Genomics accelerated isolation of a new stem rust avirulence gene-wheat resistance gene pair.

  title={Genomics accelerated isolation of a new stem rust avirulence gene-wheat resistance gene pair.},
  author={Narayana M. Upadhyaya and Rohit Mago and Vinay Panwar and Tim Hewitt and Mingcheng Luo and Jian Chen and Jana Sperschneider and Hoa Nguyen-Phuc and Aihua Wang and Diana Ortiz and Luch Hac and Dhara R Bhatt and Feng Li and Jianping Zhang and Michael Ayliffe and Melania Figueroa and Kostya Kanyuka and Jeffrey G. Ellis and Peter N. Dodds},
  journal={Nature plants},
Stem rust caused by the fungus Puccinia graminis f. sp. tritici (Pgt) is a devastating disease of the global staple crop wheat. Although this disease was largely controlled in the latter half of the twentieth century, new virulent strains of Pgt, such as Ug99, have recently evolved1,2. These strains have caused notable losses worldwide and their continued spread threatens global wheat production. Breeding for disease resistance provides the most cost-effective control of wheat rust diseases3. A… 
The stem rust effector protein AvrSr50 escapes Sr50 recognition by a substitution in a single surface exposed residue.
This study solved the crystal structure of a natural variant of AvrSr50 and used site-directed mutagenesis and transient expression assays to dissect the molecular mechanisms explaining gain of virulence.
A chromosome-level, fully phased genome assembly of the oat crown rust fungus Puccinia coronata f. sp. avenae: a resource to enable comparative genomics in the cereal rusts
The Pca203 reference marks the third fully-phased chromosome-level assembly of a cereal rust to date, and it is demonstrated that the chromosomes of these three Puccinia species are syntenous and that chromosomal size variations are primarily due to differences in repeat element content.
EffectorP 3.0: prediction of apoplastic and cytoplasmic effectors in fungi and oomycetes
It is shown that signal peptide prediction is essential for accurate effector prediction, as EffectorP 3.0 recognizes a cytoplasmic signal also in intracellular, non-secreted proteins.
Recent advances in understanding of fungal and oomycete effectors
Identification of Candidate Susceptibility Genes to Puccinia graminis f. sp. tritici in Wheat
Comparison transcriptome-based and orthology-guided approaches are used to characterize gene expression changes associated with Pgt infection in susceptible and resistant Triticum aestivum genotypes as well as the non-host Brachypodium distachyon and report several processes potentially linked to susceptibility to Pgt.


Variation in the AvrSr35 gene determines Sr35 resistance against wheat stem rust race Ug99
Fungal effectors of wheat stem rust The fungal pathogen Ug99 (named for its identification in Uganda in 1999) threatens wheat crops worldwide. Ug99 can kill entire fields of wheat and is undeterred
Loss of AvrSr50 by somatic exchange in stem rust leads to virulence for Sr50 resistance in wheat
To understand virulence evolution in Pgt, the protein ligand (AvrSr50) recognized by the Sr50 resistance protein was identified and provided molecular evidence that in addition to sexual recombination, somatic exchange can play a role in the emergence of new virulence traits in PGT.
Emergence and Spread of New Races of Wheat Stem Rust Fungus: Continued Threat to Food Security and Prospects of Genetic Control.
Enhanced research in the last decade under the umbrella of the Borlaug Global Rust Initiative has identified various race-specific resistance genes that can be utilized, preferably in combinations, to develop resistant varieties.
Emergence of the Ug99 lineage of the wheat stem rust pathogen through somatic hybridisation
Genomics-based evidence is provided supporting that Ug99 arose as a result of non-sexual genetic exchange between dikaryotic ancestors and indicates that nuclear exchange betweendikaryotes can generate genetic diversity and facilitate the emergence of new lineages in asexual fungal populations.
Stem rust of wheat in Australia
Overall inoculum levels and pathotype diversity in Pgt have declined in all wheat-growing regions since the mid 1970s, likely as a consequence of the release of cultivars with gene combinations, and resistance is still a top priority in many breeding programs.
Presence of a sexual population of Puccinia graminis f. sp. tritici in Georgia provides a hotspot for genotypic and phenotypic diversity.
The higher level of virulence and genotypic diversity observed in the 2013 samples strongly indicated that sexual recombination occurs in the Georgian P. graminis f.
Cytosolic activation of cell death and stem rust resistance by cereal MLA-family CC–NLR proteins
It is shown that, similarly to MLA10, the Sr33 and Sr50 CC domains are sufficient to induce cell death in Nicotiana benthamiana, consistent with CC-mediated induction of both cell-death signaling and stem rust resistance in the cytosolic compartment.
A recombined Sr26 and Sr61 disease resistance gene stack in wheat encodes unrelated NLR genes
The re-emergence of stem rust on wheat in Europe and Africa is reinforcing the ongoing need for durable resistance gene deployment. Here, we isolate from wheat, Sr26 and Sr61, with both genes
A five-transgene cassette confers broad-spectrum resistance to a fungal rust pathogen in wheat
This work generates polygenic Pgt resistance by introducing a transgene cassette of five resistance genes into bread wheat as a single locus and shows that at least four of the five genes are functional.
Potential for re-emergence of wheat stem rust in the United Kingdom
It is found that only 20% of UK wheat varieties are resistant to this strain and growers are urged to resume resistance breeding programs, illustrating that wheat stem rust does occur in the UK and, when climatic conditions are conducive, could severely harm wheat and barley production.