scholarly journals Leaf scorch symptoms are not correlated with bacterial populations during Pierce's disease

2007 ◽  
Vol 58 (15-16) ◽  
pp. 4037-4046 ◽  
Author(s):  
G. A. Gambetta ◽  
J. Fei ◽  
T. L. Rost ◽  
M. A. Matthews
Keyword(s):  
Pierce's Disease ◽  
Bacterial Populations ◽  
Leaf Scorch ◽  
Pierce’S Disease

scholarly journals Genetic Diversity of Pierce's Disease Strains and Other Pathotypes of Xylella fastidiosa

2001 ◽  
Vol 67 (2) ◽  
pp. 895-903 ◽  
Author(s):  
Mavis Hendson ◽  
Alexander H. Purcell ◽  
Deqiao Chen ◽  
Chris Smart ◽  
Magalie Guilhabert ◽  
...  
Keyword(s):  
Gel Electrophoresis ◽  
Xylella Fastidiosa ◽  
Random Amplified Polymorphic Dna ◽  
Consensus Sequence ◽  
23S Rrna ◽  
Pierce's Disease ◽  
Pcr Analysis ◽  
Leaf Scorch ◽  
Pierce’S Disease ◽  
Rapd Pcr

ABSTRACT Strains of Xylella fastidiosa isolated from grape, almond, maple, and oleander were characterized by enterobacterial repetitive intergenic consensus sequence-, repetitive extragenic palindromic element (REP)-, and random amplified polymorphic DNA (RAPD)-PCR; contour-clamped homogeneous electric field (CHEF) gel electrophoresis; plasmid content; and sequencing of the 16S-23S rRNA spacer region. Combining methods gave greater resolution of strain groupings than any single method. Strains isolated from grape with Pierce's disease (PD) from California, Florida, and Georgia showed greater than previously reported genetic variability, including plasmid contents, but formed a cluster based on analysis of RAPD-PCR products,NotI and SpeI genomic DNA fingerprints, and 16S-23S rRNA spacer region sequence. Two groupings of almond leaf scorch (ALS) strains were distinguished by RAPD-PCR and CHEF gel electrophoresis, but some ALS isolates were clustered within the PD group. RAPD-PCR, CHEF gel electrophoresis, and 16S-23S rRNA sequence analysis produced the same groupings of strains, with RAPD-PCR resolving the greatest genetic differences. Oleander strains, phony peach disease (PP), and oak leaf scorch (OLS) strains were distinct from other strains. DNA profiles constructed by REP-PCR analysis were the same or very similar among all grape strains and most almond strains but different among some almond strains and all other strains tested. Eight of 12 ALS strains and 4 of 14 PD strains of X. fastidiosa isolated in California contained plasmids. All oleander strains carried the same-sized plasmid; all OLS strains carried the same-sized plasmid. A plum leaf scald strain contained three plasmids, two of which were the same sizes as those found in PP strains. These findings support a division of X. fastidiosaat the subspecies or pathovar level.

scholarly journals Glassy-Winged Sharpshooters Expected to Increase Plant Disease

2000 ◽  
Vol 1 (1) ◽  
pp. 3 ◽  
Author(s):  
Alexander H. Purcell ◽  
Stuart R. Saunders
Keyword(s):  
Plant Disease ◽  
Plant Diseases ◽  
Pierce's Disease ◽  
Leaf Scorch ◽  
Pierce’S Disease ◽  
Almond Trees ◽  
Citrus Orchards ◽  
Almond Orchards ◽  
A Minor ◽  
Almond Leaf Scorch

As it moves through California, the new pest known as glassy-winged sharpshooter (GWSS) may significantly increase the spread of plant diseases caused by the bacterium Xylella fastidiosa. The bacterium causes Pierce's disease of grapevines, almond leaf scorch and the newly recognized oleander leaf scorch disease. Currently, almond leaf scorch is a minor problem for California's almonds, but if GWSS becomes established in significant numbers in or near almond orchards, it might increase the incidence of almond leaf scorch. Our studies show that GWSS and two other sharpshooter species can transmit X. fastidiosa from diseased oleanders to healthy oleanders. GWSS also can transmit Pierce's disease strains of the bacterium from grapevine to grapevine and to almond trees. The oleander strain of the bacterium did not infect grapevines, but the ability of GWSS to transmit Pierce's disease strains may increase the spread of this lethal grapevine disease in vineyards bordering citrus orchards or other habitats where invading GWSS may establish permanent populations. Posted 27 December 2000.

scholarly journals Leaf Scorch of Purple-Leafed Plum and Sweetgum Dieback: Two New Diseases in Southern California Caused by Xylella fastidiosa Strains with Different Host Ranges

Plant Disease ◽  
2009 ◽  
Vol 93 (11) ◽  
pp. 1131-1138 ◽  
Author(s):  
R. Hernandez-Martinez ◽  
D. A. Cooksey ◽  
F. P. Wong
Keyword(s):  
Southern California ◽  
Xylella Fastidiosa ◽  
Liquidambar Styraciflua ◽  
Pierce's Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
Leaf Scorch ◽  
Pierce’S Disease ◽  
Prunus Cerasifera ◽  
Almond Leaf Scorch

Sweetgum dieback and leaf scorch of purple-leafed plum are two new diseases of southern California landscape ornamentals. Samplings were conducted in 2003 and 2004 and 28 of 105 sweetgum (Liquidambar styraciflua) and 38 of 62 purple-leafed plum (Prunus cerasifera) plants tested positive for Xylella fastidiosa by enzyme linked immunosorbent assay. In all, 3 strains of X. fastidiosa were isolated from sweetgum and 13 from purple-leafed plum. All sweetgum strains and some purple-leafed plum strains grew on PW but not PD3 media. Strain PC045 from purple-leafed plum and strain LS022 from sweetgum were inoculated into their original hosts in addition to almond, oleander, and grapevine plants. Sweetgum plants also were inoculated with strains causing Pierce's disease, almond leaf scorch, and oleander leaf scorch. Strain PC045 caused symptoms in purple-leafed plum and almond plants within 6 months, and the pathogen was recovered from 93 and 100% of inoculated plants, respectively. Inoculation of grapevine and oleander plants with PC045 did not result in disease or recovery of the pathogen. In all, 5 of 25 sweetgum plants inoculated with LS022 showed symptoms after 9 months, and the pathogen was recovered from 3 of these plants. Inoculation of grapevine, oleander, and almond with LS022 resulted in no disease or recovery of the pathogen from the plants. A strain of Pierce's disease, a strain of oleander leaf scorch, and two strains from almond did not cause disease in sweetgum. These results confirm the role of X. fastidiosa strains as pathogens of purple-leafed plum and sweetgum, and that strains from sweetgum are unique in their host range.

scholarly journals Hypervariations of a Protease-Encoding Gene, PD0218 (pspB), in Xylella fastidiosa Strains Causing Almond Leaf Scorch and Pierce's Disease in California

2008 ◽  
Vol 74 (12) ◽  
pp. 3652-3657 ◽  
Author(s):  
J. Chen ◽  
E. Civerolo ◽  
K. Tubajika ◽  
S. Livingston ◽  
B. Higbee
Keyword(s):  
Genetic Variation ◽  
Tandem Repeats ◽  
Xylella Fastidiosa ◽  
Pierce's Disease ◽  
Rrna Gene ◽  
Leaf Scorch ◽  
Pierce’S Disease ◽  
Putative Protease ◽  
Encoding Gene ◽  
Almond Leaf Scorch

ABSTRACT Xylella fastidiosa is a gram-negative plant pathogenic bacterium that causes almond leaf scorch disease (ALSD) and Pierce's disease (PD) of grape in many regions of North America and Mexico. Of the two 16S rRNA gene genotypes described in California, A genotype strains cause ALSD only and G genotype strains cause both PD and ALSD. While G genotype strains cause two different diseases, little is known about their genetic variation. In this study, we identified a putative protease locus, PD0218 (pspB), in the genome of X. fastidiosa and evaluated the variation at this locus in X. fastidiosa populations. PD0218 contains tandem repeats of ACDCCA, translated to threonine and proline (TP), upstream of the putative protease conserved domain. Among 116 X. fastidiosa ALSD and PD strains isolated from seven locations in California, tandem repeat numbers (TRNs) varied from 9 to 47, with a total of 30 TRN genotypes, indicating that X. fastidiosa possesses an active mechanism for contracting and expanding tandem repeats at this locus. Significant TRN variation was found among PD strains (mean = 29.9), which could be further divided into two TRN groups: PD-Gsmall (mean = 17.3) and PD-Glarge (mean = 44.3). Less variation was found in ALSD strains (mean = 21.7). The variation was even smaller after ALSD strains were subdivided into the A and G genotypes (mean = 13.3, for the G genotype; mean = 27.1, for the A genotype). Genetic variation at the PD0218 locus is potentially useful for sensitive discrimination of X. fastidiosa strains. However, TRN stability, variation range, and correlation to phenotypes should be evaluated in epidemiological applications such as pathotype identification and delineation of pathogen origin.

Association of xylem-limited bacteria with elm, sycamore, and oak leaf scorch

1980 ◽  
Vol 58 (18) ◽  
pp. 1986-1993 ◽  
Author(s):  
Suzanne S. Hearon ◽  
James L. Sherald ◽  
Stanley J. Kostka
Keyword(s):  
Fluorescent Antibody ◽  
Pierce's Disease ◽  
Tracheary Elements ◽  
Serological Relationship ◽  
Ulmus Americana ◽  
Leaf Scorch ◽  
Pierce’S Disease ◽  
Antibody Staining ◽  
Transmission Electron ◽  
Ultrathin Sections

Ultrathin sections of leaves from American elms (Ulmus americana L.), sycamores (Platanus spp.), and two red oak species (Quercus spp.) that exhibited leaf scorch were examined by transmission electron microscopy. Rod-shaped, ripple-walled bacteria resembling the Pierce's disease organism were found consistently in tracheary elements of the primary and secondary veins of diseased plants. Smaller, ripple-walled, densely stained, irregular-shaped bodies (SDB) were found also in a matrix that lined the inner walls or filled the lumina of the tracheary elements. In leaf scorch affected American elms the bacteria were 0.3–0.4 μrn × 0.9–2.4 μm, with rounded ends. Fimbriae-like structures radiated from a few organisms. Bacteria were frequently embedded in a matrix. Pit cavities and the ends of tracheary elements were often filled with the bacteria–matrix complex. Rod-shaped bacteria were not as numerous in the diseased sycamore and oak as in diseased elm; however, SDB's were more numerous. Bacteria in sycamore (1.0–1.8 μm) and oak (1.0–2.0 μm) were slightly shorter than those in elm, many had numerous fimbriae-like hairs, and some were tapered at one end. Indirect fluorescent antibody staining showed a serological relationship between bacteria extracted from elm and oak and the Pierce's disease bacterium.

scholarly journals Landscape Epidemiology of Xylella fastidiosa in the Balearic Islands

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 473
Author(s):  
Diego Olmo ◽  
Alicia Nieto ◽  
David Borràs ◽  
Marina Montesinos ◽  
Francesc Adrover ◽  
...  
Keyword(s):  
Xylella Fastidiosa ◽  
Vascular Plant ◽  
Western Mediterranean ◽  
Balearic Islands ◽  
Wild Plants ◽  
Pierce's Disease ◽  
Leaf Scorch ◽  
Pierce’S Disease ◽  
The Impact ◽  
Almond Leaf Scorch

Xylella fastidiosa (Xf) is a vascular plant pathogen native to the Americas. In 2013, it was first reported in Europe, implicated in a massive die-off of olive trees in Apulia, Italy. This finding prompted mandatory surveys across Europe, successively revealing that the bacterium was already established in some distant areas of the western Mediterranean. To date, the Balearic Islands (Spain) hold the major known genetic diversity of Xf in Europe. Since October 2016, four sequence types (ST) belonging to the subspecies fastidiosa (ST1), multiplex (ST7, ST81), and pauca (ST80) have been identified infecting 28 host species, including grapevines, almond, olive, and fig trees. ST1 causes Pierce’s disease (PD) and together with ST81 are responsible for almond leaf scorch disease (ALSD) in California, from where they were introduced into Mallorca in around 1993, very likely via infected almond scions brought for grafting. To date, almond leaf scorch disease affects over 81% of almond trees and Pierce’s disease is widespread in vineyards across Mallorca, although producing on average little economic impact. In this perspective, we present and analyze a large Xf-hosts database accumulated over four years of field surveys, laboratory sample analyses, and research to understand the underlying causes of Xf emergence and spread among crops and wild plants in the Balearic Islands. The impact of Xf on the landscape is discussed.

scholarly journals Differentiation of Pathogenic Groups of Xylella fastidiosa Strains with Whole-Cell Protein Profiles

Plant Disease ◽  
2002 ◽  
Vol 86 (8) ◽  
pp. 875-879 ◽  
Author(s):  
R. L. Wichman ◽  
D. L. Hopkins
Keyword(s):  
Xylella Fastidiosa ◽  
Sodium Dodecyl ◽  
Mass Range ◽  
Cell Protein ◽  
Pierce's Disease ◽  
Protein Profiles ◽  
Whole Cell ◽  
Leaf Scorch ◽  
Pierce’S Disease ◽  
Whole Cell Protein

Whole-cell protein analyses of 75 Xylella fastidiosa strains by sodium dodecyl sulfatepolyacrylamide gel electrophoresis were compared, and variations in the protein banding patterns among the strains were observed. Based on the presence, absence, or difference in intensity of 10 protein bands within the 21.5 to 45.0 kDa molecular mass range, the strains could be subdivided into four distinct pathogenic groups and two miscellaneous groups whose members were pathogenic to various different hosts. Group 1 was the Pierce's disease of grapevine pathogenic group. Although 4 of these 45 strains had hosts of origin other than grapevine, they all produced Pierce's disease symptoms. Uniform, distinct protein profiles also occurred with group 2 (elderberry leaf scorch strains), group 3 (oak leaf scorch strains), and group 4 (oleander leaf scorch strains). Groups 5 and 6 were made up of strains pathogenic to almond, blackberry, lupine, mulberry, periwinkle, elm, and plum. Thus, whole-cell protein analysis was shown to be a rapid and consistent method for identifying four pathogenic groups of X. fastidiosa strains.

scholarly journals Development and Comparison of Symptom Indices for Quantifying Grapevine Resistance to Pierce's Disease

2005 ◽  
Vol 95 (1) ◽  
pp. 36-43 ◽  
Author(s):  
A. F. Krivanek ◽  
J. F. Stevenson ◽  
M. A. Walker
Keyword(s):  
Systemic Infection ◽  
Field Performance ◽  
Ease Of Use ◽  
Pierce's Disease ◽  
Bacterial Inoculation ◽  
Scoring Method ◽  
Leaf Scorch ◽  
Pierce’S Disease ◽  
Maturation Index ◽  
Resistant Genotypes

Symptoms of Pierce's disease (PD) were assessed under greenhouse conditions on field-resistant and field-susceptible grapevines in order to characterize the PD resistance phenotype in the genus Vitis. A cane maturation index (CMI) was developed to quantify the green-islands symptom, which was measured at 12 weeks post-bacterial inoculation, along with leaf scorch and percentage of xylem vessels blocked by occlusions. Canes of resistant genotypes matured normally and had a significantly lower CMI score of 0.9 (on a 0-to-6 scale) compared with 5.1 for the susceptible genotypes. The CMI scoring method had a high correlation (R2 = 0.91) with previously characterized field performance, whereas leaf scorch had only a moderate correlation (R2 = 0.51) with field performance. Average scorched area on leaves of the susceptible and resistant genotypes was 80 and 48%, respectively, demonstrating that leaf scorch can be extensive in resistant genotypes under the presented screening conditions, and suggesting that systemic infection can occur in all evaluated genotypes. Occlusions within both stem and petiole vessels were composed principally of tyloses and were significantly higher in petioles than in stems of either resistant or susceptible backgrounds. Susceptible genotypes displayed a higher level of stem tylose occlusions relative to resistant genotypes, but correlation to field performance was low (R2 = 0.13). Ease of use and high correlation to field performance makes CMI scoring a better choice for PD resistance evaluations relative to other phenotypic symptom assessments.

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