausing larvae collected from field populations of C. suppressalis and compared to laboratory populations. Among 2674 differentially expressed genes (DEGs), 32 DEGs related to pre-diapause and 239 universally expressed genes were screened; these were primarily enriched in "neuroactive ligand-receptor interaction", "lysosome" and "glycerolipid metabolism" in KEGG pathway analysis. With respect to clusters of orthologous genes (COG), DEGs were assigned to "posttranslational modification, protein turnover, chaperones", "carbohydrate transport and metabolism", and "secondary metabolite biosynthesis, transport and catabolism" categories. Further analysis also revealed that a key "circadian clock-controlled protein" gene is sensitive to photoperiod and significantly decreased during the pre-diapause phase. Genes encoding two small heat shock proteins, hsp21.4 and hsp27.2, were significantly expressed on August 15 as compared to three other sampling times in August 2018. Eight DEGs were randomly chosen and evaluated by real-time quantitative PCR (RT-qPCR) to validate the accuracy of the transcriptome data. The expression of six DEGs (gene-evm_000752, gene-evm_006486, gene-evm_008626, gene-evm_002485, gene-evm_011981 and Chilo_suppressalis_newGene_18103) showed significant same patterns of differential expression in both the RT-qPCR and RNA-Seq analyses. This study increases our understanding of the complex physiological and molecular mechanisms involved in C. suppressalis at the pre-diapause phase.
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Affiliation(s)
- Chuan-Lei Dong
- College of Horticulture and Plant Protection, Institute of Applied Entomology, Yangzhou University, Yangzhou 225009, China
| | - Ming-Xing Lu
- College of Horticulture and Plant Protection, Institute of Applied Entomology, Yangzhou University, Yangzhou 225009, China
| | - Yu-Zhou Du
- College of Horticulture and Plant Protection, Institute of Applied Entomology, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education, Yangzhou University, Yangzhou, China.
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Tatulli G, Modesti V, Pucci N, Scala V, L’Aurora A, Lucchesi S, Salustri M, Scortichini M, Loreti S. Further In Vitro Assessment and Mid-Term Evaluation of Control Strategy of Xylella fastidiosa subsp. pauca in Olive Groves of Salento (Apulia, Italy). Pathogens 2021; 10:85. [PMID: 33478174 PMCID: PMC7835972 DOI: 10.3390/pathogens10010085] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 12/13/2022] Open
Abstract
During recent years; Xylella fastidiosa subsp. pauca (Xfp) has spread in Salento causing relevant damage to the olive groves. Measures to contain the spreading of the pathogen include the monitoring of the areas bordering the so-called "infected" zone and the tree eradication in case of positive detection. In order to provide a control strategy aimed to maintain the tree productivity in the infected areas, we further evaluated the in vitro and in planta mid-term effectiveness of a zinc-copper-citric acid biocomplex. The compound showed an in vitro bactericidal activity and inhibited the biofilm formation in representative strains of X. fastidiosa subspecies, including Xfp isolated in Apulia from olive trees. The field mid-term evaluation of the control strategy assessed by quantitative real-time PCR in 41 trees of two olive groves of the "infected" area revealed a low concentration of Xfp over the seasons upon the regular spraying of the biocomplex over 3 or 4 consecutive years. In particular, the bacterial concentration lowered in July and October with respect to March, after six consecutive treatments. The trend was not affected by the cultivar and it was similar either in the Xfp-sensitive cultivars Ogliarola salentina and Cellina di Nardò or in the Xfp-resistant Leccino. Moreover, the scoring of the number of wilted twigs over the seasons confirmed the trend. The efficacy of the treatment in the management of olive groves subjected to a high pathogen pressure is highlighted by the yielded a good oil production.
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Affiliation(s)
- Giuseppe Tatulli
- Council for Agricultural Research and Economics (CREA), Research Centre for Plant Protection and Certification, 00156 Roma, Italy; (G.T.); (V.M.); (N.P.); (V.S.); (A.L.); (S.L.)
| | - Vanessa Modesti
- Council for Agricultural Research and Economics (CREA), Research Centre for Plant Protection and Certification, 00156 Roma, Italy; (G.T.); (V.M.); (N.P.); (V.S.); (A.L.); (S.L.)
| | - Nicoletta Pucci
- Council for Agricultural Research and Economics (CREA), Research Centre for Plant Protection and Certification, 00156 Roma, Italy; (G.T.); (V.M.); (N.P.); (V.S.); (A.L.); (S.L.)
| | - Valeria Scala
- Council for Agricultural Research and Economics (CREA), Research Centre for Plant Protection and Certification, 00156 Roma, Italy; (G.T.); (V.M.); (N.P.); (V.S.); (A.L.); (S.L.)
| | - Alessia L’Aurora
- Council for Agricultural Research and Economics (CREA), Research Centre for Plant Protection and Certification, 00156 Roma, Italy; (G.T.); (V.M.); (N.P.); (V.S.); (A.L.); (S.L.)
| | - Simone Lucchesi
- Council for Agricultural Research and Economics (CREA), Research Centre for Plant Protection and Certification, 00156 Roma, Italy; (G.T.); (V.M.); (N.P.); (V.S.); (A.L.); (S.L.)
| | - Manuel Salustri
- Dipartimento di Biologia Ambientale, Sapienza University of Rome, 00185 Roma, Italy;
| | - Marco Scortichini
- Council for Agricultural Research and Economics (CREA), Research Centre for Olive, Fruit and Citrus Crops, 00134 Roma, Italy
| | - Stefania Loreti
- Council for Agricultural Research and Economics (CREA), Research Centre for Plant Protection and Certification, 00156 Roma, Italy; (G.T.); (V.M.); (N.P.); (V.S.); (A.L.); (S.L.)
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Phenotypic Characterization and Transformation Attempts Reveal Peculiar Traits of Xylella fastidiosa Subspecies pauca Strain De Donno. Microorganisms 2020; 8:microorganisms8111832. [PMID: 33233703 PMCID: PMC7699976 DOI: 10.3390/microorganisms8111832] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 12/19/2022] Open
Abstract
Xylella fastidiosa subsp. pauca strain De Donno has been recently identified as the causal agent of a severe disease affecting olive trees in a wide area of the Apulia Region (Italy). While insights on the genetics and epidemiology of this virulent strain have been gained, its phenotypic and biological traits remained to be explored. We investigated in vitro behavior of the strain and compare its relevant biological features (growth rate, biofilm formation, cell-cell aggregation, and twitching motility) with those of the type strain Temecula1. The experiments clearly showed that the strain De Donno did not show fringe on the agar plates, produced larger amounts of biofilm and had a more aggregative behavior than the strain Temecula1. Repeated attempts to transform, by natural competence, the strain De Donno failed to produce a GFP-expressing and a knockout mutant for the rpfF gene. Computational prediction allowed us to identify potentially deleterious sequence variations most likely affecting the natural competence and the lack of fringe formation. GFP and rpfF- mutants were successfully obtained by co-electroporation in the presence of an inhibitor of the type I restriction-modification system. The availability of De Donno mutant strains will open for new explorations of its interactions with hosts and insect vectors.
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Singh RP, Handa R, Manchanda G. Nanoparticles in sustainable agriculture: An emerging opportunity. J Control Release 2020; 329:1234-1248. [PMID: 33122001 DOI: 10.1016/j.jconrel.2020.10.051] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 10/23/2022]
Abstract
Conventional agriculture often relies on bulky doses of fertilizers and pesticides that have adversely affected the living beings as well as the ecosystems. As a basic tenet of sustainable agriculture, minimum agrochemicals should be used so that the environment can be protected and various species can be conserved. Further, sustainable agriculture should be a low input system, where the production costs are lower and net returns are higher. The application of nanotechnology in agriculture can significantly enhance the efficiency of agricultural inputs and thus it offers a significant way to maintain sustainable development of agroecosystems via nanoparticles. In this regard, nano-plant growth promoters, nanopesticides, nanofertilizers, nano-herbicides, agrochemical encapsulated nanocarrier systems etc. have been developed for the potential applications in agriculture. These can have great benefits for agriculture, including higher production of crops, inhibition of plant pathogens, removal of unwanted weeds and insects with lesser cost, energy and waste production. However, there are several concerns related to the use of nanoparticles in agriculture. These include the approaches for synthesis, their mechanisms of penetration to applied surfaces and the risks involved. Though, advent of new technologies has significantly improved the synthesis and application of nanomaterials in agriculture, there are many uncertainties regarding nano-synthesis, their way of utilization, uptake and internalization inside the crop cells. Therefore, an elaborate investigation is required for deciphering the engineered nanomaterials, assessing their mechanistic application and agroecological toxicity. Hence, this review is aimed to critically highlight the NPs material application and points towards the vital gaps in the use of nanotechnology for sustainable agriculture.
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Affiliation(s)
- Raghvendra Pratap Singh
- Department of Research & Development, Biotechnology, Uttaranchal University, Uttarakhand 248007, India.
| | - Rahul Handa
- Department of Botany and Environment Studies, DAV University, Jalandhar, Punjab 144001, India
| | - Geetanjali Manchanda
- Department of Botany and Environment Studies, DAV University, Jalandhar, Punjab 144001, India.
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Grapevine phenolic compounds influence cell surface adhesion of Xylella fastidiosa and bind to lipopolysaccharide. PLoS One 2020; 15:e0240101. [PMID: 33007036 PMCID: PMC7531785 DOI: 10.1371/journal.pone.0240101] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 09/19/2020] [Indexed: 12/14/2022] Open
Abstract
Bacterial phytopathogen Xylella fastidiosa specifically colonizes the plant vascular tissue through a complex process of cell adhesion, biofilm formation, and dispersive movement. Adaptation to the chemical environment of the xylem is essential for bacterial growth and progression of infection. Grapevine xylem sap contains a range of plant secondary metabolites such as phenolics, which fluctuate in response to pathogen infection and plant physiological state. Phenolic compounds are often involved in host-pathogen interactions and influence infection dynamics through signaling activity, antimicrobial properties, and alteration of bacterial phenotypes. The effect of biologically relevant concentrations of phenolic compounds coumaric acid, gallic acid, epicatechin, and resveratrol on growth of X. fastidiosa was assessed in vitro. None of these compounds inhibited bacterial growth, but epicatechin and gallic acid reduced cell-surface adhesion. Cell-cell aggregation decreased with resveratrol treatment, but the other phenolic compounds tested had minimal effect on aggregation. Expression of attachment (xadA) and aggregation (fimA) related genes were altered by presence of the phenolic compounds, consistent with observed phenotypes. All four of the phenolic compounds bound to purified X. fastidiosa lipopolysaccharide (LPS), a major cell-surface component. Information regarding the impact of chemical environment on pathogen colonization in plants is important for understanding the infection process and factors associated with host susceptibility.
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Baldassarre F, Tatulli G, Vergaro V, Mariano S, Scala V, Nobile C, Pucci N, Dini L, Loreti S, Ciccarella G. Sonication-Assisted Production of Fosetyl-Al Nanocrystals: Investigation of Human Toxicity and In Vitro Antibacterial Efficacy against Xylella Fastidiosa. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E1174. [PMID: 32560195 PMCID: PMC7353234 DOI: 10.3390/nano10061174] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 06/12/2020] [Accepted: 06/12/2020] [Indexed: 12/27/2022]
Abstract
Recently, there is a growing demand in sustainable phytopathogens control research. Nanotechnology provides several tools such as new pesticides formulations, antibacterial nanomaterials and smart delivery systems. Metal nano-oxides and different biopolymers have been exploited in order to develop nanopesticides which can offer a targeted solution minimizing side effects on environment and human health. This work proposed a nanotechnological approach to obtain a new formulation of systemic fungicide fosetyl-Al employing ultrasonication assisted production of water dispersible nanocrystals. Moreover, chitosan was applicated as a coating agent aiming a synergistic antimicrobial effect between biopolymer and fungicide. Fosetyl-Al nanocrystals have been characterized by morphological and physical-chemical analysis. Nanotoxicological investigation was carried out on human keratinocytes cells through cells viability test and ultrastructural analysis. In vitro planktonic growth, biofilm production and agar dilution assays have been conducted on two Xylella fastidiosa subspecies. Fosetyl-Al nanocrystals resulted very stable over time and less toxic respect to conventional formulation. Finally, chitosan-based fosetyl-Al nanocrystals showed an interesting antibacterial activity against Xylella fastidiosa subsp. pauca and Xylella fastidiosa subsp. fastidiosa.
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Affiliation(s)
- Francesca Baldassarre
- Biological and Environmental Sciences Department, UdR INSTM of Lecce University of Salento, Via Monteroni, 73100 Lecce, Italy;
- Institute of Nanotechnology, CNR NANOTEC, Consiglio Nazionale delle Ricerche, Via Monteroni, 73100 Lecce, Italy; (C.N.); (L.D.)
| | - Giuseppe Tatulli
- Council for Agricultural Research and Economics, Research Centre for Plant Protection and Certification of Rome, 00156 Rome, Italy; (G.T.); (V.S.); (N.P.); (S.L.)
| | - Viviana Vergaro
- Biological and Environmental Sciences Department, UdR INSTM of Lecce University of Salento, Via Monteroni, 73100 Lecce, Italy;
- Institute of Nanotechnology, CNR NANOTEC, Consiglio Nazionale delle Ricerche, Via Monteroni, 73100 Lecce, Italy; (C.N.); (L.D.)
| | - Stefania Mariano
- Biological and Environmental Sciences Department, University of Salento, Via Monteroni, 73100 Lecce, Italy;
| | - Valeria Scala
- Council for Agricultural Research and Economics, Research Centre for Plant Protection and Certification of Rome, 00156 Rome, Italy; (G.T.); (V.S.); (N.P.); (S.L.)
| | - Concetta Nobile
- Institute of Nanotechnology, CNR NANOTEC, Consiglio Nazionale delle Ricerche, Via Monteroni, 73100 Lecce, Italy; (C.N.); (L.D.)
| | - Nicoletta Pucci
- Council for Agricultural Research and Economics, Research Centre for Plant Protection and Certification of Rome, 00156 Rome, Italy; (G.T.); (V.S.); (N.P.); (S.L.)
| | - Luciana Dini
- Institute of Nanotechnology, CNR NANOTEC, Consiglio Nazionale delle Ricerche, Via Monteroni, 73100 Lecce, Italy; (C.N.); (L.D.)
- Department of Biology and Biotechnology “Charles Darwin”, University of Rome “La Sapienza”, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Stefania Loreti
- Council for Agricultural Research and Economics, Research Centre for Plant Protection and Certification of Rome, 00156 Rome, Italy; (G.T.); (V.S.); (N.P.); (S.L.)
| | - Giuseppe Ciccarella
- Biological and Environmental Sciences Department, UdR INSTM of Lecce University of Salento, Via Monteroni, 73100 Lecce, Italy;
- Institute of Nanotechnology, CNR NANOTEC, Consiglio Nazionale delle Ricerche, Via Monteroni, 73100 Lecce, Italy; (C.N.); (L.D.)
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Cattò C, De Vincenti L, Cappitelli F, D’Attoma G, Saponari M, Villa F, Forlani F. Non-Lethal Effects of N-Acetylcysteine on Xylella fastidiosa Strain De Donno Biofilm Formation and Detachment. Microorganisms 2019; 7:E656. [PMID: 31817370 PMCID: PMC6955915 DOI: 10.3390/microorganisms7120656] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/28/2019] [Accepted: 12/03/2019] [Indexed: 01/03/2023] Open
Abstract
This study investigated in-vitro the non-lethal effects of N-acetylcysteine (NAC) on Xylella fastidiosa subspecies pauca strain De Donno (Xf-DD) biofilm. This strain was isolated from the olive trees affected by the olive quick decline syndrome in southern Italy. Xf-DD was first exposed to non-lethal concentrations of NAC from 0.05 to 1000 µM. Cell surface adhesion was dramatically reduced at 500 µM NAC (-47%), hence, this concentration was selected for investigating the effects of pre-, post- and co-treatments on biofilm physiology and structural development, oxidative homeostasis, and biofilm detachment. Even though 500 µM NAC reduced bacterial attachment to surfaces, compared to the control samples, it promoted Xf-DD biofilm formation by increasing: (i) biofilm biomass by up to 78% in the co-treatment, (ii) matrix polysaccharides production by up to 72% in the pre-treatment, and (iii) reactive oxygen species levels by 3.5-fold in the co-treatment. Xf-DD biofilm detachment without and with NAC was also investigated. The NAC treatment did not increase biofilm detachment, compared to the control samples. All these findings suggested that, at 500 µM, NAC diversified the phenotypes in Xf-DD biofilm, promoting biofilm formation (hyper-biofilm-forming phenotype) and discouraging biofilm detachment (hyper-attachment phenotype), while increasing oxidative stress level in the biofilm.
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Affiliation(s)
- Cristina Cattò
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy; (C.C.); (L.D.V.); (F.C.); (F.F.)
| | - Luca De Vincenti
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy; (C.C.); (L.D.V.); (F.C.); (F.F.)
| | - Francesca Cappitelli
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy; (C.C.); (L.D.V.); (F.C.); (F.F.)
| | - Giusy D’Attoma
- Institute for Sustainable Plant Protection, Consiglio Nazionale delle Ricerche, via Amendola 165/A, 70126 Bari, Italy (M.S.)
| | - Maria Saponari
- Institute for Sustainable Plant Protection, Consiglio Nazionale delle Ricerche, via Amendola 165/A, 70126 Bari, Italy (M.S.)
| | - Federica Villa
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy; (C.C.); (L.D.V.); (F.C.); (F.F.)
| | - Fabio Forlani
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy; (C.C.); (L.D.V.); (F.C.); (F.F.)
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Athinuwat D, Brooks S. The OmpA Gene of Xanthomonas axonopodis pv. glycines is Involved in Pathogenesis of Pustule Disease on Soybean. Curr Microbiol 2019; 76:879-887. [PMID: 31089795 DOI: 10.1007/s00284-019-01702-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 05/06/2019] [Indexed: 10/26/2022]
Abstract
The goal of this study was to elucidate the role of the outer membrane protein A (ompA) gene of Xanthomonas axonopodis pv. glycines in bacterial pustule pathogenesis of soybean. An ompA mutant of X. axonopodis pv. glycines KU-P-SW005 was shown to significantly decrease cellulase, pectate lyase, and polysaccharide production. The production of these proteins in the ompA mutant was approximately five times lower than that of the wildtype. The ompA mutant also exhibited modified biofilm development. More importantly, the mutant reduced disease severity to the soybean. Ten days after inoculation, the virulence rating of the susceptible soybean cv. SJ4 inoculated with the ompA mutant was 11.23%, compared with 87.98% for the complemented ompA mutant. Production of cellulase, pectate lyase, polysaccharide was restored, biofilm, and pustule numbers were restored in the complemented ompA mutant that did not differ from the wild type. Taken together, these data suggest that OmpA-mediated invasion plays an important role in protein secretion during pathogenesis to soybean.
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Affiliation(s)
- Dusit Athinuwat
- Department of Agricultural Technology, Faculty of Science and Technology, Thammasat University, Pathumthani, Thailand.
| | - Siraprapa Brooks
- School of Science, Mae Fah Luang University, Chaing Rai, 57100, Thailand
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Naranjo E, Merfa MV, Ferreira V, Jain M, Davis MJ, Bahar O, Gabriel DW, De La Fuente L. Liberibacter crescens biofilm formation in vitro: establishment of a model system for pathogenic 'Candidatus Liberibacter spp.'. Sci Rep 2019; 9:5150. [PMID: 30914689 PMCID: PMC6435755 DOI: 10.1038/s41598-019-41495-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 03/11/2019] [Indexed: 11/23/2022] Open
Abstract
The Liberibacter genus comprises insect endosymbiont bacterial species that cause destructive plant diseases, including Huanglongbing in citrus and zebra chip in potato. To date, pathogenic 'Candidatus Liberibacter spp.' (CLs) remain uncultured, therefore the plant-associated Liberibacter crescens (Lcr), only cultured species of the genus, has been used as a biological model for in vitro studies. Biofilm formation by CLs has been observed on the outer midgut surface of insect vectors, but not in planta. However, the role of biofilm formation in the life cycle of these pathogens remains unclear. Here, a model system for studying CLs biofilms was developed using Lcr. By culture media modifications, bovine serum albumin (BSA) was identified as blocking initial cell-surface adhesion. Removal of BSA allowed for the first time observation of Lcr biofilms. After media optimization for biofilm formation, we demonstrated that Lcr attaches to surfaces, and form cell aggregates embedded in a polysaccharide matrix both in batch cultures and under flow conditions in microfluidic chambers. Biofilm structures may represent excellent adaptive advantages for CLs during insect vector colonization helping with host retention, immune system evasion, and transmission. Future studies using the Lcr model established here will help in the understanding of the biology of CLs.
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Affiliation(s)
- Eber Naranjo
- Department of Entomology and Plant Pathology, Auburn University, Auburn, USA
| | - Marcus V Merfa
- Department of Entomology and Plant Pathology, Auburn University, Auburn, USA
| | - Virginia Ferreira
- Bioscience Department, College of Chemistry, University of the Republic, Montevideo, Uruguay
| | - Mukesh Jain
- Department of Plant Pathology, University of Florida, Gainesville, USA
| | - Michael J Davis
- Citrus Research and Education Center, University of Florida, Gainesville, USA
| | - Ofir Bahar
- Department of Plant Pathology and Weed Research, ARO - Volcani Center, Bet-Dagan, Israel
| | - Dean W Gabriel
- Department of Plant Pathology, University of Florida, Gainesville, USA
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18
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Manna I, Bandyopadhyay M. A review on the biotechnological aspects of utilizing engineered nanoparticles as delivery systems in plants. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.plgene.2018.100167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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19
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Aggarwal M, Hussaini MY, De La Fuente L, Navarrete F, Cogan NG. A framework for model analysis across multiple experiment regimes: Investigating effects of zinc on Xylella fastidiosa as a case study. J Theor Biol 2018; 457:88-100. [PMID: 30138631 DOI: 10.1016/j.jtbi.2018.08.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 07/14/2018] [Accepted: 08/18/2018] [Indexed: 12/13/2022]
Abstract
Mathematical models are ubiquitous in analyzing dynamical biological systems. However, it might not be possible to explicitly account for the various sources of uncertainties in the model and the data if there is limited experimental data and information about the biological processes. The presence of uncertainty introduces problems with identifiability of the parameters of the model and determining appropriate regions to explore with respect to sensitivity and estimates of parameter values. Since the model analysis is likely dependent on the numerical estimates of the parameters, parameter identifiability should be addressed beforehand to capture biologically relevant parameter space. Here, we propose a framework which uses data from different experiment regimes to identify a region in the parameter space over which subsequent mathematical analysis can be conducted. Along with building confidence in the parameter estimates, it provides us with variations in the parameters due to changes in the experimental conditions. To determine significance of these variations, we conduct global sensitivity analysis, allowing us to make testable hypothesis for effects of changes in the experimental conditions on the biological system. As a case study, we develop a model for growth dynamics and biofilm formation of a bacterial plant pathogen, and use our framework to identify possible effects of zinc on the bacterial populations in different metabolic states. The framework reveals underlying issues with parameter identifiability and identifies a suitable region in the parameter space, sensitivity analysis over which informs us about the parameters that might be affected by addition of zinc. Moreover, these parameters prove to be identifiable in this region.
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Affiliation(s)
- Manu Aggarwal
- Department of Mathematics, Florida State University, Tallahassee, Florida, USA.
| | - M Y Hussaini
- Department of Mathematics, Florida State University, Tallahassee, Florida, USA
| | - Leonardo De La Fuente
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA
| | - Fernando Navarrete
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA
| | - N G Cogan
- Department of Mathematics, Florida State University, Tallahassee, Florida, USA
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20
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Killiny N, Jones SE. Metabolic alterations in the nymphal instars of Diaphorina citri induced by Candidatus Liberibacter asiaticus, the putative pathogen of huanglongbing. PLoS One 2018; 13:e0191871. [PMID: 29370262 PMCID: PMC5785020 DOI: 10.1371/journal.pone.0191871] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 01/12/2018] [Indexed: 11/24/2022] Open
Abstract
Currently, huanglongbing is the most damaging disease of citrus causing huge economic losses. The disease is caused by the Gram-negative bacterium Candidatus Liberibacter asiaticus (CLas). The pathogen is transmitted in a persistent propagative circulative manner within its vector, the Asian citrus psyllid, Diaphorina citri. Exploring the metabolic alteration in the vector may lead to a better understanding of the nutritional needs of CLas and to designing an artificial medium for culturing the pathogen. It has been shown that the nymphal stages have a greater role in transmission mainly because they feed on plants more actively than adults. In this study, we carried out an untargeted comparative metabolomic analysis for healthy and CLas-infected 4th / 5th instar nymphs. The metabolic analysis was performed using trimethylsilylation and methyl chloroformate derivatization followed by Gas Chromatography-Mass Spectrometry (GC-MS). Overall, the changes in the nymph metabolism due to the infection with CLas were more pronounced than in adults, as we previously published. Nymphs reared on CLas-infected Valencia sweet orange were higher in many metabolites, mainly those of the TCA cycle, C16 and C18 fatty acids, glucose, sucrose, L-proline, L-serine, pyroglutamic acid, saccharic acid, threonic acid and myo-inositol than those reared on healthy plants. In contrast, CLas-infected nymphs were lower in putrescine, glycine, L -phenylalanine, L -tyrosine, L -valine, and chiro-inositol. The information provided from this study may contribute in acceleration of the availability of CLas in culture and consequent screening of antibacterial compounds to discover a definitive solution for huanglongbing.
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Affiliation(s)
- Nabil Killiny
- Citrus Research and Education Center, Department of Plant Pathology, IFAS, University of Florida, Lake Alfred, Florida, United States of America
| | - Shelley E Jones
- Citrus Research and Education Center, Department of Plant Pathology, IFAS, University of Florida, Lake Alfred, Florida, United States of America
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21
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Hao L, Johnson K, Cursino L, Mowery P, Burr TJ. Characterization of the Xylella fastidiosa PD1311 gene mutant and its suppression of Pierce's disease on grapevines. MOLECULAR PLANT PATHOLOGY 2017; 18:684-694. [PMID: 27388152 PMCID: PMC6638296 DOI: 10.1111/mpp.12428] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Revised: 04/17/2016] [Accepted: 05/13/2016] [Indexed: 05/25/2023]
Abstract
Xylella fastidiosa causes Pierce's disease (PD) on grapevines, leading to significant economic losses in grape and wine production. To further our understanding of X. fastidiosa virulence on grapevines, we examined the PD1311 gene, which encodes a putative acyl-coenzyme A (acyl-CoA) synthetase, and is highly conserved across Xylella species. It was determined that PD1311 is required for virulence, as the deletion mutant, ΔPD1311, was unable to cause disease on grapevines. The ΔPD1311 strain was impaired in behaviours known to be associated with PD development, including motility, aggregation and biofilm formation. ΔPD1311 also expressed enhanced sensitivity to H2 O2 and polymyxin B, and showed reduced survival in grapevine sap, when compared with wild-type X. fastidiosa Temecula 1 (TM1). Following inoculation, ΔPD1311 could not be detected in grape shoots, which may be related to its altered growth and sensitivity phenotypes. Inoculation with ΔPD1311 2 weeks prior to TM1 prevented the development of PD in a significant fraction of vines and eliminated detectable levels of TM1. In contrast, vines inoculated simultaneously with TM1 and ΔPD1311 developed disease at the same level as TM1 alone. In these vines, TM1 populations were distributed similarly to populations in TM1-only inoculated plants. These findings suggest that, through an indirect mechanism, pretreatment of vines with ΔPD1311 suppresses pathogen population and disease.
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Affiliation(s)
- Lingyun Hao
- Department of Plant Pathology and Plant–Microbe BiologyCornell University‐New York State Agricultural Experiment StationGenevaNY14456USA
| | - Kameka Johnson
- Department of Plant Pathology and Plant–Microbe BiologyCornell University‐New York State Agricultural Experiment StationGenevaNY14456USA
| | - Luciana Cursino
- Department of BiologyHobart and William Smith CollegesGenevaNY14456USA
- Present address:
Division of Natural SciencesKeuka CollegeKeuka ParkNY14478USA
| | - Patricia Mowery
- Department of BiologyHobart and William Smith CollegesGenevaNY14456USA
| | - Thomas J. Burr
- Department of Plant Pathology and Plant–Microbe BiologyCornell University‐New York State Agricultural Experiment StationGenevaNY14456USA
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Hao L, Zaini PA, Hoch HC, Burr TJ, Mowery P. Grape Cultivar and Sap Culture Conditions Affect the Development of Xylella fastidiosa Phenotypes Associated with Pierce's Disease. PLoS One 2016; 11:e0160978. [PMID: 27508296 PMCID: PMC4980040 DOI: 10.1371/journal.pone.0160978] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 07/27/2016] [Indexed: 11/19/2022] Open
Abstract
Xylella fastidiosa is a xylem-limited bacterium in plant hosts and causes Pierce's disease (PD) of grapevines, which differ in susceptibility according to the Vitis species (spp.). In this work we compared X. fastidiosa biofilm formation and population dynamics when cultured in xylem saps from PD-susceptible and -resistant Vitis spp. under different conditions. Behaviors in a closed-culture system were compared to those in different sap-renewal cultures that would more closely mimic the physicochemical environment encountered in planta. Significant differences in biofilm formation and growth in saps from PD-susceptible and -resistant spp. were only observed using sap renewal culture. Compared to saps from susceptible V. vinifera, those from PD-resistant V. aestivalis supported lower titers of X. fastidiosa and less biofilm and V. champinii suppressed both growth and biofilm formation, behaviors which are correlated with disease susceptibility. Furthermore, in microfluidic chambers X. fastidiosa formed thick mature biofilm with three-dimensional (3-D) structures, such as pillars and mounds, in saps from all susceptible spp. In contrast, only small aggregates of various shapes were formed in saps from four out of five of the resistant spp.; sap from the resistant spp. V. mustangensis was an exception in that it also supported thick lawns of biofilm but not the above described 3-D structures typically seen in a mature biofilm from the susceptible saps. Our findings provide not only critical technical information for future bioassays, but also suggest further understanding of PD susceptibility.
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Affiliation(s)
- Lingyun Hao
- Section of Plant Pathology and Plant-Microbe Biology, SIPS, Cornell University-New York State Agricultural Experiment Station, Geneva, New York, United States of America
| | - Paulo A. Zaini
- Section of Plant Pathology and Plant-Microbe Biology, SIPS, Cornell University-New York State Agricultural Experiment Station, Geneva, New York, United States of America
| | - Harvey C. Hoch
- Section of Plant Pathology and Plant-Microbe Biology, SIPS, Cornell University-New York State Agricultural Experiment Station, Geneva, New York, United States of America
| | - Thomas J. Burr
- Section of Plant Pathology and Plant-Microbe Biology, SIPS, Cornell University-New York State Agricultural Experiment Station, Geneva, New York, United States of America
| | - Patricia Mowery
- Department of Biology, Hobart and William Smith Colleges, Geneva, New York, United States of America
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Whidden M, Cogan N, Donahue M, Navarrete F, De La Fuente L. A Two-Dimensional Multiphase Model of Biofilm Formation in Microfluidic Chambers. Bull Math Biol 2015; 77:2161-79. [PMID: 26621357 DOI: 10.1007/s11538-015-0115-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 10/15/2015] [Indexed: 10/22/2022]
Abstract
The bacterial pathogen Xylella fastidiosa is the causal agent of many pathological conditions of economically important agricultural crops. There is no known cure for X. fastidiosa diseases, and management of the problem is based solely in controlling the population of insect vectors, which is somewhat effective. The bacterium causes disease by forming biofilms inside the vascular system of the plant, a process that is poorly understood. In microfluidic chambers, used as artificial xylem vessels, this bacterium has been observed to reproducibly cluster into a distinct, regular pattern of aggregates, spatially separated by channels of non-biofilm components. We develop a multiphase model in two dimensions, which recapitulates this spatial patterning, suggesting that bacterial growth and attachment/detachment processes are strongly influential modulators of these patterns. This indicates plausible strategies, such as the addition of metals and chelators, for mitigating the severity of diseases induced by this bacterial pathogen.
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Affiliation(s)
- Mark Whidden
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Nick Cogan
- Department of Mathematics, Florida State University, Tallahassee, FL, USA
| | - Matt Donahue
- Department of Mathematics, University of Tulsa, Tulsa, OK, USA
| | - Fernando Navarrete
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
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Navarrete F, De La Fuente L. Zinc Detoxification Is Required for Full Virulence and Modification of the Host Leaf Ionome by Xylella fastidiosa. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2015; 28:497-507. [PMID: 25561271 DOI: 10.1094/mpmi-07-14-0221-r] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Zinc (Zn) is an essential element for all forms of life because it is a structural or catalytic cofactor of many proteins, but it can have toxic effects at high concentrations; thus, microorganisms must tightly regulate its levels. Here, we evaluated the role of Zn homeostasis proteins in the virulence of the xylem-limited bacterium Xylella fastidiosa, causal agent of Pierce's disease of grapevine, among other diseases. Two mutants of X. fastidiosa 'Temecula' affected in genes which regulate Zn homeostasis (zur) and Zn detoxification (czcD) were constructed. Both knockouts showed increased sensitivity to Zn at physiologically relevant concentrations and increased intracellular accumulation of this metal compared with the wild type. Increased Zn sensitivity was correlated with decreased growth in grapevine xylem sap, reduced twitching motility, and downregulation of exopolysaccharide biosynthetic genes. Tobacco plants inoculated with either knockout mutant showed reduced foliar symptoms and a much reduced (czcD) or absent (zur) modification of the leaf ionome (i.e., the mineral nutrient and trace element composition), as well as reduced bacterial populations. The results show that detoxification of Zn is crucial for the virulence of X. fastidiosa and verifies our previous findings that modification of the host leaf ionome correlates with bacterial virulence.
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Affiliation(s)
- Fernando Navarrete
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, U.S.A
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Cursino L, Athinuwat D, Patel KR, Galvani CD, Zaini PA, Li Y, De La Fuente L, Hoch HC, Burr TJ, Mowery P. Characterization of the Xylella fastidiosa PD1671 gene encoding degenerate c-di-GMP GGDEF/EAL domains, and its role in the development of Pierce's disease. PLoS One 2015; 10:e0121851. [PMID: 25811864 PMCID: PMC4374697 DOI: 10.1371/journal.pone.0121851] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 02/16/2015] [Indexed: 01/09/2023] Open
Abstract
Xylella fastidiosa is an important phytopathogenic bacterium that causes many serious plant diseases including Pierce's disease of grapevines. X. fastidiosa is thought to induce disease by colonizing and clogging xylem vessels through the formation of cell aggregates and bacterial biofilms. Here we examine the role in X. fastidiosa virulence of an uncharacterized gene, PD1671, annotated as a two-component response regulator with potential GGDEF and EAL domains. GGDEF domains are found in c-di-GMP diguanylate cyclases while EAL domains are found in phosphodiesterases, and these domains are for c-di-GMP production and turnover, respectively. Functional analysis of the PD1671 gene revealed that it affected multiple X. fastidiosa virulence-related phenotypes. A Tn5 PD1671 mutant had a hypervirulent phenotype in grapevines presumably due to enhanced expression of gum genes leading to increased exopolysaccharide levels that resulted in elevated biofilm formation. Interestingly, the PD1671 mutant also had decreased motility in vitro but did not show a reduced distribution in grapevines following inoculation. Given these responses, the putative PD1671 protein may be a negative regulator of X. fastidiosa virulence.
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Affiliation(s)
- Luciana Cursino
- Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America
- Department of Biology, Hobart and William Smith Colleges Geneva, New York, United States of America
| | - Dusit Athinuwat
- Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America
| | - Kelly R. Patel
- Department of Biology, Hobart and William Smith Colleges Geneva, New York, United States of America
| | - Cheryl D. Galvani
- Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America
- Department of Biology, Hobart and William Smith Colleges Geneva, New York, United States of America
| | - Paulo A. Zaini
- Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America
| | - Yaxin Li
- Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America
| | - Leonardo De La Fuente
- Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America
| | - Harvey C. Hoch
- Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America
| | - Thomas J. Burr
- Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America
| | - Patricia Mowery
- Department of Biology, Hobart and William Smith Colleges Geneva, New York, United States of America
- * E-mail:
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Cruz LF, Parker JK, Cobine PA, De La Fuente L. Calcium-Enhanced Twitching Motility in Xylella fastidiosa Is Linked to a Single PilY1 Homolog. Appl Environ Microbiol 2014; 80:7176-85. [PMID: 25217013 PMCID: PMC4249194 DOI: 10.1128/aem.02153-14] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 09/08/2014] [Indexed: 11/20/2022] Open
Abstract
The plant-pathogenic bacterium Xylella fastidiosa is restricted to the xylem vessel environment, where mineral nutrients are transported through the plant host; therefore, changes in the concentrations of these elements likely impact the growth and virulence of this bacterium. Twitching motility, dependent on type IV pili (TFP), is required for movement against the transpiration stream that results in basipetal colonization. We previously demonstrated that calcium (Ca) increases the motility of X. fastidiosa, although the mechanism was unknown. PilY1 is a TFP structural protein recently shown to bind Ca and to regulate twitching and adhesion in bacterial pathogens of humans. Sequence analysis identified three pilY1 homologs in X. fastidiosa (PD0023, PD0502, and PD1611), one of which (PD1611) contains a Ca-binding motif. Separate deletions of PD0023 and PD1611 resulted in mutants that still showed twitching motility and were not impaired in attachment or biofilm formation. However, the response of increased twitching at higher Ca concentrations was lost in the pilY1-1611 mutant. Ca does not modulate the expression of any of the X. fastidiosa PilY1 homologs, although it increases the expression of the retraction ATPase pilT during active movement. The evidence presented here suggests functional differences between the PilY1 homologs, which may provide X. fastidiosa with an adaptive advantage in environments with high Ca concentrations, such as xylem sap.
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Affiliation(s)
- Luisa F Cruz
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA
| | - Jennifer K Parker
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA
| | - Paul A Cobine
- Department of Biological Sciences, Auburn University, Auburn, Alabama, USA
| | - Leonardo De La Fuente
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA
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Dugé de Bernonville T, Noël LD, SanCristobal M, Danoun S, Becker A, Soreau P, Arlat M, Lauber E. Transcriptional reprogramming and phenotypical changes associated with growth ofXanthomonas campestrispv.campestrisin cabbage xylem sap. FEMS Microbiol Ecol 2014; 89:527-41. [DOI: 10.1111/1574-6941.12345] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 04/22/2014] [Accepted: 04/22/2014] [Indexed: 11/27/2022] Open
Affiliation(s)
- Thomas Dugé de Bernonville
- Laboratoire des Interactions Plantes Micro-organismes (LIPM); UMR 441; INRA; Castanet-Tolosan France
- Laboratoire des Interactions Plantes Micro-organismes (LIPM); UMR 2594; CNRS; Castanet-Tolosan France
| | - Laurent D. Noël
- Laboratoire des Interactions Plantes Micro-organismes (LIPM); UMR 441; INRA; Castanet-Tolosan France
- Laboratoire des Interactions Plantes Micro-organismes (LIPM); UMR 2594; CNRS; Castanet-Tolosan France
| | - Magali SanCristobal
- UMR 1388 Génétique, Physiologie et Systèmes d'Elevage; INRA; Castanet-Tolosan France
- UMR 1388 Génétique, Physiologie et Systèmes d'Elevage; Université de Toulouse INPT ENSAT; Castanet-Tolosan France
- UMR 1388 Génétique, Physiologie et Systèmes d'Elevage; Université de Toulouse INPT ENVT; Toulouse France
| | - Saida Danoun
- Laboratoire de Recherches en Sciences Végétales (LRSV); UMR 5546; Université de Toulouse, UPS; Castanet-Tolosan France
- Laboratoire de Recherches en Sciences Végétales (LRSV); UMR 5546; CNRS; Castanet-Tolosan France
| | - Anke Becker
- Loewe Center for Synthetic Microbiology and Department of Biology; Philipps-Universität Marburg; Marburg Germany
| | - Paul Soreau
- CEA Cadarache; IBEB-SBVME; Research Group in Applied Phytotechnics; UMR 6191 CNRS-CEA; Aix-Marseille University; Saint-Paul-lez-Durance Cedex France
| | - Matthieu Arlat
- Laboratoire des Interactions Plantes Micro-organismes (LIPM); UMR 441; INRA; Castanet-Tolosan France
- Laboratoire des Interactions Plantes Micro-organismes (LIPM); UMR 2594; CNRS; Castanet-Tolosan France
- Université de Toulouse, UPS; Toulouse France
| | - Emmanuelle Lauber
- Laboratoire des Interactions Plantes Micro-organismes (LIPM); UMR 441; INRA; Castanet-Tolosan France
- Laboratoire des Interactions Plantes Micro-organismes (LIPM); UMR 2594; CNRS; Castanet-Tolosan France
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Navarrete F, De La Fuente L. Response of Xylella fastidiosa to zinc: decreased culturability, increased exopolysaccharide production, and formation of resilient biofilms under flow conditions. Appl Environ Microbiol 2014; 80:1097-107. [PMID: 24271184 PMCID: PMC3911211 DOI: 10.1128/aem.02998-13] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 11/20/2013] [Indexed: 12/30/2022] Open
Abstract
The bacterial plant pathogen Xylella fastidiosa produces biofilm that accumulates in the host xylem vessels, affecting disease development in various crops and bacterial acquisition by insect vectors. Biofilms are sensitive to the chemical composition of the environment, and mineral elements being transported in the xylem are of special interest for this pathosystem. Here, X. fastidiosa liquid cultures were supplemented with zinc and compared with nonamended cultures to determine the effects of Zn on growth, biofilm, and exopolysaccharide (EPS) production under batch and flow culture conditions. The results show that Zn reduces growth and biofilm production under both conditions. However, in microfluidic chambers under liquid flow and with constant bacterial supplementation (closer to conditions inside the host), a dramatic increase in biofilm aggregates was seen in the Zn-amended medium. Biofilms formed under these conditions were strongly attached to surfaces and were not removed by medium flow. This phenomenon was correlated with increased EPS production in stationary-phase cells grown under high Zn concentrations. Zn did not cause greater adhesion to surfaces by individual cells. Additionally, viability analyses suggest that X. fastidiosa may be able to enter the viable but nonculturable state in vitro, and Zn can hasten the onset of this state. Together, these findings suggest that Zn can act as a stress factor with pleiotropic effects on X. fastidiosa and indicate that, although Zn could be used as a bactericide treatment, it could trigger the undesired effect of stronger biofilm formation upon reinoculation events.
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Affiliation(s)
- Fernando Navarrete
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA
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Cogan NG, Donahue MR, Whidden M, De La Fuente L. Pattern formation exhibited by biofilm formation within microfluidic chambers. Biophys J 2013; 104:1867-74. [PMID: 23663829 DOI: 10.1016/j.bpj.2013.03.037] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 03/22/2013] [Accepted: 03/25/2013] [Indexed: 10/26/2022] Open
Abstract
This article investigates the dynamics of an important bacterial pathogen, Xylella fastidiosa, within artificial plant xylem. The bacterium is the causative agent of a variety of diseases that strike fruit-bearing plants including Pierce's disease of grapevine. Biofilm colonization within microfluidic chambers was visualized in a laboratory setting, showing robust, regular spatial patterning. We also develop a mathematical model, based on a multiphase approach that is able to capture the spacing of the pattern and points to the role of the exopolymeric substance as the main source of control of the pattern dynamics. We concentrate on estimating the attachment/detachment processes within the chamber because these are two mechanisms that have the potential to be engineered by applying various chemicals to prevent or treat the disease.
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Affiliation(s)
- N G Cogan
- Department of Mathematics, Florida State University, Tallahassee, Florida, USA.
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Cobine PA, Cruz LF, Navarrete F, Duncan D, Tygart M, De La Fuente L. Xylella fastidiosa differentially accumulates mineral elements in biofilm and planktonic cells. PLoS One 2013; 8:e54936. [PMID: 23349991 PMCID: PMC3551809 DOI: 10.1371/journal.pone.0054936] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 12/17/2012] [Indexed: 01/04/2023] Open
Abstract
Xylella fastidiosa is a bacterial plant pathogen that infects numerous plant hosts. Disease develops when the bacterium colonizes the xylem vessels and forms a biofilm. Inductively coupled plasma optical emission spectroscopy was used to examine the mineral element content of this pathogen in biofilm and planktonic states. Significant accumulations of copper (30-fold), manganese (6-fold), zinc (5-fold), calcium (2-fold) and potassium (2-fold) in the biofilm compared to planktonic cells were observed. Other mineral elements such as sodium, magnesium and iron did not significantly differ between biofilm and planktonic cells. The distribution of mineral elements in the planktonic cells loosely mirrors the media composition; however the unique mineral element distribution in biofilm suggests specific mechanisms of accumulation from the media. A cell-to-surface attachment assay shows that addition of 50 to 100 µM Cu to standard X. fastidiosa media increases biofilm, while higher concentrations (>200 µM) slow cell growth and prevent biofilm formation. Moreover cell-to-surface attachment was blocked by specific chelation of copper. Growth of X. fastidiosa in microfluidic chambers under flow conditions showed that addition of 50 µM Cu to the media accelerated attachment and aggregation, while 400 µM prevented this process. Supplementation of standard media with Mn showed increased biofilm formation and cell-to-cell attachment. In contrast, while the biofilm accumulated Zn, supplementation to the media with this element caused inhibited growth of planktonic cells and impaired biofilm formation. Collectively these data suggest roles for these minerals in attachment and biofilm formation and therefore the virulence of this pathogen.
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Affiliation(s)
- Paul A Cobine
- Department of Biological Sciences, Auburn University, Auburn, Alabama, USA.
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Cruz LF, Cobine PA, De La Fuente L. Calcium increases Xylella fastidiosa surface attachment, biofilm formation, and twitching motility. Appl Environ Microbiol 2012; 78:1321-31. [PMID: 22194297 PMCID: PMC3294462 DOI: 10.1128/aem.06501-11] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 12/12/2011] [Indexed: 01/21/2023] Open
Abstract
Xylella fastidiosa is a plant-pathogenic bacterium that forms biofilms inside xylem vessels, a process thought to be influenced by the chemical composition of xylem sap. In this work, the effect of calcium on the production of X. fastidiosa biofilm and movement was analyzed under in vitro conditions. After a dose-response study with 96-well plates using eight metals, the strongest increase of biofilm formation was observed when medium was supplemented with at least 1.0 mM CaCl(2). The removal of Ca by extracellular (EGTA, 1.5 mM) and intracellular [1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA/AM), 75 μM] chelators reduced biofilm formation without compromising planktonic growth. The concentration of Ca influenced the force of adhesion to the substrate, biofilm thickness, cell-to-cell aggregation, and twitching motility, as shown by assays with microfluidic chambers and other assays. The effect of Ca on attachment was lost when cells were treated with tetracycline, suggesting that Ca has a metabolic or regulatory role in cell adhesion. A double mutant (fimA pilO) lacking type I and type IV pili did not improve biofilm formation or attachment when Ca was added to the medium, while single mutants of type I (fimA) or type IV (pilB) pili formed more biofilm under conditions of higher Ca concentrations. The concentration of Ca in the medium did not significantly influence the levels of exopolysaccharide produced. Our findings indicate that the role of Ca in biofilm formation may be related to the initial surface and cell-to-cell attachment and colonization stages of biofilm establishment, which rely on critical functions by fimbrial structures.
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Affiliation(s)
- Luisa F. Cruz
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA
| | - Paul A. Cobine
- Department of Biological Sciences, Auburn University, Auburn, Alabama, USA
| | - Leonardo De La Fuente
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA
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Chen H, Yada R. Nanotechnologies in agriculture: New tools for sustainable development. Trends Food Sci Technol 2011. [DOI: 10.1016/j.tifs.2011.09.004] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Cursino L, Galvani CD, Athinuwat D, Zaini PA, Li Y, De La Fuente L, Hoch HC, Burr TJ, Mowery P. Identification of an operon, Pil-Chp, that controls twitching motility and virulence in Xylella fastidiosa. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2011; 24:1198-1206. [PMID: 21692637 DOI: 10.1094/mpmi-10-10-0252] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Xylella fastidiosa is an important phytopathogenic bacterium that causes many serious plant diseases, including Pierce's disease of grapevines. Disease manifestation by X. fastidiosa is associated with the expression of several factors, including the type IV pili that are required for twitching motility. We provide evidence that an operon, named Pil-Chp, with genes homologous to those found in chemotaxis systems, regulates twitching motility. Transposon insertion into the pilL gene of the operon resulted in loss of twitching motility (pilL is homologous to cheA genes encoding kinases). The X. fastidiosa mutant maintained the type IV pili, indicating that the disrupted pilL or downstream operon genes are involved in pili function, and not biogenesis. The mutated X. fastidiosa produced less biofilm than wild-type cells, indicating that the operon contributes to biofilm formation. Finally, in planta the mutant produced delayed and less severe disease, indicating that the Pil-Chp operon contributes to the virulence of X. fastidiosa, presumably through its role in twitching motility.
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Affiliation(s)
- Luciana Cursino
- Department of Plant Pathology and Palnt-Microbe Biology, Cornell University -- New York State Agricultural Experimental Station, Geneva, NY 14456, USA
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Chatelet DS, Wistrom CM, Purcell AH, Rost TL, Matthews MA. Xylem structure of four grape varieties and 12 alternative hosts to the xylem-limited bacterium Xylella fastidious. ANNALS OF BOTANY 2011; 108:73-85. [PMID: 21546428 PMCID: PMC3119617 DOI: 10.1093/aob/mcr106] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 03/21/2011] [Indexed: 05/05/2023]
Abstract
BACKGROUND AND AIMS The bacterium Xylella fastidiosa (Xf), responsible for Pierce's disease (PD) of grapevine, colonizes the xylem conduits of vines, ultimately killing the plant. However, Vitis vinifera grapevine varieties differ in their susceptibility to Xf and numerous other plant species tolerate Xf populations without showing symptoms. The aim of this study was to examine the xylem structure of grapevines with different susceptibilities to Xf infection, as well as the xylem structure of non-grape plant species that support or limit movement of Xf to determine if anatomical differences might explain some of the differences in susceptibility to Xf. METHODS Air and paint were introduced into leaves and stems to examine the connectivity between stem and leaves and the length distribution of their vessels. Leaf petiole and stem anatomies were studied to determine the basis for the free or restricted movement of Xf into the plant. KEY RESULTS There were no obvious differences in stem or petiole vascular anatomy among the grape varieties examined, nor among the other plant species that would explain differences in resistance to Xf. Among grape varieties, the more tolerant 'Sylvaner' had smaller stem vessel diameters and 20 % more parenchyma rays than the other three varieties. Alternative hosts supporting Xf movement had slightly longer open xylem conduits within leaves, and more connection between stem and leaves, when compared with alternative hosts that limit Xf movement. CONCLUSIONS Stem--leaf connectivity via open xylem conduits and vessel length is not responsible for differences in PD tolerance among grape varieties, or for limiting bacterial movement in the tolerant plant species. However, it was found that tolerant host plants had narrower vessels and more parenchyma rays, possibly restricting bacterial movement at the level of the vessels. The implications of xylem structure and connectivity for the means and regulation of bacterial movement are discussed.
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Affiliation(s)
- David S. Chatelet
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02906, USA
| | - Christina M. Wistrom
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720-3114, USA
| | - Alexander H. Purcell
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720-3114, USA
| | - Thomas L. Rost
- Department of Plant Biology, University of California, Davis, CA 95616, USA
| | - Mark A. Matthews
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA
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Shi X, Bi J, Morse JG, Toscano NC, Cooksey DA. Differential expression of genes of Xylella fastidiosa in xylem fluid of citrus and grapevine. FEMS Microbiol Lett 2010; 304:82-8. [PMID: 20070368 DOI: 10.1111/j.1574-6968.2009.01885.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Xylella fastidiosa causes a serious Pierce's disease (PD) in grapevine. Xylella fastidiosa cells from a PD strain were grown in a pure xylem fluid of a susceptible grapevine cultivar vs. xylem fluid from citrus, which is not a host for this strain of X. fastidiosa. When grown in grapevine xylem fluid, cells of the PD strain formed clumps and biofilm formed to a greater extent than in citrus xylem fluid, although the PD strain did grow in xylem fluid of three citrus varieties. The differential expression of selected genes of a PD X. fastidiosa strain cultured in the two xylem fluids was analyzed using a DNA macroarray. Compared with citrus xylem fluid, grapevine xylem fluid stimulated the expression of X. fastidiosa genes involved in virulence regulation, such as gacA, algU, xrvA, and hsq, and also genes involved in the biogenesis of pili and twitching motility, such as fimT, pilI, pilU, and pilY1. Increased gene expression likely contributes to PD expression in grapevine, whereas citrus xylem fluid did not support or possibly suppressed the expression of these virulence genes.
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Affiliation(s)
- Xiangyang Shi
- Department of Plant Pathology and Microbiology, University of California-Riverside, Riverside, CA, USA.
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da Silva Neto JF, Koide T, Gomes SL, Marques MV. Global gene expression under nitrogen starvation in Xylella fastidiosa: contribution of the σ54 regulon. BMC Microbiol 2010; 10:231. [PMID: 20799976 PMCID: PMC3224663 DOI: 10.1186/1471-2180-10-231] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Accepted: 08/28/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Xylella fastidiosa, a Gram-negative fastidious bacterium, grows in the xylem of several plants causing diseases such as citrus variegated chlorosis. As the xylem sap contains low concentrations of amino acids and other compounds, X. fastidiosa needs to cope with nitrogen limitation in its natural habitat. RESULTS In this work, we performed a whole-genome microarray analysis of the X. fastidiosa nitrogen starvation response. A time course experiment (2, 8 and 12 hours) of cultures grown in defined medium under nitrogen starvation revealed many differentially expressed genes, such as those related to transport, nitrogen assimilation, amino acid biosynthesis, transcriptional regulation, and many genes encoding hypothetical proteins. In addition, a decrease in the expression levels of many genes involved in carbon metabolism and energy generation pathways was also observed. Comparison of gene expression profiles between the wild type strain and the rpoN null mutant allowed the identification of genes directly or indirectly induced by nitrogen starvation in a σ54-dependent manner. A more complete picture of the σ54 regulon was achieved by combining the transcriptome data with an in silico search for potential σ54-dependent promoters, using a position weight matrix approach. One of these σ54-predicted binding sites, located upstream of the glnA gene (encoding glutamine synthetase), was validated by primer extension assays, confirming that this gene has a σ54-dependent promoter. CONCLUSIONS Together, these results show that nitrogen starvation causes intense changes in the X. fastidiosa transcriptome and some of these differentially expressed genes belong to the σ54 regulon.
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Affiliation(s)
- José F da Silva Neto
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes 1374, 05508-000 São Paulo, SP, Brazil
| | - Tie Koide
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-000 São Paulo, SP, Brazil
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. dos Bandeirantes 3900, 14049-900 Ribeirão Preto, SP, Brasil
| | - Suely L Gomes
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-000 São Paulo, SP, Brazil
| | - Marilis V Marques
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes 1374, 05508-000 São Paulo, SP, Brazil
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Transcriptome analysis of the phytobacterium Xylella fastidiosa growing under xylem-based chemical conditions. J Biomed Biotechnol 2010; 2010:781365. [PMID: 20625415 PMCID: PMC2896883 DOI: 10.1155/2010/781365] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 03/15/2010] [Accepted: 04/12/2010] [Indexed: 11/17/2022] Open
Abstract
Xylella fastidiosa is a xylem-limited bacterium responsible for important plant diseases, like citrus-variegated chlorosis (CVC) and grapevine Pierce's disease (PD). Interestingly, in vitro growth of X. fastidiosa in chemically defined media that resemble xylem fluid has been achieved, allowing studies of metabolic processes used by xylem-dwelling bacteria to thrive in such nutrient-poor conditions. Thus, we performed microarray hybridizations to compare transcriptomes of X. fastidiosa cells grown in 3G10-R, a medium that resembles grape sap, and in Periwinkle Wilt (PW), the complex medium traditionally used to cultivate X. fastidiosa. We identified 299 transcripts modulated in response to growth in these media. Some 3G10R-overexpressed genes have been shown to be upregulated in cells directly isolated from infected plants and may be involved in plant colonization, virulence and environmental competition. In contrast, cells cultivated in PW show a metabolic switch associated with increased aerobic respiration and enhanced bacterial growth rates.
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