1
|
Špacapan M, Myers MP, Braga L, Venturi V. Pseudomonas fuscovaginae quorum sensing studies: 5% dominates cell-to-cell conversations. Microbiol Spectr 2024; 12:e0417923. [PMID: 38511955 PMCID: PMC11064508 DOI: 10.1128/spectrum.04179-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 03/12/2024] [Indexed: 03/22/2024] Open
Abstract
A common feature of N-acyl-l-homoserine lactone (AHL) quorum-sensing (QS) systems is that the AHL signal is autoinducing. Once induced, a cell will further amplify the signal via a positive feedback loop. Pseudomonas fuscovaginae UPB0736 has two fully functional AHL QS systems, called PfsI/R and PfvI/R, which are inactive in a standard laboratory setting. In this work, we induce the QS systems with exogenous AHL signals and characterize the AHL signal amplification effect and QS activation dynamics at community and single-cell level. While the cognate signal is in both cases significantly further amplified to physiologically relevant levels, we observe only a limited response in terms of AHL synthase gene promoter activity. Additionally, the PfsI/R QS system exhibits a unique dramatic phenotypic heterogeneity, where only up to 5% of all cells amplify the signal further and are, thus, considered to be QS active. IMPORTANCE Bacteria use N-acyl-l-homoserine lactone (AHL) quorum-sensing (QS) systems for population-wide phenotypic coordination. The QS configuration in Pseudomonas fuscovaginae is dramatically different from other model examples of AHL QS signaling and, thus, represents an important exception to the norm, which usually states that QS triggers population-wide phenotypic transitions in relation to cell density. We argue that the differences in QS dynamics of P. fuscovaginae highlight its different evolutionary purpose, which is ultimately dictated by the selective pressures of its natural habitat. We hope that this example will further expand our understanding of the complex and yet unknown QS-enabled sociomicrobiology. Furthermore, we argue that exemptions to the QS norm will be found in other plant-pathogenic bacterial strains that grow in similar environments and that molecularly similar QS systems do not necessarily share a similar evolutionary purpose; therefore, generalizations about bacterial cell-to-cell signaling systems function should be avoided.
Collapse
Affiliation(s)
- Mihael Špacapan
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Michael P. Myers
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Luca Braga
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Vittorio Venturi
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
- African Genome Center, University Mohammed VI Polytechnic (UM6P), Ben Guerir, Morocco
| |
Collapse
|
2
|
De La Fuente L, Navas-Cortés JA, Landa BB. Ten Challenges to Understanding and Managing the Insect-Transmitted, Xylem-Limited Bacterial Pathogen Xylella fastidiosa. PHYTOPATHOLOGY 2024; 114:869-884. [PMID: 38557216 DOI: 10.1094/phyto-12-23-0476-kc] [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: 04/04/2024]
Abstract
An unprecedented plant health emergency in olives has been registered over the last decade in Italy, arguably more severe than what occurred repeatedly in grapes in the United States in the last 140 years. These emergencies are epidemics caused by a stealthy pathogen, the xylem-limited, insect-transmitted bacterium Xylella fastidiosa. Although these epidemics spurred research that answered many questions about the biology and management of this pathogen, many gaps in knowledge remain. For this review, we set out to represent both the U.S. and European perspectives on the most pressing challenges that need to be addressed. These are presented in 10 sections that we hope will stimulate discussion and interdisciplinary research. We reviewed intrinsic problems that arise from the fastidious growth of X. fastidiosa, the lack of specificity for insect transmission, and the economic and social importance of perennial mature woody plant hosts. Epidemiological models and predictions of pathogen establishment and disease expansion, vital for preparedness, are based on very limited data. Most of the current knowledge has been gathered from a few pathosystems, whereas several hundred remain to be studied, probably including those that will become the center of the next epidemic. Unfortunately, aspects of a particular pathosystem are not always transferable to others. We recommend diversification of research topics of both fundamental and applied nature addressing multiple pathosystems. Increasing preparedness through knowledge acquisition is the best strategy to anticipate and manage diseases caused by this pathogen, described as "the most dangerous plant bacterium known worldwide."
Collapse
Affiliation(s)
- Leonardo De La Fuente
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, U.S.A
| | - Juan A Navas-Cortés
- Department of Crop Protection. Institute for Sustainable Agriculture (IAS), Consejo Superior de Investigaciones Científicas (CSIC), Córdoba, Spain
| | - Blanca B Landa
- Department of Crop Protection. Institute for Sustainable Agriculture (IAS), Consejo Superior de Investigaciones Científicas (CSIC), Córdoba, Spain
| |
Collapse
|
3
|
He YW, Deng Y, Miao Y, Chatterjee S, Tran TM, Tian J, Lindow S. DSF-family quorum sensing signal-mediated intraspecies, interspecies, and inter-kingdom communication. Trends Microbiol 2023; 31:36-50. [PMID: 35941062 DOI: 10.1016/j.tim.2022.07.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/17/2022] [Accepted: 07/19/2022] [Indexed: 11/28/2022]
Abstract
While most bacteria are unicellular microbes they communicate with each other and with their environments to adapt their behaviors. Quorum sensing (QS) is one of the best-studied cell-cell communication modes. QS signaling is not restricted to bacterial cell-to-cell communication - it also allows communication between bacteria and their eukaryotic hosts. The diffusible signal factor (DSF) family represents an intriguing type of QS signal with multiple roles found in diverse Gram-negative bacteria. Over the last decade, extensive progress has been made in understanding DSF-mediated communication among bacteria, fungi, insects, plants, and zebrafish. This review provides an update on these new developments with the aim of building a more comprehensive picture of DSF-mediated intraspecies, interspecies, and inter-kingdom communication.
Collapse
Affiliation(s)
- Ya-Wen He
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Yinyue Deng
- School of Pharmaceutical Science (Shenzhen), Sun Yat-Sen University, Shenzhen 518107, China
| | - Yansong Miao
- School of Biological Science, Nanyang Technological University, Singapore
| | | | - Tuan Minh Tran
- Department of Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Jing Tian
- The College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Steven Lindow
- Department of Plant and Microbial Biology, University of California Berkeley, CA 94720, USA
| |
Collapse
|
4
|
Beccaccioli M, Pucci N, Salustri M, Scortichini M, Zaccaria M, Momeni B, Loreti S, Reverberi M, Scala V. Fungal and bacterial oxylipins are signals for intra- and inter-cellular communication within plant disease. FRONTIERS IN PLANT SCIENCE 2022; 13:823233. [PMID: 36186042 PMCID: PMC9524268 DOI: 10.3389/fpls.2022.823233] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 08/24/2022] [Indexed: 06/16/2023]
Abstract
Lipids are central at various stages of host-pathogen interactions in determining virulence and modulating plant defense. Free fatty acids may act as substrates for oxidizing enzymes [e.g., lipoxygenases (LOXs) and dioxygenases (DOXs)] that synthesize oxylipins. Fatty acids and oxylipins function as modulators of several pathways in cell-to-cell communication; their structural similarity among plant, fungal, and bacterial taxa suggests potential in cross-kingdom communication. We provide a prospect of the known role of fatty acids and oxylipins in fungi and bacteria during plant-pathogen interactions. In the pathogens, oxylipin-mediated signaling pathways are crucial both in development and host infection. Here, we report on case studies suggesting that oxylipins derived from oleic, linoleic, and linolenic acids are crucial in modulating the pathogenic lifestyle in the host plant. Intriguingly, overlapping (fungi-plant/bacteria-plant) results suggest that different inter-kingdom pathosystems use similar lipid signals to reshape the lifestyle of the contenders and occasionally determine the outcome of the challenge.
Collapse
Affiliation(s)
- Marzia Beccaccioli
- Department of Environmental Biology, Sapienza University of Rome, Rome, Italy
| | - Nicoletta Pucci
- Research Centre for Plant Protection and Certification, Council for Agricultural Research and the Analysis of Agricultural Economics (CREA), Rome, Italy
| | - Manuel Salustri
- Department of Environmental Biology, Sapienza University of Rome, Rome, Italy
| | - Marco Scortichini
- Research Centre for Olive, Fruit and Citrus Crops, Council for Agricultural Research and the Analysis of Agricultural Economics (CREA), Rome, Italy
| | - Marco Zaccaria
- Department of Biology, Boston College, Newton, MA, United States
| | - Babak Momeni
- Department of Biology, Boston College, Newton, MA, United States
| | - Stefania Loreti
- Research Centre for Plant Protection and Certification, Council for Agricultural Research and the Analysis of Agricultural Economics (CREA), Rome, Italy
| | - Massimo Reverberi
- Department of Environmental Biology, Sapienza University of Rome, Rome, Italy
| | - Valeria Scala
- Research Centre for Plant Protection and Certification, Council for Agricultural Research and the Analysis of Agricultural Economics (CREA), Rome, Italy
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Sharma A, Abrahamian P, Carvalho R, Choudhary M, Paret ML, Vallad GE, Jones JB. Future of Bacterial Disease Management in Crop Production. ANNUAL REVIEW OF PHYTOPATHOLOGY 2022; 60:259-282. [PMID: 35790244 DOI: 10.1146/annurev-phyto-021621-121806] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Bacterial diseases are a constant threat to crop production globally. Current management strategies rely on an array of tactics, including improved cultural practices; application of bactericides, plant activators, and biocontrol agents; and use of resistant varieties when available. However, effective management remains a challenge, as the longevity of deployed tactics is threatened by constantly changing bacterial populations. Increased scrutiny of the impact of pesticides on human and environmental health underscores the need for alternative solutions that are durable, sustainable, accessible to farmers, and environmentally friendly. In this review, we discuss the strengths and shortcomings of existing practices and dissect recent advances that may shape the future of bacterial disease management. We conclude that disease resistance through genome modification may be the most effective arsenal against bacterial diseases. Nonetheless, more research is necessary for developing novel bacterial disease management tactics to meet the food demand of a growing global population.
Collapse
Affiliation(s)
- Anuj Sharma
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA;
| | - Peter Abrahamian
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA;
- Gulf Coast Research and Education Center, University of Florida, Wimauma, Florida, USA
- Plant Pathogen Confirmatory Diagnostic Laboratory, USDA-APHIS, Beltsville, Maryland, USA
| | - Renato Carvalho
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA;
| | - Manoj Choudhary
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA;
| | - Mathews L Paret
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA;
- North Florida Research and Education Center, University of Florida, Quincy, Florida, USA
| | - Gary E Vallad
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA;
- Gulf Coast Research and Education Center, University of Florida, Wimauma, Florida, USA
| | - Jeffrey B Jones
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA;
| |
Collapse
|
7
|
Scala V, Salustri M, Loreti S, Pucci N, Cacciotti A, Tatulli G, Scortichini M, Reverberi M. Mass Spectrometry-Based Targeted Lipidomics and Supervised Machine Learning Algorithms in Detecting Disease, Cultivar, and Treatment Biomarkers in Xylella fastidiosa subsp. pauca-Infected Olive Trees. FRONTIERS IN PLANT SCIENCE 2022; 13:833245. [PMID: 35528940 PMCID: PMC9072861 DOI: 10.3389/fpls.2022.833245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
In 2013, Xylella fastidiosa (Xf) was detected for the first time in Apulia and, subsequently, recognized as the causal agent of the olive quick decline syndrome (OQDS). To contain the disease, the olive germplasm was evaluated for resistance to Xf, identifying cultivars with different susceptibility to the pathogen. Regarding this, the resistant cultivar Leccino has generally a lower bacterial titer compared with the susceptible cultivar Ogliarola salentina. Among biomolecules, lipids could have a pivotal role in the interaction of Xf with its host. In the grapevine Pierce's disease, fatty acid molecules, the diffusible signaling factors (DSFs), act as regulators of Xf lifestyle and are crucial for its virulence. Other lipid compounds derived from fatty acid oxidation, namely, oxylipins, can affect, in vitro, biofilm formation in Xf subsp. pauca (Xfp) strain De Donno, that is, the strain causing OQDS. In this study, we combined high-performance liquid chromatography-mass spectrometry-MS-based targeted lipidomics with supervised learning algorithms (random forest, support vector machine, and neural networks) to classify olive tree samples from Salento. The dataset included samples from either OQDS-positive or OQDS-negative olive trees belonging either to cultivar Ogliarola salentina or Leccino treated or not with the zinc-copper-citric acid biocomplex Dentamet®. We built classifiers using the relative differences in lipid species able to discriminate olive tree samples, namely, (1) infected and non-infected, (2) belonging to different cultivars, and (3) treated or untreated with Dentamet®. Lipid entities emerging as predictors of the thesis are free fatty acids (C16:1, C18:1, C18:2, C18:3); the LOX-derived oxylipins 9- and 13-HPOD/TrE; the DOX-derived oxylipin 10-HPOME; and diacylglyceride DAG36:4(18:1/18:3).
Collapse
Affiliation(s)
- Valeria Scala
- Council for Agricultural Research and Economics (CREA), Research Centre for Plant Protection and Certification, Rome, Italy
| | - Manuel Salustri
- Department of Environmental Biology, Sapienza University, Rome, Italy
| | - Stefania Loreti
- Council for Agricultural Research and Economics (CREA), Research Centre for Plant Protection and Certification, Rome, Italy
| | - Nicoletta Pucci
- Council for Agricultural Research and Economics (CREA), Research Centre for Plant Protection and Certification, Rome, Italy
| | - Andrea Cacciotti
- Department of Environmental Biology, Sapienza University, Rome, Italy
| | - Giuseppe Tatulli
- Council for Agricultural Research and Economics (CREA), Research Centre for Plant Protection and Certification, Rome, Italy
| | - Marco Scortichini
- Council for Agricultural Research and Economics (CREA), Research Centre for Olive, Fruit and Citrus Crops, Rome, Italy
| | - Massimo Reverberi
- Department of Environmental Biology, Sapienza University, Rome, Italy
| |
Collapse
|
8
|
Extracellular vesicles from phytobacteria: Properties, functions and uses. Biotechnol Adv 2022; 58:107934. [DOI: 10.1016/j.biotechadv.2022.107934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 02/25/2022] [Accepted: 02/26/2022] [Indexed: 11/20/2022]
|
9
|
de Souza-Neto RR, Carvalho IGB, Martins PMM, Picchi SC, Tomaz JP, Caserta R, Takita MA, de Souza AA. MqsR toxin as a biotechnological tool for plant pathogen bacterial control. Sci Rep 2022; 12:2794. [PMID: 35181693 PMCID: PMC8857320 DOI: 10.1038/s41598-022-06690-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 12/23/2021] [Indexed: 11/09/2022] Open
Abstract
Type II toxin-antitoxin (TA) systems are widespread in bacteria and are involved in important cell features, such as cell growth inhibition and antimicrobial tolerance, through the induction of persister cells. Overall, these characteristics are associated with bacterial survival under stress conditions and represent a significant genetic mechanism to be explored for antibacterial molecules. We verified that even though Xylella fastidiosa and Xanthomonas citri subsp. citri share closely related genomes, they have different Type II TA system contents. One important difference is the absence of mqsRA in X. citri. The toxin component of this TA system has been shown to inhibit the growth of X. fastidiosa. Thus, the absence of mqsRA in X. citri led us to explore the possibility of using the MqsR toxin to impair X. citri growth. We purified MqsR and confirmed that the toxin was able to inhibit X. citri. Subsequently, transgenic citrus plants producing MqsR showed a significant reduction in citrus canker and citrus variegated chlorosis symptoms caused, respectively, by X. citri and X. fastidiosa. This study demonstrates that the use of toxins from TA systems is a promising strategy to be explored aiming bacterial control.
Collapse
Affiliation(s)
- Reinaldo Rodrigues de Souza-Neto
- Citrus Research Center, Agronomic Institute - IAC, Cordeirópolis, SP, Brazil.,Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas - UNICAMP, Campinas, SP, Brazil
| | | | | | | | - Juarez Pires Tomaz
- Rural Development Institute of Parana - IAPAR-EMATER, Londrina, PR, Brazil
| | - Raquel Caserta
- Citrus Research Center, Agronomic Institute - IAC, Cordeirópolis, SP, Brazil
| | | | | |
Collapse
|
10
|
Pandey SS, Chatterjee S. Insights into the Cell-to-Cell Signaling and Iron Homeostasis in Xanthomonas Virulence and Lifestyle. PHYTOPATHOLOGY 2022; 112:209-218. [PMID: 34289715 DOI: 10.1094/phyto-11-20-0513-rvw] [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: 06/13/2023]
Abstract
The Xanthomonas group of phytopathogens causes economically important diseases that lead to severe yield loss in major crops. Some Xanthomonas species are known to have an epiphytic and in planta lifestyle that is coordinated by several virulence-associated functions, cell-to-cell signaling (using diffusible signaling factor [DSF]), and environmental conditions, including iron availability. In this review, we described the role of cell-to-cell signaling by the DSF molecule and iron in the regulation of virulence-associated functions. Although DSF and iron are involved in the regulation of several virulence-associated functions, members of the Xanthomonas group of plant pathogens exhibit atypical patterns of regulation. Atypical patterns contribute to the adaptation to different lifestyles. Studies on DSF and iron biology indicate that virulence-associated functions can be regulated in completely contrasting fashions by the same signaling system in closely related xanthomonads.
Collapse
Affiliation(s)
- Sheo Shankar Pandey
- Citrus Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL 33850, U.S.A
| | | |
Collapse
|
11
|
Controlled spatial organization of bacterial growth reveals key role of cell filamentation preceding Xylella fastidiosa biofilm formation. NPJ Biofilms Microbiomes 2021; 7:86. [PMID: 34876576 PMCID: PMC8651647 DOI: 10.1038/s41522-021-00258-9] [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: 03/15/2021] [Accepted: 11/11/2021] [Indexed: 12/21/2022] Open
Abstract
The morphological plasticity of bacteria to form filamentous cells commonly represents an adaptive strategy induced by stresses. In contrast, for diverse human and plant pathogens, filamentous cells have been recently observed during biofilm formation, but their functions and triggering mechanisms remain unclear. To experimentally identify the underlying function and hypothesized cell communication triggers of such cell morphogenesis, spatially controlled cell patterning is pivotal. Here, we demonstrate highly selective cell adhesion of the biofilm-forming phytopathogen Xylella fastidiosa to gold-patterned SiO2 substrates with well-defined geometries and dimensions. The consequent control of both cell density and distances between cell clusters demonstrated that filamentous cell formation depends on cell cluster density, and their ability to interconnect neighboring cell clusters is distance-dependent. This process allows the creation of large interconnected cell clusters that form the structural framework for macroscale biofilms. The addition of diffusible signaling molecules from supernatant extracts provides evidence that cell filamentation is induced by quorum sensing. These findings and our innovative platform could facilitate therapeutic developments targeting biofilm formation mechanisms of X. fastidiosa and other pathogens.
Collapse
|
12
|
Ge Q, Cobine PA, De La Fuente L. The Influence of Copper Homeostasis Genes copA and copB on Xylella fastidiosa Virulence Is Affected by Sap Copper Concentration. PHYTOPATHOLOGY 2021; 111:1520-1529. [PMID: 33554639 DOI: 10.1094/phyto-12-20-0531-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Xylella fastidiosa is a xylem-limited plant pathogenic bacterium that causes diseases worldwide in crops such as grape, citrus, and olive. Although copper (Cu)-containing compounds are not used for management of X. fastidiosa-caused diseases, they are widely used in X. fastidiosa hosts in vineyards and orchards. The accumulation of Cu in soils and, therefore, plant saps, could be a challenge for X. fastidiosa survival. Here, the molecular basis of Cu homeostasis was studied in relation to virulence. Although homologous Cu-related genes copA (X. fastidiosa loci PD0100) and copB (PD0101) have been characterized in other bacteria, their functions differ among bacterial species. In vitro, both copA and copB mutants were more sensitive to Cu than the wild-type (WT) strain. Interestingly, the copA mutant was more sensitive to Cu shock, while the copB mutant was more sensitive to chronic Cu treatments. In tobacco greenhouse experiments with normal watering, both mutants reduced virulence compared with WT. But when Cu was added as a drench treatment, both copA and copB mutants had increased disease severity approximately 20 and 50% compared with mutants without Cu added, respectively, which were significantly higher than the approximately 5% observed for WT under the same conditions. These results indicate that the pathogen's Cu homeostasis affects virulence and is influenced by Cu concentration in the environment. Understanding Cu homeostasis in X. fastidiosa will help discern the outcome of Cu treatments and the adaptation of this pathogen to the xylem of plants that have been exposed to high Cu concentrations because of agricultural practices.
Collapse
Affiliation(s)
- Qing Ge
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849
| | - Paul A Cobine
- Department of Biological Sciences, Auburn University, Auburn, AL 36849
| | | |
Collapse
|
13
|
Xylella fastidiosa in Olive: A Review of Control Attempts and Current Management. Microorganisms 2021; 9:microorganisms9081771. [PMID: 34442850 PMCID: PMC8397937 DOI: 10.3390/microorganisms9081771] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/09/2021] [Accepted: 08/14/2021] [Indexed: 11/17/2022] Open
Abstract
Since 2013, Xylella fastidiosa Wells et al. has been reported to infect several hosts and to be present in different areas of Europe. The main damage has been inflicted on the olive orchards of southern Apulia (Italy), where a severe disease associated with X. fastidiosa subspecies pauca strain De Donno has led to the death of millions of trees. This dramatic and continuously evolving situation has led to European and national (Italian and Spanish) measures being implemented to reduce the spread of the pathogen and the associated olive quick decline syndrome (OQDS). Research has been also carried out to find solutions to better and directly fight the bacterium and its main insect vector, Philaenus spumarius L. In the course of this frantic effort, several treatments based on chemical or biological substances have been tested, in addition to plant breeding techniques and integrated pest management approaches. This review aims to summarize the attempts made so far and describe the prospects for better management of this serious threat, which poses alarming questions for the future of olive cultivation in the Mediterranean basin and beyond.
Collapse
|
14
|
Greco D, Aprile A, De Bellis L, Luvisi A. Diseases Caused by Xylella fastidiosa in Prunus Genus: An Overview of the Research on an Increasingly Widespread Pathogen. FRONTIERS IN PLANT SCIENCE 2021; 12:712452. [PMID: 34484274 PMCID: PMC8414816 DOI: 10.3389/fpls.2021.712452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 07/14/2021] [Indexed: 06/13/2023]
Abstract
Cultivated plants belonging to the genus Prunus are globally widespread and for some countries, are economically important crops; and they play a key role in the composition of a landscape. Xylella fastidiosa is a key threat to plant health, and several Prunus species are heavily stressed by this pathogen, such as almond, peach, and plum; many strain types of different subspecies can cause severe diseases. This review highlights different approaches to managing epidemic events related to X. fastidiosa in stone fruit plants. In fact, in most new European and Asian outbreaks, almond is the main and very common host and peach, plum, apricot, and cherry are widespread and profitable crops for the involved areas. Various diseases associated with stone fruit plants show different degrees of severity in relation to cultivar, although investigations are still limited. The development and selection of tolerant and resistant cultivars and the study of resistance mechanisms activated by the plant against X. fastidiosa infections seem to be the best way to find long-term solutions aimed at making affected areas recover. In addition, observations in orchards severely affected by the disease can be essential for collecting tolerant or resistant materials within the local germplasm. In areas where the bacterium is not yet present, a qualitative-quantitative study on entomofauna is also important for the timely identification of potential vectors and for developing effective control strategies.
Collapse
|
15
|
HPLC-MS/MS method applied to an untargeted metabolomics approach for the diagnosis of "olive quick decline syndrome". Anal Bioanal Chem 2021; 414:465-473. [PMID: 33765220 PMCID: PMC8748322 DOI: 10.1007/s00216-021-03279-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/09/2021] [Accepted: 03/05/2021] [Indexed: 11/04/2022]
Abstract
Olive quick decline syndrome (OQDS) is a disorder associated with bacterial infections caused by Xylella fastidiosa subsp. pauca ST53 in olive trees. Metabolic profile changes occurring in infected olive trees are still poorly investigated, but have the potential to unravel reliable biomarkers to be exploited for early diagnosis of infections. In this study, an untargeted metabolomic method using high-performance liquid chromatography coupled to quadrupole-time-of-flight high-resolution mass spectrometry (HPLC-ESI-Q-TOF-MS) was used to detect differences in samples (leaves) from healthy (Ctrl) and infected (Xf) olive trees. Both unsupervised and supervised data analysis clearly differentiated the groups. Different metabolites have been identified as potential specific biomarkers, and their characterization strongly suggests that metabolism of flavonoids and long-chain fatty acids is perturbed in Xf samples. In particular, a decrease in the defence capabilities of the host after Xf infection is proposed because of a significant dysregulation of some metabolites belonging to flavonoid family. Moreover, oleic acid is confirmed as a putative diffusible signal factor (DSF). This study provides new insights into the host-pathogen interactions and confirms LC-HRMS-based metabolomics as a powerful approach for disease-associated biomarkers discovery in plants.
Collapse
|
16
|
Monteiro MP, Hernandez-Montelongo J, Sahoo PK, Hernández Montelongo R, de Oliveira DS, Piazzeta MHO, García Sandoval JP, de Souza AA, Gobbi AL, Cotta MA. Functionalized microchannels as xylem-mimicking environment: Quantifying X. fastidiosa cell adhesion. Biophys J 2021; 120:1443-1453. [PMID: 33607085 DOI: 10.1016/j.bpj.2021.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 01/27/2021] [Accepted: 02/08/2021] [Indexed: 11/28/2022] Open
Abstract
Microchannels can be used to simulate xylem vessels and investigate phytopathogen colonization under controlled conditions. In this work, we explore surface functionalization strategies for polydimethylsiloxane and glass microchannels to study microenvironment colonization by Xylella fastidiosa subsp. pauca cells. We closely monitored cell initial adhesion, growth, and motility inside microfluidic channels as a function of chemical environments that mimic those found in xylem vessels. Carboxymethylcellulose (CMC), a synthetic cellulose, and an adhesin that is overexpressed during early stages of X. fastidiosa biofilm formation, XadA1 protein, were immobilized on the device's internal surfaces. This latter protocol increased bacterial density as compared with CMC. We quantitatively evaluated the different X. fastidiosa attachment affinities to each type of microchannel surface using a mathematical model and experimental observations acquired under constant flow of culture medium. We thus estimate that bacterial cells present ∼4 and 82% better adhesion rates in CMC- and XadA1-functionalized channels, respectively. Furthermore, variable flow experiments show that bacterial adhesion forces against shear stresses approximately doubled in value for the XadA1-functionalized microchannel as compared with the polydimethylsiloxane and glass pristine channels. These results show the viability of functionalized microchannels to mimic xylem vessels and corroborate the important role of chemical environments, and particularly XadA1 adhesin, for early stages of X. fastidiosa biofilm formation, as well as adhesivity modulation along the pathogen life cycle.
Collapse
Affiliation(s)
- Moniellen P Monteiro
- Departamento de Física Aplicada, Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil.
| | - Jacobo Hernandez-Montelongo
- Departamento de Física Aplicada, Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil.
| | - Prasana K Sahoo
- Departamento de Física Aplicada, Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil
| | - Rosaura Hernández Montelongo
- Departamento de Electrónica, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Guadalajara, Jalisco, México
| | - Douglas S de Oliveira
- Campus Avançado de Jandaia do Sul, Universidade Federal do Paraná, Jandaia do Sul, Paraná, Brasil
| | - Maria H O Piazzeta
- Laboratório Nacional de Nanotecnologia, Centro Nacional de Pesquisa em Energia e Materiais/CNPEM, Campinas, São Paulo, Brasil
| | - Juan P García Sandoval
- Departamento de Ingeniería Química, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Guadalajara, Jalisco, México
| | - Alessandra A de Souza
- Instituto Agronômico de Campinas, Centro de Citricultura Sylvio Moreira, Cordeirópolis, São Paulo, Brasil
| | - Angelo L Gobbi
- Laboratório Nacional de Nanotecnologia, Centro Nacional de Pesquisa em Energia e Materiais/CNPEM, Campinas, São Paulo, Brasil
| | - Mônica A Cotta
- Departamento de Física Aplicada, Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil.
| |
Collapse
|
17
|
Quorum Sensing Regulation in Phytopathogenic Bacteria. Microorganisms 2021; 9:microorganisms9020239. [PMID: 33498890 PMCID: PMC7912708 DOI: 10.3390/microorganisms9020239] [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: 12/03/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 11/17/2022] Open
Abstract
Quorum sensing is a type of chemical communication by which bacterial populations control expression of their genes in a coordinated manner. This regulatory mechanism is commonly used by pathogens to control the expression of genes encoding virulence factors and that of genes involved in the bacterial adaptation to variations in environmental conditions. In phytopathogenic bacteria, several mechanisms of quorum sensing have been characterized. In this review, we describe the different quorum sensing systems present in phytopathogenic bacteria, such as those using the signal molecules named N-acyl-homoserine lactone (AHL), diffusible signal factor (DSF), and the unknown signal molecule of the virulence factor modulating (VFM) system. We focus on studies performed on phytopathogenic bacteria of major importance, including Pseudomonas, Ralstonia, Agrobacterium, Xanthomonas, Erwinia, Xylella,Dickeya, and Pectobacterium spp. For each system, we present the mechanism of regulation, the functions targeted by the quorum sensing system, and the mechanisms by which quorum sensing is regulated.
Collapse
|
18
|
de Souza JB, Almeida-Souza HO, Zaini PA, Alves MN, de Souza AG, Pierry PM, da Silva AM, Goulart LR, Dandekar AM, Nascimento R. Xylella fastidiosa subsp. pauca Strains Fb7 and 9a5c from Citrus Display Differential Behavior, Secretome, and Plant Virulence. Int J Mol Sci 2020; 21:E6769. [PMID: 32942709 PMCID: PMC7555403 DOI: 10.3390/ijms21186769] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 09/12/2020] [Accepted: 09/13/2020] [Indexed: 12/20/2022] Open
Abstract
Xylella fastidiosa colonizes the xylem of various cultivated and native plants worldwide. Citrus production in Brazil has been seriously affected, and major commercial varieties remain susceptible to Citrus Variegated Chlorosis (CVC). Collective cellular behaviors such as biofilm formation influence virulence and insect transmission of X. fastidiosa. The reference strain 9a5c produces a robust biofilm compared to Fb7 that remains mostly planktonic, and both were isolated from symptomatic citrus trees. This work deepens our understanding of these distinct behaviors at the molecular level, by comparing the cellular and secreted proteomes of these two CVC strains. Out of 1017 identified proteins, 128 showed differential abundance between the two strains. Different protein families were represented such as proteases, hemolysin-like proteins, and lipase/esterases, among others. Here we show that the lipase/esterase LesA is among the most abundant secreted proteins of CVC strains as well, and demonstrate its functionality by complementary activity assays. More severe symptoms were observed in Nicotiana tabacum inoculated with strain Fb7 compared to 9a5c. Our results support that systemic symptom development can be accelerated by strains that invest less in biofilm formation and more in plant colonization. This has potential application in modulating the bacterial-plant interaction and reducing disease severity.
Collapse
Affiliation(s)
- Jessica Brito de Souza
- Institute of Biotechnology, Federal University of Uberlandia, Av. Amazonas, Bloco 2E, Campus Umuarama, Uberlandia MG 38400-902, Brazil; (J.B.d.S.); (H.O.A.-S.); (A.G.d.S.); (L.R.G.); (R.N.)
| | - Hebréia Oliveira Almeida-Souza
- Institute of Biotechnology, Federal University of Uberlandia, Av. Amazonas, Bloco 2E, Campus Umuarama, Uberlandia MG 38400-902, Brazil; (J.B.d.S.); (H.O.A.-S.); (A.G.d.S.); (L.R.G.); (R.N.)
| | - Paulo Adriano Zaini
- Department of Plant Sciences, College of Agriculture and Environmental Sciences, University of California, Davis, 1 Shields Ave, Davis, CA 95616, USA;
| | - Mônica Neli Alves
- Department of Technology, School of Agricultural and Veterinary Studies, São Paulo State University (FCAV/UNESP), Via de Acesso Prof. Paulo Donato Castellane, Jaboticabal SP 14884-900, Brazil;
- Citriculture Defense Fund (Fundecitrus), Av. Dr. Adhemar Pereira de Barros 201, Araraquara SP 14807-040, Brazil
| | - Aline Gomes de Souza
- Institute of Biotechnology, Federal University of Uberlandia, Av. Amazonas, Bloco 2E, Campus Umuarama, Uberlandia MG 38400-902, Brazil; (J.B.d.S.); (H.O.A.-S.); (A.G.d.S.); (L.R.G.); (R.N.)
| | - Paulo Marques Pierry
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, São Paulo SP 05508-000, Brazil; (P.M.P.); (A.M.d.S.)
| | - Aline Maria da Silva
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, São Paulo SP 05508-000, Brazil; (P.M.P.); (A.M.d.S.)
| | - Luiz Ricardo Goulart
- Institute of Biotechnology, Federal University of Uberlandia, Av. Amazonas, Bloco 2E, Campus Umuarama, Uberlandia MG 38400-902, Brazil; (J.B.d.S.); (H.O.A.-S.); (A.G.d.S.); (L.R.G.); (R.N.)
| | - Abhaya M. Dandekar
- Department of Plant Sciences, College of Agriculture and Environmental Sciences, University of California, Davis, 1 Shields Ave, Davis, CA 95616, USA;
| | - Rafael Nascimento
- Institute of Biotechnology, Federal University of Uberlandia, Av. Amazonas, Bloco 2E, Campus Umuarama, Uberlandia MG 38400-902, Brazil; (J.B.d.S.); (H.O.A.-S.); (A.G.d.S.); (L.R.G.); (R.N.)
| |
Collapse
|
19
|
Vergine M, Nicolì F, Sabella E, Aprile A, De Bellis L, Luvisi A. Secondary Metabolites in Xylella fastidiosa-Plant Interaction. Pathogens 2020; 9:pathogens9090675. [PMID: 32825425 PMCID: PMC7559865 DOI: 10.3390/pathogens9090675] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/12/2020] [Accepted: 08/18/2020] [Indexed: 12/24/2022] Open
Abstract
During their evolutionary history, plants have evolved the ability to synthesize and accumulate small molecules known as secondary metabolites. These compounds are not essential in the primary cell functions but play a significant role in the plants’ adaptation to environmental changes and in overcoming stress. Their high concentrations may contribute to the resistance of the plants to the bacterium Xylella fastidiosa, which has recently re-emerged as a plant pathogen of global importance. Although it is established in several areas globally and is considered one of the most dangerous plant pathogens, no cure has been developed due to the lack of effective bactericides and the difficulties in accessing the xylem vessels where the pathogen grows and produces cell aggregates and biofilm. This review highlights the role of secondary metabolites in the defense of the main economic hosts of X. fastidiosa and identifies how knowledge about biosynthetic pathways could improve our understanding of disease resistance. In addition, current developments in non-invasive techniques and strategies of combining molecular and physiological techniques are examined, in an attempt to identify new metabolic engineering options for plant defense.
Collapse
|
20
|
Wallis CM, Zeilinger AR, Sicard A, Beal DJ, Walker MA, Almeida RPP. Impact of phenolic compounds on progression of Xylella fastidiosa infections in susceptible and PdR1-locus containing resistant grapevines. PLoS One 2020; 15:e0237545. [PMID: 32764829 PMCID: PMC7413749 DOI: 10.1371/journal.pone.0237545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/28/2020] [Indexed: 11/19/2022] Open
Abstract
Pierce’s disease is of major concern for grapevine (Vitis vinifera) production wherever the bacterial pathogen Xylella fastidiosa and its vectors are present. Long-term management includes the deployment of resistant grapevines such as those containing the PdR1 locus from the wild grapevine species Vitis arizonica, which do not develop Pierce’s disease symptoms upon infection. However, little is understood about how the PdR1 locus functions to prevent disease symptom development. Therefore, we assessed the concentrations of plant defense-associated compounds called phenolics in healthy and X. fastidiosa-infected PdR1-resistant and susceptible grapevine siblings over time. Soluble foliar phenolic levels, especially flavonoids, in X. fastidiosa-infected PdR1-resistant grapevines were discovered to be significantly lower than those in infected susceptible grapevines. Therefore, it was hypothesized that PdR1-resistant grapevines, by possessing lowered flavonoid levels, affects biofilm formation and causes reduced X. fastidiosa intra-plant colonization, thus limiting the ability to increase pathogen populations and cause Pierce’s disease. These results therefore reveal that differences in plant metabolite levels might be a component of the mechanisms that PdR1 utilizes to prevent Pierce’s disease.
Collapse
Affiliation(s)
- Christopher M. Wallis
- Crop Diseases, Pests and Genetics Research Unit, USDA-ARS San Joaquin Valley Agricultural Sciences Center, Parlier, California, United States of America
- * E-mail:
| | - Adam R. Zeilinger
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, United States of America
| | - Anne Sicard
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, United States of America
| | - Dylan J. Beal
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, United States of America
| | - M. Andrew Walker
- Department of Viticulture and Enology, University of California, Davis, California, United States of America
| | - Rodrigo P. P. Almeida
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, United States of America
| |
Collapse
|
21
|
From Nucleotides to Satellite Imagery: Approaches to Identify and Manage the Invasive Pathogen Xylella fastidiosa and Its Insect Vectors in Europe. SUSTAINABILITY 2020. [DOI: 10.3390/su12114508] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Biological invasions represent some of the most severe threats to local communities and ecosystems. Among invasive species, the vector-borne pathogen Xylella fastidiosa is responsible for a wide variety of plant diseases and has profound environmental, social and economic impacts. Once restricted to the Americas, it has recently invaded Europe, where multiple dramatic outbreaks have highlighted critical challenges for its management. Here, we review the most recent advances on the identification, distribution and management of X. fastidiosa and its insect vectors in Europe through genetic and spatial ecology methodologies. We underline the most important theoretical and technological gaps that remain to be bridged. Challenges and future research directions are discussed in the light of improving our understanding of this invasive species, its vectors and host–pathogen interactions. We highlight the need of including different, complimentary outlooks in integrated frameworks to substantially improve our knowledge on invasive processes and optimize resources allocation. We provide an overview of genetic, spatial ecology and integrated approaches that will aid successful and sustainable management of one of the most dangerous threats to European agriculture and ecosystems.
Collapse
|
22
|
Abstract
Approaches to manipulating disease resistance in plants is expanding exponentially due to advances in our understanding of plant defense mechanisms and new tools for manipulating the plant genome. The application of effective strategies is only limited now by adoption of rapid classical genetic techniques and the acceptance of genetically engineered traits for some problems. The use of genome editing and cis-genetics, where possible, may facilitate applications that otherwise require considerable time or genetic engineering, depending on settling legal definitions of the products. Nonetheless, the variety of approaches to developing disease resistance has never been greater.
Collapse
Affiliation(s)
- Anuj Sharma
- Department of Plant Pathology, University of Florida, Gainesville, FL, USA
| | - Jeffrey B. Jones
- Department of Plant Pathology, University of Florida, Gainesville, FL, USA
| | - Frank F. White
- Department of Plant Pathology, University of Florida, Gainesville, FL, USA
| |
Collapse
|
23
|
Lessons from One Fastidious Bacterium to Another: What Can We Learn about Liberibacter Species from Xylella fastidiosa. INSECTS 2019; 10:insects10090300. [PMID: 31527458 PMCID: PMC6780969 DOI: 10.3390/insects10090300] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/11/2019] [Accepted: 09/12/2019] [Indexed: 02/06/2023]
Abstract
Huanglongbing is causing economic devastation to the citrus industry in Florida, and threatens the industry everywhere the bacterial pathogens in the Candidatus Liberibacter genus and their insect vectors are found. Bacteria in the genus cannot be cultured and no durable strategy is available for growers to control plant infection or pathogen transmission. However, scientists and grape growers were once in a comparable situation after the emergence of Pierce’s disease, which is caused by Xylella fastidiosa and spread by its hemipteran insect vector. Proactive quarantine and vector control measures coupled with interdisciplinary data-driven science established control of this devastating disease and pushed the frontiers of knowledge in the plant pathology and vector biology fields. Our review highlights the successful strategies used to understand and control X. fastidiosa and their potential applicability to the liberibacters associated with citrus greening, with a focus on the interactions between bacterial pathogen and insect vector. By placing the study of Candidatus Liberibacter spp. within the current and historical context of another fastidious emergent plant pathogen, future basic and applied research to develop control strategies can be prioritized.
Collapse
|
24
|
Roper C, Castro C, Ingel B. Xylella fastidiosa: bacterial parasitism with hallmarks of commensalism. CURRENT OPINION IN PLANT BIOLOGY 2019; 50:140-147. [PMID: 31229798 DOI: 10.1016/j.pbi.2019.05.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 05/17/2019] [Accepted: 05/20/2019] [Indexed: 06/09/2023]
Abstract
All organisms evolve in the presence of other organisms and these intimate associations are major drivers of evolution. Broadly speaking, these interactions are considered symbioses and can take on a full range of positive, negative or seemingly neutral interactions. Just two examples of these symbiotic interactions are parasitism and commensalism. Parasitism results in one partner benefitting while one partner suffers adverse consequences. Commensalism is a form of symbiosis where one partner benefits and the other partner is neutrally affected. Research efforts are more often focused on understanding parasitic symbioses related to disease, hence, much research is performed on identifying virulence factors to understand the fundamentals of pathogenesis. In turn, much less is understood about the fundamentals of commensal relationships. Here, we will take an introspective look at the plant-associated bacterium, Xylella fastidiosa. In some of its many plant hosts, this bacterium participates in seemingly commensal relationships while in other hosts, it causes devastating diseases that result in epidemics, making it a good model for exploring the determinants of where bacteria fall on the spectrum of parasitic and commensal relationships from both the microbial and the plant host perspective. Recent discoveries in how pathogenic X. fastidiosa imposes self-limiting behaviors upon itself indicate that even in its parasitic form, X. fastidiosa displays hallmarks of a commensal lifestyle. Understanding how commensalism can 'go wrong' and manifest into pathologies in specific hosts is a useful vantage point from which to study the determinants of virulence and pathogenicity.
Collapse
Affiliation(s)
- Caroline Roper
- Department of Microbiology and Plant Pathology, University of California, Riverside, 900 University Avenue, Riverside, CA 92521, United States.
| | - Claudia Castro
- Department of Microbiology and Plant Pathology, University of California, Riverside, 900 University Avenue, Riverside, CA 92521, United States
| | - Brian Ingel
- Department of Microbiology and Plant Pathology, University of California, Riverside, 900 University Avenue, Riverside, CA 92521, United States
| |
Collapse
|
25
|
Bragard C, Dehnen-Schmutz K, Di Serio F, Gonthier P, Jacques MA, Jaques Miret JA, Justesen AF, MacLeod A, Magnusson CS, Milonas P, Navas-Cortés JA, Potting R, Reignault PL, Thulke HH, Van der Werf W, Vicent Civera A, Yuen J, Zappalà L, Makowski D, Delbianco A, Maiorano A, Muñoz Guajardo I, Stancanelli G, Guzzo M, Parnell S. Effectiveness of in planta control measures for Xylella fastidiosa. EFSA J 2019; 17:e05666. [PMID: 32626300 PMCID: PMC7009266 DOI: 10.2903/j.efsa.2019.5666] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
This opinion updates the information included in the previous EFSA Scientific Opinion concerning the in planta control measures for Xylella fastidiosa, with a systematic review and critical analysis of the potential treatment solutions that have been published against this pest so far. The output of this opinion focuses on the application of chemical or biological treatments on living plants. In vitro studies, hot water treatments, use of resistant varieties and vector control are excluded from the review. The use of antibiotics is not considered due to the risk of antimicrobial resistance development. The use of weakly virulent or avirulent strains of X. fastidiosa is covered in this review, although this organism is an EU quarantine plant pest and its introduction in the EU territory is banned. Experiments were recently conducted to assess the effect of application of zinc, copper, and citric acid biocomplex, of N-acetylcysteine, and of 'diffusible signal factor' (and of its homologs). Their results showed that these control measures were sometimes able to reduce symptoms caused by X. fastidiosa. Recent experiments also showed that several species of endophytic microorganisms, some bacteriophages and inoculation of weakly virulent/avirulent strains of X. fastidiosa could offer some protection against the Pierce's disease. However, based on the reviewed results, the Panel concludes that, although several published experiments show some effects in reducing symptoms development, the tested control measures are not able to completely eliminate X. fastidiosa from diseased plants. The Panel confirms as previously stated that there is currently no control measure available to eliminate the bacteria from a diseased plant in open field conditions.
Collapse
|
26
|
Dandekar AM, Jacobson A, Ibáñez AM, Gouran H, Dolan DL, Agüero CB, Uratsu SL, Just R, Zaini PA. Trans-Graft Protection Against Pierce's Disease Mediated by Transgenic Grapevine Rootstocks. FRONTIERS IN PLANT SCIENCE 2019; 10:84. [PMID: 30787937 PMCID: PMC6372540 DOI: 10.3389/fpls.2019.00084] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 01/21/2019] [Indexed: 05/03/2023]
Abstract
A field study showed that transgenic grapevine rootstocks can provide trans-graft-mediated protection to a wild type scion against Pierce's disease (PD) development. We individually field-tested two distinct strategies. The first expressed a chimeric antimicrobial protein (CAP) that targeted the functionality of the lipopolysaccharide (LPS) surface of Xylella fastidiosa (Xf), the causative agent of PD. The second expressed a plant polygalacturonase inhibitory protein (PGIP) that prevents PD by inhibiting breakdown of pectin present in primary cell walls. Both proteins are secreted to the apoplast and then into the xylem, where they migrate past the graft union, transiting into the xylem of the grafted scion. Transgenic Vitis vinifera cv. Thompson Seedless (TS) expressing ether CAP or PGIP were tested in the greenhouse and those lines that showed resistance to PD were grafted with wild type TS scions. Grafted grapevines were introduced into the field and tested over 7 years. Here we present data on the field evaluation of trans-graft protection using four CAP and four PGIP independent rootstock lines, compared to an untransformed rootstock. There was 30 to 95% reduction in vine mortality among CAP- and PGIP-expressing lines after three successive yearly infections with virulent Xf. Shoot tissues grafted to either CAP or PGIP transgenic rootstocks supported lower pathogen titers and showed fewer disease symptoms. Grafted plants on transgenic rootstocks also had more spring bud break following infection, more shoots, and more vigorous growth compared to those grafted to wild type rootstocks. No yield penalty was observed in the transgenic lines and some PGIP-expressing vines had enhanced yield potential. Trans-graft protection is an efficient way to protect grape scions against PD while preserving their valuable varietal genotypes and clonal properties.
Collapse
Affiliation(s)
- Abhaya M. Dandekar
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Aaron Jacobson
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Ana M. Ibáñez
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Hossein Gouran
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - David L. Dolan
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Cecilia B. Agüero
- Department of Enology and Viticulture, University of California, Davis, Davis, CA, United States
| | - Sandie L. Uratsu
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Robert Just
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Paulo A. Zaini
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| |
Collapse
|
27
|
Lindow S. Money Matters: Fueling Rapid Recent Insight Into Xylella fastidiosa-An Important and Expanding Global Pathogen. PHYTOPATHOLOGY 2019; 109:210-212. [PMID: 30644806 DOI: 10.1094/phyto-09-18-0325-per] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Xylella fastidiosa has emerged from relative obscurity into one of the most well-studied bacterial plant pathogens. While Pierce's disease of grape caused by this pathogen has been recognized as an important disease in warmer regions of the United States for nearly 100 years, the causal pathogen, X. fastidiosa has spread throughout much of the world and now also causes serious diseases of citrus, coffee, almond, olive, and other important crop plants. Our knowledge of this pathogen has been driven by the recent substantial research support justified by the economic importance of these diseases.
Collapse
Affiliation(s)
- Steven Lindow
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720
| |
Collapse
|
28
|
Baccari C, Antonova E, Lindow S. Biological Control of Pierce's Disease of Grape by an Endophytic Bacterium. PHYTOPATHOLOGY 2019; 109:248-256. [PMID: 30540526 DOI: 10.1094/phyto-07-18-0245-fi] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Effective preventive measures and therapies are lacking for control of Pierce's disease of grape caused by the xylem-colonizing bacterium Xylella fastidiosa responsible for serious losses in grape production. In this study we explored the potential for endophytic bacteria to alter the disease process. While most endophytic bacteria found within grape did not grow or multiply when inoculated into mature grape vines, Paraburkholderia phytofirmans strain PsJN achieved population sizes as large as 106 cells/g and moved 1 m or more within 4 weeks after inoculation into vines. While X. fastidiosa achieved large population sizes and moved extensively in grape when inoculated alone, few viable cells were recovered from plants in which it was co-inoculated with strain PsJN and the incidence of leaves exhibiting scorching symptoms typical of Pierce's disease was consistently greatly reduced from that in control plants. Suppression of disease symptoms occurred not only when strain PsJN was co-inoculated with the pathogen by puncturing stems in the same site in plants, but also when inoculated at the same time but at different sites in the plant. Large population sizes of strain PsJN could be established in both leaf lamina and petioles by topical application of cell suspensions in 0.2% of an organo-silicon surfactant conferring low surface tension, and such treatments were as effective as direct puncture inoculations of this biocontrol strain in reducing disease severity. While inoculation of strain PsJN into plants by either method at the same time as or even 4 weeks after that of the pathogen resulted in large reductions in disease severity, much less disease control was conferred by inoculation of PsJN 4 weeks prior to that of the pathogen. The expression of grapevine PR1 and ETR1 within 3 weeks of inoculation was substantially higher in plants inoculated with both X. fastidiosa and strain PsJN compared with that in plants inoculated only with the pathogen or strain PsJN, suggesting that this biological control agent reduces disease by priming expression of innate disease resistance pathways in plants that otherwise would have exhibited minimal responses to the pathogen. Strain PsJN thus appears highly efficacious for the control of Pierce's disease when used as an eradicant treatment that can be easily made even by spray application.
Collapse
Affiliation(s)
- Clelia Baccari
- Department of Plant and Microbial Biology, University of California, Berkeley 94720
| | - Elena Antonova
- Department of Plant and Microbial Biology, University of California, Berkeley 94720
| | - Steven Lindow
- Department of Plant and Microbial Biology, University of California, Berkeley 94720
| |
Collapse
|
29
|
Kalia VC, Patel SKS, Kang YC, Lee JK. Quorum sensing inhibitors as antipathogens: biotechnological applications. Biotechnol Adv 2018; 37:68-90. [PMID: 30471318 DOI: 10.1016/j.biotechadv.2018.11.006] [Citation(s) in RCA: 167] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 10/19/2018] [Accepted: 11/18/2018] [Indexed: 12/20/2022]
Abstract
The mechanisms through which microbes communicate using signal molecules has inspired a great deal of research. Microbes use this exchange of information, known as quorum sensing (QS), to initiate and perpetuate infectious diseases in eukaryotic organisms, evading the eukaryotic defense system by multiplying and expressing their pathogenicity through QS regulation. The major issue to arise from such networks is increased bacterial resistance to antibiotics, resulting from QS-dependent mediation of the formation of biofilm, the induction of efflux pumps, and the production of antibiotics. QS inhibitors (QSIs) of diverse origins have been shown to act as potential antipathogens. In this review, we focus on the use of QSIs to counter diseases in humans as well as plants and animals of economic importance. We also discuss the challenges encountered in the potential applications of QSIs.
Collapse
Affiliation(s)
- Vipin Chandra Kalia
- Department of Chemical Engineering, Konkuk University, Seoul 05029, Republic of Korea.
| | - Sanjay K S Patel
- Department of Chemical Engineering, Konkuk University, Seoul 05029, Republic of Korea
| | - Yun Chan Kang
- Department of Materials Science and Engineering, Korea University, Anam-Dong, Seongbuk-Gu, Seoul 02841, Republic of Korea
| | - Jung-Kul Lee
- Department of Chemical Engineering, Konkuk University, Seoul 05029, Republic of Korea.
| |
Collapse
|
30
|
Zeilinger AR, Turek D, Cornara D, Sicard A, Lindow SE, Almeida RPP. Bayesian vector transmission model detects conflicting interactions from transgenic disease‐resistant grapevines. Ecosphere 2018. [DOI: 10.1002/ecs2.2494] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Adam R. Zeilinger
- Department of Environmental Science, Policy, and Management University of California 130 Mulford Hall Berkeley California 94720 USA
| | - Daniel Turek
- Department of Mathematics and Statistics Williams College Williamstown Massachusetts 01267 USA
| | - Daniele Cornara
- Instituto de Ciencias Agrarias Consejo Superior de Investigaciones Cientificas ICA‐CSIC Calle Serrano 115 dpdo Madrid 28006 Spain
| | - Anne Sicard
- Department of Environmental Science, Policy, and Management University of California 130 Mulford Hall Berkeley California 94720 USA
| | - Steven E. Lindow
- Department of Plant and Microbial Biology University of California Berkeley Berkeley California 94720 USA
| | - Rodrigo P. P. Almeida
- Department of Environmental Science, Policy, and Management University of California 130 Mulford Hall Berkeley California 94720 USA
| |
Collapse
|
31
|
Matilla MA, Krell T. The effect of bacterial chemotaxis on host infection and pathogenicity. FEMS Microbiol Rev 2018; 42:4563582. [PMID: 29069367 DOI: 10.1093/femsre/fux052] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 10/19/2017] [Indexed: 12/26/2022] Open
Abstract
Chemotaxis enables microorganisms to move according to chemical gradients. Although this process requires substantial cellular energy, it also affords key physiological benefits, including enhanced access to growth substrates. Another important implication of chemotaxis is that it also plays an important role in infection and disease, as chemotaxis signalling pathways are broadly distributed across a variety of pathogenic bacteria. Furthermore, current research indicates that chemotaxis is essential for the initial stages of infection in different human, animal and plant pathogens. This review focuses on recent findings that have identified specific bacterial chemoreceptors and corresponding chemoeffectors associated with pathogenicity. Pathogenicity-related chemoeffectors are either host and niche-specific signals or intermediates of the host general metabolism. Plant pathogens were found to contain an elevated number of chemotaxis signalling genes and functional studies demonstrate that these genes are critical for their ability to enter the host. The expanding body of knowledge of the mechanisms underlying chemotaxis in pathogens provides a foundation for the development of new therapeutic strategies capable of blocking infection and preventing disease by interfering with chemotactic signalling pathways.
Collapse
Affiliation(s)
- Miguel A Matilla
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
| | - Tino Krell
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
| |
Collapse
|
32
|
Kyrkou I, Pusa T, Ellegaard-Jensen L, Sagot MF, Hansen LH. Pierce's Disease of Grapevines: A Review of Control Strategies and an Outline of an Epidemiological Model. Front Microbiol 2018; 9:2141. [PMID: 30258423 PMCID: PMC6143690 DOI: 10.3389/fmicb.2018.02141] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 08/21/2018] [Indexed: 11/13/2022] Open
Abstract
Xylella fastidiosa is a notorious plant pathogenic bacterium that represents a threat to crops worldwide. Its subspecies, Xylella fastidiosa subsp. fastidiosa is the causal agent of Pierce's disease of grapevines. Pierce's disease has presented a serious challenge for the grapevine industry in the United States and turned into an epidemic in Southern California due to the invasion of the insect vector Homalodisca vitripennis. In an attempt to minimize the effects of Xylella fastidiosa subsp. fastidiosa in vineyards, various studies have been developing and testing strategies to prevent the occurrence of Pierce's disease, i.e., prophylactic strategies. Research has also been undertaken to investigate therapeutic strategies to cure vines infected by Xylella fastidiosa subsp. fastidiosa. This report explicitly reviews all the strategies published to date and specifies their current status. Furthermore, an epidemiological model of Xylella fastidiosa subsp. fastidiosa is proposed and key parameters for the spread of Pierce's disease deciphered in a sensitivity analysis of all model parameters. Based on these results, it is concluded that future studies should prioritize therapeutic strategies, while investments should only be made in prophylactic strategies that have demonstrated promising results in vineyards.
Collapse
Affiliation(s)
- Ifigeneia Kyrkou
- Laboratory of Environmental Microbiology and Biotechnology, Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - Taneli Pusa
- INRIA Grenoble Rhône-Alpes, Montbonnot-Saint-Martin, France
- Laboratoire de Biométrie et Biologie Évolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon 1, Villeurbanne, France
- Department of Computer, Automatic and Management Engineering, Sapienza University of Rome, Rome, Italy
| | - Lea Ellegaard-Jensen
- Laboratory of Environmental Microbiology and Biotechnology, Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - Marie-France Sagot
- INRIA Grenoble Rhône-Alpes, Montbonnot-Saint-Martin, France
- Laboratoire de Biométrie et Biologie Évolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon 1, Villeurbanne, France
| | - Lars Hestbjerg Hansen
- Laboratory of Environmental Microbiology and Biotechnology, Department of Environmental Science, Aarhus University, Roskilde, Denmark
| |
Collapse
|
33
|
Su H, Jiao YT, Wang FF, Liu YE, Niu WL, Liu GT, Xu Y. Overexpression of VpPR10.1 by an efficient transformation method enhances downy mildew resistance in V. vinifera. PLANT CELL REPORTS 2018; 37:819-832. [PMID: 29511799 DOI: 10.1007/s00299-018-2271-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 03/01/2018] [Indexed: 05/04/2023]
Abstract
Putrescine and spermidine increase the transformation efficiency of Vitis vinifera L. cv. Thompson seedless. Accumulation of VpPR10.1 in transgenic V. vinifera Thompson seedless, likely increases its resistance to downy mildew. A more efficient method is described for facilitating Agrobacterium-mediated transformation of Vitis vinifera L. cv. Thompson Seedless somatic embryogenesis using polyamines (PAs). The efficacies of putrescine, spermidine and spermine are identified at a range of concentrations (10 µM, 100 µM and 1 mM) added to the culture medium during somatic embryo growth. Putrescine (PUT) and spermidine (SPD) promote the recovery of proembryonic masses (PEM) and the development of somatic embryos (SE) after co-cultivation. Judging from the importance of the time-frame in genetic transformation, PAs added at the co-cultivation stage have a stronger effect than delayed selection treatments, which are superior to antibiotic treatments in the selection stage. Best embryogenic responses are with 1 mM PUT and 100 µM SPD added to the co-culture medium. Using the above method, a pathogenesis-related gene (VpPR10.1) from Chinese wild Vitis pseudoreticulata was transferred into Thompson Seedless for functional evaluation. The transgenic line, confirmed by western blot analysis, was inoculated with Plasmopara viticola to test for downy mildew resistance. Based on observed restrictions of hyphal growth and increases in H2O2 accumulation in the transgenic plants, the accumulation of VpPR10.1 likely enhanced the transgenic plants resistance to downy mildew.
Collapse
Affiliation(s)
- Hang Su
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, People's Republic of China
| | - Yun-Tong Jiao
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, People's Republic of China
| | - Fang-Fang Wang
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, People's Republic of China
| | - Yue-E Liu
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, People's Republic of China
| | - Wei-Li Niu
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, People's Republic of China
| | - Guo-Tian Liu
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, People's Republic of China.
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, People's Republic of China.
| | - Yan Xu
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, People's Republic of China.
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, People's Republic of China.
| |
Collapse
|
34
|
Rapicavoli J, Ingel B, Blanco‐Ulate B, Cantu D, Roper C. Xylella fastidiosa: an examination of a re-emerging plant pathogen. MOLECULAR PLANT PATHOLOGY 2018; 19:786-800. [PMID: 28742234 PMCID: PMC6637975 DOI: 10.1111/mpp.12585] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Revised: 07/13/2017] [Accepted: 07/19/2017] [Indexed: 05/10/2023]
Abstract
UNLABELLED Xylella fastidiosa is a Gram-negative bacterial plant pathogen with an extremely wide host range. This species has recently been resolved into subspecies that correlate with host specificity. This review focuses on the status of X. fastidiosa pathogenic associations in plant hosts in which the bacterium is either endemic or has been recently introduced. Plant diseases associated with X. fastidiosa have been documented for over a century, and much about what is known in the context of host-pathogen interactions is based on these hosts, such as grape and citrus, in which this pathogen has been well described. Recent attention has focused on newly emerging X. fastidiosa diseases, such as in olives. TAXONOMY Bacteria; Gammaproteobacteria; family Xanthomonadaceae; genus Xylella; species fastidiosa. MICROBIOLOGICAL PROPERTIES Gram-negative rod (0.25-0.35 × 0.9-3.5 μm), non-flagellate, motile via Type IV pili-mediated twitching, fastidious. HOST RANGE Xylella fastidiosa has a broad host range that includes ornamental, ecological and agricultural plants belonging to over 300 different species in 63 different families. To date, X. fastidiosa has been found to be pathogenic in over 100 plant species. In addition, it can establish non-symptomatic associations with many plants as a commensal endophyte. Here, we list the four distinct subspecies of X. fastidiosa and some of the agriculturally relevant diseases caused by them: X. fastidiosa ssp. fastidiosa causes Pierce's disease (PD) of grapevine (Vitis vinifera); X. fastidiosa ssp. multiplex causes almond leaf scorch (ALS) and diseases on other nut and shade tree crops; X. fastidiosa ssp. pauca causes citrus variegated chlorosis (CVC) (Citrus spp.), coffee leaf scorch and olive quick decline syndrome (OQDS) (Olea europaea); X. fastidiosa ssp. sandyi causes oleander leaf scorch (OLS) (Nerium oleander). Significant host specificity seemingly exists for some of the subspecies, although this could be a result of technical biases based on the limited number of plants tested, whereas some subspecies are not as stringent in their host range and can infect several plant hosts. DISEASE SYMPTOMS Most X. fastidiosa-related diseases appear as marginal leaf necrosis and scorching of the leaves. In the case of PD, X. fastidiosa can also cause desiccation of berries (termed 'raisining'), irregular periderm development and abnormal abscission of petioles. In olive trees affected with OQDS, leaves exhibit marginal necrosis and defoliation, and overall tree decline occurs. Plants with ALS and OLS also exhibit the characteristic leaf scorch symptoms. Not all X. fastidiosa-related diseases exhibit the typical leaf scorch symptoms. These include CVC and Phony Peach disease, amongst others. In the case of CVC, symptoms include foliar wilt and interveinal chlorosis on the upper surfaces of the leaves (similar to zinc deficiency), which correspond to necrotic, gum-like regions on the undersides of the leaves. Additional symptoms of CVC include defoliation, dieback and hardening of fruits. Plants infected with Phony Peach disease exhibit a denser, more compact canopy (as a result of shortened internodes, darker green leaves and delayed leaf senescence), premature bloom and reduced fruit size. Some occlusions occur in the xylem vessels, but there are no foliar wilting, chlorosis or necrosis symptoms . USEFUL WEBSITES: http://www.piercesdisease.org/; https://pubmlst.org/xfastidiosa/; http://www.xylella.lncc.br/; https://nature.berkeley.edu/xylella/; https://ec.europa.eu/food/plant/plant_health_biosecurity/legislation/emergency_measures/xylella-fastidiosa_en.
Collapse
Affiliation(s)
- Jeannette Rapicavoli
- Department of Plant Pathology and MicrobiologyUniversity of CaliforniaRiversideCA 92521USA
| | - Brian Ingel
- Department of Plant Pathology and MicrobiologyUniversity of CaliforniaRiversideCA 92521USA
| | | | - Dario Cantu
- Department of Viticulture and EnologyUniversity of CaliforniaDavisCA 95616USA
| | - Caroline Roper
- Department of Plant Pathology and MicrobiologyUniversity of CaliforniaRiversideCA 92521USA
| |
Collapse
|
35
|
Zaini PA, Nascimento R, Gouran H, Cantu D, Chakraborty S, Phu M, Goulart LR, Dandekar AM. Molecular Profiling of Pierce's Disease Outlines the Response Circuitry of Vitis vinifera to Xylella fastidiosa Infection. FRONTIERS IN PLANT SCIENCE 2018; 9:771. [PMID: 29937771 PMCID: PMC6002507 DOI: 10.3389/fpls.2018.00771] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 05/18/2018] [Indexed: 05/19/2023]
Abstract
Pierce's disease is a major threat to grapevines caused by the bacterium Xylella fastidiosa. Although devoid of a type 3 secretion system commonly employed by bacterial pathogens to deliver effectors inside host cells, this pathogen is able to influence host parenchymal cells from the xylem lumen by secreting a battery of hydrolytic enzymes. Defining the cellular and biochemical changes induced during disease can foster the development of novel therapeutic strategies aimed at reducing the pathogen fitness and increasing plant health. To this end, we investigated the transcriptional, proteomic, and metabolomic responses of diseased Vitis vinifera compared to healthy plants. We found that several antioxidant strategies were induced, including the accumulation of gamma-aminobutyric acid (GABA) and polyamine metabolism, as well as iron and copper chelation, but these were insufficient to protect the plant from chronic oxidative stress and disease symptom development. Notable upregulation of phytoalexins, pathogenesis-related proteins, and various aromatic acid metabolites was part of the host responses observed. Moreover, upregulation of various cell wall modification enzymes followed the proliferation of the pathogen within xylem vessels, consistent with the intensive thickening of vessels' secondary walls observed by magnetic resonance imaging. By interpreting the molecular profile changes taking place in symptomatic tissues, we report a set of molecular markers that can be further explored to aid in disease detection, breeding for resistance, and developing therapeutics.
Collapse
Affiliation(s)
- Paulo A. Zaini
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Rafael Nascimento
- Institute of Genetics and Biochemistry, Federal University of Uberlândia, Uberlândia, Brazil
| | - Hossein Gouran
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Dario Cantu
- Department of Viticulture and Enology, University of California, Davis, Davis, CA, United States
| | - Sandeep Chakraborty
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - My Phu
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Luiz R. Goulart
- Institute of Genetics and Biochemistry, Federal University of Uberlândia, Uberlândia, Brazil
| | - Abhaya M. Dandekar
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
- *Correspondence: Abhaya M. Dandekar,
| |
Collapse
|
36
|
Caserta R, Souza-Neto RR, Takita MA, Lindow SE, De Souza AA. Ectopic Expression of Xylella fastidiosa rpfF Conferring Production of Diffusible Signal Factor in Transgenic Tobacco and Citrus Alters Pathogen Behavior and Reduces Disease Severity. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2017; 30:866-875. [PMID: 28777044 DOI: 10.1094/mpmi-07-17-0167-r] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The pathogenicity of Xylella fastidiosa is associated with its ability to colonize the xylem of host plants. Expression of genes contributing to xylem colonization are suppressed, while those necessary for insect vector acquisition are increased with increasing concentrations of diffusible signal factor (DSF), whose production is dependent on RpfF. We previously demonstrated that transgenic citrus plants ectopically expressing rpfF from a citrus strain of X. fastidiosa subsp. pauca exhibited less susceptibility to Xanthomonas citri subsp. citri, another pathogen whose virulence is modulated by DSF accumulation. Here, we demonstrate that ectopic expression of rpfF in both transgenic tobacco and sweet orange also confers a reduction in disease severity incited by X. fastidiosa and reduces its colonization of those plants. Decreased disease severity in the transgenic plants was generally associated with increased expression of genes conferring adhesiveness to the pathogen and decreased expression of genes necessary for active motility, accounting for the reduced population sizes achieved in the plants, apparently by limiting pathogen dispersal through the plant. Plant-derived DSF signal molecules in a host plant can, therefore, be exploited to interfere with more than one pathogen whose virulence is controlled by DSF signaling.
Collapse
Affiliation(s)
- R Caserta
- 1 Centro de Citricultura Sylvio Moreira/IAC, Corderiópolis, SP, Brazil
| | - R R Souza-Neto
- 1 Centro de Citricultura Sylvio Moreira/IAC, Corderiópolis, SP, Brazil
- 2 Universidade Estadual de Campinas-UNICAMP, Campinas, SP, Brazil; and
| | - M A Takita
- 1 Centro de Citricultura Sylvio Moreira/IAC, Corderiópolis, SP, Brazil
| | - S E Lindow
- 3 University of California, Berkeley, CA, U.S.A
| | - A A De Souza
- 1 Centro de Citricultura Sylvio Moreira/IAC, Corderiópolis, SP, Brazil
| |
Collapse
|
37
|
A Single Regulator Mediates Strategic Switching between Attachment/Spread and Growth/Virulence in the Plant Pathogen Ralstonia solanacearum. mBio 2017; 8:mBio.00895-17. [PMID: 28951474 PMCID: PMC5615195 DOI: 10.1128/mbio.00895-17] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The PhcA virulence regulator in the vascular wilt pathogen Ralstonia solanacearum responds to cell density via quorum sensing. To understand the timing of traits that enable R. solanacearum to establish itself inside host plants, we created a ΔphcA mutant that is genetically locked in a low-cell-density condition. Comparing levels of gene expression of wild-type R. solanacearum and the ΔphcA mutant during tomato colonization revealed that the PhcA transcriptome includes an impressive 620 genes (>2-fold differentially expressed; false-discovery rate [FDR], ≤0.005). Many core metabolic pathways and nutrient transporters were upregulated in the ΔphcA mutant, which grew faster than the wild-type strain in tomato xylem sap and on dozens of specific metabolites, including 36 found in xylem. This suggests that PhcA helps R. solanacearum to survive in nutrient-poor environmental habitats and to grow rapidly during early pathogenesis. However, after R. solanacearum reaches high cell densities in planta, PhcA mediates a trade-off from maximizing growth to producing costly virulence factors. R. solanacearum infects through roots, and low-cell-density-mode-mimicking ΔphcA cells attached to tomato roots better than the wild-type cells, consistent with their increased expression of several adhesins. Inside xylem vessels, ΔphcA cells formed aberrantly dense mats. Possibly as a result, the mutant could not spread up or down tomato stems as well as the wild type. This suggests that aggregating improves R. solanacearum survival in soil and facilitates infection and that it reduces pathogenic fitness later in disease. Thus, PhcA mediates a second strategic switch between initial pathogen attachment and subsequent dispersal inside the host. PhcA helps R. solanacearum optimally invest resources and correctly sequence multiple steps in the bacterial wilt disease cycle. Ralstonia solanacearum is a destructive soilborne crop pathogen that wilts plants by colonizing their water-transporting xylem vessels. It produces its costly virulence factors only after it has grown to a high population density inside a host. To identify traits that this pathogen needs in other life stages, we studied a mutant that mimics the low-cell-density condition. This mutant (the ΔphcA mutant) cannot sense its own population density. It grew faster than and used many nutrients not available to the wild-type bacterium, including metabolites present in tomato xylem sap. The mutant also attached much better to tomato roots, and yet it failed to spread once it was inside plants because it was trapped in dense mats. Thus, PhcA helps R. solanacearum succeed over the course of its complex life cycle by ensuring avid attachment to plant surfaces and rapid growth early in disease, followed by high virulence and effective dispersal later in disease.
Collapse
|
38
|
Parmar N, Singh KH, Sharma D, Singh L, Kumar P, Nanjundan J, Khan YJ, Chauhan DK, Thakur AK. Genetic engineering strategies for biotic and abiotic stress tolerance and quality enhancement in horticultural crops: a comprehensive review. 3 Biotech 2017; 7:239. [PMID: 28702937 PMCID: PMC5507805 DOI: 10.1007/s13205-017-0870-y] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 07/02/2017] [Indexed: 11/28/2022] Open
Abstract
Genetic engineering technique offers myriads of applications in improvement of horticultural crops for biotic and abiotic stress tolerance, and produce quality enhancement. During last two decades, a large number of transgenic horticultural crops has been developed and more are underway. A number of genes including natural and synthetic Cry genes, protease inhibitors, trypsin inhibitors and cystatin genes have been used to incorporate insect and nematode resistance. For providing protection against fungal and bacterial diseases, various genes like chitinase, glucanase, osmotin, defensin and pathogenesis-related genes are being transferred to many horticultural crops world over. RNAi technique has been found quite successful in inducing virus resistance in horticultural crops in addition to coat protein genes. Abiotic stresses such as drought, heat and salinity adversely affect production and productivity of horticultural crops and a number of genes encoding for biosynthesis of stress protecting compounds including mannitol, glycine betaine and heat shock proteins have been employed for abiotic stress tolerance besides various transcription factors like DREB1, MAPK, WRKY, etc. Antisense gene and RNAi technologies have revolutionized the pace of improvement of horticultural crops, particularly ornamentals for color modification, increasing shelf-life and reducing post-harvest losses. Precise genome editing tools, particularly CRISPR/Cas9, have been efficiently applied in tomato, petunia, citrus, grape, potato and apple for gene mutation, repression, activation and epigenome editing. This review provides comprehensive overview to draw the attention of researchers for better understanding of genetic engineering advancements in imparting biotic and abiotic stress tolerance as well as on improving various traits related to quality, texture, plant architecture modification, increasing shelf-life, etc. in different horticultural crops.
Collapse
Affiliation(s)
- Nehanjali Parmar
- Dr. Y.S. Parmar University of Horticulture and Forestry, Nauni, Solan, HP, 173 230, India.
| | | | - Deepika Sharma
- ICAR-Directorate of Rapeseed-Mustard Research, Bharatpur, Rajasthan, 321 303, India
| | - Lal Singh
- ICAR-Directorate of Rapeseed-Mustard Research, Bharatpur, Rajasthan, 321 303, India
| | - Pankaj Kumar
- National Institute of Plant Genome Research, New Delhi, 110 067, India
| | - J Nanjundan
- ICAR-Indian Agricultural Research Institute, Regional Station, Wellington, The Nilgiris, Tamilnadu, 643 231, India
| | - Yasin Jeshima Khan
- Division of Genomic Resources, ICAR-National Bureau of Plant Genetic Resources, PUSA Campus, New Delhi, 110 012, India
| | - Devendra Kumar Chauhan
- Division of Plant Breeding and Genetics, Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, Chatha, Jammu, J&K, 180 009, India
| | - Ajay Kumar Thakur
- ICAR-Directorate of Rapeseed-Mustard Research, Bharatpur, Rajasthan, 321 303, India
| |
Collapse
|
39
|
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.
Collapse
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
| |
Collapse
|
40
|
Sustainable Management of Plant Quarantine Pests: The Case of Olive Quick Decline Syndrome. SUSTAINABILITY 2017. [DOI: 10.3390/su9040659] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The disease outbreak of Xylella fastidiosa subsp. pauca strain CoDiRO (Complesso del Disseccamento Rapido dell’Olivo) in Salento (Apulia, South Italy) associated with severe cases of olive quick decline syndrome may represent not just a new disease paradigm, but a challenge for policy formulation and science communication in plant pathology. Plant health management can be achieved by applying a technocratic model, in which objective science is thought to directly inform policy-making, or via decisionistic or inclusive models, in which scientific considerations drive risk assessment. Each could be applied to X. fastidiosa and CoDiRO strain management, thanks to consistent literature related to pathogen/host interactions, hosts, vectors, and diagnostic tools, reviewed here. However, consensus among stakeholders seems to be necessary in order to avoid plant health management failures or gridlocks, due to environmental, economic, and social implications in the X. fastidiosa threat. Here we discuss the role of consensus in building scientific opinion, reporting different approaches of governance after severe disease outbreaks in Europe. These case studies, and the available risk analysis for Xylella strains, should drive policy formulations towards more cooperative networks.
Collapse
|
41
|
Zhou L, Zhang LH, Cámara M, He YW. The DSF Family of Quorum Sensing Signals: Diversity, Biosynthesis, and Turnover. Trends Microbiol 2017; 25:293-303. [DOI: 10.1016/j.tim.2016.11.013] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 11/09/2016] [Accepted: 11/22/2016] [Indexed: 01/18/2023]
|
42
|
Sundin GW, Castiblanco LF, Yuan X, Zeng Q, Yang C. Bacterial disease management: challenges, experience, innovation and future prospects: Challenges in Bacterial Molecular Plant Pathology. MOLECULAR PLANT PATHOLOGY 2016; 17:1506-1518. [PMID: 27238249 PMCID: PMC6638406 DOI: 10.1111/mpp.12436] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Plant diseases caused by bacterial pathogens place major constraints on crop production and cause significant annual losses on a global scale. The attainment of consistent effective management of these diseases can be extremely difficult, and management potential is often affected by grower reliance on highly disease-susceptible cultivars because of consumer preferences, and by environmental conditions favouring pathogen development. New and emerging bacterial disease problems (e.g. zebra chip of potato) and established problems in new geographical regions (e.g. bacterial canker of kiwifruit in New Zealand) grab the headlines, but the list of bacterial disease problems with few effective management options is long. The ever-increasing global human population requires the continued stable production of a safe food supply with greater yields because of the shrinking areas of arable land. One major facet in the maintenance of the sustainability of crop production systems with predictable yields involves the identification and deployment of sustainable disease management solutions for bacterial diseases. In addition, the identification of novel management tactics has also come to the fore because of the increasing evolution of resistance to existing bactericides. A number of central research foci, involving basic research to identify critical pathogen targets for control, novel methodologies and methods of delivery, are emerging that will provide a strong basis for bacterial disease management into the future. Near-term solutions are desperately needed. Are there replacement materials for existing bactericides that can provide effective disease management under field conditions? Experience should inform the future. With prior knowledge of bactericide resistance issues evolving in pathogens, how will this affect the deployment of newer compounds and biological controls? Knowledge is critical. A comprehensive understanding of bacterial pathosystems is required to not only identify optimal targets in the pathogens, but also optimal seasonal timings for deployment. Host resistance to effectors must be exploited, carefully and correctly. Are there other candidate genes that could be targeted in transgenic approaches? How can new technologies (CRISPR, TALEN, etc.) be most effectively used to add sustainable disease resistance to existing commercially desirable plant cultivars? We need an insider's perspective on the management of systemic pathogens. In addition to host resistance or reduced sensitivity, are there other methods that can be used to target these pathogen groups? Biological systems are variable. Can biological control strategies be improved for bacterial disease management and be made more predictable in function? The answers to the research foci outlined above are not all available, as will become apparent in this article, but we are heading in the right direction. In this article, we summarize the contributions from past experiences in bacterial disease management, and also describe how advances in bacterial genetics, genomics and host-pathogen interactions are informing novel strategies in virulence inhibition and in host resistance. We also outline potential innovations that could be exploited as the pressures to maximize a safe and productive food supply continue to become more numerous and more complex.
Collapse
Affiliation(s)
- George W. Sundin
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMI48824USA
| | - Luisa F. Castiblanco
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMI48824USA
| | - Xiaochen Yuan
- Department of Biological SciencesUniversity of Wisconsin‐MilwaukeeMilwaukeeWI53211USA
| | - Quan Zeng
- Department of Plant Pathology and Ecology, Connecticut Agricultural Experiment StationNew HavenCT06504USA
| | - Ching‐Hong Yang
- Department of Biological SciencesUniversity of Wisconsin‐MilwaukeeMilwaukeeWI53211USA
| |
Collapse
|
43
|
Dow J. Diffusible signal factor-dependent quorum sensing in pathogenic bacteria and its exploitation for disease control. J Appl Microbiol 2016; 122:2-11. [DOI: 10.1111/jam.13307] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 09/16/2016] [Accepted: 09/23/2016] [Indexed: 12/25/2022]
Affiliation(s)
- J.M. Dow
- School of Microbiology; University College Cork; Cork Ireland
| |
Collapse
|
44
|
Ionescu M, Yokota K, Antonova E, Garcia A, Beaulieu E, Hayes T, Iavarone AT, Lindow SE. Promiscuous Diffusible Signal Factor Production and Responsiveness of the Xylella fastidiosa Rpf System. mBio 2016; 7:e01054-16. [PMID: 27435463 PMCID: PMC4958263 DOI: 10.1128/mbio.01054-16] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 06/16/2016] [Indexed: 01/30/2023] Open
Abstract
UNLABELLED Cell density-dependent regulation of gene expression in Xylella fastidiosa that is crucial to its switching between plant hosts and insect vectors is dependent on RpfF and its production of 2-enoic acids known as diffusible signal factor (DSF). We show that X. fastidiosa produces a particularly large variety of similar, relatively long-chain-length 2-enoic acids that are active in modulating gene expression. Both X. fastidiosa itself and a Pantoea agglomerans surrogate host harboring X. fastidiosa RpfF (XfRpfF) is capable of producing a variety of both saturated and unsaturated free fatty acids. However, only 2-cis unsaturated acids were found to be biologically active in X. fastidiosa X. fastidiosa produces, and is particularly responsive to, a novel DSF species, 2-cis-hexadecanoic acid that we term XfDSF2. It is also responsive to other, even longer 2-enoic acids to which other taxa such as Xanthomonas campestris are unresponsive. The 2-enoic acids that are produced by X. fastidiosa are strongly affected by the cellular growth environment, with XfDSF2 not detected in culture media in which 2-tetradecenoic acid (XfDSF1) had previously been found. X. fastidiosa is responsive to much lower concentrations of XfDSF2 than XfDSF1. Apparently competitive interactions can occur between various saturated and unsaturated fatty acids that block the function of those agonistic 2-enoic fatty acids. By altering the particular 2-enoic acids produced and the relative balance of free enoic and saturated fatty acids, X. fastidiosa might modulate the extent of DSF-mediated quorum sensing. IMPORTANCE X. fastidiosa, having a complicated lifestyle in which it moves and multiplies within plants but also must be vectored by insects, utilizes DSF-based quorum sensing to partition the expression of traits needed for these two processes within different cells in this population based on local cellular density. The finding that it can produce a variety of DSF species in a strongly environmentally context-dependent manner provides insight into how it coordinates the many genes under the control of DSF signaling to successfully associate with its two hosts. Since the new DSF variant XfDSF2 described here is much more active than the previously recognized DSF species, it should contribute to plant disease control, given that the susceptibility of plants can be greatly reduced by artificially elevating the levels of DSF in plants, creating "pathogen confusion," resulting in lower virulence.
Collapse
Affiliation(s)
- Michael Ionescu
- Department of Plant and Microbial Biology, University of California, Berkeley, California, USA
| | - Kenji Yokota
- Department of Applied Biology and Chemistry, Tokyo University of Agriculture, Tokyo, Japan
| | - Elena Antonova
- Department of Plant and Microbial Biology, University of California, Berkeley, California, USA
| | - Angelica Garcia
- Department of Plant and Microbial Biology, University of California, Berkeley, California, USA
| | - Ellen Beaulieu
- Biosciences Division, SRI International, Menlo Park, California, USA
| | - Terry Hayes
- Biosciences Division, SRI International, Menlo Park, California, USA
| | - Anthony T Iavarone
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, California, USA
| | - Steven E Lindow
- Department of Plant and Microbial Biology, University of California, Berkeley, California, USA
| |
Collapse
|
45
|
Dow JM, Naughton LM, Hollmann B, An SQ, Ryan RP. The Diffusible Signal Factor Family of Bacterial CellCell Signals. Isr J Chem 2016. [DOI: 10.1002/ijch.201500075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
46
|
Cheng S, Xie X, Xu Y, Zhang C, Wang X, Zhang J, Wang Y. Genetic transformation of a fruit-specific, highly expressed stilbene synthase gene from Chinese wild Vitis quinquangularis. PLANTA 2016; 243:1041-53. [PMID: 26781778 DOI: 10.1007/s00425-015-2459-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 12/22/2015] [Indexed: 05/09/2023]
Abstract
The stilbene synthase gene VqSTS6, from Chinese wild type Vitis quinquangularis accession Danfeng-2, increases the resveratrol content and pathogen resistance of transgenic plants of V. vinifera Thompson Seedless. This study successfully created transgenic plants of V. vinifera Thompson Seedless which overexpressed VqSTS6, cloned from Chinese wild type V. quinquangularis accession Danfeng-2. Western blot and qRT-PCR showed a variable range in transcript levels among transgenic lines. The resistance to powdery mildew (Uncinula necator) was particularly enhanced in lines most highly expressing VqSTS6. Compared with the non-transformed controls, trans-resveratrol and other stilbene compounds were significantly increased in the transgenic lines. The correlation between high resveratrol content and high pathogen resistance in transgenic grapes is discussed. We hypothesize that the fruit-specific, highly expressed gene VqSTS6 from Chinese wild V. quinquangularis accession Danfeng-2, is directly involved in the resveratrol synthesis pathway in grapes, and plays an important role in the plant's defense against pathogens. Genetic transformation of VqSTS6 explored the potential of the wild Chinese grape species for use in breeding, the results of which would raise both the disease resistance and the fruit quality of V. vinifera grapevines.
Collapse
Affiliation(s)
- Siyan Cheng
- College of Horticulture, Northwest A & F University, No.3, Taicheng Road, Yangling, 712100, Shaanxi, People's Republic of China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, 712100, Shaanxi, People's Republic of China
- State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China
| | - Xiaoqing Xie
- College of Horticulture, Northwest A & F University, No.3, Taicheng Road, Yangling, 712100, Shaanxi, People's Republic of China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, 712100, Shaanxi, People's Republic of China
- State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China
| | - Yan Xu
- College of Horticulture, Northwest A & F University, No.3, Taicheng Road, Yangling, 712100, Shaanxi, People's Republic of China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, 712100, Shaanxi, People's Republic of China
- State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China
| | - Chaohong Zhang
- College of Horticulture, Northwest A & F University, No.3, Taicheng Road, Yangling, 712100, Shaanxi, People's Republic of China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, 712100, Shaanxi, People's Republic of China
- State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China
| | - Xiping Wang
- College of Horticulture, Northwest A & F University, No.3, Taicheng Road, Yangling, 712100, Shaanxi, People's Republic of China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, 712100, Shaanxi, People's Republic of China
- State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China
| | - Jianxia Zhang
- College of Horticulture, Northwest A & F University, No.3, Taicheng Road, Yangling, 712100, Shaanxi, People's Republic of China.
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, 712100, Shaanxi, People's Republic of China.
- State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China.
| | - Yuejin Wang
- College of Horticulture, Northwest A & F University, No.3, Taicheng Road, Yangling, 712100, Shaanxi, People's Republic of China.
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, 712100, Shaanxi, People's Republic of China.
- State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China.
| |
Collapse
|
47
|
Barel V, Chalupowicz L, Barash I, Sharabani G, Reuven M, Dror O, Burdman S, Manulis-Sasson S. Virulence and in planta movement of Xanthomonas hortorum pv. pelargonii are affected by the diffusible signal factor (DSF)-dependent quorum sensing system. MOLECULAR PLANT PATHOLOGY 2015; 16:710-23. [PMID: 25530086 PMCID: PMC6638389 DOI: 10.1111/mpp.12230] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Xanthomonas hortorum pv. pelargonii (Xhp), the causal agent of bacterial blight in pelargonium, is the most threatening bacterial disease of this ornamental worldwide. To gain an insight into the regulation of virulence in Xhp, we have disrupted the quorum sensing (QS) genes, which mediate the biosynthesis and sensing of the diffusible signal factor (DSF). Mutations in rpfF (encoding the DSF synthase) and rpfC (encoding the histidine sensor kinase of the two-component system RfpC/RpfG) and overexpression of rpfF showed a significant reduction in incidence and severity of the disease on pelargonium. Confocal laser scanning microscopy images of inoculated plants with a green fluorescent protein (GFP)-labelled wild-type strain showed that the pathogen is homogeneously dispersed in the lumen of xylem vessels, reaching the apex and invading the intercellular spaces of the leaf mesophyll tissue within 21 days. In contrast, the rpfF and rpfC knockout mutants, as well as the rpfF-overexpressing strain, remained confined to the vicinity of the inoculation site. The rpfF and rpfC mutants formed large incoherent aggregates in the xylem vessels that might interfere with upward movement of the bacterium within the plant. Both mutants also formed extended aggregates under in vitro conditions, whereas the wild-type strain formed microcolonies. Expression levels of putative virulence genes in planta were substantially reduced within 48 h after inoculation with the QS mutants when compared with the wild-type. The results presented indicate that an optimal DSF concentration is crucial for successful colonization and virulence of Xhp in pelargonium.
Collapse
Affiliation(s)
- Victoria Barel
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, The Volcani Center, Bet Dagan, 50250, Israel
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Laura Chalupowicz
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, The Volcani Center, Bet Dagan, 50250, Israel
| | - Isaac Barash
- Department of Molecular Biology and Ecology of Plants, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 61390, Israel
| | - Galit Sharabani
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, The Volcani Center, Bet Dagan, 50250, Israel
| | - Michal Reuven
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, The Volcani Center, Bet Dagan, 50250, Israel
| | - Orit Dror
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, The Volcani Center, Bet Dagan, 50250, Israel
| | - Saul Burdman
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Shulamit Manulis-Sasson
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, The Volcani Center, Bet Dagan, 50250, Israel
| |
Collapse
|
48
|
Ryan RP, An SQ, Allan JH, McCarthy Y, Dow JM. The DSF Family of Cell-Cell Signals: An Expanding Class of Bacterial Virulence Regulators. PLoS Pathog 2015; 11:e1004986. [PMID: 26181439 PMCID: PMC4504480 DOI: 10.1371/journal.ppat.1004986] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Many pathogenic bacteria use cell–cell signaling systems involving the synthesis and perception of diffusible signal molecules to control virulence as a response to cell density or confinement to niches. Bacteria produce signals of diverse structural classes. Signal molecules of the diffusible signal factor (DSF) family are cis-2-unsaturated fatty acids. The paradigm is cis-11-methyl-2-dodecenoic acid from Xanthomonas campestris pv. campestris (Xcc), which controls virulence in this plant pathogen. Although DSF synthesis was thought to be restricted to the xanthomonads, it is now known that structurally related molecules are produced by the unrelated bacteria Burkholderia cenocepacia and Pseudomonas aeruginosa. Furthermore, signaling involving these DSF family members contributes to bacterial virulence, formation of biofilms and antibiotic tolerance in these important human pathogens. Here we review the recent advances in understanding DSF signaling and its regulatory role in different bacteria. These advances include the description of the pathway/mechanism of DSF biosynthesis, identification of novel DSF synthases and new members of the DSF family, the demonstration of a diversity of DSF sensors to include proteins with a Per-Arnt-Sim (PAS) domain and the description of some of the signal transduction mechanisms that impinge on virulence factor expression. In addition, we address the role of DSF family signals in interspecies signaling that modulates the behavior of other microorganisms. Finally, we consider a number of recently reported approaches for the control of bacterial virulence through the modulation of DSF signaling.
Collapse
Affiliation(s)
- Robert P. Ryan
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
- * E-mail: (RPR); (JMD)
| | - Shi-qi An
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - John H. Allan
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Yvonne McCarthy
- School of Microbiology, Biosciences Institute, University College Cork, Cork, Ireland
| | - J. Maxwell Dow
- School of Microbiology, Biosciences Institute, University College Cork, Cork, Ireland
- * E-mail: (RPR); (JMD)
| |
Collapse
|
49
|
Burketova L, Trda L, Ott PG, Valentova O. Bio-based resistance inducers for sustainable plant protection against pathogens. Biotechnol Adv 2015; 33:994-1004. [PMID: 25617476 DOI: 10.1016/j.biotechadv.2015.01.004] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 01/05/2015] [Accepted: 01/16/2015] [Indexed: 01/10/2023]
Abstract
An increasing demand for environmentally acceptable alternative for traditional pesticides provides an impetus to conceive new bio-based strategies in crop protection. Employing induced resistance is one such strategy, consisting of boosting the natural plant immunity. Upon infections, plants defend themselves by activating their immune mechanisms. These are initiated after the recognition of an invading pathogen via the microbe-associated molecular patterns (MAMPs) or other microbe-derived molecules. Triggered responses inhibit pathogen spread from the infected site. Systemic signal transport even enables to prepare, i.e. prime, distal uninfected tissues for more rapid and enhanced response upon the consequent pathogen attack. Similar defense mechanisms can be triggered by purified MAMPs, pathogen-derived molecules, signal molecules involved in plant resistance to pathogens, such as salicylic and jasmonic acid, or a wide range of other chemical compounds. Induced resistance can be also conferred by plant-associated microorganisms, including beneficial bacteria or fungi. Treatment with resistance inducers or beneficial microorganisms provides long-lasting resistance for plants to a wide range of pathogens. This study surveys current knowledge on resistance and its mechanisms provided by microbe-, algae- and plant-derived elicitors in different crops. The main scope deals with bacterial substances and fungus-derived molecules chitin and chitosan and algae elicitors, including naturally sulphated polysaccharides such as ulvans, fucans or carageenans. Recent advances in the utilization of this strategy in practical crop protection are also discussed.
Collapse
Affiliation(s)
- Lenka Burketova
- Institute of Experimental Botany, The Czech Academy of Sciences, Rozvojová 313, 165 02 Prague 6-Lysolaje, Czech Republic
| | - Lucie Trda
- Institute of Experimental Botany, The Czech Academy of Sciences, Rozvojová 313, 165 02 Prague 6-Lysolaje, Czech Republic
| | - Peter G Ott
- Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Otto Str. 15, H-1022 Budapest, Hungary
| | - Olga Valentova
- Department of Biochemistry and Microbiology, Institute of Chemical Technology Prague, Technická 5, 166 28 Prague 6, Czech Republic
| |
Collapse
|
50
|
Scientific Opinion on the risks to plant health posed byXylella fastidiosain the EU territory, with the identification and evaluation of risk reduction options. EFSA J 2015. [DOI: 10.2903/j.efsa.2015.3989] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
|