1
|
Lavado-Benito C, Murillo J, Martínez-Gil M, Ramos C, Rodríguez-Moreno L. GacA reduces virulence and increases competitiveness in planta in the tumorigenic olive pathogen Pseudomonas savastanoi pv. savastanoi. Front Plant Sci 2024; 15:1347982. [PMID: 38375080 PMCID: PMC10875052 DOI: 10.3389/fpls.2024.1347982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 01/08/2024] [Indexed: 02/21/2024]
Abstract
GacS/GacA is a widely distributed two-component system playing an essential role as a key global regulator, although its characterization in phytopathogenic bacteria has been deeply biased, being intensively studied in pathogens of herbaceous plants but barely investigated in pathogens of woody hosts. P. savastanoi pv. savastanoi (Psv) is characterized by inducing tumours in the stem and branches of olive trees. In this work, the model strain Psv NCPPB 3335 and a mutant derivative with a complete deletion of gene gacA were subjected to RNA-Seq analyses in a minimum medium and a medium mimicking in planta conditions, accompanied by RT-qPCR analyses of selected genes and phenotypic assays. These experiments indicated that GacA participates in the regulation of at least 2152 genes in strain NCPPB 3335, representing 37.9 % of the annotated CDSs. GacA also controls the expression of diverse rsm genes, and modulates diverse phenotypes, including motility and resistance to oxidative stresses. As occurs with other P. syringae pathovars of herbaceous plants, GacA regulates the expression of the type III secretion system and cognate effectors. In addition, GacA also regulates the expression of WHOP genes, specifically encoded in P. syringe strains isolated from woody hosts, and genes for the biosynthesis of phytohormones. A gacA mutant of NCPPB 3335 showed increased virulence, producing large immature tumours with high bacterial populations, but showed a significantly reduced competitiveness in planta. Our results further extend the role of the global regulator GacA in the virulence and fitness of a P. syringae pathogen of woody hosts.
Collapse
Affiliation(s)
- Carla Lavado-Benito
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, Spain
| | - Jesús Murillo
- Institute for Multidisciplinary Research in Applied Biology, Universidad Pública de Navarra (UPNA), Edificio de Agrobiotecnología, Mutilva Baja, Spain
| | - Marta Martínez-Gil
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Cayo Ramos
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, Spain
| | - Luis Rodríguez-Moreno
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, Spain
| |
Collapse
|
2
|
Moreno-Pérez A, Ramos C, Rodríguez-Moreno L. HrpL Regulon of Bacterial Pathogen of Woody Host Pseudomonas savastanoi pv. savastanoi NCPPB 3335. Microorganisms 2021; 9:microorganisms9071447. [PMID: 34361883 PMCID: PMC8303149 DOI: 10.3390/microorganisms9071447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 06/29/2021] [Accepted: 06/29/2021] [Indexed: 11/17/2022] Open
Abstract
The Pseudomonas savastanoi species comprises a group of phytopathogenic bacteria that cause symptoms of disease in woody hosts. This is mediated by the rapid activation of a pool of virulence factors that suppress host defences and hijack the host’s metabolism to the pathogen’s benefit. The hrpL gene encodes an essential transcriptional regulator of virulence functions, including the type III secretion system (T3SS), in pathogenic bacteria. Here, we analyzed the contribution of HrpL to the virulence of four pathovars (pv.) of P. savastanoi isolated from different woody hosts (oleander, ash, broom, and dipladenia) and characterized the HrpL regulon of P. savastanoi pv. savastanoi NCPPB 3335 using two approaches: whole transcriptome sequencing (RNA-seq) and the bioinformatic prediction of candidate genes containing an hrp-box. Pathogenicity tests carried out for the P. savastanoi pvs. showed that HrpL was essential for symptom development in both non-host and host plants. The RNA-seq analysis of the HrpL regulon in P. savastanoi revealed a total of 53 deregulated genes, 49 of which were downregulated in the ΔhrpL mutant. Bioinformatic prediction resulted in the identification of 50 putative genes containing an hrp-box, 16 of which were shared with genes previously identified by RNA-seq. Although most of the genes regulated by HrpL belonged to the T3SS, we also identified some genes regulated by HrpL that could encode potential virulence factors in P. savastanoi.
Collapse
Affiliation(s)
- Alba Moreno-Pérez
- Área de Genética, Facultad de Ciencias, Campus Teatinos s/n, Universidad de Málaga, E-29010 Málaga, Spain;
- Departamento de Microbiología y Protección de Cultivos, Instituto de Hortofruticultura Subtropical y Mediterránea «La Mayora», Extensión Campus de Teatinos, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), E-29010 Málaga, Spain
| | - Cayo Ramos
- Área de Genética, Facultad de Ciencias, Campus Teatinos s/n, Universidad de Málaga, E-29010 Málaga, Spain;
- Departamento de Microbiología y Protección de Cultivos, Instituto de Hortofruticultura Subtropical y Mediterránea «La Mayora», Extensión Campus de Teatinos, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), E-29010 Málaga, Spain
- Correspondence: (C.R.); (L.R.-M.); Tel.: +34-952-132-146 (C.R.); +34-952-132-131 (L.R.-M.)
| | - Luis Rodríguez-Moreno
- Área de Genética, Facultad de Ciencias, Campus Teatinos s/n, Universidad de Málaga, E-29010 Málaga, Spain;
- Departamento de Microbiología y Protección de Cultivos, Instituto de Hortofruticultura Subtropical y Mediterránea «La Mayora», Extensión Campus de Teatinos, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), E-29010 Málaga, Spain
- Correspondence: (C.R.); (L.R.-M.); Tel.: +34-952-132-146 (C.R.); +34-952-132-131 (L.R.-M.)
| |
Collapse
|
3
|
Chávez-Alderete J, Gochicoa-Rangel L, Del-Río-Hidalgo R, Guerrero-Zúñiga S, Mora-Romero U, Benítez-Pérez R, Rodríguez-Moreno L, Torre-Bouscoulet L, Vargas MH. Salivary concentrations of cytokines and other analytes in healthy children. Cytokine 2020; 138:155379. [PMID: 33271384 DOI: 10.1016/j.cyto.2020.155379] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/01/2020] [Accepted: 11/18/2020] [Indexed: 01/22/2023]
Abstract
BACKGROUND Blood has been the usual biological fluid for measuring analytes, but there is mounting evidence that saliva may be also useful for detecting cytokines in a noninvasive way. Thus, in this study we aimed to determine concentration of cytokines and other analytes in saliva from a population of healthy children. METHODS We collected un-stimulated whole saliva samples from clinically healthy children, and concentration of 17 cytokines and 12 other analytes were measured in supernatants. All values were adjusted by albumin content and were log-transformed before multivariate statistical analysis. RESULTS We included 114 children (53.5% females) between 6.0 and 11.9 years old. The highest concentrations (medians, pg/µg albumin) were seen for visfatin (183.70) and adiponectin (162.26) and the lowest for IL-13 and IL-2 (~0.003). Albumin concentration was associated with age (rS = 0.39, p < 0.001). In the multivariate analysis, five analytes (C peptide, ghrelin, GLP-1, glucagon, leptin) inversely correlated with age and positively with height-for-age. Age was also positively associated with PAI-1, while height-for-age was also positively associated with insulin and visfatin. Finally, BMI-for-age had a positive correlation with GM-CSF and insulin. CONCLUSIONS Herein, we provided concentration values for 29 analytes in saliva from healthy children that may be useful as preliminary reference framework in the clinical research setting.
Collapse
Affiliation(s)
- Jaime Chávez-Alderete
- Departamento de Investigación en Hiperreactividad Bronquial, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
| | - Laura Gochicoa-Rangel
- Departamento de Fisiología Respiratoria, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico; Laboratorio de Función Pulmonar, Instituto de Desarrollo e Innovación en Fisiología Respiratoria, Mexico City, Mexico
| | - Rodrigo Del-Río-Hidalgo
- Departamento de Fisiología Respiratoria, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
| | - Selene Guerrero-Zúñiga
- Departamento de Fisiología Respiratoria, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
| | - Uri Mora-Romero
- Departamento de Fisiología Respiratoria, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
| | - Rosaura Benítez-Pérez
- Laboratorio de Función Pulmonar, Instituto de Desarrollo e Innovación en Fisiología Respiratoria, Mexico City, Mexico
| | - Luis Rodríguez-Moreno
- Laboratorio de Función Pulmonar, Instituto de Desarrollo e Innovación en Fisiología Respiratoria, Mexico City, Mexico
| | - Luis Torre-Bouscoulet
- Laboratorio de Función Pulmonar, Instituto de Desarrollo e Innovación en Fisiología Respiratoria, Mexico City, Mexico
| | - Mario H Vargas
- Departamento de Investigación en Hiperreactividad Bronquial, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico.
| |
Collapse
|
4
|
Gochicoa-Rangel L, del Río-Hidalgo R, Hernández-Ruiz J, Rodríguez-Moreno L, Martínez-Briseño D, Mora-Romero U, Cid-Juárez S, García-Sancho C, Torre-Bouscoulet L. Validating Reference Equations for Impulse Oscillometry in Healthy Mexican Children. Respir Care 2017; 62:1156-1165. [DOI: 10.4187/respcare.05247] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
5
|
Gochicoa-Rangel L, Vargas MH, Alonso-Gómez JL, Rodríguez-Moreno L, Martínez-Briseño D, Baños-Mejía O, Torre-Bouscoulet L. Respiratory impedance in patients with Duchenne muscular dystrophy. Pediatr Pulmonol 2016; 51:1072-1079. [PMID: 27129130 DOI: 10.1002/ppul.23434] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 01/09/2016] [Accepted: 02/23/2016] [Indexed: 12/27/2022]
Abstract
UNLABELLED Impulse oscillometry (IOS) evaluates non-effort-dependent respiratory mechanics, and thus it may be useful to evaluate patients with Duchenne muscular dystrophy (DMD). OBJECTIVES We aimed (1) to describe the behavior of IOS parameters in patients with DMD, and compare it to those from a control group; (2) to determine whether resistances and reactances differ in relation to the severity of DMD; and (3) to compare IOS parameters with spirometry and maximal inspiratory (MIP) and expiratory (MEP) pressures. METHODS Children and adolescents (<20 years old) with biopsy-confirmed DMD and age-paired subjects were cross-sectionally evaluated. All results were transformed to z scores with respect to the healthy subjects (reference population). RESULTS Anthropometric characteristics did not differ between the 31 patients and 69 controls included in the study. Compared with controls, patients with DMD had higher IOS resistances and lower reactances. As expected, FEV1 and FVC were lower in patients and always declined as age increased. By contrast, MIP and MEP were lower-than-normal in youngest patients, tended to improve around puberty initiation, and declined thereafter. In general, there was a poor correlation between IOS parameters and spirometric variables or respiratory pressures, excepting for X20 Hz, which had an inverse correlation with FEV1 . Interestingly, IOS resistances were higher in patients with less disability (lower Vignos score; better FVC), but tended to be normalized in advanced stages of the disease. CONCLUSION This study showed that IOS is feasible in children and adolescents with DMD and yields information about respiratory function not achievable with the usual forced techniques. Pediatr Pulmonol. 2016;51:1072-1079. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Laura Gochicoa-Rangel
- Departamento de Fisiología Respiratoria, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", Calzada de Tlalpan 4502, Colonia Sección XVI, CP 14080, México DF, México.,Centro de Evaluación del Paciente Asmático Infantil, Centro Médico Santa Teresa, Texcoco, Estado de México, México
| | - Mario H Vargas
- Departamento de Investigación en Hiperreactividad Bronquial, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", México DF, México
| | - José Luis Alonso-Gómez
- Departamento de Fisiología Respiratoria, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", Calzada de Tlalpan 4502, Colonia Sección XVI, CP 14080, México DF, México
| | - Luis Rodríguez-Moreno
- Centro de Evaluación del Paciente Asmático Infantil, Centro Médico Santa Teresa, Texcoco, Estado de México, México
| | - David Martínez-Briseño
- Departamento de Epidemiología y Ciencias Sociales en Salud, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", México DF, México
| | - Omar Baños-Mejía
- Departamento de Rehabilitación Pulmonar, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", México DF, México
| | - Luis Torre-Bouscoulet
- Departamento de Fisiología Respiratoria, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", Calzada de Tlalpan 4502, Colonia Sección XVI, CP 14080, México DF, México.
| |
Collapse
|
6
|
Gochicoa-Rangel L, Pérez-Padilla JR, Rodríguez-Moreno L, Montero-Matamoros A, Ojeda-Luna N, Martínez-Carbajal G, Hernández-Raygoza R, Ruiz-Pedraza D, Fernández-Plata MR, Torre-Bouscoulet L. Altitude Above Sea Level and Body Mass Index as Determinants of Oxygen Saturation in Children: The SON@ Study. Rev Invest Clin 2015; 67:366-371. [PMID: 26950741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
BACKGROUND Altitude above sea level and body mass index are well-recognized determinants of oxygen saturation in adult populations; however, the contribution of these factors to oxygen saturation in children is less clear. OBJECTIVE To explore the contribution of altitude above sea level and body mass index to oxygen saturation in children. METHODS A multi-center, cross-sectional study conducted in nine cities in Mexico. Parents signed informed consent forms and completed a health status questionnaire. Height, weight, and pulse oximetry were recorded. RESULTS We studied 2,200 subjects (52% girls) aged 8.7 ± 3.0 years. Mean body mass index, z-body mass index, and oxygen saturation were 18.1 ± 3.6 kg·m-2, 0.58 ± 1.3, and 95.5 ± 2.4%, respectively. By multiple regression analysis, altitude proved to be the main predictor of oxygen saturation, with non-significant contributions of age, gender, and body mass index. According to quantile regression, the median estimate of oxygen saturation was 98.7 minus 1.7% per km of altitude above sea level, and the oxygen saturation fifth percentile 97.4 minus 2.7% per km of altitude. CONCLUSIONS Altitude was the main determinant of oxygen saturation, which on average decreased 1.7% per km of elevation from a percentage of 98.7 at sea level. In contrast with adults, this study in children found no association between oxygen saturation and obesity or age.
Collapse
Affiliation(s)
- Laura Gochicoa-Rangel
- Department of Respiratory Physiology, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
- Centro Médico Santa Teresa, Texcoco, Edo. de México, Mexico
| | - José Rogelio Pérez-Padilla
- Department of Respiratory Physiology, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
| | - Luis Rodríguez-Moreno
- Centro Médico Santa Teresa, Texcoco, Edo. de México, Mexico
- Laboratorio de Función Pulmonar S de RL, Mexico City, Mexico
| | - Arturo Montero-Matamoros
- Instituto de Seguridad Social al Servicio de los Trabajadores del Estado, Tepic, Nayarit, Mexico
| | - Nancy Ojeda-Luna
- Respirar, Centro de Atención Pulmonar del Sureste, Mérida, Yucatán, Mexico
| | | | - Roberto Hernández-Raygoza
- Hospital de Pediatría, Unidad Médica de Alta Especialidad, Centro Médico de Occidente, IMSS, Guadalajara, Jalisco, Mexico
| | | | | | - Luis Torre-Bouscoulet
- Department of Respiratory Physiology, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
- Laboratorio de Función Pulmonar S de RL, Mexico City, Mexico
| |
Collapse
|
7
|
Rubio M, Rodríguez-Moreno L, Ballester AR, de Moura MC, Bonghi C, Candresse T, Martínez-Gómez P. Analysis of gene expression changes in peach leaves in response to Plum pox virus infection using RNA-Seq. Mol Plant Pathol 2015; 16:164-76. [PMID: 24989162 PMCID: PMC6638525 DOI: 10.1111/mpp.12169] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Differences in gene expression were studied after Plum pox virus (PPV, sharka disease) infection in peach GF305 leaves with and without sharka symptoms using RNA-Seq. For each sample, more than 80% of 100-nucleotide paired-end (PE) Illumina reads were aligned on the peach reference genome. In the symptomatic sample, a significant proportion of reads were mapped to PPV reference genomes (1.04% compared with 0.00002% in non-symptomatic leaves), allowing for the ultra-deep assembly of the complete genome of the PPV isolate used (9775 nucleotides, missing only 11 nucleotides at the 5' genome end). In addition, significant alternative splicing events were detected in 359 genes and 12 990 single nucleotide polymorphisms (SNPs) were identified, 425 of which could be annotated. Gene ontology annotation revealed that the high-ranking mRNA target genes associated with the expression of sharka symptoms are mainly related to the response to biotic stimuli, to lipid and carbohydrate metabolism and to the negative regulation of catalytic activity. A greater number of differentially expressed genes were observed in the early asymptomatic phase of PPV infection in comparison with the symptomatic phase. These early infection events were associated with the induction of genes related to pathogen resistance, such as jasmonic acid, chitinases, cytokinin glucosyl transferases and Lys-M proteins. Once the virus had accumulated, the overexpression of Dicer protein 2a genes suggested a gene silencing plant response that was suppressed by the virus HCPro and P1 proteins. These results illustrate the dynamic nature of the peach-PPV interaction at the transcriptome level and confirm that sharka symptom expression is a complex process that can be understood on the basis of changes in plant gene expression.
Collapse
Affiliation(s)
- Manuel Rubio
- Department of Plant Breeding, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), PO Box 164, E-30100, Espinardo-Murcia, Spain
| | | | | | | | | | | | | |
Collapse
|
8
|
Mathioudakis MM, Rodríguez-Moreno L, Sempere RN, Aranda MA, Livieratos I. Multifaceted capsid proteins: multiple interactions suggest multiple roles for Pepino mosaic virus capsid protein. Mol Plant Microbe Interact 2014; 27:1356-69. [PMID: 25162316 DOI: 10.1094/mpmi-07-14-0195-r] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Pepino mosaic virus (PepMV) (family Alphaflexiviridae, genus Potexvirus) is a mechanically transmitted tomato pathogen that, over the last decade, has evolved from emerging to endemic worldwide. Here, two heat-shock cognate (Hsc70) isoforms were identified as part of the coat protein (CP)/Hsc70 complex in vivo, following full-length PepMV and CP agroinoculation. PepMV accumulation was severely reduced in Hsp70 virus-induced gene silenced and in quercetin-treated Nicotiana benthamiana plants. Similarly, in vitro-transcribed as well as virion RNA input levels were reduced in quercetin-treated protoplasts, suggesting an essential role for Hsp70 in PepMV replication. As for Potato virus X, the PepMV CP and triple gene-block protein 1 (TGBp1) self-associate and interact with each other in vitro but, unlike in the prototype, both PepMV proteins represent suppressors of transgene-induced RNA silencing with different modes of action; CP is a more efficient suppressor of RNA silencing, sequesters the silencing signal by preventing its spread to neighboring cells and its systemic movement. Here, we provide evidence for additional roles of the PepMV CP and host-encoded Hsp70 in viral infection, the first as a truly multifunctional protein able to specifically bind to a host chaperone and to counterattack an RNA-based defense mechanism, and the latter as an essential factor for PepMV infection.
Collapse
|
9
|
Matas IM, Lambertsen L, Rodríguez-Moreno L, Ramos C. Identification of novel virulence genes and metabolic pathways required for full fitness of Pseudomonas savastanoi pv. savastanoi in olive (Olea europaea) knots. New Phytol 2012; 196:1182-1196. [PMID: 23088618 DOI: 10.1111/j.1469-8137.2012.04357.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 08/17/2012] [Indexed: 05/20/2023]
Abstract
Comparative genomics and functional analysis of Pseudomonas syringae and related pathogens have mainly focused on diseases of herbaceous plants; however, there is a general lack of knowledge about the virulence and pathogenicity determinants required for infection of woody plants. Here, we applied signature-tagged mutagenesis (STM) to Pseudomonas savastanoi pv. savastanoi during colonization of olive (Olea europaea) knots, with the goal of identifying the range of genes linked to growth and symptom production in its plant host. A total of 58 different genes were identified, and most mutations resulted in hypovirulence in woody olive plants. Sequence analysis of STM mutations allowed us to identify metabolic pathways required for full fitness of P. savastanoi in olive and revealed novel mechanisms involved in the virulence of this pathogen, some of which are essential for full colonization of olive knots by the pathogen and for the lysis of host cells. This first application of STM to a P. syringae-like pathogen provides confirmation of functional capabilities long believed to play a role in the survival and virulence of this group of pathogens but not adequately tested before, and unravels novel factors not correlated previously with the virulence of other plant or animal bacterial pathogens.
Collapse
Affiliation(s)
- Isabel M Matas
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Área de Genética, Facultad de Ciencias, Campus Teatinos s/n, E-29010, Málaga, Spain
| | - Lotte Lambertsen
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Área de Genética, Facultad de Ciencias, Campus Teatinos s/n, E-29010, Málaga, Spain
| | - Luis Rodríguez-Moreno
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Área de Genética, Facultad de Ciencias, Campus Teatinos s/n, E-29010, Málaga, Spain
| | - Cayo Ramos
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Área de Genética, Facultad de Ciencias, Campus Teatinos s/n, E-29010, Málaga, Spain
| |
Collapse
|
10
|
Bardaji L, Pérez-Martínez I, Rodríguez-Moreno L, Rodríguez-Palenzuela P, Sundin GW, Ramos C, Murillo J. Sequence and role in virulence of the three plasmid complement of the model tumor-inducing bacterium Pseudomonas savastanoi pv. savastanoi NCPPB 3335. PLoS One 2011; 6:e25705. [PMID: 22022435 PMCID: PMC3191145 DOI: 10.1371/journal.pone.0025705] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Accepted: 09/08/2011] [Indexed: 12/18/2022] Open
Abstract
Pseudomonas savastanoi pv. savastanoi NCPPB 3335 is a model for the study of the molecular basis of disease production and tumor formation in woody hosts, and its draft genome sequence has been recently obtained. Here we closed the sequence of the plasmid complement of this strain, composed of three circular molecules of 78,357 nt (pPsv48A), 45,220 nt (pPsv48B), and 42,103 nt (pPsv48C), all belonging to the pPT23A-like family of plasmids widely distributed in the P. syringae complex. A total of 152 coding sequences were predicted in the plasmid complement, of which 38 are hypothetical proteins and seven correspond to putative virulence genes. Plasmid pPsv48A contains an incomplete Type IVB secretion system, the type III secretion system (T3SS) effector gene hopAF1, gene ptz, involved in cytokinin biosynthesis, and three copies of a gene highly conserved in plant-associated proteobacteria, which is preceded by a hrp box motif. A complete Type IVA secretion system, a well conserved origin of transfer (oriT), and a homolog of the T3SS effector gene hopAO1 are present in pPsv48B, while pPsv48C contains a gene with significant homology to isopentenyl-diphosphate delta-isomerase, type 1. Several potential mobile elements were found on the three plasmids, including three types of MITE, a derivative of IS801, and a new transposon effector, ISPsy30. Although the replication regions of these three plasmids are phylogenetically closely related, their structure is diverse, suggesting that the plasmid architecture results from an active exchange of sequences. Artificial inoculations of olive plants with mutants cured of plasmids pPsv48A and pPsv48B showed that pPsv48A is necessary for full virulence and for the development of mature xylem vessels within the knots; we were unable to obtain mutants cured of pPsv48C, which contains five putative toxin-antitoxin genes.
Collapse
Affiliation(s)
- Leire Bardaji
- Departamento de Producción Agraria, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Pública de Navarra, Pamplona, Spain
| | - Isabel Pérez-Martínez
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Málaga, Spain
| | - Luis Rodríguez-Moreno
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Málaga, Spain
| | - Pablo Rodríguez-Palenzuela
- Centro de Biotecnología y Genómica de Plantas, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, Madrid, Spain
| | - George W. Sundin
- Department of Plant Pathology and Center for Microbial Ecology, Michigan State University, East Lansing, Michigan, United States of America
| | - Cayo Ramos
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Málaga, Spain
| | - Jesús Murillo
- Departamento de Producción Agraria, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Pública de Navarra, Pamplona, Spain
- * E-mail:
| |
Collapse
|
11
|
Rodríguez-Moreno L, González VM, Benjak A, Martí MC, Puigdomènech P, Aranda MA, Garcia-Mas J. Determination of the melon chloroplast and mitochondrial genome sequences reveals that the largest reported mitochondrial genome in plants contains a significant amount of DNA having a nuclear origin. BMC Genomics 2011; 12:424. [PMID: 21854637 PMCID: PMC3175227 DOI: 10.1186/1471-2164-12-424] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 08/20/2011] [Indexed: 01/31/2023] Open
Abstract
Background The melon belongs to the Cucurbitaceae family, whose economic importance among vegetable crops is second only to Solanaceae. The melon has a small genome size (454 Mb), which makes it suitable for molecular and genetic studies. Despite similar nuclear and chloroplast genome sizes, cucurbits show great variation when their mitochondrial genomes are compared. The melon possesses the largest plant mitochondrial genome, as much as eight times larger than that of other cucurbits. Results The nucleotide sequences of the melon chloroplast and mitochondrial genomes were determined. The chloroplast genome (156,017 bp) included 132 genes, with 98 single-copy genes dispersed between the small (SSC) and large (LSC) single-copy regions and 17 duplicated genes in the inverted repeat regions (IRa and IRb). A comparison of the cucumber and melon chloroplast genomes showed differences in only approximately 5% of nucleotides, mainly due to short indels and SNPs. Additionally, 2.74 Mb of mitochondrial sequence, accounting for 95% of the estimated mitochondrial genome size, were assembled into five scaffolds and four additional unscaffolded contigs. An 84% of the mitochondrial genome is contained in a single scaffold. The gene-coding region accounted for 1.7% (45,926 bp) of the total sequence, including 51 protein-coding genes, 4 conserved ORFs, 3 rRNA genes and 24 tRNA genes. Despite the differences observed in the mitochondrial genome sizes of cucurbit species, Citrullus lanatus (379 kb), Cucurbita pepo (983 kb) and Cucumis melo (2,740 kb) share 120 kb of sequence, including the predicted protein-coding regions. Nevertheless, melon contained a high number of repetitive sequences and a high content of DNA of nuclear origin, which represented 42% and 47% of the total sequence, respectively. Conclusions Whereas the size and gene organisation of chloroplast genomes are similar among the cucurbit species, mitochondrial genomes show a wide variety of sizes, with a non-conserved structure both in gene number and organisation, as well as in the features of the noncoding DNA. The transfer of nuclear DNA to the melon mitochondrial genome and the high proportion of repetitive DNA appear to explain the size of the largest mitochondrial genome reported so far.
Collapse
Affiliation(s)
- Luis Rodríguez-Moreno
- Departamento de Biología del Estrés y Patología Vegetal, Centro deEdafología y Biología Aplicada del Segura (CEBAS)-CSIC, 30100 Espinardo(Murcia), Spain
| | | | | | | | | | | | | |
Collapse
|
12
|
Nieto C, Rodríguez-Moreno L, Rodríguez-Hernández AM, Aranda MA, Truniger V. Nicotiana benthamiana resistance to non-adapted Melon necrotic spot virus results from an incompatible interaction between virus RNA and translation initiation factor 4E. Plant J 2011; 66:492-501. [PMID: 21255163 DOI: 10.1111/j.1365-313x.2011.04507.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Nicotiana benthamiana has been described as non-host for Melon necrotic spot virus (MNSV). We investigated the basis of this resistance using the unique opportunity provided by strain MNSV-264, a recombinant virus that is able to overcome the resistance. Analysis of chimeric MNSV mutants showed that virulence in N. benthamiana is conferred by a 49 nucleotide section of the MNSV-264 3'-UTR, which acts in this host as a cap-independent translational enhancer (3'-CITE). Although the 3'-CITE of non-adapted MNSV-Mα5 is active in susceptible melon, it does not promote efficient translation in N. benthamiana, thus preventing expression of proteins required for virus replication. However, MNSV-Mα5 gains the ability to multiply in N. benthamiana cells if eIF4E from a susceptible melon variety (Cm-eIF4E-S) is supplied in trans. These data show that N. benthamiana resistance to MNSV-Mα5 results from incompatibility between the MNSV-Mα5 3'-CITE and N. benthamiana eIF4E in initiating efficient translation of the viral genome. Therefore, non-host resistance conferred by the inability of a host susceptibility factor to support viral multiplication may be a possible mechanism for this type of resistance to viruses.
Collapse
Affiliation(s)
- Cristina Nieto
- Centro de Edafología y Biología Aplicada del Segura (CEBAS), Consejo Superior de Investigaciones Científicas (CSIC), PO Box 164, 30100 Espinardo, Murcia, Spain
| | | | | | | | | |
Collapse
|
13
|
González VM, Rodríguez-Moreno L, Centeno E, Benjak A, Garcia-Mas J, Puigdomènech P, Aranda MA. Genome-wide BAC-end sequencing of Cucumis melo using two BAC libraries. BMC Genomics 2010; 11:618. [PMID: 21054843 PMCID: PMC3091759 DOI: 10.1186/1471-2164-11-618] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Accepted: 11/05/2010] [Indexed: 11/10/2022] Open
Abstract
Background Although melon (Cucumis melo L.) is an economically important fruit crop, no genome-wide sequence information is openly available at the current time. We therefore sequenced BAC-ends representing a total of 33,024 clones, half of them from a previously described melon BAC library generated with restriction endonucleases and the remainder from a new random-shear BAC library. Results We generated a total of 47,140 high-quality BAC-end sequences (BES), 91.7% of which were paired-BES. Both libraries were assembled independently and then cross-assembled to obtain a final set of 33,372 non-redundant, high-quality sequences. These were grouped into 6,411 contigs (4.5 Mb) and 26,961 non-assembled BES (14.4 Mb), representing ~4.2% of the melon genome. The sequences were used to screen genomic databases, identifying 7,198 simple sequence repeats (corresponding to one microsatellite every 2.6 kb) and 2,484 additional repeats of which 95.9% represented transposable elements. The sequences were also used to screen expressed sequence tag (EST) databases, revealing 11,372 BES that were homologous to ESTs. This suggests that ~30% of the melon genome consists of coding DNA. We observed regions of microsynteny between melon paired-BES and six other dicotyledonous plant genomes. Conclusion The analysis of nearly 50,000 BES from two complementary genomic libraries covered ~4.2% of the melon genome, providing insight into properties such as microsatellite and transposable element distribution, and the percentage of coding DNA. The observed synteny between melon paired-BES and six other plant genomes showed that useful comparative genomic data can be derived through large scale BAC-end sequencing by anchoring a small proportion of the melon genome to other sequenced genomes.
Collapse
Affiliation(s)
- Víctor M González
- Molecular Genetics Department, Center for Research in Agricultural Genomics CRAG (CSIC-IRTA-UAB), Jordi Girona, 18-26, 08034 Barcelona, Spain
| | | | | | | | | | | | | |
Collapse
|
14
|
Pérez-Martínez I, Rodríguez-Moreno L, Lambertsen L, Matas IM, Murillo J, Tegli S, Jiménez AJ, Ramos C. Fate of a Pseudomonas savastanoi pv. savastanoi type III secretion system mutant in olive plants (Olea europaea L.). Appl Environ Microbiol 2010; 76:3611-9. [PMID: 20363790 PMCID: PMC2876471 DOI: 10.1128/aem.00133-10] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Accepted: 03/26/2010] [Indexed: 01/16/2023] Open
Abstract
Pseudomonas savastanoi pv. savastanoi strain NCPPB 3335 is a model bacterial pathogen for studying the molecular basis of disease production in woody hosts. We report the sequencing of the hrpS-to-hrpZ region of NCPPB 3335, which has allowed us to determine the phylogenetic position of this pathogen with respect to previously sequenced Pseudomonas syringae hrp clusters. In addition, we constructed a mutant of NCPPB 3335, termed T3, which carries a deletion from the 3' end of the hrpS gene to the 5' end of the hrpZ operon. Despite its inability to multiply in olive tissues and to induce tumor formation in woody olive plants, P. savastanoi pv. savastanoi T3 can induce knot formation on young micropropagated olive plants. However, the necrosis and formation of internal open cavities previously reported in knots induced by the wild-type strain were not observed in those induced by P. savastanoi pv. savastanoi T3. Tagging of P. savastanoi pv. savastanoi T3 with green fluorescent protein (GFP) allowed real-time monitoring of its behavior on olive plants. In olive plant tissues, the wild-type strain formed aggregates that colonized the intercellular spaces and internal cavities of the hypertrophic knots, while the mutant T3 strain showed a disorganized distribution within the parenchyma of the knot. Ultrastructural analysis of knot sections revealed the release of extensive outer membrane vesicles from the bacterial cell surface of the P. savastanoi pv. savastanoi T3 mutant, while the wild-type strain exhibited very few vesicles. This phenomenon has not been described before for any other bacterial phytopathogen during host infection.
Collapse
Affiliation(s)
- Isabel Pérez-Martínez
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Área de Genética, Facultad de Ciencias, Universidad de Málaga, Campus Teatinos s/n, E-29010 Málaga, Spain, Departamento de Producción Agraria, Universidad Pública de Navarra, Campus de Arrosadía, E-31006 Pamplona, Spain, Dipartimento di Biotecnologie Agrarie, Universitá degli Studi di Firenze, Sez. Patologia Vegetale, Laboratorio di Patologia Vegetale Molecolare, Via della Lastruccia 10, 50019 Sesto Fiorentino, Italy
| | - Luis Rodríguez-Moreno
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Área de Genética, Facultad de Ciencias, Universidad de Málaga, Campus Teatinos s/n, E-29010 Málaga, Spain, Departamento de Producción Agraria, Universidad Pública de Navarra, Campus de Arrosadía, E-31006 Pamplona, Spain, Dipartimento di Biotecnologie Agrarie, Universitá degli Studi di Firenze, Sez. Patologia Vegetale, Laboratorio di Patologia Vegetale Molecolare, Via della Lastruccia 10, 50019 Sesto Fiorentino, Italy
| | - Lotte Lambertsen
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Área de Genética, Facultad de Ciencias, Universidad de Málaga, Campus Teatinos s/n, E-29010 Málaga, Spain, Departamento de Producción Agraria, Universidad Pública de Navarra, Campus de Arrosadía, E-31006 Pamplona, Spain, Dipartimento di Biotecnologie Agrarie, Universitá degli Studi di Firenze, Sez. Patologia Vegetale, Laboratorio di Patologia Vegetale Molecolare, Via della Lastruccia 10, 50019 Sesto Fiorentino, Italy
| | - Isabel M. Matas
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Área de Genética, Facultad de Ciencias, Universidad de Málaga, Campus Teatinos s/n, E-29010 Málaga, Spain, Departamento de Producción Agraria, Universidad Pública de Navarra, Campus de Arrosadía, E-31006 Pamplona, Spain, Dipartimento di Biotecnologie Agrarie, Universitá degli Studi di Firenze, Sez. Patologia Vegetale, Laboratorio di Patologia Vegetale Molecolare, Via della Lastruccia 10, 50019 Sesto Fiorentino, Italy
| | - Jesús Murillo
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Área de Genética, Facultad de Ciencias, Universidad de Málaga, Campus Teatinos s/n, E-29010 Málaga, Spain, Departamento de Producción Agraria, Universidad Pública de Navarra, Campus de Arrosadía, E-31006 Pamplona, Spain, Dipartimento di Biotecnologie Agrarie, Universitá degli Studi di Firenze, Sez. Patologia Vegetale, Laboratorio di Patologia Vegetale Molecolare, Via della Lastruccia 10, 50019 Sesto Fiorentino, Italy
| | - Stefania Tegli
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Área de Genética, Facultad de Ciencias, Universidad de Málaga, Campus Teatinos s/n, E-29010 Málaga, Spain, Departamento de Producción Agraria, Universidad Pública de Navarra, Campus de Arrosadía, E-31006 Pamplona, Spain, Dipartimento di Biotecnologie Agrarie, Universitá degli Studi di Firenze, Sez. Patologia Vegetale, Laboratorio di Patologia Vegetale Molecolare, Via della Lastruccia 10, 50019 Sesto Fiorentino, Italy
| | - Antonio J. Jiménez
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Área de Genética, Facultad de Ciencias, Universidad de Málaga, Campus Teatinos s/n, E-29010 Málaga, Spain, Departamento de Producción Agraria, Universidad Pública de Navarra, Campus de Arrosadía, E-31006 Pamplona, Spain, Dipartimento di Biotecnologie Agrarie, Universitá degli Studi di Firenze, Sez. Patologia Vegetale, Laboratorio di Patologia Vegetale Molecolare, Via della Lastruccia 10, 50019 Sesto Fiorentino, Italy
| | - Cayo Ramos
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Área de Genética, Facultad de Ciencias, Universidad de Málaga, Campus Teatinos s/n, E-29010 Málaga, Spain, Departamento de Producción Agraria, Universidad Pública de Navarra, Campus de Arrosadía, E-31006 Pamplona, Spain, Dipartimento di Biotecnologie Agrarie, Universitá degli Studi di Firenze, Sez. Patologia Vegetale, Laboratorio di Patologia Vegetale Molecolare, Via della Lastruccia 10, 50019 Sesto Fiorentino, Italy
| |
Collapse
|
15
|
Abstract
The endophytic phase of Pseudomonas savastanoi pv. savastanoi in olive stems and the structural and ultrastructural histogenesis of olive knots have been studied. Construction of a stable plasmid vector expressing the green fluorescent protein, in combination with the use of in vitro olive plants, allowed real‐time monitoring of P. savastanoi pv. savastanoi infection. The infection process was also examined by bright field and epifluorescence microscopy as well as by scanning and transmission electron microscopy. Hypertrophy of the stem tissue was concomitant with the formation of bacterial aggregates, microcolonies and multilayer biofilms, over the cell surfaces and the interior of plasmolysed cells facing the air‐tissue interface of internal opened fissures, and was followed by invasion of the outer layers of the hypertrophied tissue. Pathogenic invasion of the internal lumen of newly formed xylem vessels, which were connected with the stem vascular system, was also observed in late stages of infection. Ultrastructural analysis of knot sections showed the release of outer membrane vesicles from the pathogen surface, a phenomenon not described before for bacterial phytopathogens during host infection. This is the first real‐time monitoring of P. savastanoi disease development and the first illustrated description of the ultrastructure of P. savastanoi‐induced knots.
Collapse
Affiliation(s)
- Luis Rodríguez-Moreno
- Departamento de Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus de Teatinos s/n, E-29071, Málaga, Spain
| | | | | |
Collapse
|
16
|
Rodríguez-Moreno L, Barceló-Muñoz A, Ramos C. In vitro analysis of the interaction of Pseudomonas savastanoi pvs. savastanoi and nerii with micropropagated olive plants. Phytopathology 2008; 98:815-22. [PMID: 18943258 DOI: 10.1094/phyto-98-7-0815] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
This study assessed the use of in vitro olive plants to evaluate the virulence of Pseudomonas savastanoi pv. savastanoi strains isolated from olive and P. savastanoi pv. nerii strains isolated from oleander knots. First, different olive isolates were inoculated into stem wounds and differences in knot formation and weight of overgrowths were observed for the selected strains. Tissue proliferation was clearly visible in all inoculated plants 30 days after inoculation. Virulence of P. savastanoi pv. nerii mutants with defects in regard to biosynthesis of indole-3-acetic acid and/or cytokinins was tested using this system. In agreement with data previously reported, all mutant strains multiplied in olive but induced attenuated symptoms. To analyze the virulence of P. savastanoi pv. savastanoi affected in their ability to grow in olive tissue, a trpE tryptophan auxotroph mutant was generated using a collection of signature tagged mutagenesis transposons. Virulence of this mutant was clearly reduced as evidenced by swelling of the olive tissue that evolved into attenuated knots. Furthermore, mixed infections with its parental strain revealed that the wild-type strain completely out-competed the trpE mutant. Results shown here demonstrate the usefulness of in vitro olive plants for the analysis of P. savastanoi pvs. savastanoi and nerii virulence. In addition, this system offers the possibility of quantifying virulence differences as weight of overgrowths. Moreover, we established the basis for the use of mixed infections in combination with signature tagged mutagenesis for high-throughput functional genomic analysis of this bacterial pathogen.
Collapse
Affiliation(s)
- Luis Rodríguez-Moreno
- Area de Genética, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, Málaga, Spain
| | | | | |
Collapse
|
17
|
Rodríguez-Moreno L, Pineda M, Soukupová J, Macho AP, Beuzón CR, Barón M, Ramos C. Early detection of bean infection by Pseudomonas syringae in asymptomatic leaf areas using chlorophyll fluorescence imaging. Photosynth Res 2008; 96:27-35. [PMID: 18000760 DOI: 10.1007/s11120-007-9278-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Accepted: 10/25/2007] [Indexed: 05/04/2023]
Abstract
Chlorophyll fluorescence imaging has been used to analyse the response elicited in Phaseolus vulgaris after inoculation with Pseudomonas syringae pv. phaseolicola 1448A (compatible interaction) and P. syringae pv. tomato DC3000 (incompatible interaction). With the aim of modulating timing of symptom development, different cell densities were used to inoculate bean plants and the population dynamics of both bacterial strains was followed within the leaf tissue. Fluorescence quenching analysis was carried out and images of the different chlorophyll fluorescence parameters were obtained for infected as well as control plants at different timepoints post-infection. Among the different parameters analysed, we observed that non-photochemical quenching maximised the differences between the compatible and the incompatible interaction before the appearance of visual symptom. A decrease in non-photochemical quenching, evident in both infiltrated and non-infiltrated leaf areas, was observed in P. syringae pv. phaseolicola-infected plants as compared with corresponding values from controls and P. syringae pv. tomato-infected plants. No photoinhibitory damage was detected, as the maximum photosystem II quantum yield remained stable during the infection period analysed.
Collapse
|