Abstract
The biotrophic fungal pathogen Cladosporium fulvum (syn. Passalora fulva) is the causal agent of tomato leaf mold. The Avr4 protein belongs to a set of effectors that is secreted by C. fulvum during infection and is thought to play a role in pathogen virulence. Previous studies have shown that Avr4 binds to chitin present in fungal cell walls and that, through this binding, Avr4 can protect these cell walls against hydrolysis by plant chitinases. In this study, we demonstrate that Avr4 expression in Arabidopsis results in increased virulence of several fungal pathogens with exposed chitin in their cell walls, whereas the virulence of a bacterium and an oomycete remained unaltered. Heterologous expression of Avr4 in tomato increased the virulence of Fusarium oxysporum f. sp. lycopersici. Through tomato GeneChip analyses, we demonstrate that Avr4 expression in tomato results in the induced expression of only a few genes. Finally, we demonstrate that silencing of the Avr4 gene in C. fulvum decreases its virulence on tomato. This is the first report on the intrinsic function of a fungal avirulence protein that has a counter-defensive activity required for full virulence of the pathogen.
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Claims 6
Claim · model-written summary
Avr4 expression in Arabidopsis increased virulence of several chitin-exposed fungal pathogens.
- Taxon
- Arabidopsis
Arabidopsise0 - Treatment
- Avr4 expressione0
- Interactor
- fungal pathogense0pathogen
- Gene
- Avr4e0
- Outcome
- virulence of several fungal pathogense0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Avr4 expression in Arabidopsis results in increased virulence of several fungal pathogens with exposed chitin in their cell walls”
Claim · model-written summary
Avr4 expression in Arabidopsis left bacterial virulence unaltered.
- Taxon
- ArabidopsisArabidopsise1
- Treatment
- Avr4 expressione1
- Outcome
- virulence of a bacteriume0
- Direction
- unalterede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“whereas the virulence of a bacterium and an oomycete remained unaltered”
e1“Avr4 expression in Arabidopsis”
Claim · model-written summary
Avr4 expression in Arabidopsis left oomycete virulence unaltered.
- Taxon
- ArabidopsisArabidopsise1
- Treatment
- Avr4 expressione1
- Interactor
- oomycetee0pathogen
- Outcome
- virulence of a bacterium and an oomycetee0
- Direction
- unalterede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“whereas the virulence of a bacterium and an oomycete remained unaltered”
e1“Avr4 expression in Arabidopsis”
Claim · model-written summary
Heterologous Avr4 expression in tomato increased Fusarium oxysporum f. sp. lycopersici virulence.
- Taxon
- tomato
Solanum lycopersicume0 - Treatment
- Heterologous expression of Avr4e0
- Interactor
- Fusarium oxysporum f. sp. lycopersici
Fusarium oxysporum f. sp. lycopersicie0pathogen - Outcome
- virulence of Fusarium oxysporum f. sp. lycopersicie0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Heterologous expression of Avr4 in tomato increased the virulence of Fusarium oxysporum f. sp. lycopersici.”
Claim · model-written summary
Avr4 expression induced only a few tomato genes.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- Avr4 expressione0
- Gene
- Avr4e0
- Outcome
- expression of only a few genese0
- Direction
- inducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Avr4 expression in tomato results in the induced expression of only a few genes.”
Claim · model-written summary
Silencing Avr4 in C. fulvum decreased virulence on tomato.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- silencing of the Avr4 genee0
- Interactor
- C. fulvum
Fulvia fulvae0pathogen - Gene
- Avr4e0
- Outcome
- virulence on tomatoe0
- Direction
- decreasese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“silencing of the Avr4 gene in C. fulvum decreases its virulence on tomato.”
The same questions in other papers
loss of function · Fulvia fulva · Solanum lycopersicum (tomato)Positive and negative results
2 papers in the same direction as this paper · 10 in the opposite direction
- negative
- negative
- negative
9 papers more in this group
See all 13 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.