Fastidious plant pathogens
156 views | +0 today
Follow
Your new post is loading...
Your new post is loading...
Scooped by Ofir bahar
Scoop.it!

Complete Genome Sequence of the Olive-Infecting Strain Xylella fastidiosa subsp. pauca De Donno. - PubMed - NCBI

Complete Genome Sequence of the Olive-Infecting Strain Xylella fastidiosa subsp. pauca De Donno. - PubMed - NCBI | Fastidious plant pathogens | Scoop.it
Genome Announc. 2017 Jul 6;5(27). pii: e00569-17. doi: 10.1128/genomeA.00569-17.
more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Two 'Candidatus Liberibacter asiaticus' Strains Recently Found in California Harbor Different Prophages. - PubMed - NCBI

Two 'Candidatus Liberibacter asiaticus' Strains Recently Found in California Harbor Different Prophages. - PubMed - NCBI | Fastidious plant pathogens | Scoop.it
Phytopathology. 2017 Jun;107(6):662-668. doi: 10.1094/PHYTO-10-16-0385-R. Epub 2017 Apr 10. Research Support, Non-U.S. Gov't
more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Susceptibility of Olea europaea L. varieties to Xylella fastidiosa subsp. pauca ST53: systematic literature search up to 24 March 2017

Susceptibility of Olea europaea L. varieties to Xylella fastidiosa subsp. pauca ST53: systematic literature search up to 24 March 2017 | Fastidious plant pathogens | Scoop.it
EFSA was requested by the European Commission to produce a report on the susceptibility of olive varieties to the Apulian strain of Xylella fastidiosa (subsp. pauca strain CoDiRO, ST53). A systemati
more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Quantification and ecological study of Candidatus Liberibacter asiaticus in citrus hosts, rootstocks and the Asian citrus psyllid

Quantification and ecological study of Candidatus Liberibacter asiaticus in citrus hosts, rootstocks and the Asian citrus psyllid | Fastidious plant pathogens | Scoop.it
Using proper managements for Citrus Huanglongbing (HLB), which caused by Candidatus Liberibacter asiaticus (Las) and transmitted by Asian citrus psyllid (ACP) (Diaphorina citri), is a priority issue
more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Vessel occlusion in three cultivars of Olea europaea naturally exposed to Xylella fastidiosa in open field

Vessel occlusion in three cultivars of Olea europaea naturally exposed to Xylella fastidiosa in open field | Fastidious plant pathogens | Scoop.it
Xylella fastidiosa is a Gram‐negative, xylem‐limited, bacterium which is responsible, in Italy, for the olive quick decline syndrome (OQDS). The disease is caused by the subspecies pauca and emerge
more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

‘Candidatus Liberibacter asiaticus’ Encodes a Functional Salicylic Acid (SA) Hydroxylase That Degrades SA to Suppress Plant Defenses

Molecular Plant-Microbe Interactions, Ahead of Print.
more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

The influence of maturity and variety of pot... [Environ Entomol. 2014] - PubMed - NCBI

PubMed comprises more than 23 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Ofir bahar's insight:

The ecological theory on host plant choice by herbivores suggests that mothers should choose plants that will maximize their offspring's success. In annual host plants, physiology (and therefore host suitability) is sometimes influenced by maturity and growth stage, which may influence female choice. Potato plants were grown under greenhouse conditions and used in choice and no-choice bioassays to determine the effect of plant maturity and variety on oviposition and number of stylet sheaths (which approximate stylet insertions) by tomato/potato psyllids. No-choice bioassays suggested that maturity (time since planting) did not influence oviposition behavior, but oviposition varied significantly among potato plant varieties. There was a significant effect of both maturity and variety on the number of stylet sheaths, which peak toward the middle of the growing season. We also examined tomato/potato psyllid responses to plants grown in a commercial field and again found no effect on oviposition but differences in stylet sheaths. The results suggest that differential susceptibility to zebra chip disease may be associated with unequal feeding rates. Future studies should examine whether the maturity of plants influences larval fitness. Finally, potato variety has an influence on both oviposition and "probing," and has implications for management strategies and the development of resistant potato varieties

more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Bacterial tricks for turning plants into zombies

Bacterial tricks for turning plants into zombies | Fastidious plant pathogens | Scoop.it
Microbe deploys proteins that manipulate both the plant it infects and the insects that spread it.
more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Recognition of floral homeotic MADS-domain transcription factors by a phytoplasmal effector, phyllogen, induces phyllody - Maejima - The Plant Journal - Wiley Online Library

Recognition of floral homeotic MADS-domain transcription factors by a phytoplasmal effector, phyllogen, induces phyllody - Maejima - The Plant Journal - Wiley Online Library | Fastidious plant pathogens | Scoop.it
Ofir bahar's insight:

Plant pathogens can alter the course of plant developmental processes, resulting in abnormal morphology in infected host plants. Phytoplasmas are unique plant-pathogenic bacteria that transform plant floral organs into leaf-like structures and cause the emergence of secondary flowers. These distinctive symptoms have attracted considerable interest for many years. Here, we revealed the molecular mechanisms of the floral symptoms by focusing on a phytoplasma-secreted protein, PHYL1, which induces morphological changes in flowers that are similar to those seen in phytoplasma-infected plants. PHYL1 was found as a homolog of the phytoplasmal effector SAP54 that also alters floral development. Using yeast two-hybrid and in planta transient coexpression assays, we found that PHYL1 interacts with and degrades floral homeotic MADS-domain proteins (SEPALLATA3 [SEP3], APETALA1 [AP1], CAULIFLOWER [CAL]). This degradation of the MADS-domain proteins was dependent on the ubiquitin-proteasome pathway. The expression of floral development genes downstream of SEP3 and AP1 was disrupted in 35S::PHYL1 transgenic plants. PHYL1was genetically and functionally conserved among other phytoplasma strains and species. We designated PHYL1, SAP54, and their homologs as members of the phyllody-inducing gene family “phyllogen

more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Citrus tristeza virus-based RNAi in citrus plants induces gene silencing in Diaphorina citri, a phloem-sap sucking insect vector of citrus greening disease (Huanglongbing)

Citrus tristeza virus-based RNAi in citrus plants induces gene silencing in Diaphorina citri, a phloem-sap sucking insect vector of citrus greening disease (Huanglongbing) | Fastidious plant pathogens | Scoop.it
Ofir bahar's insight:

A transient expression vector based on Citrus tristeza virus (CTV) is unusually stable. Because of its stability it is being considered for use in the field to control Huanglongbing (HLB), which is caused by CandidatusLiberibacter asiaticus (CLas) and vectored by Asian citrus psyllid, Diaphorina citri. In the absence of effective control strategies for CLas, emphasis has been on control of D. citri. Coincident cohabitation in phloem tissue by CLas, D. citri and CTV was exploited to develop a novel method to mitigate HLB through RNA interference (RNAi). Since CTV has three RNA silencing suppressors, it was not known if CTV-based vector could induce RNAi in citrus. Yet, expression of sequences targeting citrus phytoene desaturase gene by CTV-RNAi resulted in photo-bleaching phenotype. CTV-RNAi vector, engineered with truncated abnormal wing disc (Awd) gene of D. citri, induced altered Awd expression when silencing triggers ingested by feeding D. citrinymphs. Decreased Awd in nymphs resulted in malformed-wing phenotype in adults and increased adult mortality. This impaired ability of D. citri to fly would potentially limit the successful vectoring of CLas bacteria between citrus trees in the grove. CTV-RNAi vector would be relevant for fast-track screening of candidate sequences for RNAi-mediated pest control.

more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Molecular and physiological properties associated with zebra complex disease in potatoes and its relation with Candidatus Liberibacter contents in psyllid vectors

Molecular and physiological properties associated with zebra complex disease in potatoes and its relation with Candidatus Liberibacter contents in psyllid vectors | Fastidious plant pathogens | Scoop.it

Zebra complex (ZC) disease on potatoes is associated with Candidatus Liberibacter solanacearum (CLs), an α-proteobacterium that resides in the plant phloem and is transmitted by the potato psyllid Bactericera cockerelli (Šulc). The name ZC originates from the brown striping in fried chips of infected tubers, but the whole plants also exhibit a variety of morphological features and symptoms for which the physiological or molecular basis are not understood. We determined that compared to healthy plants, stems of ZC-plants accumulate starch and more than three-fold total protein, including gene expression regulatory factors (e.g. cyclophilin) and tuber storage proteins (e.g., patatins), indicating that ZC-affected stems are reprogrammed to exhibit tuber-like physiological properties. Furthermore, the total phenolic content in ZC potato stems was elevated two-fold, and amounts of polyphenol oxidase enzyme were also high, both serving to explain the ZC-hallmark rapid brown discoloration of air-exposed damaged tissue. Newly developed quantitative and/or conventional PCR demonstrated that the percentage of psyllids in laboratory colonies containing detectable levels of CLs and its titer could fluctuate over time with effects on colony prolificacy, but presumed reproduction-associated primary endosymbiont levels remained stable. Potato plants exposed in the laboratory to psyllid populations with relatively low-CLs content survived while exposure of plants to high-CLs psyllids rapidly culminated in a lethal collapse. In conclusion, we identified plant physiological biomarkers associated with the presence of ZC and/or CLs in the vegetative potato plant tissue and determined that the titer of CLs in the psyllid population directly affects the rate of disease development in plants

more...
No comment yet.
Rescooped by Ofir bahar from B.S. Weir publications
Scoop.it!

Plant Disease: A New ‘Candidatus Liberibacter’ Species Associated with Diseases of Solanaceous Crops

Plant Disease: A New ‘Candidatus Liberibacter’ Species Associated with Diseases of Solanaceous Crops | Fastidious plant pathogens | Scoop.it

A new disease of glasshouse-grown tomato and pepper in New Zealand has resulted in plant decline and yield loss. Affected plants are characterized by spiky, chlorotic apical growth, curling or cupping of the leaves, and overall stunting. Transmission electron microscopy revealed the presence of phloem-limited bacterium-like organisms in symptomatic plants. The strategy used to identify the bacterium involved using specific prokaryote polymerase chain reaction (PCR) primers in combination with universal 16S rRNA primers. Sequence analysis of the 16S rRNA gene, the 16S/23S rRNA spacer region, and the rplKAJL-rpoBC operon revealed that the bacterium shared high identity with ‘Candidatus Liberibacter’ species. Phylogenetic analysis showed that the bacterium is distinct from the three citrus liberibacter species previously described and has been named ‘Candidatus Liberibacter solanacearum’. This is the first report of a liberibacter naturally infecting a host outside the Rutaceae family. A specific PCR primer pair was developed for its detection.


Via Bevan Weir
more...
No comment yet.
Rescooped by Ofir bahar from Plant pathology
Scoop.it!

Molecular Plant-Microbe Interactions: Production of Xylella fastidiosa Diffusible Signal Factor in Transgenic Grape Causes Pathogen Confusion and Reduction in Severity of Pierce's Disease

Molecular Plant-Microbe Interactions: Production of Xylella fastidiosa Diffusible Signal Factor in Transgenic Grape Causes Pathogen Confusion and Reduction in Severity of Pierce's Disease | Fastidious plant pathogens | Scoop.it

ABSTRACT: The rpfF gene from Xylella fastidiosa, encoding the synthase for diffusible signal factor (DSF), was expressed in ‘Freedom’ grape to reduce the pathogen's growth and mobility within the plant. Symptoms in such plants were restricted to near the point of inoculation and incidence of disease was two- to fivefold lower than in the parental line. Both the longitudinal and lateral movement of X. fastidiosa in the xylem was also much lower. DSF was detected in both leaves and xylem sap of RpfF-expressing plants using biological sensors, and both 2-Z-tetradecenoic acid, previously identified as a component of X. fastidiosa DSF, and cis-11-methyl-2-dodecenoic acid were detected in xylem sap using electrospray ionization mass spectrometry. A higher proportion of X. fastidiosa cells adhered to xylem vessels of the RpfF-expressing line than parental ‘Freedom’ plants, reflecting a higher adhesiveness of the pathogen in the presence of DSF. Disease incidence in RpfF-expressing plants in field trials in which plants were either mechanically inoculated with X. fastidiosa or subjected to natural inoculation by sharpshooter vectors was two- to fourfold lower in than that of the parental line. The number of symptomatic leaves on infected shoots was reduced proportionally more than the incidence of infection, reflecting a decreased ability of X. fastidiosa to move within DSF-producing plants.


Via fundoshi
more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Characterization and purification of proteins suitable for the production of antibodies against 'Ca. Liberibacter asiaticus'. - PubMed - NCBI

Characterization and purification of proteins suitable for the production of antibodies against 'Ca. Liberibacter asiaticus'. - PubMed - NCBI | Fastidious plant pathogens | Scoop.it
Protein Expr Purif. 2017 Jul 18. pii: S1046-5928(16)30260-1. doi: 10.1016/j.pep.2017.07.010. [Epub ahead of print]
more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Xylella fastidiosa: An examination of a re‐emerging plant pathogen

Xylella fastidiosa: An examination of a re‐emerging plant pathogen | Fastidious plant pathogens | Scoop.it
Xylella fastidiosa is a Gram‐negative bacterial plant pathogen with an extremely wide host range. This species has recently been resolved into subspecies that correlate with host specificity. Thi
more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Outbreak of Xylella in Spain: action of eradication in compliance with the Commission Implementing Decision 2015/789 - POnTE Project

Following the detection of Xf in an almond orchard in Alicante (Spain), all plants of listed species within the 100 m radius are being removed.
more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Several subspecies and sequence types are associated with the emergence of Xylella fastidiosa in natural settings in France

Several subspecies and sequence types are associated with the emergence of Xylella fastidiosa in natural settings in France | Fastidious plant pathogens | Scoop.it
Xylella fastidiosa is a plant pathogenic bacterium emerging in Europe. In France its emergence has been demonstrated through interceptions of contaminated coffee plants and, in 2015, by a survey o
more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Assessment of the genetic diversity of Xylella fastidiosa in imported ornamental Coffea arabica plants

Assessment of the genetic diversity of Xylella fastidiosa in imported ornamental Coffea arabica plants | Fastidious plant pathogens | Scoop.it
A study was performed in order to assess the presence of Xylella fastidiosa in imported ornamental plants, among them Olea europaea, Coffea arabica and Nerium oleander. Positive results were onl
more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Metabolomic analysis reveals the potential metabolites and pathogenesis involved in mulberry yellow dwarf disease - GAI - 2014 - Plant, Cell & Environment - Wiley Online Library

Metabolomic analysis reveals the potential metabolites and pathogenesis involved in mulberry yellow dwarf disease - GAI - 2014 - Plant, Cell & Environment - Wiley Online Library | Fastidious plant pathogens | Scoop.it
Ofir bahar's insight:

To analyse the molecular mechanisms of phytoplasma pathogenicity, the comprehensive metabolomic changes of mulberry leaf and phloem sap in response to phytoplasma infection were examined using gas chromatography-mass spectrometry. The metabolic profiles obtained revealed that the metabolite compositions of leaf and phloem sap were different, and phytoplasma infection has a greater impact on the metabolome of phloem sap than of leaf. Phytoplasma infection brought about the content changes in various metabolites, such as carbohydrates, amino acids, organic acids, etc. Meanwhile, the results of biochemical analysis showed that the degradation of starch was repressed, and the starch content was increased in the infected leaves. In addition, we found that phytoplasma infection changed the levels of abscisic acid and cytokinin and break phytohormone balance. Interestingly, our data showed that the contents of H2O2 and superoxide were increased in the infected leaves, but not in the phloem saps. Based on the results, the expression levels of the genes involved in the metabolism of some changed metabolites were examined, and the potential molecular mechanisms of these changes were discussed. It can be concluded that both the leaf and phloem saps have a complicated metabolic response to phytoplasma infection, but their response mechanisms were different.

more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

GroEL from the endosymbiont Buchnera aphidicola betrays the aphid by triggering plant defense

GroEL from the endosymbiont Buchnera aphidicola betrays the aphid by triggering plant defense | Fastidious plant pathogens | Scoop.it
more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Phytoplasma Effector SAP54 Hijacks Plant Reproduction by Degrading MADS-box Proteins and Promotes Insect Colonization in a RAD23-Dependent Manner

Phytoplasma Effector SAP54 Hijacks Plant Reproduction by Degrading MADS-box Proteins and Promotes Insect Colonization in a RAD23-Dependent Manner | Fastidious plant pathogens | Scoop.it

Parasites that colonize multiple hosts often coerce these hosts into improving their own survival and reproduction rates. However, how parasites do this is largely unknown. Phytoplasmas are bacterial plant parasites that require sap-feeding insect vectors—leafhoppers—for their propagation and dispersal. It has been known for a long time that phytoplasmas stimulate dramatic developmental changes in a broad range of plant species, such as the conversion of flowers into leaves known as phyllody and the proliferation of stems known as “witches' broom.” Here we report how and why phytoplasmas cause these dramatic developmental changes. We identified a phytoplasma virulence protein, SAP54, which transforms flowers into leaves and converts plants into more attractive hosts for the egg-laying and reproduction of their leafhopper vectors. We show that SAP54 exerts its effect by promoting the degradation of proteins that regulate important developmental processes in flowering plants. These proteins are highly conserved transcription factors of the MADS-box family, and reducing their activity through SAP54–mediated degradation curtails flower development, generating sterile plants. This degradation process requires RAD23, a protein that recruits the transcription factors to the protein degradation machinery. The resulting sterile plants, which form leaves in place of flowers, are more attractive to leafhoppers, arguably making phytoplasmas master manipulators of the parasite world

more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

Phytoplasma Effector SAP54 Induces Indeterminate Leaf-Like Flower Development in Arabidopsis Plants

Phytoplasma Effector SAP54 Induces Indeterminate Leaf-Like Flower Development in Arabidopsis Plants | Fastidious plant pathogens | Scoop.it
Ofir bahar's insight:

Phytoplasma AY-WB alters the phenotype of infected Arabidopsis. A, Healthy (left) and infected (right) plants. Infected plants show evidence of stunted growth (reduced height) and witches’ broom phenotype (B and C). B, Close-up of the healthy plant depicted in A. C, Close-up of the infected plant depicted in A shows an increased number of axillary stems. Bars = 1 cm. D and F, Images of flowers from healthy Arabidopsis plants show white petals. E and G, Flowers from infected plants show evidence of virescence (green petals and stamens) and phyllody (leaf-like sepals and petals). Note the increased flower size of the infected plants

more...
No comment yet.
Rescooped by Ofir bahar from Plant Immunity And Microbial Effectors
Scoop.it!

The small phytoplasma virulence effector SAP11 contains distinct domains required for nuclear targeting and CIN-TCP binding and destabilization

The small phytoplasma virulence effector SAP11 contains distinct domains required for nuclear targeting and CIN-TCP binding and destabilization | Fastidious plant pathogens | Scoop.it
Summary
Phytoplasmas are insect-transmitted bacterial phytopathogens that secrete virulence effectors and induce changes in the architecture and defense response of their plant hosts.

Via IPM Lab
more...
No comment yet.
Scooped by Ofir bahar
Scoop.it!

First report of ‘Candidatus Liberibacter solanacearum’ in carrot in Spain (mainland & Canary Islands)

First report of ‘Candidatus Liberibacter solanacearum’ in carrot in Spain (mainland & Canary Islands) | Fastidious plant pathogens | Scoop.it

‘Candidatus Liberibacter solanacearum’ is reported for the first time in carrot in mainland Spain. It was found in mixed infections with Spiroplasma citri.

The pathogen was also detected in Canary Islands in carrot crops infested by Bactericera trigonica.

 

Alfaro-Fernandez et al. (2012) First Report of ‘Candidatus Liberibacter solanacearum’ in Carrot in Mainland Spain. Plant Disease 96(4), p 582.

http://www.apsnet.org/publications/plantdisease/2012/April/Pages/96_4_582.1.aspx

 

 Alfaro-Fernandez et al. (2012) ‘Candidatus Liberibacter solanacearum’ Associated with Bactericera trigonica-Affected Carrots in the Canary Islands. Plant Disease 96(4), p 581.

http://www.apsnet.org/publications/plantdisease/2012/April/Pages/96_4_581.3.aspx

more...
No comment yet.
Rescooped by Ofir bahar from Phytoplasma
Scoop.it!

Vegetable scientists make expertise available online - Capital Press

Vegetable scientists make expertise available online - Capital Press | Fastidious plant pathogens | Scoop.it
Capital Press
Vegetable scientists make expertise available online
Capital Press
That image depicts an infection of phytoplasma and spiroplasma such as "Aster yellows" phytoplasma, transmitted by the beet leafhopper.

Via Edel Perez Lopez
more...
Edel Perez Lopez's curator insight, August 23, 2013 8:22 AM

News about phytoplasmas avaible on line...aster yellows !!!!