1
|
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
|
2
|
Pierry PM, de Santana WO, Kitajima JP, Martins-Junior J, Zaini PA, Uceda-Campos G, Feitosa-Junior OR, Pessoa PIS, Coletta-Filho HD, de Souza AA, Machado MA, Gesteira ADS, Martins LF, Amaral MS, Beckedorff FC, de Almeida LGP, de Vasconcelos ATR, Verjovski-Almeida S, Setubal JC, da Silva AM. High-Quality Draft Genome Sequence Resources of Eight Xylella fastidiosa Strains Isolated from Citrus, Coffee, Plum, and Hibiscus in South America. PHYTOPATHOLOGY 2020; 110:1751-1755. [PMID: 32520631 DOI: 10.1094/phyto-05-20-0162-a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Xylella fastidiosa subsp. pauca, once confined to South America and infecting mainly citrus and coffee plants, has been found to be associated with other hosts and in other geographic regions. We present high-quality draft genome sequences of X. fastidiosa subsp. pauca strains J1a12, B111, U24D, and XRB isolated from citrus plants in Brazil, strain Fb7 isolated from a citrus plant in Argentina and strains 3124, Pr8x, and Hib4 isolated, respectively, from coffee, plum, and hibiscus plants in Brazil. Sequencing was performed using Roche 454-GS FLX, MiSeq-Illumina or Pacific Biosciences platforms. These high-quality genome assemblies will be useful for further studies about the genomic diversity, evolution, and biology of X. fastidiosa.
Collapse
Affiliation(s)
- Paulo Marques Pierry
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | | | | | - Joaquim Martins-Junior
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Paulo Adriano Zaini
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
- Department of Plant Sciences, University of California, Davis, CA, U.S.A
| | - Guillermo Uceda-Campos
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Oseias R Feitosa-Junior
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | | | | | | | - Marcos Antonio Machado
- Centro de Citricultura Sylvio Moreira, Instituto Agronômico de Campinas, Cordeirópolis, SP, Brazil
| | | | - Layla Farage Martins
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Murilo Sena Amaral
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Felipe Cesar Beckedorff
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | | | | | - Sergio Verjovski-Almeida
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - João Carlos Setubal
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Aline Maria da Silva
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| |
Collapse
|
3
|
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
|
4
|
Lopes SA, Raiol-Júnior LL, Torres SCZ, Martins EC, Prado SS, Beriam LOS. Differential Responses of Tobacco to the Citrus Variegated Chlorosis and Coffee Stem Atrophy Strains of Xylella fastidiosa. PHYTOPATHOLOGY 2020; 110:567-573. [PMID: 31750792 DOI: 10.1094/phyto-10-19-0374-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Xylella fastidiosa comprises a diverse group of xylem-limited, insect-transmitted bacterial pathogens. In Brazil, the citrus variegated chlorosis (CVC) and coffee stem atrophy (CSA) diseases are caused by X. fastidiosa subspecies pauca transmitted by common insect vectors. No simple protocol allowing strain discrimination exists, making epidemiological studies, which are important for devising control measures, difficult to undertake. Here, we show that both strains can easily be distinguished based on the pattern of leaf symptoms that they induce on pin prick-inoculated tobacco seedlings, namely small orange lesions and large necrotic lesions induced by the CVC and CSA strains, respectively. These differential responses allowed us to investigate whether mixed strain infections would occur in citrus or coffee trees in the field. Seedlings were individually inoculated with X. fastidiosa colonies recovered from citrus or coffee plants from various locations at three different times. No mixed infections were detected. In two experiments, the citrus and coffee strains infected only their original hosts as well as tobacco. The usefulness of this tobacco bioassay as a tool to study X. fastidiosa spread was demonstrated. It provided evidence that, over the years, the CVC and CSA pathogens have remained limited to their original hosts, despite crop proximity and the presence of sharpshooter vectors that favor transmission of the bacteria to and between both host species.
Collapse
Affiliation(s)
- Silvio A Lopes
- Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil
- Fundo de Defesa da Citricultura, Araraquara, São Paulo, Brazil
| | - Laudecir L Raiol-Júnior
- Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil
- Fundo de Defesa da Citricultura, Araraquara, São Paulo, Brazil
| | | | | | - Simone S Prado
- Empresa Brasileira de Pesquisa Agropecuária, Jaguariuna, São Paulo, Brazil
| | | |
Collapse
|
5
|
Burbank LP, Ortega BC. Novel amplification targets for rapid detection and differentiation of Xylella fastidiosa subspecies fastidiosa and multiplex in plant and insect tissues. J Microbiol Methods 2018; 155:8-18. [PMID: 30408500 DOI: 10.1016/j.mimet.2018.11.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 10/29/2018] [Accepted: 11/03/2018] [Indexed: 12/31/2022]
Abstract
Xylella fastidiosa is an insect-transmitted bacterial plant pathogen which causes a variety of economically important diseases worldwide. Molecular identification of X. fastidiosa is used for quarantine screening, surveillance, and research applications; many of which require subspecies level differentiation of pathogen isolates. This study describes quantitative PCR (qPCR) and isothermal amplification assays which can rapidly identify X. fastidiosa isolates belonging to the fastidiosa and multiplex subspecies. The TaqMan qPCR primers described here are used to differentiate X. fastidiosa strains by subspecies in plant and insect tissue in a single reaction, with the inclusion of a general amplification control probe to identify potential false negative samples. This TaqMan qPCR protocol can identify between 103 and 104 cfu/ml concentrations of X. fastidiosa at the subspecies level in a variety of sample types. Additionally, loop-mediated isothermal amplification (LAMP) targets were designed for faster detection of X. fastidiosa subspecies fastidiosa and multiplex, applicable to a field setting. These assays are effective for strain differentiation in artificially and naturally inoculated plant material, and in field collected insect vectors.
Collapse
Affiliation(s)
- Lindsey P Burbank
- Agricultural Research Service, United States Department of Agriculture, San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Ave, Parlier, CA 93648-9757, USA.
| | - Brandon C Ortega
- Agricultural Research Service, United States Department of Agriculture, San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Ave, Parlier, CA 93648-9757, USA
| |
Collapse
|
6
|
Kandel PP, Chen H, De La Fuente L. A Short Protocol for Gene Knockout and Complementation in Xylella fastidiosa Shows that One of the Type IV Pilin Paralogs (PD1926) Is Needed for Twitching while Another (PD1924) Affects Pilus Number and Location. Appl Environ Microbiol 2018; 84:e01167-18. [PMID: 29980551 PMCID: PMC6121978 DOI: 10.1128/aem.01167-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 06/29/2018] [Indexed: 11/20/2022] Open
Abstract
Twitching motility is one of the major virulence factors of the plant-pathogenic bacterium Xylella fastidiosa, and it is mediated by type IV pili (TFP) that are present at one of the cell poles. Genome analysis of X. fastidiosa showed the presence of at least four paralogs of the gene pilA, which encodes the TFP major pilin subunit. However, whether all of these paralogs have a functional role in TFP structure and function is unknown. Here, using a short and reliable protocol based on overlap extension PCR and natural transformation, deletion mutants of two pilA paralogs (pilA1 PD1924 and pilA2 PD1926) were generated in two X. fastidiosa subsp. fastidiosa strains, WM1-1 and TemeculaL, followed by assessment of twitching motility and biofilm formation. Deletion of pilA2 caused loss of twitching motility, whereas deletion of pilA1 did not influence twitching motility but caused hyperpiliation and extended distribution of TFP along the sides of the cell. Loss of twitching motility due to pilA2 deletion was restored when a wild-type copy of the pilA2 gene was added at a neutral site in the genome of mutants in both wild-type backgrounds. This study demonstrates that PCR templates generated by overlap extension PCR can be successfully used to rapidly generate gene knockouts and perform genetic complementation in X. fastidiosa, and that twitching motility in X. fastidiosa is controlled by regulating the transcription of the major pilin subunit, pilA2IMPORTANCE The bacterial plant pathogen Xylella fastidiosa causes incurable diseases in multiple hosts, including grape, citrus, and blueberry. Historically restricted to the Americas, it was recently found to cause epidemics in olives in Italy and to infect other hosts in Europe and Asia. In this study, we report a short protocol to create deletion and complemented mutants using fusion PCR and natural transformation. We also determined the distinct function of two pilin paralogs, the main structural component of TFP involved in twitching motility, which allows this bacterium to move inside the xylem vessels against the flow. One of the paralogs is needed for twitching movement, whereas the other does not have an effect on motility but influences the number and position of TFP. Since twitching motility is fundamental for the virulence of this xylem-limited bacterium, this study contributes to the understanding of the regulation of virulence by this pathogen.
Collapse
Affiliation(s)
- Prem P Kandel
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA
| | - Hongyu Chen
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA
| | - Leonardo De La Fuente
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA
| |
Collapse
|
7
|
The unusual cellulose utilization system of the aerobic soil bacterium Cytophaga hutchinsonii. Appl Microbiol Biotechnol 2017; 101:7113-7127. [PMID: 28849247 DOI: 10.1007/s00253-017-8467-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 08/05/2017] [Indexed: 10/19/2022]
Abstract
Cellulolytic microorganisms play important roles in global carbon cycling and have evolved diverse strategies to digest cellulose. Some are 'generous,' releasing soluble sugars from cellulose extracellularly to feed both themselves and their neighbors. The gliding soil bacterium Cytophaga hutchinsonii exhibits a more 'selfish' strategy. It digests crystalline cellulose using cell-associated cellulases and releases little soluble sugar outside of the cell. The mechanism of C. hutchinsonii cellulose utilization is still poorly understood. In this review, we discuss novel aspects of the C. hutchinsonii cellulolytic system. Recently developed genetic manipulation tools allowed the identification of proteins involved in C. hutchinsonii cellulose utilization. These include periplasmic and cell-surface endoglucanases and novel cellulose-binding proteins. The recently discovered type IX secretion system is needed for cellulose utilization and appears to deliver some of the cellulolytic enzymes and other proteins to the cell surface. The requirement for periplasmic endoglucanases for cellulose utilization is unusual and suggests that cello-oligomers must be imported across the outer membrane before being further digested. Cellobiohydrolases or other predicted processive cellulases that play important roles in many other cellulolytic bacteria appear to be absent in C. hutchinsonii. Cells of C. hutchinsonii attach to and glide along cellulose fibers, which may allow them to find sites most amenable to attack. A model of C. hutchinsonii cellulose utilization summarizing recent progress is proposed.
Collapse
|
8
|
Alencar VC, Jabes DL, Menegidio FB, Sassaki GL, de Souza LR, Puzer L, Meneghetti MCZ, Lima MA, Tersariol ILDS, de Oliveira RC, Nunes LR. Functional and Evolutionary Characterization of a UDP-Xylose Synthase Gene from the Plant Pathogen Xylella fastidiosa, Involved in the Synthesis of Bacterial Lipopolysaccharide. Biochemistry 2017; 56:779-792. [PMID: 28125217 DOI: 10.1021/acs.biochem.6b00886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Xylella fastidiosa is a plant-infecting bacillus, responsible for many important crop diseases, such as Pierce's disease of vineyards, citrus variegated chlorosis, and coffee leaf scorch (CLS), among others. Recent genomic comparisons involving two CLS-related strains, belonging to X. fastidiosa subsp. pauca, revealed that one of them carries a frameshift mutation that inactivates a gene encoding an oxidoreductase of the short-chain dehydrogenase/reductase (SDR) superfamily, which may play important roles in determining structural variations in bacterial glycans and glycoconjugates. However, the exact nature of this SDR has been a matter of controversy, as different annotations of X. fastidiosa genomes have implicated it in distinct reactions. To confirm the nature of this mutated SDR, a comparative analysis was initially performed, suggesting that it belongs to a subgroup of SDR decarboxylases, representing a UDP-xylose synthase (Uxs). Functional assays, using a recombinant derivative of this enzyme, confirmed its nature as XfUxs, and carbohydrate composition analyses, performed with lipopolysaccharide (LPS) molecules obtained from different strains, indicate that inactivation of the X. fastidiosa uxs gene affects the LPS structure among CLS-related X. fastidiosa strains. Finally, a comparative sequence analysis suggests that this mutation is likely to result in a morphological and evolutionary hallmark that differentiates two subgroups of CLS-related strains, which may influence interactions between these bacteria and their plant and/or insect hosts.
Collapse
Affiliation(s)
- Valquíria Campos Alencar
- Núcleo Integrado de Biotecnologia, Universidade de Mogi das Cruzes (UMC) , Av. Dr. Cândido Xavier de Almeida Souza, 200, Mogi das Cruzes, SP CEP 08780-911, Brazil
| | - Daniela Leite Jabes
- Núcleo Integrado de Biotecnologia, Universidade de Mogi das Cruzes (UMC) , Av. Dr. Cândido Xavier de Almeida Souza, 200, Mogi das Cruzes, SP CEP 08780-911, Brazil
| | - Fabiano Bezerra Menegidio
- Núcleo Integrado de Biotecnologia, Universidade de Mogi das Cruzes (UMC) , Av. Dr. Cândido Xavier de Almeida Souza, 200, Mogi das Cruzes, SP CEP 08780-911, Brazil
| | - Guilherme Lanzi Sassaki
- Setor de Ciências Biológicas-Departamento de Bioquímica e Biologia Molecular Laboratório de Química de Carboidratos, Universidade Federal do Paraná (UFPR) , Rua Cel. Francisco H. dos Santos, 100, Curitiba, Paraná CEP 81531-980, Brazil
| | - Lucas Rodrigo de Souza
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC (UFABC) , Rua Santa Adélia, 166, Santo André, SP CEP 09210-170, Brazil
| | - Luciano Puzer
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC (UFABC) , Rua Santa Adélia, 166, Santo André, SP CEP 09210-170, Brazil
| | - Maria Cecília Zorél Meneghetti
- Departamento de Bioquímica, Universidade Federal de São Paulo (UNIFESP) , Rua Três de Maio, Vila Clementino, São Paulo CEP 04044-020, Brazil
| | - Marcelo Andrade Lima
- Departamento de Bioquímica, Universidade Federal de São Paulo (UNIFESP) , Rua Três de Maio, Vila Clementino, São Paulo CEP 04044-020, Brazil
| | - Ivarne Luis Dos Santos Tersariol
- Departamento de Bioquímica, Universidade Federal de São Paulo (UNIFESP) , Rua Três de Maio, Vila Clementino, São Paulo CEP 04044-020, Brazil
| | - Regina Costa de Oliveira
- Núcleo Integrado de Biotecnologia, Universidade de Mogi das Cruzes (UMC) , Av. Dr. Cândido Xavier de Almeida Souza, 200, Mogi das Cruzes, SP CEP 08780-911, Brazil
| | - Luiz R Nunes
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC (UFABC) , Rua Santa Adélia, 166, Santo André, SP CEP 09210-170, Brazil
| |
Collapse
|
9
|
Leite NR, Faro AR, Dotta MAO, Faim LM, Gianotti A, Silva FH, Oliva G, Thiemann OH. The crystal structure of the cysteine protease Xylellain from Xylella fastidiosa reveals an intriguing activation mechanism. FEBS Lett 2013; 587:339-44. [PMID: 23333295 DOI: 10.1016/j.febslet.2013.01.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 12/21/2012] [Accepted: 01/03/2013] [Indexed: 10/27/2022]
Abstract
Xylella fastidiosa is responsible for a wide range of economically important plant diseases. We report here the crystal structure and kinetic data of Xylellain, the first cysteine protease characterized from the genome of the pathogenic X. fastidiosa strain 9a5c. Xylellain has a papain-family fold, and part of the N-terminal sequence blocks the enzyme active site, thereby mediating protein activity. One novel feature identified in the structure is the presence of a ribonucleotide bound outside the active site. We show that this ribonucleotide plays an important regulatory role in Xylellain enzyme kinetics, possibly functioning as a physiological mediator.
Collapse
Affiliation(s)
- Ney Ribeiro Leite
- Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP 13566-590, Brazil
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Development of replicative oriC plasmids and their versatile use in genetic manipulation of Cytophaga hutchinsonii. Appl Microbiol Biotechnol 2011; 93:697-705. [DOI: 10.1007/s00253-011-3572-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Revised: 08/15/2011] [Accepted: 09/08/2011] [Indexed: 10/17/2022]
|
11
|
da Silva Neto JF, Koide T, Gomes SL, Marques MV. Global gene expression under nitrogen starvation in Xylella fastidiosa: contribution of the σ54 regulon. BMC Microbiol 2010; 10:231. [PMID: 20799976 PMCID: PMC3224663 DOI: 10.1186/1471-2180-10-231] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Accepted: 08/28/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Xylella fastidiosa, a Gram-negative fastidious bacterium, grows in the xylem of several plants causing diseases such as citrus variegated chlorosis. As the xylem sap contains low concentrations of amino acids and other compounds, X. fastidiosa needs to cope with nitrogen limitation in its natural habitat. RESULTS In this work, we performed a whole-genome microarray analysis of the X. fastidiosa nitrogen starvation response. A time course experiment (2, 8 and 12 hours) of cultures grown in defined medium under nitrogen starvation revealed many differentially expressed genes, such as those related to transport, nitrogen assimilation, amino acid biosynthesis, transcriptional regulation, and many genes encoding hypothetical proteins. In addition, a decrease in the expression levels of many genes involved in carbon metabolism and energy generation pathways was also observed. Comparison of gene expression profiles between the wild type strain and the rpoN null mutant allowed the identification of genes directly or indirectly induced by nitrogen starvation in a σ54-dependent manner. A more complete picture of the σ54 regulon was achieved by combining the transcriptome data with an in silico search for potential σ54-dependent promoters, using a position weight matrix approach. One of these σ54-predicted binding sites, located upstream of the glnA gene (encoding glutamine synthetase), was validated by primer extension assays, confirming that this gene has a σ54-dependent promoter. CONCLUSIONS Together, these results show that nitrogen starvation causes intense changes in the X. fastidiosa transcriptome and some of these differentially expressed genes belong to the σ54 regulon.
Collapse
Affiliation(s)
- José F da Silva Neto
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes 1374, 05508-000 São Paulo, SP, Brazil
| | - Tie Koide
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-000 São Paulo, SP, Brazil
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. dos Bandeirantes 3900, 14049-900 Ribeirão Preto, SP, Brasil
| | - Suely L Gomes
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-000 São Paulo, SP, Brazil
| | - Marilis V Marques
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes 1374, 05508-000 São Paulo, SP, Brazil
| |
Collapse
|
12
|
Gimenes F, Gouveia FDS, Fiorini A, Fernandez MA. Intrinsic bent DNA sites in the chromosomal replication origin of Xylella fastidiosa 9a5c. Braz J Med Biol Res 2008; 41:295-304. [PMID: 18392452 DOI: 10.1590/s0100-879x2008000400007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Accepted: 03/05/2008] [Indexed: 11/21/2022] Open
Abstract
The features of the nucleotide sequences in both replication and promoter regions have been investigated in many organisms. Intrinsically bent DNA sites associated with transcription have been described in several prokaryotic organisms. The aim of the present study was to investigate intrinsic bent DNA sites in the segment that holds the chromosomal replication origin, oriC, of Xylella fastidiosa 9a5c. Electrophoretic behavior analyses, as well as in silico analyses of both the 2-D projection and helical parameters, were performed. The chromosomal segment analyzed contains the initial sequence of the rpmH gene, an intergenic region, the dnaA gene, the oriC sequence, and the 5' partial sequence of the dnaN gene. The analysis revealed fragments with reduced electrophoretic mobility, which indicates the presence of curved DNA segments. The analysis of the helical parameter ENDS ratio revealed three bent DNA sites (b1, b2, and b3) located in the rpmH-dnaA intergenic region, the dnaA gene, and the oriC 5' end, respectively. The chromosomal segment of X. fastidiosa analyzed here is rich in phased AT tracts and in CAnT motifs. The 2-D projection indicated a segment whose structure was determined by the cumulative effect of all bent DNA sites. Further, the in silico analysis of the three different bacterial oriC sequences indicated similar negative roll and twist >34.00 degrees values. The DnaA box sequences, and other motifs in them, may be associated with the intrinsic DNA curvature.
Collapse
Affiliation(s)
- F Gimenes
- Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | | | | | | |
Collapse
|
13
|
da Silva Neto JF, Koide T, Abe CM, Gomes SL, Marques MV. Role of sigma54 in the regulation of genes involved in type I and type IV pili biogenesis in Xylella fastidiosa. Arch Microbiol 2007; 189:249-61. [PMID: 17985115 DOI: 10.1007/s00203-007-0314-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Revised: 10/05/2007] [Accepted: 10/15/2007] [Indexed: 11/30/2022]
Abstract
The phytopathogen Xylella fastidiosa produces long type IV pili and short type I pili involved in motility and adhesion. In this work, we have investigated the role of sigma factor sigma(54) (RpoN) in the regulation of fimbrial biogenesis in X. fastidiosa. An rpoN null mutant was constructed from the non-pathogenic citrus strain J1a12, and microarray analyses of global gene expression comparing the wild type and rpoN mutant strains showed few genes exhibiting differential expression. In particular, gene pilA1 (XF2542), which encodes the structural pilin protein of type IV pili, showed decreased expression in the rpoN mutant, whereas two-fold higher expression of an operon encoding proteins of type I pili was detected, as confirmed by quantitative RT-PCR (qRT-PCR) analysis. The transcriptional start site of pilA1 was determined by primer extension, downstream of a sigma(54)-dependent promoter. Microarray and qRT-PCR data demonstrated that expression of only one of the five pilA paralogues, pilA1, was significantly reduced in the rpoN mutant. The rpoN mutant made more biofilm than the wild type strain and presented a cell-cell aggregative phenotype. These results indicate that sigma(54) differentially regulates genes involved in type IV and type I fimbrial biogenesis, and is involved in biofilm formation in X. fastidiosa.
Collapse
Affiliation(s)
- José F da Silva Neto
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes 1374, 05508-000 São Paulo, SP, Brazil
| | | | | | | | | |
Collapse
|
14
|
da Silva Neto JF, Koide T, Gomes SL, Marques MV. The single extracytoplasmic-function sigma factor of Xylella fastidiosa is involved in the heat shock response and presents an unusual regulatory mechanism. J Bacteriol 2006; 189:551-60. [PMID: 17098905 PMCID: PMC1797396 DOI: 10.1128/jb.00986-06] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Genome sequence analysis of the bacterium Xylella fastidiosa revealed the presence of two genes, named rpoE and rseA, predicted to encode an extracytoplasmic function (ECF) sigma factor and an anti-sigma factor, respectively. In this work, an rpoE null mutant was constructed in the citrus strain J1a12 and shown to be sensitive to exposure to heat shock and ethanol. To identify the X. fastidiosa sigma(E) regulon, global gene expression profiles were obtained by DNA microarray analysis of bacterial cells under heat shock, identifying 21 sigma(E)-dependent genes. These genes encode proteins belonging to different functional categories, such as enzymes involved in protein folding and degradation, signal transduction, and DNA restriction modification and hypothetical proteins. Several putative sigma(E)-dependent promoters were mapped by primer extension, and alignment of the mapped promoters revealed a consensus sequence similar to those of ECF sigma factor promoters of other bacteria. Like other ECF sigma factors, rpoE and rseA were shown to comprise an operon in X. fastidiosa, together with a third open reading frame (XF2241). However, upon heat shock, rpoE expression was not induced, while rseA and XF2241 were highly induced at a newly identified sigma(E)-dependent promoter internal to the operon. Therefore, unlike many other ECF sigma factors, rpoE is not autoregulated but instead positively regulates the gene encoding its putative anti-sigma factor.
Collapse
|
15
|
Broetto L, Cecagno R, Sant'anna FH, Weber S, Schrank IS. Stable transformation of Chromobacterium violaceum with a broad-host-range plasmid. Appl Microbiol Biotechnol 2006; 71:450-4. [PMID: 16172890 DOI: 10.1007/s00253-005-0140-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 08/15/2005] [Accepted: 08/18/2005] [Indexed: 11/26/2022]
Abstract
Stable transformants of Chromobacterium violaceum were obtained by high-voltage electroporation with a 7-kilobase binary plasmid. The technique was reliable, reproducible, and simple, with efficiencies of 10(5) transformants/microg of plasmid DNA. The electrical conditions that resulted in the highest efficiencies were short pulse length (4.4-4.5 ms) and high voltage (12.5 kV/cm). The numbers of transformants were almost the same during the growth exponential phase (variation at optical density) and resulted in the highest efficiencies at DNA concentration of 250 pg/ml. Saturation appeared to begin at 4 microg/ml of DNA. This method of C. violaceum transformation should enhance the genetic and biotechnological research by providing a valuable, widely used procedure of introducing DNA into this bacterium.
Collapse
Affiliation(s)
- L Broetto
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500-Prédio 43421, C.P. 15005-CEP: 91501-970, Porto Alegre, RS, Brazil
| | | | | | | | | |
Collapse
|
16
|
Souza LCA, Wulff NA, Gaurivaud P, Mariano AG, Virgílio ACD, Azevedo JL, Monteiro PB. Disruption of Xylella fastidiosa CVC gumB and gumF genes affects biofilm formation without a detectable influence on exopolysaccharide production. FEMS Microbiol Lett 2006; 257:236-42. [PMID: 16553859 DOI: 10.1111/j.1574-6968.2006.00176.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Xylella fastidiosa causes citrus variegated chlorosis (CVC), a destructive disease of citrus. Xylella fastidiosa forms a biofilm inside plants and insect vectors. Biofilms are complex structures involving X. fastidiosa cells and an extracellular matrix which blocks water and nutrient transport in diseased plants. It is hypothesized that the matrix might be composed of an extracellular polysaccharide (EPS), coded by a cluster of nine genes closely related to the xanthan gum operon of Xanthomonas campestris pv. campestris. To understand the role of X. fastidiosa gum genes on biofilm formation and EPS biosynthesis, we produced gumB and gumF mutants. Xylella fastidiosa mutants were obtained by insertional duplication mutagenesis and recovered after triply cloning the cells. Xylella fastidiosa gumB and gumF mutants exhibited normal cell characteristics; typical colony morphology and EPS biosynthesis were not altered. It was of note that X. fastidiosa mutants showed a reduced capacity to form biofilm when BCYE was used as the sustaining medium, a difference not observed with PW medium. Unlike X. campestris pv. campestris, the expression of the X. fastidiosa gumB or gumF genes was not regulated by glucose.
Collapse
Affiliation(s)
- Leonardo C A Souza
- Fundo de Defesa da Citricultura (Fundecitrus), Araraquara, São Paulo, Brazil
| | | | | | | | | | | | | |
Collapse
|
17
|
Picchi SC, Vilas-Boas LA, Ceresini PC, de Macedo Lemos EG, Lemos MVF. Strain variability in the DNA immigration control region (ICR) of Xylella fastidiosa. Res Microbiol 2005; 157:254-62. [PMID: 16125907 DOI: 10.1016/j.resmic.2005.07.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2005] [Revised: 06/24/2005] [Accepted: 07/05/2005] [Indexed: 12/01/2022]
Abstract
The genome of the bacterium Xylella fastidiosa contains four ORFs (XF2721, XF2725, XF2739 and XF0295) related to the restriction modification type I system, ordinarily named R-M. This system belongs to the DNA immigration control region (ICR). Each ORF is related to different operon structures, which are homologues among themselves and with subunit Hsd R from the endonuclease coding genes. In addition, these ORFs are highly homologous to genes in Pseudomonas aeruginosa, Methylococcus capsulatus str. Bath, Legionella pneumophila, Helicobacter pylori, Xanthomonas oryzae pv. Oryzae and Silicibacter pomeroyi, as well as to genes from X. fastidiosa strains that infect grapevine, almond and oleander plants. This study was carried out on R-M ORFs from forty-three X. fastidiosa strains isolated from citrus, coffee, grapevine, periwinkle, almond and plum trees, in order to assess the genetic diversity of these loci through PCR-RFLP. PCR-RFLP analysis of the four ORFs related to the R-M system from these strains enabled the detection of haplotypes for these loci. When the haplotypes were defined, wide genetic diversity and a large range of similar strains originating from different hosts were observed. This analysis also provided information indicating differences in population genetic structures, which led to detection of different levels of gene transfer among the groups of strains.
Collapse
Affiliation(s)
- Simone Cristina Picchi
- Departamento de Biologia Aplicada à Agropecuária, Faculdade de Ciências Agrárias e Veterinárias-FCAV/UNESP, Jaboticabal, SP, Brazil.
| | | | | | | | | |
Collapse
|
18
|
Amaral AMD, Toledo CP, Baptista JC, Machado MA. Transformation of Xanthomonas axonopodis pv. citri by electroporation. ACTA ACUST UNITED AC 2005. [DOI: 10.1590/s0100-41582005000300013] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This study describes the use of electroporation for transforming Xanthomonas axonopodis pv. citri (Xac), the causal agent of citrus (Citrus spp.) canker. It also evaluates the methodology used for this species under different electrical parameters. The bacterium used in the study (Xac 306) was the same strain used for recent complete sequencing of the organism. The use of a plasmid (pUFR047, gentamycin r) is reported here to be able to replicate in cells of Xac. Following the preparation and resuspension of competent cells of Xac at a density of ~4 x 10(10) cfu/ml, in 10% glycerol, and the addition of the replicative plasmid, an electrical pulse was applied to each treatment. Selection of transformants showed a high efficiency of transformation (1.1 x 10(6) transformants/mug DNA), which indicates an effective, and inverse, combination between electrical resistance (50 W) and capacitance (50 µF) for this species, with an electrical field strength of 12.5 kV.cm-1 and 2.7-ms pulse duration. Besides the description of a method for electroporation of Xac 306, this study provides additional information for the use of the technique on studies for production of mutants of this species.
Collapse
|
19
|
Teixeira DDC, Rocha SRP, de Santos MA, Mariano AG, Li WB, Monteiro PB. A Suitable Xylella fastidiosa CVC Strain for Post-Genome Studies. Curr Microbiol 2004; 49:396-9. [PMID: 15696614 DOI: 10.1007/s00284-004-4363-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The genome sequence of the pathogen Xylella fastidiosa Citrus Variegated Chlorosis (CVC) strain 9a5c has revealed many genes related to pathogenicity mechanisms and virulence determinants. However, strain 9a5c is resistant to genetic transformation, impairing mutant production for the analysis of pathogenicity mechanisms and virulence determinants of this fastidious phytopathogen. By screening different strains, we found out that cloned strains J1a12, B111, and S11400, all isolated from citrus trees affected by CVC, are amenable to transformation, and J1a12 has been used as a model strain in a functional genomics program supported by FAPESP (São Paulo State Research Foundation). However, we have found that strain J1a12, unlike strains 9a5c and B111, was incapable of inducing CVC symptoms when inoculated in citrus plants. We have now determined that strain B111 is an appropriate candidate for post-genome studies of the CVC strain of X. fastidiosa.
Collapse
Affiliation(s)
- Diva do Carmo Teixeira
- Fundo de Defesa da Citricultura (Fundecitrus), Av. Dr. Adhemar Pereira de Barros, 201, 14807-040, V. Melhado-Araraquara, SP, Brazil.
| | | | | | | | | | | |
Collapse
|
20
|
Koide T, Zaini PA, Moreira LM, Vêncio RZN, Matsukuma AY, Durham AM, Teixeira DC, El-Dorry H, Monteiro PB, da Silva ACR, Verjovski-Almeida S, da Silva AM, Gomes SL. DNA microarray-based genome comparison of a pathogenic and a nonpathogenic strain of Xylella fastidiosa delineates genes important for bacterial virulence. J Bacteriol 2004; 186:5442-9. [PMID: 15292146 PMCID: PMC490883 DOI: 10.1128/jb.186.16.5442-5449.2004] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2004] [Accepted: 03/22/2004] [Indexed: 12/15/2022] Open
Abstract
Xylella fastidiosa is a phytopathogenic bacterium that causes serious diseases in a wide range of economically important crops. Despite extensive comparative analyses of genome sequences of Xylella pathogenic strains from different plant hosts, nonpathogenic strains have not been studied. In this report, we show that X. fastidiosa strain J1a12, associated with citrus variegated chlorosis (CVC), is nonpathogenic when injected into citrus and tobacco plants. Furthermore, a DNA microarray-based comparison of J1a12 with 9a5c, a CVC strain that is highly pathogenic and had its genome completely sequenced, revealed that 14 coding sequences of strain 9a5c are absent or highly divergent in strain J1a12. Among them, we found an arginase and a fimbrial adhesin precursor of type III pilus, which were confirmed to be absent in the nonpathogenic strain by PCR and DNA sequencing. The absence of arginase can be correlated to the inability of J1a12 to multiply in host plants. This enzyme has been recently shown to act as a bacterial survival mechanism by down-regulating host nitric oxide production. The lack of the adhesin precursor gene is in accordance with the less aggregated phenotype observed for J1a12 cells growing in vitro. Thus, the absence of both genes can be associated with the failure of the J1a12 strain to establish and spread in citrus and tobacco plants. These results provide the first detailed comparison between a nonpathogenic strain and a pathogenic strain of X. fastidiosa, constituting an important step towards understanding the molecular basis of the disease.
Collapse
Affiliation(s)
- Tie Koide
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, SP, Brazil
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Feil H, Feil WS, Detter JC, Purcel AH, Lindow SE. Site-Directed Disruption of the fimA and fimF Fimbrial Genes of Xylella fastidiosa. PHYTOPATHOLOGY 2003; 93:675-682. [PMID: 18943053 DOI: 10.1094/phyto.2003.93.6.675] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
ABSTRACT Xylella fastidiosa causes Pierce's disease, a serious disease of grape, citrus variegated chlorosis, almond and oleander leaf scorches, and many other similar diseases. Although the complete genome sequences of several strains of this organism are now available, the function of most genes in this organism, especially those conferring virulence, is lacking. Attachment of X. fastidiosa to xylem vessels and insect vectors may be required for virulence and transmission; therefore, we disrupted fimA and fimF, genes encoding the major fimbrial protein FimA and a homolog of the fimbrial adhesin MrkD, to determine their role in the attachment process. Disruption of the fimA and fimF genes in Temecula1 and STL grape strains of X. fastidiosa was obtained by homologous recombination using plasmids pFAK and pFFK, respectively. These vectors contained a kanamycin resistance gene cloned into either the fimA or fimF genes of X. fastidiosa grape strains Temecula1 or STL. Efficiency of transformation was sufficiently high ( approximately 600 transformants per mug of pFFK DNA) to enable selection of rare recombination events. Polymerase chain reaction and Southern blot analyses of the mutants indicated that a double crossover event had occurred exclusively within the fimA and fimF genes, replacing the chromosomal gene with the disrupted gene and abolishing production of the corresponding proteins, FimA or FimF. Scanning electron microscopy revealed that fimbriae size and number, cell aggregation, and cell size were reduced for the FimA or FimF mutants of X. fastidiosa when compared with the parental strain. FimA or FimF mutants of X. fastidiosa remained pathogenic to grapevines, with bacterial populations slightly reduced compared with those of the wild-type X. fastidiosa cells. These mutants maintained their resistance to kanamycin in planta for at least 6 months in the greenhouse.
Collapse
|
22
|
Hoffman LM, Jendrisak JJ. Transposomes: a system for identifying genes involved in bacterial pathogenesis. Methods Enzymol 2003; 358:128-40. [PMID: 12474383 DOI: 10.1016/s0076-6879(02)58085-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Les M Hoffman
- Epicentre Technologies, Madison, Wisconsin 53713, USA
| | | |
Collapse
|
23
|
Rhodes LD, Coady AM, Strom MS. Expression of duplicate msa genes in the salmonid pathogen Renibacterium salmoninarum. Appl Environ Microbiol 2002; 68:5480-7. [PMID: 12406741 PMCID: PMC129909 DOI: 10.1128/aem.68.11.5480-5487.2002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Renibacterium salmoninarum is a gram-positive bacterium responsible for bacterial kidney disease of salmon and trout. R. salmoninarum has two identical copies of the gene encoding major soluble antigen (MSA), an immunodominant, extracellular protein. To determine whether one or both copies of msa are expressed, reporter plasmids encoding a fusion of MSA and green fluorescent protein controlled by 0.6 kb of promoter region from msa1 or msa2 were constructed and introduced into R. salmoninarum. Single copies of the reporter plasmids integrated into the chromosome by homologous recombination. Expression of mRNA and protein from the integrated plasmids was detected, and transformed cells were fluorescent, demonstrating that both msa1 and msa2 are expressed under in vitro conditions. This is the first report of successful transformation and homologous recombination in R. salmoninarum.
Collapse
Affiliation(s)
- Linda D Rhodes
- Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, United States Department of Commerce, Seattle, Washington 98112, USA.
| | | | | |
Collapse
|
24
|
Li WB, Zhou CH, Pria WD, Teixeira DC, Miranda VS, Pereira EO, Ayres AJ, He CX, Costa PI, Hartung JS. Citrus and Coffee Strains of Xylella fastidiosa Induce Pierce's Disease in Grapevine. PLANT DISEASE 2002; 86:1206-1210. [PMID: 30818468 DOI: 10.1094/pdis.2002.86.11.1206] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Xylella fastidiosa causes citrus variegated chlorosis (CVC) disease in Brazil and Pierce's disease of grapevines in the United States. Both of these diseases cause significant production problems in the respective industries. The recent establishment of the glassy-winged sharpshooter in California has radically increased the threat posed by Pierce's disease to California viticulture. Populations of this insect reach very high levels in citrus groves in California and move from the orchards into the vineyards, where they acquire inoculum and spread Pierce's disease in the vineyards. Here we show that strains of X. fastidiosa isolated from diseased citrus and coffee in Brazil can incite symptoms of Pierce's disease after mechanical inoculation into seven commercial Vitis vinifera varieties grown in Brazil and California. Thus, any future introduction of the CVC strains of X. fastidiosa into the United States would pose a threat to both the sweet orange and grapevine industries. Previous work has clearly shown that the strains of X. fastidiosa isolated from Pierce's disease- and CVC-affected plants are the most distantly related of all strains in the diverse taxon X. fastidiosa. The ability of citrus strains of X. fastidiosa to incite disease in grapevine is therefore surprising and creates an experimental system with which to dissect mechanisms used by X. fastidiosa in plant colonization and disease development using the full genome sequence data that has recently become available for both the citrus and grapevine strains of this pathogen.
Collapse
Affiliation(s)
- W-B Li
- USDA-ARS, Beltsville, MD 20705
| | | | - W D Pria
- Fundecitrus, Araraquara, 14807-040, SP, Brazil
| | | | - V S Miranda
- Fundecitrus, Araraquara, 14807-040, SP, Brazil
| | - E O Pereira
- Fundecitrus, Araraquara, 14807-040, SP, Brazil
| | - A J Ayres
- Fundecitrus, Araraquara, 14807-040, SP, Brazil
| | - C-X He
- Institute of Chemistry, UNESP, Araraquara, SP, Brazil
| | - P I Costa
- Institute of Chemistry, UNESP, Araraquara, SP, Brazil
| | | |
Collapse
|
25
|
Campoy S, Mazón G, Fernández de Henestrosa AR, Llagostera M, Monteiro PB, Barbé J. A new regulatory DNA motif of the gamma subclass Proteobacteria: identification of the LexA protein binding site of the plant pathogen Xylella fastidiosa. MICROBIOLOGY (READING, ENGLAND) 2002; 148:3583-3597. [PMID: 12427949 DOI: 10.1099/00221287-148-11-3583] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Escherichia coli LexA protein is the repressor of a gene network whose members are directly involved in the repair of damaged DNA and in the survival of bacterial cells until DNA lesions have been eliminated. The lexA gene is widely present in bacteria, although the sequences of only three LexA-binding sites are known: Gram-positive, alpha Proteobacteria and some members of gamma Proteobacteria represented by E. coli. Taking advantage of the fact that the genome sequence of the plant-pathogenic bacterium Xylella fastidiosa has been determined, its lexA gene has been cloned and overexpressed in E. coli to purify its product. After demonstration that X. fastidiosa lexA and recA genes are co-transcribed, gel mobility shift assays and directed mutagenesis experiments using the promoter of the lexA-recA transcriptional unit demonstrated that the X. fastidiosa LexA protein specifically binds the imperfect palindrome TTAGN(6)TACTA. This is the first LexA binding sequence identified in the gamma Proteobacteria differing from the E. coli-like LexA box. Although a computational search has revealed the presence of TTAGN(6)TACTA-like motifs upstream of X. fastidiosa genes other than lexA, X. fastidiosa LexA only binds the promoter of one of them, XF2313, encoding a putative DNA-modification methylase. Moreover, X. fastidiosa LexA protein does not bind any of the other genes whose homologues are regulated by the LexA repressor in E. coli (uvrA, uvrB, ssb, ruvAB, ftsK, dinG, recN and ybfE). RT-PCR quantitative analysis has also demonstrated that lexA-recA and XF2313 genes, as well as the X. fastidiosa genes which are homologues to those of E. coli belonging to the LexA regulon, with the exception of ssb, are DNA damage-inducible in X. fastidiosa.
Collapse
Affiliation(s)
- Susana Campoy
- Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain1
| | - Gerard Mazón
- Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain1
| | | | - Montserrat Llagostera
- Centre de Recerca en Sanitat Animal (CReSA), Universitat Autònoma de Barcelona-Institut de Recerca i Tecnologia Agroalimentària (UAB-IRTA), Bellaterra, 08193 Barcelona, Spain3
- Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain1
| | - Patricia Brant Monteiro
- Fundo de Defesa da Citricultura (Fundecitrus), 14807-040, VI. Melhado- C. P. 391, Araraquara, Sao Paulo, Brazil2
| | - Jordi Barbé
- Centre de Recerca en Sanitat Animal (CReSA), Universitat Autònoma de Barcelona-Institut de Recerca i Tecnologia Agroalimentària (UAB-IRTA), Bellaterra, 08193 Barcelona, Spain3
- Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain1
| |
Collapse
|
26
|
Gaurivaud P, Souza LCA, Virgílio ACD, Mariano AG, Palma RR, Monteiro PB. Gene disruption by homologous recombination in the Xylella fastidiosa citrus variegated chlorosis strain. Appl Environ Microbiol 2002; 68:4658-65. [PMID: 12200328 PMCID: PMC124079 DOI: 10.1128/aem.68.9.4658-4665.2002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mutagenesis by homologous recombination was evaluated in Xylella fastidiosa by using the bga gene, coding for beta-galactosidase, as a model. Integration of replicative plasmids by homologous recombination between the cloned truncated copy of bga and the endogenous gene was produced by one or two crossover events leading to beta-galactosidase mutants. A promoterless chloramphenicol acetyltransferase gene was used to monitor the expression of the target gene and to select a cvaB mutant.
Collapse
Affiliation(s)
- Patrice Gaurivaud
- Fundo de Defesa da Citricultura (Fundecitrus), Araraquara, São Paulo, Brazil
| | | | | | | | | | | |
Collapse
|
27
|
Yen MR, Lin NT, Hung CH, Choy KT, Weng SF, Tseng YH. oriC region and replication termination site, dif, of the Xanthomonas campestris pv. campestris 17 chromosome. Appl Environ Microbiol 2002; 68:2924-33. [PMID: 12039751 PMCID: PMC123971 DOI: 10.1128/aem.68.6.2924-2933.2002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A 13-kb DNA fragment containing oriC and the flanking genes thdF, orf900, yidC, rnpA, rpmH, oriC, dnaA, dnaN, recF, and gyrB was cloned from the gram-negative plant pathogen Xanthomonas campestris pv. campestris 17. These genes are conserved in order with other eubacterial oriC genes and code for proteins that share high degrees of identity with their homologues, except for orf900, which has a homologue only in Xylella fastidiosa. The dnaA/dnaN intergenic region (273 bp) identified to be the minimal oriC region responsible for autonomous replication has 10 pure AT clusters of four to seven bases and only three consensus DnaA boxes. These findings are in disagreement with the notion that typical oriCs contain four or more DnaA boxes located upstream of the dnaA gene. The X. campestris pv. campestris 17 attB site required for site-specific integration of cloned fragments from filamentous phage phiLf replicative form DNA was identified to be a dif site on the basis of similarities in nucleotide sequence and function with the Escherichia coli dif site required for chromosome dimer resolution and whose deletion causes filamentation of the cells. The oriC and dif sites were located at 12:00 and 6:00, respectively, on the circular X. campestris pv. campestris 17 chromosome map, similar to the locations found for E. coli sites. Computer searches revealed the presence of both the dif site and XerC/XerD recombinase homologues in 16 of the 42 fully sequenced eubacterial genomes, but eight of the dif sites are located far away from the 6:00 point instead of being placed opposite the cognate oriC. The differences in the relative position suggest that mechanisms different from that of E. coli may participate in the control of chromosome replication.
Collapse
Affiliation(s)
- Ming-Ren Yen
- Institute of Molecular Biology, National Chung Hsing University, Taichung 402, Taiwan, Republic of China
| | | | | | | | | | | |
Collapse
|
28
|
Leite B, Ishida ML, Alves E, Carrer H, Pascholati SF, Kitajima EW. Genomics and X-ray microanalysis indicate that Ca2+ and thiols mediate the aggregation and adhesion of Xylella fastidiosa. Braz J Med Biol Res 2002; 35:645-50. [PMID: 12045828 DOI: 10.1590/s0100-879x2002000600003] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The availability of the genome sequence of the bacterial plant pathogen Xylella fastidiosa, the causal agent of citrus variegated chlorosis, is accelerating important investigations concerning its pathogenicity. Plant vessel occlusion is critical for symptom development. The objective of the present study was to search for information that would help to explain the adhesion of X. fastidiosa cells to the xylem. Scanning electron microscopy revealed that adhesion may occur without the fastidium gum, an exopolysaccharide produced by X. fastidiosa, and X-ray microanalysis demonstrated the presence of elemental sulfur both in cells grown in vitro and in cells found inside plant vessels, indicating that the sulfur signal is generated by the pathogen surface. Calcium and magnesium peaks were detected in association with sulfur in occluded vessels. We propose an explanation for the adhesion and aggregation process. Thiol groups, maintained by the enzyme peptide methionine sulfoxide reductase, could be active on the surface of the bacteria and appear to promote cell-cell aggregation by forming disulfide bonds with thiol groups on the surface of adjacent cells. The enzyme methionine sulfoxide reductase has been shown to be an auxiliary component in the adhesiveness of some human pathogens. The negative charge conferred by the ionized thiol group could of itself constitute a mechanism of adhesion by allowing the formation of divalent cation bridges between the negatively charged bacteria and predominantly negatively charged xylem walls.
Collapse
Affiliation(s)
- B Leite
- Departamento de Entomologia, Fitopatologia e Zoologia Agrícola, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, SP, Brasil.
| | | | | | | | | | | |
Collapse
|
29
|
da Silva Neto JF, Koide T, Gomes SL, Marques MV. Site-directed gene disruption in Xylella fastidiosa. FEMS Microbiol Lett 2002; 210:105-10. [PMID: 12023085 DOI: 10.1111/j.1574-6968.2002.tb11167.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
As a first approach to generate mutations by DNA insertion, we have developed a shuttle vector, called pSP3, which replicates both in Escherichia coli and in Xylella. Vector pSP3 was constructed by ligating to the E. coli plasmid pBluescript, a kanamycin resistance gene under the control of the Xylella 16S rRNA promoter and the indigenous Xylella plasmid pXF1.3. Transformation experiments have shown that pSP3 replicates stably in Xylella. When a DNA fragment encompassing part of the Xylella xpsD gene was cloned into pSP3, specific integration of the construct into this gene was observed in 10% of the transformants, as early as after two passages of the culture. These results indicate that this vector can be used to generate site-specific gene disruption by homologous recombination in Xylella fastidiosa.
Collapse
Affiliation(s)
- José F da Silva Neto
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes 1374, 05508-900, SP, Brazil
| | | | | | | |
Collapse
|