Involvement of three pathogenicity factors of <i>Erwinia amylovora</i> in the oxidative stress associated with compatible interaction in pear

Venisse, Jean-Stéphane; Barny, Marie‐Anne; Paulin, J.P.; Brisset, Marie-Noëlle

doi:10.1016/s0014-5793(03)00123-6

Cited by 72 publications

(67 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…'Enterprise' accumulation of free SA occurred in two phases (24 and 144 hpi) and correlated with massive gSA synthesis. These changes resemble the two phases of classic oxidative burst in incompatible plant-pathogen interactions (Venisse et al 2003). In our opinion, the resistance of 'Enterprise' might be related to the two-phase accumulation of free SA (Fig.…”

Section: Discussionsupporting

confidence: 52%

Phenolic profiles in apple leaves and the efficacy of selected phenols against fire blight (Erwinia amylovora)

et al. 2017

View full text Add to dashboard Cite

The content and type of phenolic compounds in apple leaves as potential markers of resistance to fire blight were analysed. The amounts of phenolic acids and flavonoids were determined before and after E. amylovora inoculation of leaves of two cultivars: 'Enterprise' (highly resistant) and 'Idared' (highly susceptible). The basic levels of phenolics in both cultivars was similar but, following the inoculation, in the resistant one faster and more distinguishable changes were observed. The difference between the cultivars was related to the content of the compounds and the rate of release of free phenols from their glucosides. Regarding age dependency, the levels of eight out of 15 phenolics was significantly higher in young leaves of 'Idaredt han in 'Enterprise'. In the older leaves the differences were limited to four compounds. The amount of salicylic acid in 'Idared' was lower than in 'Enterprise'. In 'Idared' accumulation of salicylate after infection was better pronounced than in 'Enterprise'. Higher levels of naringenin glucosides, 4-hydroxbenzoic acid and gentisic acid were found in 'Enterprise'. The activity of 13 phenolics tested in vitro against the pathogen showed that gallic acid, phloroglucinol, hydroquinone and phloretin, suppressed its growth. The aqueous solutions of gallic acid, phloroglucinol and hydroquinone also significantly limited the development of disease on pear fruitlet slices but only hydroquinone maintained its protective activity for longer time. It also showed very high efficacy in preventing disease spread on apple shoots. The study adds novel information on the contribution of specific phenolics to apple resistance to fire blight.

show abstract

Section: Discussionsupporting

confidence: 52%

Phenolic profiles in apple leaves and the efficacy of selected phenols against fire blight (Erwinia amylovora)

et al. 2017

View full text Add to dashboard Cite

show abstract

“…E. amylovora apparently induces an initial host defense response early after infection (71,72); the bacterium is capable of surviving this plant oxidative burst, with the initial plant cell death and nutrient leakage being thought to provide the impetus for further spreading of the pathogen within the plant. The role of individual proteins in oxidative stress survival is currently unknown in E. amylovora; however, the alkyl hydroperoxide reductase AhpC is a known virulence factor in several plantpathogenic bacteria, contributing to protection from oxidative stress from an active plant defense response (53).…”

Section: Discussionmentioning

confidence: 99%

Identification of Erwinia amylovora Genes Induced during Infection of Immature Pear Tissue

2005

View full text Add to dashboard Cite

The enterobacterium Erwinia amylovora is a devastating plant pathogen causing necrotrophic fire blight disease of apple, pear, and other rosaceous plants. In this study, we used a modified in vivo expression technology system to identify E. amylovora genes that are activated during infection of immature pear tissue, a process that requires the major pathogenicity factors of this organism. We identified 394 unique pear fruit-induced (pfi) genes on the basis of sequence similarity to known genes and separated them into nine putative function groups including host-microbe interactions (3.8%), stress response (5.3%), regulation (11.9%), cell surface (8.9%), transport (13.5%), mobile elements (1.0%), metabolism (20.3%), nutrient acquisition and synthesis (15.5%), and unknown or hypothetical proteins (19.8%). Known virulence genes, including hrp/hrc components of the type III secretion system, the major effector gene dspE, type II secretion, levansucrase (lsc), and regulators of levansucrase and amylovoran biosynthesis, were upregulated during pear tissue infection. Known virulence factors previously identified in E. (Pectobacterium) carotovora and Pseudomonas syringae were identified for the first time in E. amylovora and included HecA hemagglutinin family adhesion, Peh polygalacturonase, new effector HopPtoC EA , and membrane-bound lytic murein transglycosylase MltE EA . An insertional mutation within hopPtoC EA did not result in reduced virulence; however, an mltE EA knockout mutant was reduced in virulence and growth in immature pears. This study suggests that E. amylovora utilizes a variety of strategies during plant infection and to overcome the stressful and poor nutritional environment of its plant hosts.

show abstract

“…One possible cause of selection on this gene is its virulence function, suggested by Venisse et al (2003) and Debroy et al (2004). According to Debroy et al (2004), avrE in P. syringae functions as a suppressor of salicylic-acidmediated basal defense, and amino acid changes in AvrE might affect this function.…”

Section: Discussionmentioning

confidence: 99%

Molecular Evolution of Pathogenicity-Island Genes in Pseudomonas viridiflava

et al. 2007

View full text Add to dashboard Cite

The bacterial pathogen Pseudomonas viridiflava possesses two pathogenicity islands (PAIs) that share many gene homologs, but are structurally and phenotypically differentiated (T-PAI and S-PAI). These PAIs are paralogous, but only one is present in each isolate. While this dual presence/absence polymorphism has been shown to be maintained by balancing selection, little is known about the molecular evolution of individual genes on the PAIs. Here we investigate genetic variation of 12 PAI gene loci (7 on T-PAI and 5 on S-PAI) in 96 worldwide isolates of P. viridiflava. These genes include avirulence genes (hopPsyA and avrE ), their putative chaperones (shcA and avrF ), and genes encoding the type III outer proteins (hrpA, hrpZ, and hrpW ). Average nucleotide diversities in these genes (p ¼ 0.004-0.020) were close to those in the genetic background. Large numbers of recombination events were found within PAIs and a sign of positive selection was detected in avrE. These results suggest that the PAI genes are evolving relatively freely from each other on the PAIs, rather than as a single unit under balancing selection. Evolutionarily stable PAIs may be preferable in this species because preexisting genetic variation enables P. viridiflava to respond rapidly to natural selection.

show abstract

Involvement of three pathogenicity factors of Erwinia amylovora in the oxidative stress associated with compatible interaction in pear

Cited by 72 publications

References 28 publications

Phenolic profiles in apple leaves and the efficacy of selected phenols against fire blight (Erwinia amylovora)

Phenolic profiles in apple leaves and the efficacy of selected phenols against fire blight (Erwinia amylovora)

Identification of Erwinia amylovora Genes Induced during Infection of Immature Pear Tissue

Molecular Evolution of Pathogenicity-Island Genes in Pseudomonas viridiflava

Contact Info

Product

Resources

About