Abstract
The continued deployment of resistance genes in Australian wheat varieties plays a crucial role in the prevention of crop losses as a result of rust infection. Resistance genes in plants act as an immune system by recognising specific components of the rust pathogen, encoded by avirulence (Avr) genes, and initiating defence responses. Recent advances in the model rust species, Melampsora lini, which infects cultivated flax (Linum usitatissimum), has led to the identification of several avirulence genes. These encode secreted proteins that are expressed in haustoria, specialised rust structures that penetrate the host cell wall. The AvrL567, AvrM, AvrP4, and AvrP123 proteins are recognised when expressed intracellularly in resistant plants, and the AvrL567 proteins interact directly with the corresponding L5 and L6 cytoplasmic resistance proteins. These observations imply that rusts deliver a range of small effector proteins directly into the plant cytoplasm, which are likely to perform key functions in facilitating pathogen infection. The plants’ resistance protein system has evolved to recognise the presence of these effectors during infection. Selection imposed by host resistance genes has led to the diversification of flax rust Avr genes to escape recognition. Nevertheless, virulent strains of flax rust retain variant forms of the Avr genes, suggesting that they have a positive fitness value to the pathogen. This knowledge is now being applied to develop screens for avirulence and pathogenicity-related proteins from important rust pathogens of wheat.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 8
Claim · model-written summary
Flax rust avirulence genes were identified.
- Taxon
- flax
Linum usitatissimume0 - Interactor
- Melampsora lini
.jpeg?width=60)
Melampsora linie0pathogen - Outcome
- identification of several avirulence genese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpeg?width=500)
Verbatim
e0“Melampsora lini, which infects cultivated flax (Linum usitatissimum), has led to the identification of several avirulence genes.”
Claim · model-written summary
Avirulence genes encode secreted proteins expressed in haustoria.
- Taxon
- flaxLinum usitatissimume1
- Interactor
- Melampsora liniMelampsora linie2pathogen
- Outcome
- secreted proteins that are expressed in haustoriae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“These encode secreted proteins that are expressed in haustoria, specialised rust structures that penetrate the host cell wall.”
t0“host–haustorium barrier”
e1“cultivated flax (Linum usitatissimum)”
e2“Melampsora lini”
Claim · model-written summary
Four Avr proteins are recognized intracellularly in resistant plants.
- Taxon
- plantsViridiplantaee0
- Gene
- AvrL567, AvrM, AvrP4, and AvrP123e0
- Outcome
- recognised when expressed intracellularly in resistant plantse0
Verbatim
e0“The AvrL567, AvrM, AvrP4, and AvrP123 proteins are recognised when expressed intracellularly in resistant plants”
Claim · model-written summary
AvrL567 directly interacts with L5 and L6 resistance proteins.
- Taxon
- flaxLinum usitatissimume1
- Gene
- L5 and L6e0
- Outcome
- interact directly with the corresponding L5 and L6 cytoplasmic resistance proteinse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the AvrL567 proteins interact directly with the corresponding L5 and L6 cytoplasmic resistance proteins.”
t0“host–haustorium barrier”
e1“cultivated flax (Linum usitatissimum)”
e2“Melampsora lini”
Claim · model-written summary
Rust effectors are inferred to enter plant cytoplasm and facilitate infection.
- Taxon
- plante0
- Interactor
- rustsPuccinialese0pathogen
- Outcome
- facilitating pathogen infectione0
- Qualifier
- deliver a range of small effector proteins directly into the plant cytoplasme0
Verbatim
e0“These observations imply that rusts deliver a range of small effector proteins directly into the plant cytoplasm, which are likely to perform key functions in facilitating pathogen infection.”
Claim · model-written summary
Host resistance selection diversified flax rust Avr genes.
- Taxon
- flaxLinum usitatissimume0
- Interactor
- flax rustMelampsora linie0pathogen
- Gene
- host resistance genese0
- Outcome
- diversification of flax rust Avr genese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Selection imposed by host resistance genes has led to the diversification of flax rust Avr genes to escape recognition.”
Claim · model-written summary
Virulent flax rust retains variant Avr genes.
- Taxon
- flaxLinum usitatissimume0
- Interactor
- flax rustMelampsora linie0pathogen
- Outcome
- retain variant forms of the Avr genese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“virulent strains of flax rust retain variant forms of the Avr genes, suggesting that they have a positive fitness value to the pathogen.”
Claim · model-written summary
Screens for wheat rust avirulence and pathogenicity proteins are being developed.
- Taxon
- wheat
Triticum aestivume0 - Interactor
- rust pathogense0pathogen
- Outcome
- screens for avirulence and pathogenicity-related proteinse0
Not reportedComparatorValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This knowledge is now being applied to develop screens for avirulence and pathogenicity-related proteins from important rust pathogens of wheat.”