scholarly journals Fluid dynamics in the functional foregut of xylem-sap feeding insects: A comparative study of two Xylella fastidiosa vectors

2020 ◽  
Vol 120 ◽  
pp. 103995 ◽  
Author(s):  
Emanuele Ranieri ◽  
Gianluca Zitti ◽  
Paola Riolo ◽  
Nunzio Isidoro ◽  
Sara Ruschioni ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Comparative Study ◽  
Xylella Fastidiosa ◽  
Xylem Sap ◽  
Sap Feeding

scholarly journals Microbe Profile: Xylella fastidiosa – a devastating agricultural pathogen with an endophytic lifestyle

Microbiology ◽  
2021 ◽  
Vol 167 (10) ◽  
Author(s):  
Lindsey P. Burbank ◽  
M. Caroline Roper
Keyword(s):  
Type Species ◽  
Xylella Fastidiosa ◽  
Xylem Sap ◽  
Disease Outbreaks ◽  
Plant Tissues ◽  
Content Type ◽  
Link Type ◽  
Quarantine Pathogen ◽  
Sap Feeding ◽  
Vector Borne

Xylella fastidiosa is a vector-borne plant vascular pathogen that has caused devastating disease outbreaks in diverse agricultural crops worldwide. A major global quarantine pathogen, X. fastidiosa can infect hundreds of plant species and can be transmitted by many different xylem sap-feeding insects. Several decades of research have revealed a complex lifestyle dependent on adaptation to the xylem and insect environments and interactions with host plant tissues.

scholarly journals Transmission of Xylella fastidiosa Subspecies Pauca Sequence Type 53 by Different Insect Species

Insects ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 324 ◽  
Author(s):  
Vincenzo Cavalieri ◽  
Giuseppe Altamura ◽  
Giulio Fumarola ◽  
Michele di Carolo ◽  
Maria Saponari ◽  
...  
Keyword(s):  
Xylella Fastidiosa ◽  
Severe Disease ◽  
Xylem Sap ◽  
Seasonal Abundance ◽  
Philaenus Spumarius ◽  
Olive Groves ◽  
Sap Feeding ◽  
Olive Quick Decline Syndrome ◽  
Exotic Pathogen

Diseases associated with Xylella fastidiosa have been described mostly in North and South America. However, during the last five years, widespread X. fastidiosa infections have been reported in a constrained area of the Apulia region (southern Italy), in olives trees suffering a severe disease, denoted as Olive Quick Decline Syndrome (OQDS). Because many xylem sap-feeding insects can function as vectors for the transmission of this exotic pathogen in EU, several research programs are ongoing to assess the role of candidate vectors in the spread of the infections. Initial investigations identified Philaenus spumarius (L.) as the predominant vector species in the olive orchards affected by the OQDS. Additional experiments have been carried out during 2016 and 2017 to assess the role of other species. More specifically, adults of the spittlebugs Philaenus italosignus Drosopolous and Remane, Neophilaenus campestris (Fallen) and of the planthopper Latilica tunetana (Matsumura) (Issidae) have been tested in transmission experiments to assess their ability to acquire the bacterium from infected olives and to infect different susceptible hosts (olives, almond, myrtle –leaf milkwort, periwinkle). Acquisition rates determined by testing individual insects in quantitative PCR assays, ranging from 5.6% in N. campestris to 22.2% in P. italosignus, whereas no acquisition was recorded for L. tunetana. Successful transmissions were detected in the recipient plants exposed to P. italosignus and N. campestris, whereas no trasmissions occurred with L. tunetana. The known vector Philaenus spumarius has been included in all the experiments for validation. The systematic surveys conducted in 2016 and 2017 provided further evidence on the population dynamics and seasonal abundance of the spittlebug populations in the olive groves.

scholarly journals Causal Role of Xylella fastidiosa in Oleander Leaf Scorch Disease

1999 ◽  
Vol 89 (1) ◽  
pp. 53-58 ◽  
Author(s):  
A. H. Purcell ◽  
S. R. Saunders ◽  
M. Hendson ◽  
M. E. Grebus ◽  
M. J. Henry
Keyword(s):  
Prunus Persica ◽  
Xylella Fastidiosa ◽  
Xylem Sap ◽  
Nerium Oleander ◽  
Madagascar Periwinkle ◽  
Leaf Scorch ◽  
Valley Oak ◽  
Sap Feeding ◽  
Negative Controls

A lethal leaf scorch disease of oleander (Nerium oleander) appeared in southern California in 1993. A bacterium, Xylella fastidiosa, was detected by culturing, enzyme-linked immunoassay, and polymerase chain reaction in most symptomatic plants but not in symptomless plants or negative controls. Inoculating oleanders mechanically with X. fastidiosa cultures from diseased oleanders caused oleander leaf scorch (OLS) disease. The bacterium was reisolated from inoculated plants that became diseased. Three species of xylem sap-feeding leafhoppers transmitted the bacterium from oleander to oleander. The bacterium multiplied, moved systemically, and caused wilting in Madagascar periwinkle (Catharanthus rosea) and leaf scorch in periwinkle (Vinca major) in a greenhouse after inoculation with needle puncture. No bacterium was reisolated from grapevine (Vitis vinifera), peach (Prunus persica), olive (Olea europaea), California blackberry (Rubus ursinus), or valley oak (Quercus lobata) mechanically inoculated with OLS strains of X. fastidiosa. A 500-bp sequence of the 16S-23S ribosomal intergenic region of oleander strains showed 99.2% identity with Pierce's disease strains, 98.4% identity with oak leaf scorch strains, and 98.6% identity with phony peach, plum leaf scald, and almond leaf scorch strains.

scholarly journals Genetic and endosymbiotic diversity of Greek populations of Philaenus spumarius, Philaenus signatus and Neophilaenus campestris, vectors of Xylella fastidiosa

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Despoina Ev. Kapantaidaki ◽  
Spyridon Antonatos ◽  
Vasiliki Evangelou ◽  
Dimitrios P. Papachristos ◽  
Panagiotis Milonas
Keyword(s):  
Xylella Fastidiosa ◽  
Management Strategies ◽  
Xylem Sap ◽  
Infection Status ◽  
Effective Management ◽  
Potential Threat ◽  
High Genetic Diversity ◽  
Philaenus Spumarius ◽  
Olive Cultivation ◽  
Sap Feeding

AbstractThe plant-pathogenic bacterium Xylella fastidiosa which causes significant diseases to various plant species worldwide, is exclusively transmitted by xylem sap-feeding insects. Given the fact that X. fastidiosa poses a serious potential threat for olive cultivation in Greece, the main aim of this study was to investigate the genetic variation of Greek populations of three spittlebug species (Philaenus spumarius, P. signatus and Neophilaenus campestris), by examining the molecular markers Cytochrome Oxidase I, cytochrome b and Internal Transcribed Spacer. Moreover, the infection status of the secondary endosymbionts Wolbachia, Arsenophonus, Hamiltonella, Cardinium and Rickettsia, among these populations, was determined. According to the results, the ITS2 region was the less polymorphic, while the analyzed fragments of COI and cytb genes, displayed high genetic diversity. The phylogenetic analysis placed the Greek populations of P. spumarius into the previously obtained Southwest clade in Europe. The analysis of the bacterial diversity revealed a diverse infection status. Rickettsia was the most predominant endosymbiont while Cardinium was totally absent from all examined populations. Philaenus spumarius harbored Rickettsia, Arsenophonus, Hamiltonella and Wolbachia, N. campestris carried Rickettsia, Hamiltonella and Wolbachia while P. signatus was infected only by Rickettsia. The results of this study will provide an important knowledge resource for understanding the population dynamics of vectors of X. fastidiosa with a view to formulate effective management strategies towards the bacterium.

In situ probing of Xylella fastidiosa in honeydew of a xylem sap-feeding insect using 16S rRNA-targeted fluorescent oligonucleotides

2006 ◽  
Vol 8 (4) ◽  
pp. 747-754 ◽  
Author(s):  
Jorge L. M. Rodrigues ◽  
Maria E. Silva-Stenico ◽  
Adriane N. de Souza ◽  
Joao R. S. Lopes ◽  
Siu M. Tsai
Keyword(s):  
16S Rrna ◽  
Xylella Fastidiosa ◽  
Xylem Sap ◽  
Sap Feeding

scholarly journals First Report of Xylella fastidiosa on Catharanthus roseus in Brazil

Plant Disease ◽  
1998 ◽  
Vol 82 (6) ◽  
pp. 712-712 ◽  
Author(s):  
B. Ueno ◽  
C. K. Funada ◽  
M. A. Yorinori ◽  
R. P. Leite
Keyword(s):  
Catharanthus Roseus ◽  
Xylella Fastidiosa ◽  
Xylem Sap ◽  
Glass Slide ◽  
Bacterial Cells ◽  
First Report ◽  
Vein Clearing ◽  
The Media ◽  
Agar Media ◽  
The U.S

In 1998, plants of periwinkle (Catharanthus roseus L.) showing small leaves, short internodes, and dieback symptoms were observed in a garden at the Instituto Agronomico do Parana (IAPAR), Londrina, PR, Brazil. Stems of these plants were cut into short sections and the sap extracted from the tissue by squeezing with pliers. The sap was blotted onto a glass slide and examined for the presence of bacteria by light microscopy (×400). Microscopy observations revealed the presence of a large number of slender, rod-shaped bacterial cells. The bacteria present in the stems of periwinkle were isolated on buffered cysteine-yeast extract (BCYE) and periwinkle wilt (PW) agar media. Stems were disinfected in 70% alcohol and cut into short sections, and the sap extracted as described above. The sap was blotted directly onto the media and the plates were incubated at 28°C. Typical colonies of Xylella fastidiosa were observed 10 days after isolation on both media. Indirect immunofluorescence tests with antibody specific to X. fastidiosa and anti-IgG conjugated with tetrametylrhodamine isothiocyanate (TRITC) were carried out with xylem sap of periwinkle stem and the isolated bacteria. In both cases, immunofluorescence tests were positive for X. fastidiosa. These results confirm that periwinkle plants were infected with X. fastidiosa. This is the first report of the association of X. fastidiosa with periwinkle plants in Brazil. However, the symptoms observed for the X. fastidiosa-infected periwinkle plants differed from those described previously in the U.S. (1): those symptoms consisted of marginal chlorosis and occasional vein clearing of leaves and wilting of the plants. Reference: (1) R. E. McCoy et al. Plant Dis. Rep. 62:1022, 1978.

scholarly journals Zinc Detoxification Is Required for Full Virulence and Modification of the Host Leaf Ionome by Xylella fastidiosa

2015 ◽  
Vol 28 (4) ◽  
pp. 497-507 ◽  
Author(s):  
Fernando Navarrete ◽  
Leonardo De La Fuente
Keyword(s):  
Xylella Fastidiosa ◽  
Xylem Sap ◽  
Essential Element ◽  
Trace Element Composition ◽  
Mineral Nutrient ◽  
Knockout Mutant ◽  
Bacterial Populations ◽  
Zn Homeostasis ◽  
Increased Sensitivity ◽  
High Concentrations

Zinc (Zn) is an essential element for all forms of life because it is a structural or catalytic cofactor of many proteins, but it can have toxic effects at high concentrations; thus, microorganisms must tightly regulate its levels. Here, we evaluated the role of Zn homeostasis proteins in the virulence of the xylem-limited bacterium Xylella fastidiosa, causal agent of Pierce’s disease of grapevine, among other diseases. Two mutants of X. fastidiosa ‘Temecula’ affected in genes which regulate Zn homeostasis (zur) and Zn detoxification (czcD) were constructed. Both knockouts showed increased sensitivity to Zn at physiologically relevant concentrations and increased intracellular accumulation of this metal compared with the wild type. Increased Zn sensitivity was correlated with decreased growth in grapevine xylem sap, reduced twitching motility, and downregulation of exopolysaccharide biosynthetic genes. Tobacco plants inoculated with either knockout mutant showed reduced foliar symptoms and a much reduced (czcD) or absent (zur) modification of the leaf ionome (i.e., the mineral nutrient and trace element composition), as well as reduced bacterial populations. The results show that detoxification of Zn is crucial for the virulence of X. fastidiosa and verifies our previous findings that modification of the host leaf ionome correlates with bacterial virulence.

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