Xylella fastidiosa causes transcriptional shifts that precede tylose formation and starch depletion in xylem

Scanning Electron Microscopy Reveals Different Response Pattern of Four Vitis Genotypes to Xylella fastidiosa Infection

Plant Disease ◽

10.1094/pdis-92-2-0276 ◽

2008 ◽

Vol 92 (2) ◽

pp. 276-286 ◽

Cited By ~ 21

Author(s):

Felix B. Fritschi ◽

Hong Lin ◽

M. Andrew Walker

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Xylella Fastidiosa ◽

Systemic Infection ◽

The Other ◽

Enzyme Linked Immunosorbent Assay ◽

Treatment Comparisons ◽

Different Response ◽

Scanning Electron ◽

Tylose Formation

The xylem-limited bacterium Xylella fastidiosa causes Pierce's disease (PD), whose disease symptoms are primarily the result of xylem vessel blockage in susceptible grapevines. Stem internode and petiole tissues from infected and uninfected control plants of four grape genotypes (Vitis vinifera, V. rufotomentosa, V. smalliana, and V. arizonica/candicans) differing in PD susceptibility were examined using scanning electron microscopy (SEM). Tyloses, fibrillar networks, and gum plugs were observed in lumens of tracheary elements in petioles and internodes of both water-inoculated control plants and X. fastidiosa–inoculated plants of all genotypes. Bacteria were not observed in control plants. In both petiole and internode tissues, the greatest number of occluded xylem vessels were observed in V. vinifera and the smallest number in V. arizonica/candicans. The number of xylem vessels infested with X. fastidiosa was greatest in V. vinifera and did not differ among the other three genotypes. Systemic infection was found in all genotypes. The frequency with which X. fastidiosa infested vessels were observed using SEM corresponded well with bacterial levels estimated by enzyme-linked immunosorbent assay. Among infected plants, tylose formation in internodes was lowest in V. arizonica/candicans and did not differ among the other three genotypes. Infection with X. fastidiosa strongly induced tylose formation in V. vinifera and V. smalliana but not in V. arizonica/candicans. Analysis across tissues and genotypes indicated an induction of fibrillar networks and gum occlusions in response to X. fastidiosa infection, whereas treatment comparisons within genotypes were not significant except for V. vinifera petioles. Limiting the spread of X. fastidiosa infection by xylem conduit occlusions does not appear to be the mechanism conferring PD resistance or tolerance to V. arizonica/candicans, V. smalliana, or V. rufotomentosa. In contrast, the strong induction of tyloses may be detrimental rather than beneficial for V. vinifera survival after X. fastidiosa infection.

Exemplar Abstract for Xylella fastidiosa Wells et al. 1987.

The NamesforLife Abstracts ◽

10.1601/ex.16603 ◽

2003 ◽

Author(s):

Charles Thomas Parker ◽

Dorothea Taylor ◽

George M Garrity

Keyword(s):

Xylella Fastidiosa

Nomenclature Abstract for Xylella fastidiosa fastidiosa (Wells et al. 1987) Schaad et al. 2009.

The NamesforLife Abstracts ◽

10.1601/nm.14240 ◽

2003 ◽

Author(s):

Charles Thomas Parker ◽

Sarah Wigley ◽

George M Garrity

Keyword(s):

Xylella Fastidiosa

Nomenclature Abstract for Xylella fastidiosa Wells et al. 1987.

The NamesforLife Abstracts ◽

10.1601/nm.2267 ◽

2003 ◽

Author(s):

Charles Thomas Parker ◽

George M Garrity

Keyword(s):

Xylella Fastidiosa

Semi-Automatic Method for Early Detection of Xylella fastidiosa in Olive Trees Using UAV Multispectral Imagery and Geostatistical-Discriminant Analysis

Remote Sensing ◽

10.3390/rs13010014 ◽

2020 ◽

Vol 13 (1) ◽

pp. 14

Author(s):

Annamaria Castrignanò ◽

Antonella Belmonte ◽

Ilaria Antelmi ◽

Ruggiero Quarto ◽

Francesco Quarto ◽

...

Keyword(s):

Discriminant Analysis ◽

Early Detection ◽

Plant Pathogens ◽

Early Stage ◽

Xylella Fastidiosa ◽

Mediterranean Countries ◽

Parametric Classification ◽

Aerial Vehicle ◽

Olive Groves ◽

Olive Trees

Xylella fastidiosa subsp. pauca (Xfp) is one of the most dangerous plant pathogens in the world. Identified in 2013 in olive trees in south–eastern Italy, it is spreading to the Mediterranean countries. The bacterium is transmitted by insects that feed on sap, and causes rapid wilting in olive trees. The paper explores the use of Unmanned Aerial Vehicle (UAV) in combination with a multispectral radiometer for early detection of infection. The study was carried out in three olive groves in the Apulia region (Italy) and involved four drone flights from 2017 to 2019. To classify Xfp severity level in olive trees at an early stage, a combined method of geostatistics and discriminant analysis was implemented. The results of cross-validation for the non-parametric classification method were of overall accuracy = 0.69, mean error rate = 0.31, and for the early detection class of accuracy 0.77 and misclassification probability 0.23. The results are promising and encourage the application of UAV technology for the early detection of Xfp infection.

HPLC-MS/MS method applied to an untargeted metabolomics approach for the diagnosis of “olive quick decline syndrome”

Analytical and Bioanalytical Chemistry ◽

10.1007/s00216-021-03279-7 ◽

2021 ◽

Author(s):

Sabrina Di Masi ◽

Giuseppe E. De Benedetto ◽

Cosimino Malitesta ◽

Maria Saponari ◽

Cinzia Citti ◽

...

Keyword(s):

Bacterial Infections ◽

High Performance ◽

High Resolution Mass Spectrometry ◽

Xylella Fastidiosa ◽

Long Chain Fatty Acids ◽

Powerful Approach ◽

Diffusible Signal Factor ◽

Profile Changes ◽

Olive Quick Decline Syndrome ◽

Olive Trees

AbstractOlive quick decline syndrome (OQDS) is a disorder associated with bacterial infections caused by Xylella fastidiosa subsp. pauca ST53 in olive trees. Metabolic profile changes occurring in infected olive trees are still poorly investigated, but have the potential to unravel reliable biomarkers to be exploited for early diagnosis of infections. In this study, an untargeted metabolomic method using high-performance liquid chromatography coupled to quadrupole-time-of-flight high-resolution mass spectrometry (HPLC-ESI-Q-TOF-MS) was used to detect differences in samples (leaves) from healthy (Ctrl) and infected (Xf) olive trees. Both unsupervised and supervised data analysis clearly differentiated the groups. Different metabolites have been identified as potential specific biomarkers, and their characterization strongly suggests that metabolism of flavonoids and long-chain fatty acids is perturbed in Xf samples. In particular, a decrease in the defence capabilities of the host after Xf infection is proposed because of a significant dysregulation of some metabolites belonging to flavonoid family. Moreover, oleic acid is confirmed as a putative diffusible signal factor (DSF). This study provides new insights into the host-pathogen interactions and confirms LC-HRMS-based metabolomics as a powerful approach for disease-associated biomarkers discovery in plants. Graphical abstract

Controlling the Spatial Spread of a Xylella Epidemic

Bulletin of Mathematical Biology ◽

10.1007/s11538-021-00861-z ◽

2021 ◽

Vol 83 (4) ◽

Author(s):

Sebastian Aniţa ◽

Vincenzo Capasso ◽

Simone Scacchi

Keyword(s):

Spatial Structure ◽

Numerical Simulations ◽

Control Strategies ◽

Xylella Fastidiosa ◽

Cost Effective ◽

Olive Tree ◽

Control Measures ◽

Weed Biomass ◽

Spatial Spread ◽

Olive Trees

AbstractIn a recent paper by one of the authors and collaborators, motivated by the Olive Quick Decline Syndrome (OQDS) outbreak, which has been ongoing in Southern Italy since 2013, a simple epidemiological model describing this epidemic was presented. Beside the bacterium Xylella fastidiosa, the main players considered in the model are its insect vectors, Philaenus spumarius, and the host plants (olive trees and weeds) of the insects and of the bacterium. The model was based on a system of ordinary differential equations, the analysis of which provided interesting results about possible equilibria of the epidemic system and guidelines for its numerical simulations. Although the model presented there was mathematically rather simplified, its analysis has highlighted threshold parameters that could be the target of control strategies within an integrated pest management framework, not requiring the removal of the productive resource represented by the olive trees. Indeed, numerical simulations support the outcomes of the mathematical analysis, according to which the removal of a suitable amount of weed biomass (reservoir of Xylella fastidiosa) from olive orchards and surrounding areas resulted in the most efficient strategy to control the spread of the OQDS. In addition, as expected, the adoption of more resistant olive tree cultivars has been shown to be a good strategy, though less cost-effective, in controlling the pathogen. In this paper for a more realistic description and a clearer interpretation of the proposed control measures, a spatial structure of the epidemic system has been included, but, in order to keep mathematical technicalities to a minimum, only two players have been described in a dynamical way, trees and insects, while the weed biomass is taken to be a given quantity. The control measures have been introduced only on a subregion of the whole habitat, in order to contain costs of intervention. We show that such a practice can lead to the eradication of an epidemic outbreak. Numerical simulations confirm both the results of the previous paper and the theoretical results of the model with a spatial structure, though subject to regional control only.

Hexane extract from Spiranthera odoratissima A. St.-hil. leaves: chemical composition and its bioactive potential against Candida pathogenic species, Leishmania amazonensis and Xylella fastidiosa

Natural Product Research ◽

10.1080/14786419.2021.1931188 ◽

2021 ◽

pp. 1-6

Author(s):

Amanda de O. Souza ◽

Paulo S. Pereira ◽

Cassia C. Fernandes ◽

Géssica Andrade ◽

Regina H. Pires ◽

...

Keyword(s):

Chemical Composition ◽

Xylella Fastidiosa ◽

Leishmania Amazonensis ◽

Hexane Extract ◽

Pathogenic Species ◽

Bioactive Potential

Further In Vitro Assessment and Mid-Term Evaluation of Control Strategy of Xylella fastidiosa subsp. pauca in Olive Groves of Salento (Apulia, Italy)

Pathogens ◽

10.3390/pathogens10010085 ◽

2021 ◽

Vol 10 (1) ◽

pp. 85

Author(s):

Giuseppe Tatulli ◽

Vanessa Modesti ◽

Nicoletta Pucci ◽

Valeria Scala ◽

Alessia L’Aurora ◽

...

Keyword(s):

Control Strategy ◽

Xylella Fastidiosa ◽

In Planta ◽

Bacterial Concentration ◽

Infected Area ◽

Olive Groves ◽

Term Evaluation ◽

In Vitro Assessment ◽

Olive Trees

During recent years; Xylella fastidiosa subsp. pauca (Xfp) has spread in Salento causing relevant damage to the olive groves. Measures to contain the spreading of the pathogen include the monitoring of the areas bordering the so-called “infected” zone and the tree eradication in case of positive detection. In order to provide a control strategy aimed to maintain the tree productivity in the infected areas, we further evaluated the in vitro and in planta mid-term effectiveness of a zinc-copper-citric acid biocomplex. The compound showed an in vitro bactericidal activity and inhibited the biofilm formation in representative strains of X. fastidiosa subspecies, including Xfp isolated in Apulia from olive trees. The field mid-term evaluation of the control strategy assessed by quantitative real-time PCR in 41 trees of two olive groves of the “infected” area revealed a low concentration of Xfp over the seasons upon the regular spraying of the biocomplex over 3 or 4 consecutive years. In particular, the bacterial concentration lowered in July and October with respect to March, after six consecutive treatments. The trend was not affected by the cultivar and it was similar either in the Xfp-sensitive cultivars Ogliarola salentina and Cellina di Nardò or in the Xfp-resistant Leccino. Moreover, the scoring of the number of wilted twigs over the seasons confirmed the trend. The efficacy of the treatment in the management of olive groves subjected to a high pathogen pressure is highlighted by the yielded a good oil production

Novel Virulent Bacteriophages Infecting Mediterranean Isolates of the Plant Pest Xylella fastidiosa and Xanthomonas albilineans

Viruses ◽

10.3390/v13050725 ◽

2021 ◽

Vol 13 (5) ◽

pp. 725

Author(s):

Fernando Clavijo-Coppens ◽

Nicolas Ginet ◽

Sophie Cesbron ◽

Martial Briand ◽

Marie-Agnès Jacques ◽

...

Keyword(s):

Phage Therapy ◽

Xylella Fastidiosa ◽

Infected Plant ◽

Mediterranean Area ◽

Genomic Features ◽

Phylogeny Analysis ◽

Plant Pest ◽

European Regulations ◽

Surrogate Host

Xylella fastidiosa (Xf) is a plant pathogen causing significant losses in agriculture worldwide. Originating from America, this bacterium caused recent epidemics in southern Europe and is thus considered an emerging pathogen. As the European regulations do not authorize antibiotic treatment in plants, alternative treatments are urgently needed to control the spread of the pathogen and eventually to cure infected crops. One such alternative is the use of phage therapy, developed more than 100 years ago to cure human dysentery and nowadays adapted to agriculture. The first step towards phage therapy is the isolation of the appropriate bacteriophages. With this goal, we searched for phages able to infect Xf strains that are endemic in the Mediterranean area. However, as Xf is truly a fastidious organism, we chose the phylogenetically closest and relatively fast-growing organism X. albineans as a surrogate host for the isolation step. Our results showed the isolation from various sources and preliminary characterization of several phages active on different Xf strains, namely, from the fastidiosa (Xff), multiplex (Xfm), and pauca (Xfp) subspecies, as well as on X. albilineans. We sequenced their genomes, described their genomic features, and provided a phylogeny analysis that allowed us to propose new taxonomic elements. Among the 14 genomes sequenced, we could identify two new phage species, belonging to two new genera of the Caudoviricetes order, namely, Usmevirus (Podoviridae family) and Subavirus (Siphoviridae family). Interestingly, no specific phages could be isolated from infected plant samples, whereas one was isolated from vector insects captured in a contaminated area, and several from surface and sewage waters from the Marseille area.